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Sample records for ligands synthesis spectral

  1. Microwave Assisted Synthesis Spectral and Antibacterial Investigations on Complexes of Mn(II) With Amide Containing Ligands

    OpenAIRE

    N. Bhojak; D. D. Gudasaria; N. Khiwani; Jain, R.

    2007-01-01

    The present research work describes the synthesis, spectral and antibacterial studies on the complexes of Mn(II) with amide group containing ligands. Synthesis of complexes has been carried out by conventional method as well as by microwave method. The complexes have been characterized on the basis of elemental analysis, infrared, electronic spectra and magnetic susceptibility studies. The diffuse reflectance spectrums of the complexes show bands in the region 20,000 cm-1 to 26,000 cm-1 ass...

  2. Microwave Assisted Synthesis Spectral and Antibacterial Investigations on Complexes of Mn(II With Amide Containing Ligands

    Directory of Open Access Journals (Sweden)

    N. Bhojak

    2007-01-01

    Full Text Available The present research work describes the synthesis, spectral and antibacterial studies on the complexes of Mn(II with amide group containing ligands. Synthesis of complexes has been carried out by conventional method as well as by microwave method. The complexes have been characterized on the basis of elemental analysis, infrared, electronic spectra and magnetic susceptibility studies. The diffuse reflectance spectrums of the complexes show bands in the region 20,000 cm-1 to 26,000 cm-1 assignable to 6A1g → 4T2g and 6A1g → 4E1g transitions. These are also typical of tetrahedral environment around the manganese. The magnetic moment (5.80 BM of the complex indicates high spin tetrahedral environment. The microwave method of synthesis of complexes have been found easier, convenient and ecofriendly.

  3. Synthesis, spectral, thermal, potentiometric and antimicrobial studies of transition metal complexes of tridentate ligand

    Directory of Open Access Journals (Sweden)

    Sarika M. Jadhav

    2014-01-01

    Full Text Available A series of metal complexes of Cu(II, Ni(II, Co(II, Fe(III and Mn(II have been synthesized with newly synthesized biologically active tridentate ligand. The ligand was synthesized by condensation of dehydroacetic acid (3-acetyl-6-methyl-(2H pyran-2,4(3H-dione or DHA, o-phenylene diamine and fluoro benzaldehyde and characterized by elemental analysis, molar conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, 1H-NMR, UV–Vis spectroscopy and mass spectra. From the analytical data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand with octahedral geometry. The molar conductance values suggest the non-electrolyte nature of metal complexes. The IR spectral data suggest that the ligand behaves as a dibasic tridentate ligand with ONN donor atoms sequence towards central metal ion. Thermal behaviour (TG/DTA and kinetic parameters calculated by the Coats–Redfern and Horowitz–Metzger method suggest more ordered activated state in complex formation. To investigate the relationship between stability constants of metal complexes and antimicrobial activity, the dissociation constants of Schiff bases and stability constants of their binary metal complexes have been determined potentiometrically in THF–water (60:40% solution at 25 ± 1 °C and at 0.1 M NaClO4 ionic strength. The potentiometric study suggests 1:1 and 1:2 complexation. Antibacterial and antifungal activities in vitro were performed against Staphylococcus aureus, Escherichia coli and Aspergillus niger, Trichoderma, respectively. The stability constants of the metal complexes were calculated by the Irving–Rosotti method. A relation between the stability constant and antimicrobial activity of complexes has been discussed. It is observed that the activity enhances upon complexation and the order of antifungal activity is in accordance with stability order of metal ions.

  4. New mixed ligand complexes of ruthenium(II) that incorporate a modified phenanthroline ligand: Synthesis, spectral characterization and DNA binding

    Indian Academy of Sciences (India)

    S Murali; C V Sastri; Bhaskar G Maiya

    2002-08-01

    The hexafluorophosphate and chloride salts of two ruthenium(II) complexes, viz. [Ru(phen)(ptzo)2]2+ and [Ru(ptzo)3]2+, where ptzo = 1,10-phenanthrolino[5,6-]1,2,4-triazine-3-one (ptzo) - a new modified phenanthroline (phen) ligand, have been synthesised. These complexes have been characterised by infrared, UV-Vis, steady-state emission and 1H NMR spectroscopic methods. Results of absorption and fluorescence titration as well as thermal denaturation studies reveal that both the bis- and tris-complexes of ptzo show moderately strong affinity for binding with calf thymus (CT) DNA with the binding constants being close to 105M-1 in each case. An intercalative mode of DNA binding has been suggested for both the complexes. Emission studies carried out in non-aqueous solvents and in aqueous media without DNA reveal that both [Ru(phen)(ptzo)2]2+ and [Ru(ptzo)3]2+ are weakly luminescent under these solution conditions. Successive addition of CT DNA to buffered aqueous solutions containing [Ru(phen)(ptzo)2]2+ results in an enhancement of the emission. These results have been discussed in the light of the dependence of the structure-specific deactivation processes of the MLCT state of the metallointercalator with the characteristic features of its DNA interaction. In doing so, attempts have been made to compare and contrast its properties with those of the analogous phenanthroline-based complexes including the ones reported by us previously.

  5. Transition metal complexes with oxygen donor ligands: a synthesis, spectral, thermal and antimicrobial study

    Directory of Open Access Journals (Sweden)

    VAIBHAV N. PATANGE

    2008-10-01

    Full Text Available Transition metal complexes of chalcones derived from the conden¬sation of 3-acetyl-6-methyl-2H-pyran-2,4(3H-dione (dehydroacetic acid and p-methoxybenzaldehyde (HL1 or p-nitrobenzaldehyde (HL2 were synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic measurements, IR, 1H-NMR, UV–Vis spectroscopy and a microbial study. From the analytical and thermal data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand. The molar conductance data revealed that all the metal chelates were non-electrolytes. The thermal stability of the complexes was studied by thermogravimetry and the decomposition schemes of the complexes are given. The ligands and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli, and fungicidal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum.

  6. Novel Low Spin Mixed Ligand Thiohydrazide Complexes of Iron(III: Synthesis, Spectral Characterization, Molecular Modeling, and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Dolan Sengupta

    2014-01-01

    Full Text Available Mixed ligand complexes of Fe(III with aromatic thiohydrazides of general composition [Fe(acac(L2] have been synthesized and characterized (acac-acetylacetonate, L = bidentate uninegative aromatic thiohydrazide ligand, for example, thiobenzhydrazide, 2-hydroxythiobenzhydrazide, furan-2-thiohydrazide, and thiophen-2-thiohydrazide. The magnetic susceptibility data and the EPR spectra of these complexes suggested the formation of rhombically distorted low spin iron center (d5 in octahedral environment, which was also supported by the UV-vis spectral data of the complexes. Biological studies of these complexes also indicated that the iron-thiohydrazido complexes have superior antibacterial properties compared to the corresponding ligands.

  7. Some new IIB group complexes of an imidazolidine ligand: Synthesis, spectral characterization, electrochemical, thermal and antimicrobial propert

    Indian Academy of Sciences (India)

    Morteza Montazerozohori; Sayed Alireza Musavi; Asghar Naghiha; Somayeh Veyseh

    2014-01-01

    An imidazolidine Schiff base ligand, (E)-N-(4-nitrobenzylidene)-2-(2-(4-nitrophenyl) imidazolidine-1-yl) ethaneamine (L) has been synthesized by a condensation reaction between N'-(2-aminoethyl)-ethane-1,2-diamine and 4-nitrobenzaldehyde in 1:2 ratio and then characterized by physical and spectral data. Some new complexes with general formula of MLX2(wherein M is Zn(II),Cd(II) and Hg(II) and X is chloride, bromide and/or iodide) have been prepared and characterized by physical and spectroscopic studies such as elemental analysis, molar conductance measurements, FT-IR, 1H and 13C NMR and UV-Visible electronic spectra. The spectral data indicate that the ligand is coordinated to zinc(II) as a bidentate ligand in imidazolidine form but it binds to other metal salts as bis-imine tridentate ligand. Furthermore, cyclic voltammetry technique was applied for recording the electrochemical behaviour of the ligand and its complexes. Cyclic voltamogram of the ligand showed that it is reduced at four cathodic potentials and then oxidized only in two anodic potentials in reverse direction. The electrochemical behaviour of ligand is affected by coordination. Thermal analysis of ligand and its complexes revealed that they are decomposed via 3-4 thermal steps. Moreover, some activation thermodynamic parameters such as A, E∗, H∗, S∗ and G∗ were calculated based on TG/DTA plots using Coats-Redfern relation. The Schiff base ligand and its complexes have also been tested in vitro to evaluate their antimicrobial activities.

  8. Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: spectral, thermal, XRD and antimicrobial studies.

    Science.gov (United States)

    Sundararajan, M L; Jeyakumar, T; Anandakumaran, J; Karpanai Selvan, B

    2014-10-15

    Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, (1)H NMR, (13)C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base.

  9. Synthesis, spectral characterization, molecular modeling, thermal study and biological evaluation of transition metal complexes of a bidentate Schiff base ligand.

    Science.gov (United States)

    Chandra, Sulekh; Bargujar, Savita; Nirwal, Rita; Qanungo, Kushal; Sharma, Saroj K

    2013-09-01

    Complexes of copper(II) and nickel(II) of general composition M(L)2X2, have been synthesized [where L=3-Bromoacetophenone thiosemicarbazone and X=CH3COO(-), Cl(-) and NO3(-)]. All the complexes were characterized by elemental analysis, magnetic moments, IR, electronic and EPR spectral studies. The ligand behaved as bidentate and coordinated through sulfur of -C=S group and nitrogen atoms of -C=N group. The copper(II) and nickel(II) complexes were found to have magnetic moments 1.94-2.02 BM, 2.96-3.02 BM respectively which was corresponding to one and two unpaired electrons respectively. The molar conductance of the complexes in solution of DMSO lies in the range of 10-20 Ω(-1) cm(2) mol(-1) indicating their non-electrolytic behavior. On the basis of EPR, electronic and infrared spectral studies, tetragonal geometry has been assigned for copper(II) complexes and an octahedral geometry for nickel(II) complexes. The values of Nephelauxetic parameter β lie in the range 0.19-0.37 which indicated the covalent character in metal ligand 'σ' bond. Synthesized ligand and its copper(II) and nickel(II) complexes have also been screened against different bacterial and fungal species which suggested that complexes are more active than the ligands in antimicrobial activities.

  10. Synthesis, spectral, thermal and antimicrobial studies of transition metal complexes of 14-membered tetraaza[N4] macrocyclic ligand

    Science.gov (United States)

    Shankarwar, Sunil G.; Nagolkar, Bhagwat B.; Shelke, Vinod A.; Chondhekar, Trimbak K.

    2015-06-01

    A series of metal complexes of Mn(II), Co(II), Ni(II), Cu(II), have been synthesized with newly synthesized biologically active macrocyclic ligand. The ligand was synthesized by condensation of β-diketone 1-(4-chlorophenyl)-3-(2-hydroxyphenyl)propane-1,3-dione and o-phenylene diamine. All the complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, 1H-NMR, UV-Vis spectroscopy and mass spectroscopy. From the analytical data, stoichiometry of the complexes was found to be 1:2 (metal:ligand). Thermal behavior (TG/DTA) and kinetic parameters suggest more ordered activated state in complex formation. All the complexes are of high spin type and six coordinated. On the basis of IR, electronic spectral studies and magnetic behavior, an octahedral geometry has been assigned to these complexes. The antibacterial and antifungal activities of the ligand and its metal complexes, has been screened in vitro against Staphylococcus aureus, Escherichia coli and Aspergillus niger, Trichoderma respectively.

  11. Synthesis, spectral, thermal and antimicrobial studies of transition metal complexes of 14-membered tetraaza[N₄] macrocyclic ligand.

    Science.gov (United States)

    Shankarwar, Sunil G; Nagolkar, Bhagwat B; Shelke, Vinod A; Chondhekar, Trimbak K

    2015-06-15

    A series of metal complexes of Mn(II), Co(II), Ni(II), Cu(II), have been synthesized with newly synthesized biologically active macrocyclic ligand. The ligand was synthesized by condensation of β-diketone 1-(4-chlorophenyl)-3-(2-hydroxyphenyl)propane-1,3-dione and o-phenylene diamine. All the complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, (1)H-NMR, UV-Vis spectroscopy and mass spectroscopy. From the analytical data, stoichiometry of the complexes was found to be 1:2 (metal:ligand). Thermal behavior (TG/DTA) and kinetic parameters suggest more ordered activated state in complex formation. All the complexes are of high spin type and six coordinated. On the basis of IR, electronic spectral studies and magnetic behavior, an octahedral geometry has been assigned to these complexes. The antibacterial and antifungal activities of the ligand and its metal complexes, has been screened in vitro against Staphylococcus aureus, Escherichia coli and Aspergillus niger, Trichoderma respectively.

  12. Synthesis, NMR spectral and structural studies on mixed ligand complexes of Pd(II) dithiocarbamates: First structural report on palladium(II) dithiocarbamate with SCN-ligand

    Science.gov (United States)

    Prakasam, Balasubramaniam Arul; Lahtinen, Manu; Peuronen, Anssi; Muruganandham, Manickavachagam; Kolehmainen, Erkki; Haapaniemi, Esa; Sillanpää, Mika

    2016-03-01

    Three new mixed ligand complexes of palladium(II) dithiocarbamates; [Pd(4-dpmpzdtc)(PPh3)(SCN)] (1), [Pd(4-dpmpzdtc)(PPh3)Cl] (2) and [Pd(bzbudtc)(PPh3)Cl] (3), (where, 4-dpmpzdtc = 4-(diphenylmethyl)piperazinecarbodithioato anion, bzbudtc = N-benzyl-N-butyldithiocarbamato anion and PPh3 = triphenylphosphine) have been synthesized from their respective parent dithiocarbamates by ligand exchange reactions and characterized by IR and NMR (1H, 13C and 31P) spectroscopy. IR and NMR spectral data support the isobidentate coordination of the dithiocarbamate ligands in all complexes (1-3) in solid and in solution, respectively. Single crystal diffraction analysis of complexes 1-3 evidences that all three complexes are exhibiting distorted square planar geometry. The Pd-S distances in 1-3 vary in accordance with the differences in trans influences of PPh3, SCN- and Cl- and it is in the order of PPh3 > SCN- > and Cl-. Interchange of the anionic auxiliary ligand (SCN- to Cl-) induces asymmetry to the dithiocarbamate-metal bonds. Thioureide C-N bond distances are short in 1-3, supporting a contribution of thioureide form to the structures. The observed distortions in the square planar geometry for 1-3, are in the order of 1 > 2 > 3.

  13. Synthesis, spectral characterization, computational calculations and biological activity of complexes designed from NNO donor Schiff-base ligand.

    Science.gov (United States)

    El-Gammal, Ola A; Abu El-Reash, G M; Yousef, T A; Mefreh, M

    2015-07-05

    A new series of Co(II), Ni(II) and Cu(II) complexes of (Z)-2-oxo-2-(phenylamino)-N'-(1-(pyridin-2-yl)ethylidene)acetohydrazide (H2OPPAH) have been prepared and characterized by conventional techniques. The spectral data indicated that the ligand acts as neutral or mononegative NNO tridentate. On the basis of magnetic and electronic spectral data an octahedral geometry for Ni(II) and Cu(II) complexes and a tetrahedral geometry for Co(II) complex have been proposed. The molecular modeling using DFT method are drawn showing the bond length, bond angle, chemical reactivity, energy components (kcal/mol) and binding energy (kcal/mol) for all title compounds. The Kinetic parameters were determined for each thermal degradation stages of the ligand and its complexes using Coats-Redfern and Horowitz-Metzger methods. Also, the compounds were screened for antioxidant activity using ABTS free radical, anti-hemolytic, and in vitro cytotoxic assay. H2OPPAH showed the potent antioxidant activity followed by Co(II) and Cu(II) complexes. On the other hand Ni(II) complex exhibited weak antioxidant activity using ABTS free radical and Erlich and strong erythrocyte hemolysis activity.

  14. Synthesis, spectral characterization, computational calculations and biological activity of complexes designed from NNO donor Schiff-base ligand

    Science.gov (United States)

    El-Gammal, Ola A.; El-Reash, G. M. Abu; Yousef, T. A.; Mefreh, M.

    2015-07-01

    A new series of Co(II), Ni(II) and Cu(II) complexes of (Z)-2-oxo-2-(phenylamino)-N‧-(1-(pyridin-2-yl)ethylidene)acetohydrazide (H2OPPAH) have been prepared and characterized by conventional techniques. The spectral data indicated that the ligand acts as neutral or mononegative NNO tridentate. On the basis of magnetic and electronic spectral data an octahedral geometry for Ni(II) and Cu(II) complexes and a tetrahedral geometry for Co(II) complex have been proposed. The molecular modeling using DFT method are drawn showing the bond length, bond angle, chemical reactivity, energy components (kcal/mol) and binding energy (kcal/mol) for all title compounds. The Kinetic parameters were determined for each thermal degradation stages of the ligand and its complexes using Coats-Redfern and Horowitz-Metzger methods. Also, the compounds were screened for antioxidant activity using ABTS free radical, anti-hemolytic, and in vitro cytotoxic assay. H2OPPAH showed the potent antioxidant activity followed by Co(II) and Cu(II) complexes. On the other hand Ni(II) complex exhibited weak antioxidant activity using ABTS free radical and Erlich and strong erythrocyte hemolysis activity.

  15. Synthesis and spectral studies on metal complexes of s-triazine based ligand and non linear optical properties

    Science.gov (United States)

    Shanmugakala, R.; Tharmaraj, P.; Sheela, C. D.

    2014-11-01

    A series of transition metal complexes of type [ML] and [ML2]Cl2 (where M = Cu(II), Ni(II), Co(II) have synthesized from 2-phenylamino-4,6-dichloro-s-triazine and 3,5-dimethyl pyrazole; their characteristics have been investigated by means of elemental analyses, magnetic susceptibility, molar conductance, IR, UV-Vis, Mass, NMR and ESR spectra. The electrochemical behavior of copper(II) complexes we have studied, by using cyclic voltammetry. The ESR spectra of copper(II) complexes are recorded at 300 K and 77 K and their salient features are appropriately reported. Spectral datas, we found, show that the ligand acts as a neutral tridentate, and coordinates through the triazine ring nitrogen and pyrazolyl ring nitrogen atoms to the metal ion. Evident from our findings, the metal(II) complexes of [ML] type exhibit square pyramidal geometry, and that of [ML2]Cl2 exhibit octahedral geometry. The in vitro antimicrobial activities of the ligand and its complexes are evaluated against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus vulgaris, Cryptococcus neoformans, Pseudomonas aeruginosa, Salmonella typhi, Serratia marcescens, Shigella flexneri, Vibrio cholera, Vibris parahaemolyticus, Aspergillus niger, Candida albicans and Penicillium oxalicum by well-diffusion method. The second harmonic generation efficiency of the ligand and its complexes are determined and compared with urea and KDP.

  16. Unsymmetrical Schiff base (ON) ligand on complexation with some transition metal ions: Synthesis, spectral characterization, antibacterial, fluorescence and thermal studies

    Science.gov (United States)

    Ali, Omyma A. M.; El-Medani, Samir M.; Abu Serea, Maha R.; Sayed, Abeer S. S.

    2015-02-01

    A series of eight metal Schiff base complexes were synthesized by the thermal reaction of Cu(II), Ni(II), Fe(III), Co(II), Zn(II), Hg(II), La(III) or Sm(III) with a Schiff base "L" produced by the condensation of furfuraldehyde and 1,2-diaminobenzene. These compounds were characterized by elemental analysis, UV-Vis, FT-IR, molar conductance, mass spectrometry, thermal and fluorescence studies. The studies suggested the coordination of the ligand L to metal through azomethine imine nitrogen and furan oxygen atoms of Schiff base moiety. Thermogravimetric (TG/DTG) analyses data were studied and indicated high stability for all complexes and suggested the presence of lattice and/or coordinated water molecules in the complexes. Coats-Redfern method has been used to calculate the kinetic and thermodynamic parameters of the metal complexes. The spectral and thermal analysis reveal that all complexes have octahedral geometry except Cu(II) and Ni(II) complexes which can attain a square planner arrangements. The ligand and its complexes exhibited intraligand (π-π∗) fluorescence and can potentially serve as photoactive materials. Both the ligand and its complexes have been screened for antibacterial activities.

  17. Unsymmetrical Schiff base (ON) ligand on complexation with some transition metal ions: synthesis, spectral characterization, antibacterial, fluorescence and thermal studies.

    Science.gov (United States)

    Ali, Omyma A M; El-Medani, Samir M; Abu Serea, Maha R; Sayed, Abeer S S

    2015-02-05

    A series of eight metal Schiff base complexes were synthesized by the thermal reaction of Cu(II), Ni(II), Fe(III), Co(II), Zn(II), Hg(II), La(III) or Sm(III) with a Schiff base "L" produced by the condensation of furfuraldehyde and 1,2-diaminobenzene. These compounds were characterized by elemental analysis, UV-Vis, FT-IR, molar conductance, mass spectrometry, thermal and fluorescence studies. The studies suggested the coordination of the ligand L to metal through azomethine imine nitrogen and furan oxygen atoms of Schiff base moiety. Thermogravimetric (TG/DTG) analyses data were studied and indicated high stability for all complexes and suggested the presence of lattice and/or coordinated water molecules in the complexes. Coats-Redfern method has been used to calculate the kinetic and thermodynamic parameters of the metal complexes. The spectral and thermal analysis reveal that all complexes have octahedral geometry except Cu(II) and Ni(II) complexes which can attain a square planner arrangements. The ligand and its complexes exhibited intraligand (π-π(∗)) fluorescence and can potentially serve as photoactive materials. Both the ligand and its complexes have been screened for antibacterial activities.

  18. Studies on some metal complexes of quinoxaline based unsymmetric ligand: Synthesis, spectral characterization, in vitro biological and molecular modeling studies.

    Science.gov (United States)

    Dhanaraj, Chellaian Justin; Johnson, Jijo

    2016-08-01

    Mononuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes of an unsymmetric Schiff base ligand, 3-(-(3-(-3,5-dichloro-2-hydroxybenzylideneamino)propylimino)methyl)quinoxalin-2(1H) -one (L) were synthesized and characterized by various analytical and spectral techniques. The molar conductance values of metal complexes indicate non-electrolytic behavior of the metal complexes. The Schiff base act as tetra dentate ONNO donor ligand in Co(II), Ni(II), Zn(II) complexes and tridentate NNO donor in Cu(II) complex. Thermal stabilities of the newly synthesized compounds were determined by thermal analysis. Crystallinity, average grain size and unit cell parameters were determined from powder X-ray diffraction study. Electrochemical behaviors of the compounds were examined by cyclic voltammetry technique. The Schiff base and its complexes have been screened for their in vitro antimicrobial activities against some bacterial and fungal strains by disc diffusion method. The interaction of the compounds with calf thymus DNA (CT DNA) has been investigated by electronic absorption spectral titration and viscosity measurement (hydrodynamic) methods. Furthermore, the pUC18 DNA cleavage activities of the complexes have been explored. The compounds were also subjected to in vitro antioxidant, anticancer activity screening, druglikeness and bioactivity predictions using Molinspiration software. Molecular docking studies of the present compounds were carried out against B-DNA dodecamer d(CGCGAATTCGCG)2 and vascular endothelial growth factor receptor (VEGFR-2) kinase. Quantum chemical calculations were done with DFT method to determine the optimum geometry of the ligand and its metal complexes. From the quantum chemical parameters, the reactivity parameters of the compounds were established.

  19. Synthesis, spectral and thermal studies of some transition metal mixed ligand complexes: modeling of equilibrium composition and biological activity.

    Science.gov (United States)

    Neelakantan, M A; Sundaram, M; Nair, M Sivasankaran

    2011-09-01

    Several mixed ligand Ni(II), Cu(II) and Zn(II) complexes of 2-amino-3-hydroxypyridine (AHP) and imidazoles viz., imidazole (him), benzimidazole (bim), histamine (hist) and L-histidine (his) have been synthesized and characterized by elemental and spectral (vibrational, electronic, 1H NMR and EPR) data as well as by magnetic moment values. On the basis of elemental analysis and molar conductance values, all the complexes can be formulated as [MAB]Cl except histidine complexes as MAB. Thermogravimetric studies reveal the presence of coordinated water molecules in most of the complexes. From the magnetic measurements and electronic spectral data, octahedral structure was proposed for Ni(II) and Cu(II)-AHP-his, tetrahedral for Cu(II)-AHP-him/bim/hist, but square planar for the Cu(II)-AHP complex. The g∥/A∥ calculated supports tetrahedral environment around the Cu(II) in Cu(II)-AHP-him/bim/hist and distorted octahedral for Cu(II)-AHP-his complexes. The morphology of the reported metal complexes was investigated by scanning electron micrographs (SEM). The potentiometric study has been performed in aqueous solution at 37 °C and I=0.15 mol dm(-3) NaClO4. MABH, MAB and MAB2 species has been identified in the present systems. Proton dissociation constants of AHP and stability constants of metal complexes were determined using MINIQUAD-75. The most probable structure of the mixed ligand species is discussed based upon their stability constants. The in vitro biological activity of the complexes was tested against the Gram positive and Gram negative bacteria, fungus and yeast. The oxidative DNA cleavage studies of the complexes were performed using gel electrophoresis method. Cu(II) complexes have been found to promote DNA cleavage in presence of biological reductant such as ascorbate and oxidant like hydrogen peroxide.

  20. Synthesis, spectral and thermal studies of some transition metal mixed ligand complexes: Modeling of equilibrium composition and biological activity

    Science.gov (United States)

    Neelakantan, M. A.; Sundaram, M.; Nair, M. Sivasankaran

    2011-09-01

    Several mixed ligand Ni(II), Cu(II) and Zn(II) complexes of 2-amino-3-hydroxypyridine (AHP) and imidazoles viz., imidazole (him), benzimidazole (bim), histamine (hist) and L-histidine (his) have been synthesized and characterized by elemental and spectral (vibrational, electronic, 1H NMR and EPR) data as well as by magnetic moment values. On the basis of elemental analysis and molar conductance values, all the complexes can be formulated as [MAB]Cl except histidine complexes as MAB. Thermogravimetric studies reveal the presence of coordinated water molecules in most of the complexes. From the magnetic measurements and electronic spectral data, octahedral structure was proposed for Ni(II) and Cu(II)-AHP-his, tetrahedral for Cu(II)-AHP-him/bim/hist, but square planar for the Cu(II)-AHP complex. The g∥/ A∥ calculated supports tetrahedral environment around the Cu(II) in Cu(II)-AHP-him/bim/hist and distorted octahedral for Cu(II)-AHP-his complexes. The morphology of the reported metal complexes was investigated by scanning electron micrographs (SEM). The potentiometric study has been performed in aqueous solution at 37 °C and I = 0.15 mol dm -3 NaClO 4. MABH, MAB and MAB 2 species has been identified in the present systems. Proton dissociation constants of AHP and stability constants of metal complexes were determined using MINIQUAD-75. The most probable structure of the mixed ligand species is discussed based upon their stability constants. The in vitro biological activity of the complexes was tested against the Gram positive and Gram negative bacteria, fungus and yeast. The oxidative DNA cleavage studies of the complexes were performed using gel electrophoresis method. Cu(II) complexes have been found to promote DNA cleavage in presence of biological reductant such as ascorbate and oxidant like hydrogen peroxide.

  1. Mixed-ligand copper(II) phenolate complexes: Synthesis, spectral characterization, phosphate-hydrolysis, antioxidant, DNA interaction and cytotoxic studies

    Science.gov (United States)

    Gurumoorthy, Perumal; Mahendiran, Dharmasivam; Prabhu, Durai; Arulvasu, Chinnasamy; Rahiman, Aziz Kalilur

    2015-01-01

    A series of phenol-based mixed-ligand copper(II) complexes of the type [CuL1-4(diimine)] (1-8), where L1-4 = N1,N2-bis(5-substituted-2-hydroxybenzylidene)-1,2-ethylene/phenylenediimine and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen), have been isolated and fully characterized by analytical and spectral techniques. Electronic spectra of complexes suggest Cu(II) cation has a d9 electronic configuration, adopting distorted octahedral geometry with axial elongation, due to Jahn-Teller effect. Electrochemical studies of complexes evidenced one-electron irreversible reduction wave in the cathodic region. The observed rate constant (k) values for the hydrolysis of 4-nitrophenylphosphate (4-NPP) are in the range of 0.25-3.82 × 10-2 min-1. The obtained room temperature magnetic moment values (1.79-1.90 BM) lies within the range observed for octahedral copper(II) complexes. Antioxidant studies revealed that these complexes possess considerable radical scavenging potency against DPPH. The binding studies of complexes with calf thymus DNA (CT-DNA) revealed intercalation with minor-groove binding, and the complex 4 exhibits highest binding activity than the other complexes. The cleavage activity on supercoiled pBR322 DNA revealed the involvement of hydroxyl radical and singlet-oxygen as reactive oxygen species, and complexes encourage binding to minor-groove. Further, the cytotoxicity of complex 4 on human hepatocellular liver carcinoma HepG2 cell line implies the cell death through apoptosis.

  2. Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

    Science.gov (United States)

    Abd El-Halim, Hanan F.; Mohamed, Gehad G.; Khalil, Eman A. M.

    2017-10-01

    A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV-Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats-Redfern and Horowitz-Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram-Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

  3. Synthesis, structure, spectral properties and theoretical studies of two half-sandwich titanium-complexes with adamantoxy ligands

    Science.gov (United States)

    Varga, Vojtech; Mach, Karel; Pinkas, Jiří; Kubišta, Jiří; Szarka, Katarína; Gyepes, Róbert

    2017-08-01

    Two novel half-sandwich Ti complexes, both incorporating two adamantoxy (OAd) ligands coordinated to their central atoms were synthesized. The complexes were characterized by 1H, 13C, 19F NMR, EI-MS and IR spectroscopy and by single-crystal X-ray diffraction. In both complexes, the coordination environment is pseudo-tetrahedral and is assembled of two O-coordinated adamantoxy and one η5-coordinated permethylcyclopentadienyl ligand. The fourth ligand in complex 1 is a methyl group coordinated through a regular σ-bond, whereas in complex 2 the same coordination site is occupied by the methyl group of the balancing (C6F5)3BMeˉ anion. DFT computations complemented with NBO analyses of 2 have unveiled, that in addition to the electrostatic interactions occurring between the half-sandwich titanocene moiety and the anionic ligand, delocalization of one methyl Csbnd H bond into the available acceptor orbital on the central atom takes place. AIM analyses of 2 have revealed the presence of a Bond Critical Point between the metal atom and the anionic methyl group. These results prove foundation for the description of 2 as a zwitterionic complex coupled with a concurrent Ti⋯Csbnd H agostic interaction in its molecule. The comparison of 2 with its analogous complex equipped with two Ot-Bu ligands instead of both OAd has suggested only a minor change in the extent of the agostic interaction, despite significant geometric differences between the two complexes.

  4. Half-sandwich pentamethylcyclopentadienyl group 9 metal complexes of 2-aminopyridyl ligands: Synthesis, spectral and molecular study

    Indian Academy of Sciences (India)

    Mahesh Kalidasan; Scott Forbes; Yurij Mozharivskyj; Mohan Rao Kollipara

    2015-06-01

    Thereaction of [Cp*M(-Cl)Cl]2 (M = Rh, Ir) with 2-aminopyridyl based ligands lead to the formation of mononuclear neutral complexes of general formula [Cp*MCl2(L)] {where L1= 2-aminopyridine, L2= 2-amino-3-picoline, L3= 2-amino-3-nirtopyridine, and L4= 2-amino-3-pyridine carboxyaldehyde}. The complexes have been characterized by FT-IR, UV-Vis, 1H-13C NMR and mass spectroscopic methods. X-ray crystallographic studies of the complexes have shown typical piano-stool geometry around the metal centre in which 2-aminopyridyl ligand acts as an N-monodentate ligand and the amino functionality is not involved in metal coordination. The intra/intermolecular arrangement is due to hydrogen bonding.

  5. Synthesis, spectral, and thermal characterizations of Ni(II) and Cu(II) β-diketone complexes with thenoyltrifluoroacetone ligand

    Science.gov (United States)

    Chen, Zhimin; Wu, Yiqun; Huang, Fuxin; Gu, Donghong; Gan, Fuxi

    2007-04-01

    Two kinds of nickel(II) and copper(II) β-diketone complexes derived from thenoyltrifluoroacetone ligand with blue-violet light absorption were synthesized by reacting free ligand and different metal(II) ions in sodium methoxide solution. Their structures were postulated based on elemental analysis, ESI-MS, FT-IR spectra and UV-vis electronic absorption spectra. Smooth films on K9 glass substrates were prepared using the spin-coating method. Their solubility in organic solvents, absorption properties of thin film and thermal stability of these complexes were evaluated.

  6. Synthesis, spectral, and thermal characterizations of Ni(II) and Cu(II) beta-diketone complexes with thenoyltrifluoroacetone ligand.

    Science.gov (United States)

    Chen, Zhimin; Wu, Yiqun; Huang, Fuxin; Gu, Donghong; Gan, Fuxi

    2007-04-01

    Two kinds of nickel(II) and copper(II) beta-diketone complexes derived from thenoyltrifluoroacetone ligand with blue-violet light absorption were synthesized by reacting free ligand and different metal(II) ions in sodium methoxide solution. Their structures were postulated based on elemental analysis, ESI-MS, FT-IR spectra and UV-vis electronic absorption spectra. Smooth films on K9 glass substrates were prepared using the spin-coating method. Their solubility in organic solvents, absorption properties of thin film and thermal stability of these complexes were evaluated.

  7. Synthesis, characterisation, spectral, thermal, XRD, molecular modelling and potential antibacterial study of metal complexes containing octadentate azodye ligands

    Science.gov (United States)

    Mahapatra, Bipin Bihari; Chaulia, Satyanarayan; Sarangi, Ashish Kumar; Dehury, Satyanarayan; Panda, Jnyanaranjan

    2015-05-01

    Twelve tetrametallic complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with two new octadentate azodye ligands, 4,4‧-bis(2‧,4‧-dihydroxy-5‧carboxyphenylazo) diphenylether (LH6) and 4,4‧-bis(2‧,4‧-dihydroxy-5‧-acylphenylazo) diphenylether (L‧H4) have been synthesised. The structural elucidation of the complexes was made basing upon analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, ESI-MS, TG, DTG, DTA and X-ray diffraction (powder pattern) data. The cobalt (II) and nickel (II) complexes are found to be octahedral, copper (II) complexes are distorted octahedral and a tetrahedral stereochemistry has been suggested to zinc (II), cadmium (II) and mercury (II) complexes. The thermal analysis data provided the kinetic parameters as order of decomposition reaction, activation energy and frequency factor. The geometry of the ligands and their Co(II), Ni(II), Cu(II) and Zn(II) complexes were optimised and their physicochemical properties were calculated by using molecular modelling procedure. The ESI-MS determination supports the molecular formula and molecular weight of the ligands and the complexes. The Ni(II) complex is found to have a triclinic crystal system. The potential antibacterial study of the two ligands and eight metal complexes was made by cup-plate method against one gram positive and one gram negative bacteria. The results showed increase in the activity of some metal complexes as compare with azodye ligands.

  8. Microwave synthesis and spectral, thermal and antimicrobial activities of some novel transition metal complexes with tridentate Schiff base ligands

    Directory of Open Access Journals (Sweden)

    Jain Rajendra

    2012-01-01

    Full Text Available Some novel Schiff base metal complexes of Cr(III, Co(II, Ni(II and Cu(II derived from 2-[(5-bromo-2-hydroxybenzylideneamino]pyridin-3-ol (BSAP and {5-chloro-2-[(2-hydroxynaphthylideneamino]phenyl}-phenylmethanone (HNAC were synthesized by conventional as well as microwave methods. These compounds were characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility, thermal, cyclic voltammetry, electrical conductivity and XRD analyses. Analytical data revealed that all the complexes exhibited 1:1 (metal:ligand ratio with coordination number 4 or 6. IR data showed that the ligand coordinates with the metal ions in a tridentate manner. FAB-mass and thermal data showed degradation pattern of the complexes. The thermal behaviour of metal complexes showed that the hydrated complexes lose water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The crystal system, lattice parameter, unit cell volume and number of molecules in unit cell in the lattice of complexes were determined by XRD analysis. XRD patterns indicate crystalline nature for the complexes. The solid state electrical conductivity of the metal complexes was also measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes displayed a good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans. The antimicrobial results also indicate that the metal complexes displayed better antimicrobial activity as compared to the Schiff bases.

  9. Novel amide-type ligand bearing bis-pyridine cores: Synthesis, spectral characterizations and X-ray structure analyses

    Science.gov (United States)

    Ke, Shaoyong

    2016-08-01

    The novel salicylamide-type ligand containing bis-pyridine moieties, i.e. 2-((6-chloropyridin-3-yl)methoxy)-N-(2-((6-chloropyridin-3-yl)methylthio)phenyl)benzamide, which has been successfully synthesized and characterized by typical spectroscopic techniques mainly including IR, 1H NMR and ESI-MS. The structure of target compound was further determined by single crystal X-ray diffraction method and which crystallized in the monoclinic system with space group P2(1)/c.

  10. Synthesis and spectral characterization of homo- and hetero-dinuclear complexes with a new septadentate Schiff base ligand

    Indian Academy of Sciences (India)

    J K Nag; D Das; S Pal; C Sinha

    2001-02-01

    Reaction between 3-formylsalicylic acid and bis-(2-aminophenyl)-disulphide yields a septadentate Schiff base with N2SO4 donor frame of which the inner compartment is N2SO2 and the outer is O2O2 type. It forms several complexes with inner copper centre and outer nontransition/transition metal ions. The complexes have been characterised by elemental analyses, spectral (IR, absorption, diffused reflectance), thermal and magnetic data. Dinuclear copper complexes exhibit subnormal magnetic moments ( 0 80 BM), showing magnetic exchange, and six-line solid-state ESR spectra at 77 K.

  11. DNA binding, anti-inflammatory and analgesic evaluation of metal complexes of N/S/O donor ligands; Synthesis, spectral characterization

    Science.gov (United States)

    Kumar Naik, K. H.; Ashok, B.; Naik, Nagaraja; Mulla, Jameel Ahmed S.; Prakasha, Avinash

    2015-04-01

    Transition metal complexes containing tri-dentate NSN donor ligands i.e., 5-((1(aminomethyl)cyclohexyl)methyl)-1,3,4-thiadiazol-2-amine (AMTA) (2) and 5-(2-aminophenyl)-1,3,4-thiadiazol-2-amine (ATA) (4i-ii) have been synthesized. The newly synthesized ligands and their respective complexes were characterized by elemental analysis, molar conductance measurement and various spectral studies [infrared (IR), electronic, and NMR (for ligands only)]. Metal complexes are like [M(AMTA)2], [M(ATA)2] type, where M = Mn(II), Co(II) and Cu(II). The proposed geometries of the complexes are octahedral in nature. The synthesized ligands and their complexes were exhibits effective anti-inflammatory, analgesic and DNA binding activities. All the tested compounds exhibited significant analgesic activity, whereas the compound 4i, 4(ia) and 4(iib) is equipotent with Diclofenac sodium.

  12. Microwave Assisted Synthesis, Spectral and Antifungal Studies of 2-Phenyl-N,N′-bis(pyridin-4-ylcarbonylbutanediamide Ligand and Its Metal Complexes

    Directory of Open Access Journals (Sweden)

    Rayees Ahmad Shiekh

    2014-01-01

    Full Text Available 2-Phenyl-N,N′-bis(pyridin-4-ylcarbonylbutanediamide ligand with a series of transition metal complexes has been synthesized via two routes: microwave irradiation and conventional heating method. Microwave irritation method happened to be the efficient and versatile route for the synthesis of these metal complexes. These complexes were found to have the general composition M(LCl2/M(L(CH3COO2 (where M = Cu(II, Co(II, Ni(II, and L = ligand. Different physical and spectroscopic techniques were used to investigate the structural features of the synthesized compounds, which supported an octahedral geometry for these complexes. In vitro antifungal activity of the ligand and its metal complexes revealed that the metal complexes are highly active compared to the standard drug. Metal complexes showed enhanced activity compared to the ligand, which is an important step towards the designing of antifungal drug candidates.

  13. Microwave assisted synthesis, spectral and antifungal studies of 2-phenyl-N,N'-bis(pyridin-4-ylcarbonyl)butanediamide ligand and its metal complexes.

    Science.gov (United States)

    Shiekh, Rayees Ahmad; Malik, Maqsood Ahmad; Al-Thabaiti, Shaeel Ahmed; Wani, Mohmmad Younus; Nabi, Arshid

    2014-01-01

    2-Phenyl-N,N'-bis(pyridin-4-ylcarbonyl)butanediamide ligand with a series of transition metal complexes has been synthesized via two routes: microwave irradiation and conventional heating method. Microwave irritation method happened to be the efficient and versatile route for the synthesis of these metal complexes. These complexes were found to have the general composition M(L)Cl2/M(L)(CH3COO)2 (where M = Cu(II), Co(II), Ni(II), and L = ligand). Different physical and spectroscopic techniques were used to investigate the structural features of the synthesized compounds, which supported an octahedral geometry for these complexes. In vitro antifungal activity of the ligand and its metal complexes revealed that the metal complexes are highly active compared to the standard drug. Metal complexes showed enhanced activity compared to the ligand, which is an important step towards the designing of antifungal drug candidates.

  14. Microwave Assisted Synthesis, Spectral and Antifungal Studies of 2-Phenyl-N,N′-bis(pyridin-4-ylcarbonyl)butanediamide Ligand and Its Metal Complexes

    OpenAIRE

    Rayees Ahmad Shiekh; Maqsood Ahmad Malik; Shaeel Ahmed Al-Thabaiti; Mohmmad Younus Wani; Arshid Nabi

    2014-01-01

    2-Phenyl-N,N′-bis(pyridin-4-ylcarbonyl)butanediamide ligand with a series of transition metal complexes has been synthesized via two routes: microwave irradiation and conventional heating method. Microwave irritation method happened to be the efficient and versatile route for the synthesis of these metal complexes. These complexes were found to have the general composition M(L)Cl2/M(L)(CH3COO)2 (where M = Cu(II), Co(II), Ni(II), and L = ligand). Different physical and spectroscopic techniques...

  15. Synthesis, spectral, photolysis and electrochemical studies of mononuclear copper(II) complex with a new asymmetric tetradentate ligand: Application as copper nanoparticle precursor

    Science.gov (United States)

    Habibi, Mohammad Hossein; Mikhak, Maryam

    2012-10-01

    A copper(II) complex with asymmetric tetradentate Schiff base ligand, obtained by the single condensation of 1,2-diaminopropane with 2-hydroxy-5-methoxy benzaldehyde was prepared. The ligand and complex were characterized by their IR, UV-Vis, FT-IR, NMR spectra and CV. Crystal structures of the mononuclear copper complex have been obtained by X-ray diffraction studies which revealed to be distorted square planner coordination geometry. The spectral data confirm coordination of ligand to copper ion center. The redox properties of complex at different scan rates exhibit grossly similar features consisting of an electrochemically pseudo-reversible Cu(II)/Cu(I) reduction at ca. -0.97 V and pseudo-reversible Cu(I)/Cu(II) oxidation at ca. -0.81 V. The copper nanoparticles with average size of 73 nm were formed by thermal reduction of copper complex in the presence of triphenylphosphine.

  16. Synthesis, spectral, photolysis and electrochemical studies of mononuclear copper(II) complex with a new asymmetric tetradentate ligand: application as copper nanoparticle precursor.

    Science.gov (United States)

    Habibi, Mohammad Hossein; Mikhak, Maryam

    2012-10-01

    A copper(II) complex with asymmetric tetradentate Schiff base ligand, obtained by the single condensation of 1,2-diaminopropane with 2-hydroxy-5-methoxy benzaldehyde was prepared. The ligand and complex were characterized by their IR, UV-Vis, FT-IR, NMR spectra and CV. Crystal structures of the mononuclear copper complex have been obtained by X-ray diffraction studies which revealed to be distorted square planner coordination geometry. The spectral data confirm coordination of ligand to copper ion center. The redox properties of complex at different scan rates exhibit grossly similar features consisting of an electrochemically pseudo-reversible Cu(II)/Cu(I) reduction at ca. -0.97 V and pseudo-reversible Cu(I)/Cu(II) oxidation at ca. -0.81 V. The copper nanoparticles with average size of 73 nm were formed by thermal reduction of copper complex in the presence of triphenylphosphine.

  17. Synthesis, spectral, thermal and antibacterial investigations of mixed ligand complexes of thorium(IV) derived from 8-hydroxyquinoline and some amino acids.

    Science.gov (United States)

    Patil, Sunil S; Thakur, Ganesh A; Shaikh, Manzoor M

    2012-01-01

    Mixed ligand Th(IV) complexes of the type [M(Q)(L)(NO3)2] x 2 H2O have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and N- and/or O- donor amino acids (HL) such as L-lysine, L-aspartic acid and L-cysteine as secondary ligands. The metal complexes have been characterized on the basis of elemental analysis, electrical conductance, room temperature magnetic susceptibility measurements,spectral and thermal studies. The electrical conductance studies of the complexes in DMF in 10(-3) M concentration indicate their non-electrolytic nature. Room temperature magnetic susceptibility measurements revealed diamagnetic nature of the complexes. Electronic absorption spectra of the complexes show intra-ligand and charge transfer transitions, respectively. Bonding of the metal ion through N- and O- donor atoms of the ligands revealed by IR studies and the chemical environment of the protons is also confirmed by NMR studies. The thermal analysis data of the complexes indicate the presence of crystallized water molecules. The agar cup and tube dilution method have been used to study the antibacterial activity of the complexes against the pathogenic bacteria S. aureus, C. diphtheriae, S. typhi and E. coli.

  18. Synthesis of mononuclear copper(II) complexes of acyclic Schiff's base ligands: Spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity

    Science.gov (United States)

    Jayamani, Arumugam; Thamilarasan, Vijayan; Sengottuvelan, Nallathambi; Manisankar, Paramasivam; Kang, Sung Kwon; Kim, Young-Inn; Ganesan, Vengatesan

    2014-03-01

    The mononuclear copper(II) complexes (1&2) of ligands L1 [N,N";-bis(2-hydroxy-5-methylbenzyl)-1,4-bis(3-iminopropyl)piperazine] or L2 [N,N";-bis(2-hydroxy-5-bromobenzyl)-1,4-bis(3-iminopropyl) piperazine] have been synthesized and characterised. The single crystal X-ray study had shown that ligands L1 and L2 crystallize in a monoclinic crystal system with P21/c space group. The mononuclear copper(II) complexes show one quasireversible cyclic voltammetric response near cathodic region (-0.77 to -0.85 V) in DMF assignable to the Cu(II)/Cu(I) couple. Binding interaction of the complexes with calf thymus DNA (CT DNA) investigated by absorption studies and fluorescence spectral studies show good binding affinity to CT DNA, which imply both the copper(II) complexes can strongly interact with DNA efficiently. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid as reducing agent through a mechanistic pathway involving formation of singlet oxygen as the reactive species. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activities which indicates that the complexes exhibited higher antimicrobial activity than the free ligands.

  19. Synthesis, crystal structure, spectral characterization and photoluminescence property of three Cd(II) complexes with a pyrazole based Schiff-base ligand

    Science.gov (United States)

    Mandal, Susmita; Saha, Rajat; Saha, Manan; Pradhan, Rajesh; Butcher, Ray J.; Saha, Nitis Chandra

    2016-04-01

    Substituted pyrazole containing Schiff-base ligand, 5-methyl-3-formylpyrazole-N-(2‧-methylphenoxy)methyleneimine, (MPzOA), afforded three new Cd(II) complexes, [Cd(MPzOA)Cl2]2.CH3OH (I), [Cd(MPzOA)2(H2O)2](ClO4)2 (II) and [Cd(MPzOA)(H2O)(NO3)2] (III). In the reported complex species the coordination number and geometry of Cd(II) vary. In complex I and II, Cd(II) adopts six and in (III) it adopts eight coordination modes, with prismatic, octahedral and distorted dodecahedral geometry, respectively. All the complexes are characterized by IR, 1H NMR, UV-Vis spectral parameters and X-ray analyses. The complexes have 1D, 2D and 3D supramolecular frameworks formed by non-covalent interactions, like hydrogen bonding, π … π stacking, C-H … π interactions.

  20. Spectral Synthesis of SDSS Galaxies

    CERN Document Server

    Sodre, J; Mateus, A; Stasinska, G; Gomes, J M

    2005-01-01

    We investigate the power of spectral synthesis as a mean to estimate physical properties of galaxies. Spectral synthesis is nothing more than the decomposition of an observed spectrum in terms of a superposition of a base of simple stellar populations of various ages and metallicities (here from Bruzual & Charlot 2003), producing as output the star-formation and chemical histories of a galaxy, its extinction and velocity dispersion. We discuss the reliability of this approach and apply it to a volume limited sample of 50362 galaxies from the SDSS Data Release 2, producing a catalog of stellar population properties. A comparison with recent estimates of both observed and physical properties of these galaxies obtained by other groups shows good qualitative and quantitative agreement, despite substantial differences in the method of analysis. The confidence in the method is further strengthened by several empirical and astrophysically reasonable correlations between synthesis results and independent quantiti...

  1. Binary and ternary copper(II) complexes of a tridentate ONS ligand derived from 2-aminochromone-3 carboxaldehyde and thiosemicarbazide: Synthesis, spectral studies and antimicrobial activity

    Science.gov (United States)

    Shebl, Magdy; Ibrahim, M. A.; Khalil, Saied M. E.; Stefan, S. L.; Habib, H.

    2013-11-01

    A tridentate ONS donor ligand, HL, was synthesized by the condensation of 2-aminochromone-3-carboxaldehyde with thiosemicarbazide. The structure of the ligand was elucidated by elemental analyses, IR, 1H and 13C NMR, electronic and mass spectra. Reaction of the ligand with several copper(II) salts, including AcO-, NO3-, SO42-, Cl-, Br- and ClO4- afforded different metal complexes that reflect the non-coordinating or weakly coordinating power of the ClO4- and Br- anions as compared to the strongly coordinating power of AcO-, SO42-, Cl- and NO3- anions. Also, the ligand was allowed to react with Cu(II) ion in the presence of a secondary ligand (L‧) [N,O-donor; 8-hydroxyquinoline or N,N-donor; 1,10-phenanthroline]. Characterization and structure elucidation of the prepared complexes were achieved by elemental and thermal analyses, IR, electronic, mass and EPR spectra as well as conductivity and magnetic susceptibility measurements. The EPR spin Hamiltonian parameters of some complexes were calculated. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. The ligand and most of its metal complexes showed antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus).

  2. Organometallic Gold(Ⅲ)Derivatives with Anionic Oxygen Ligands-mononuclear Hydroxo,Alkoxo,and Acetato Complexes:Synthesis and Spectral Study

    Institute of Scientific and Technical Information of China (English)

    Prithwiraj Byabartta

    2008-01-01

    A variety of gold(Ⅲ) adducts having a-ligated oxygen-donor ligands have been prepared from [Au(ppy)Cl2](ppy·phenylpyridine)(1) either by partial or total replacement of the chloride ions.The new species comprise hydroxo-[Au(ppy)(OH)Cl](2),and[Au(ppy)(OH)2](3),oxo-[Au2(ppy)2(μ-O)2](4),acetate-[Au(ppy)(O2CMe2)] (5),and alkoxo complexes-[Au(ppy)(OR)Cl](6,7)and[Au(ppy)(OR)2](8-10)(R=Me,6 and 8;Et,7 and 9;Pri,10).The dihydroxo and the OXO complexes Can be interconverted by refluxing the former in anhydrous THF and the latter in water.The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution(R=Me,Et or Pri) to give the corresponding alkoxides.

  3. Synthesis, structural, spectral, thermal and antimicrobial studies of palladium(II), platinum(II), ruthenium(III) and iridium(III) complexes derived from N,N,N,N-tetradentate macrocyclic ligand.

    Science.gov (United States)

    Rani, Soni; Kumar, Sumit; Chandra, Sulekh

    2011-05-01

    Palladium(II), platinum(II), ruthenium(III) and iridium(III) complexes of general stoichiometry [PdL]Cl(2), [PtL]Cl(2), [Ru(L)Cl(2)]Cl and [Ir(L)Cl(2)]Cl are synthesized with a tetradentate macrocyclic ligand, derived from 2,6-diaminopyridine with 3-ethyl 2,4-pentanedione. Ligand was characterized on the basis of elemental analyses, IR, mass, and (1)H NMR and (13)C NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, mass, electronic spectral techniques and thermal studies. The value of magnetic moments indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moments corresponding its one unpaired electron. The macrocyclic ligand and all its metal complexes were also evaluated in vitro against some plant pathogenic fungi and bacteria to assess their biocidal properties.

  4. Tetra- and hexadentate Schiff base ligands and their Ni(II), Cu(II) and Zn(II) complexes. Synthesis, spectral, magnetic and thermal studies.

    Science.gov (United States)

    Ismail, Tarek M A; Saleh, Akila A; El Ghamry, Mosad A

    2012-02-01

    Tetradentate N(2)O(2), N(4) Schiff bases, 1,2-bis(4-oxopent-2-ylideneamino) benzene (BOAB), 1-(4-oxopent-2-ylideneamino-2-[(2-hydroxyphenyl)ethylideneamino] benzene (OAHAB), 7,16-bis(4-chlorobenzylidene)-6,8,15,17-tetra-methyl-7,16-dihydro -5,9,14,18-tetraza-dibenzo[a,h] cyclo tetradecene (BCBDCT), 7,16-bis(2-hydroxy-benzylidene)-6,8,15,17-tetramethyl-7,16-dihydro-5,9,14,18-tetraza-dibenzo [a,h] cyclo tetradecene (BHBDCT) and hexadentate N(4)O(2) Schiff bases, 2,4-bis {2-[1-(2-hydroxyphenyl) ethylideneamino] phenylimino}-3-(2-hydroxybenzylidene) pentane (BHAPHP), 2,4-bis {2-[1-(2-hydroxyphenyl) ethylideneamino] phenylimino}-3-(4-chlorobenzylidene) pentane (BHAPCP) were prepared and characterized by elemental analysis, IR, UV-Vis, (1)H NMR and mass spectra. The solid complexes of the prepared Schiff base ligands with Ni(II), Cu(II) and Zn(II) ions were isolated and characterized by elemental and thermal analyses, IR, electronic and ESR spectra as well as conductance and magnetic susceptibility measurements. The results showed that most complexes have octahedral geometry but few can attain the tetrahedral arrangement. The TG analyses suggest high stability for most complexes followed by thermal decomposition in different steps. The kinetic and thermodynamic parameters for decomposition steps in Cu(II) complexes thermograms have been calculated.

  5. Synthesis, spectroscopic and X-ray characterization of a copper(II) complex with the Schiff base derived from pyridoxal and aminoguanidine: NMR spectral studies of the ligand.

    Science.gov (United States)

    Leovac, Vukadin M; Joksović, Milan D; Divjaković, Vladimir; Jovanović, Ljiljana S; Saranović, Zana; Pevec, Andrej

    2007-07-01

    A copper(II) complex with the pyridoxal-aminoguanidine (PL-AG) Schiff base adduct, as an organic compound of the very potent biological activity and promising pharmacological importance in the treatment of diabetic complications, has been prepared and characterized. The X-ray structural analysis of the [CuCl2(PL-AG)] complex showed that it has a distorted pseudo-square-pyramidal (4+1) structure with the tridentate ONN Schiff base in the equatorial plane, with the Cu-O(1), Cu-N(1) and Cu-N(3) bond lengths of 1.917(2)A, 1.930(2)A and 1.984(2)A, respectively. The bond length of the equatorial Cu-Cl(1) is 2.279(1)A, while that of the apical Cu-Cl(2) is 2.792(1)A. Pyridoxal fragment is coordinated in its zwitterionic form. In addition to the X-ray structural analysis, the complex was characterized by IR spectrometric, conductometric and magnetic techniques, and the ligand itself by IR, 1H and 13C NMR spectra.

  6. Synthesis and spectral studies of Cu(II, Ni(II, Co(II, Mn(II, Zn(II and Cd(II complexes of a new macroacyclic ligand N,N’-bis(2-benzothiazolyl-2,6-pyridinedicarboxamide

    Directory of Open Access Journals (Sweden)

    KALAGOUDA B. GUDASI

    2006-05-01

    Full Text Available A new macroacyclic amide ligand N,N’-bis(2-benzothiazolyl-2,6-pyridinedicarboxamide (BPD, formed by the condensation of 2,6-pyridinedicarbonyldichloride with 2-aminobenzothiazole, and its Cu(II, Ni(II, Co(II, Mn(II, Zn(II and Cd(II complexes were synthesized. Their structures were elucidated on the basis of elemental analyses, conductance measurements, magnetic moments, spectral (IR, NMR, UV-Visible, EPR and FAB and thermal studies. The complexes exhibit an octahedral geometry around the metal center. Conductance data of the complexes suggested them to be 1:1 electrolytes. The pentadentate behavior of the ligand was proposed on the basis of spectral studies. The X-band EPR spectra of the Cu(II and Mn(II complexes in the polycrystalline state at room (300 K and liquid nitrogen temperature (77 K were recorded and their salient features are reported.

  7. Coordination behavior and bio-potent aspects of Ni(II) with 2-aminobenzamide and some amino acid mixed ligands--Part II: Synthesis, spectral, morphological, pharmacological and DNA interaction studies.

    Science.gov (United States)

    Dharmaraja, Jeyaprakash; Subbaraj, Paramasivam; Esakkidurai, Thirugnanasamy; Shobana, Sutha

    2014-11-11

    A series of novel bioactive mixed ligand Ni(II) complexes (1a-1d) have been synthesised by using 2-aminobenzamide (2AB) and some bio-relevant amino acid ligands. The synthesised Ni(II) complexes were structurally characterized by various physico-chemical and spectral studies. Elemental analysis and molar conductance values suggest that 1:1:1 stoichiometry with non-electrolytic nature. Based on the spectral studies, both the ligands act as bidentate and they chelate with Ni(II) ion via amino-NH2 and amido-O and deprotonated carboxylato-O and amino-NH2 atoms respectively to form a stable six, five membered chelate rings with mononuclear octahedral geometry. Thermal studies show the presence of coordinated water and acetate molecules in the coordination. The powder X-ray diffractogram and SEM pictograph imply that all the complexes have fine crystalline peaks with homogeneous surface morphology. In vitro antimicrobial and antioxidant studies indicate the complexes are more active than free 2-aminobenzamide ligand. The Ni(II)-2AB-gly/phe complexes (1a and 1d) show significant oxidative cleavage and DNA binding activities. Moreover, the 3D molecular modeling, analysis of the complexes has also been studied.

  8. Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: Synthesis, spectral characterization, antimicrobial and nuclease studies

    Science.gov (United States)

    Subbaraj, P.; Ramu, A.; Raman, N.; Dharmaraja, J.

    2014-01-01

    A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA = Schiff base and B = 2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, 1H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, 1H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

  9. SYNTHESIS, SPECTRAL, THERMAL AND ANTIBACTERIAL INVESTIGATION OF NI(II MIXED LIGAND COMPLEXES WITH CLIOQUINOL AND COUMARIN DERIVATIVE Synthese, SPECTRAL, thermische und ANTIBACTERIAL UNTERSUCHUNG NI (II-Komplexe MIT MIXED Clioquinol UND COUMARIN DERIVATE

    Directory of Open Access Journals (Sweden)

    G. J. Kharadi and K. S. Patel

    2013-10-01

    Full Text Available The antibiotic agent clioquinol is well known for its drug design and coordinating ability towards metal ions. Ni(II complexes of clioquinol with various monobasic bidentate ligands have been prepared. All the complexes have been synthesized, characterized and screened for their in vitro antibacterial activity against a range of Gram-positive and Gramnegative bacteria. Structural and spectroscopic properties have been studied on the basis of elemental analysis, infrared spectra, NMR spectra, electronic spectra, magnetic measurements, FAB mass spectrum and thermo gravimetric analysis. The kinetic parameters such as order of reaction (n = 0.97 to1.51 and the energy of activation (Ea = 3.76 to 88.40 kJmol-1 have been reported using Freeman-Carroll method. The pre-exponential factor (A, the activation entropy (S* = -175 to -283 JK-1mol-1, the activation enthalpy (H* = 0.856 to 80.97 kJmol-1 and the free energy of activation (G* = 97.6 to 251 kJmol-1 have been calculated.

  10. Synthesis of symmetrical and non-symmetrical bivalent neurotransmitter ligands

    DEFF Research Database (Denmark)

    Stuhr-Hansen, Nicolai; Andersen, Jacob; Thygesen, Mikkel Boas

    2016-01-01

    A novel procedure for synthesis of bivalent neurotransmitter ligands was developed by reacting O-benzyl protected N-nosylated dopamine and serotonin with alkyl- or PEG-linked diols under Fukuyama-Mitsunobu conditions in the presence of DIAD/PPh3 generating three different bivalent neurotransmitter...... ligands in a one-pot reaction. The methodol. establishes a facile route towards bivalent neurotransmitter ligands, and libraries of in total 40 sym. and non-sym. bivalent and monovalent dopamine and serotonin compds. linked through alkyl or PEG spacers of varying length were prepd. Interestingly...

  11. Efficient chemoenzymatic synthesis of chiral pincer ligands.

    Science.gov (United States)

    Felluga, Fulvia; Baratta, Walter; Fanfoni, Lidia; Pitacco, Giuliana; Rigo, Pierluigi; Benedetti, Fabio

    2009-05-01

    Chiral, nonracemic pincer ligands based on the 6-phenyl-2-aminomethylpyridine and 2-aminomethylbenzo[h]quinoline scaffolds were obtained by a chemoenzymatic approach starting from 2-pyridyl and 2-benzoquinolyl ethanone. In the enantiodifferentiating step, secondary alcohols of opposite absolute configuration were obtained by a baker's yeast reduction of the ketones and by lipase-mediated dynamic kinetic resolution of the racemic alcohols. Their transformation into homochiral 1-methyl-1-heteroarylethanamines occurred without loss of optical purity, giving access to pincer ligands used in enantioselective catalysis.

  12. Synthesis and evaluation of potential ligands for nuclear waste processing

    NARCIS (Netherlands)

    Iqbal, M.

    2012-01-01

    The research presented in this thesis deals with the synthesis and evaluation of new potential ligands for the complexation of actinide and lanthanide ions either for their extraction from bulk radioactive waste or their stripping from an extracted organic phase for final processing of the waste. In

  13. Solid-Phase Parallel Synthesis of Phosphite Ligands

    NARCIS (Netherlands)

    Swennenhuis, Bert H.G.; Chen, Ruifang; Leeuwen, Piet W.N.M. van; Vries, Johannes G. de; Kamer, Paul C.J.

    2008-01-01

    Various routes for the synthesis of polymer-bound phosphites and phosphoramidites have been investigated. In the presence of a suitable activator the supported phosphoramidites react cleanly with alcohols to give the corresponding monodentate phosphite ligands in solution. We have applied this novel

  14. Synthesis and evaluation of potential ligands for nuclear waste processing

    NARCIS (Netherlands)

    Iqbal, M.

    2012-01-01

    The research presented in this thesis deals with the synthesis and evaluation of new potential ligands for the complexation of actinide and lanthanide ions either for their extraction from bulk radioactive waste or their stripping from an extracted organic phase for final processing of the waste. In

  15. Stellar Spectral Synthesis with OpenGL

    Science.gov (United States)

    Hill, Nicholas R.; Townsend, R.

    2011-01-01

    Given an appropriate model atmosphere, synthesizing the spectrum of a star is a relatively straightforward task -- *if* the star is spherical and homogeneous across its surface. Many astronomically interesting objects do not, however, fall into this category. Examples include single stars that are spotted, rapidly rotating or pulsating, and binary stars in eclipsing or ellipsoidal-variable configurations. To synthesize a spectrum in such cases, it is necessary to construct a 3-D model of the stellar surface; determine which regions of the surface are visible to an external observer; and then calculate the observer-directed radiation from these regions. The Open Graphics Library (OpenGL), a cross-platform application programming interface for creation of 2-D and 3-D graphics, already includes much of the functionality required to implement these steps. We describe a new approach to stellar spectral synthesis that leverages this functionality. A 3-D mesh is constructed to represent the (possibly non-spherical) geometry of the stellar surface (or surfaces, in the case of binary or multiple systems). Textures are laid over this mesh to represent the run of physical attributes such as temperature, gravity, velocity, etc. The textured mesh is then rendered by OpenGL into a framebuffer, a step which naturally takes care of projection and occultation effects. The attributes of each framebuffer pixel are used to look up an appropriate spectrum in pre-calculated tables of specific intensities; and finally, summing the spectra from all pixels gives the disk-integrated synthetic flux spectrum of the star. The advantage of this approach lies in its efficiency (many OpenGL features are hardware-implemented), flexibility and manifest simplicity. Possible applications include binary light-curve modeling, mode identification in pulsating stars, and stellar population synthesis.

  16. Polydentate cyclotriphosphazene ligands: Design, synthesis and bioactivity

    Institute of Scientific and Technical Information of China (English)

    Le Wang; Yong Ye; Shang Bin Zhong; Yu Fen Zhao

    2009-01-01

    Five multinuelear cyclotriphosphazene ligands were synthesized and tested for their cleavage activities to plasmid DNA. All of these new compounds were confirmed by MS, 1H NMR, 31p NMR, 13C NMR and IR. Preliminary studies on the cleavage of pUC19 DNA in the presence of metal complexes were performed. The results revealed that these complexes could act as powerful catalysts under physiological conditions. The complexes 3b + Cu can effectively cleave DNA to nicked form, giving hydrolysis rate constant of 0.08/h under physiological conditions. An acid-base catalyzed DNA phosphate-diester hydrolysis mechanism was also proposed.

  17. Mono and binuclear Ag(I), Cu(II), Zn(II) and Hg(II) complexes of a new azo-azomethine as ligand: synthesis, potentiometric, spectral and thermal studies.

    Science.gov (United States)

    Ahmed, Ibrahim S; Moustafa, Moustafa M; Abd El Aziz, Mohamed M

    2011-05-01

    New azo-azomethine dyes were prepared by reaction of p-aminobenzoic acid, o-anisidine, o-nitroaniline, and p-bromoaniline with salicylaldehyde respectively to form azo compounds and then condensation by urea to form 4-(R-arylazo 2-salicylaldene)-urea azo-azomethine derivatives (I(a-d)). The complexes of these ligands with Ag(I), Cu(II), Zn(II) and Hg(II) metal ions were prepared. The structure of the free ligands and their complexes were characterized by using elemental analysis (C, H, N), (1)H NMR, IR and UV-Vis-spectra. The proton dissociation constants of the ligands and the stability constant of their complexes have been determined potentiometrically in 40% (v/v) alcohol-water medium as well as the stoichiometry of complexes were determined conductometrically. The data reveal that the stoichiometries for all complexes were prepared in molar ratios (1:1) and (1:2) (M:L). The electrolytic and nonelectrolytic natures of the complexes were assigned based on molar conductance measurements. The thermogravimetric (TG), and differential thermal analyses (DTA) were studied in nitrogen atmosphere with heating rate 10°C/min. The kinetic and thermodynamic parameters for thermal decomposition of complexes have been calculated by graphical method using Coats-Redfern (CR) method.

  18. SLGRID: spectral synthesis software in the grid

    Science.gov (United States)

    Sabater, J.; Sánchez, S.; Verdes-Montenegro, L.

    2011-11-01

    SLGRID (http://www.e-ciencia.es/wiki/index.php/Slgrid) is a pilot project proposed by the e-Science Initiative of Andalusia (eCA) and supported by the Spanish e-Science Network in the frame of the European Grid Initiative (EGI). The aim of the project was to adapt the spectral synthesis software Starlight (Cid-Fernandes et al. 2005) to the Grid infrastructure. Starlight is used to estimate the underlying stellar populations (their ages and metallicities) using an optical spectrum, hence, it is possible to obtain a clean nebular spectrum that can be used for the diagnostic of the presence of an Active Galactic Nucleus (Sabater et al. 2008, 2009). The typical serial execution of the code for big samples of galaxies made it ideal to be integrated into the Grid. We obtain an improvement on the computational time of order N, being N the number of nodes available in the Grid. In a real case we obtained our results in 3 hours with SLGRID instead of the 60 days spent using Starlight in a PC. The code has already been ported to the Grid. The first tests were made within the e-CA infrastrusture and, later, itwas tested and improved with the colaboration of the CETA-CIEMAT. The SLGRID project has been recently renewed. In a future it is planned to adapt the code for the reduction of data from Integral Field Units where each dataset is composed of hundreds of spectra. Electronic version of the poster at http://www.iaa.es/~jsm/SEA2010

  19. Arene ruthenium(II) azido complexes incorporating N intersection O chelate ligands: Synthesis, spectral studies and 1,3-dipolar-cycloaddition to a coordinated azide in ruthenium(II) compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Kaminsky, W.

    Synthesis of (η6-arene) ruthenium (II) complexes has attracted considerable attention owing to their anti-cancer [1-3], antiviral [4] and catalytic properties [5-7]. The catalytic activities of these complexes range from hydrogen transfer to ring closing...

  20. Synthesis and Characterization of a Triphos Ligand Derivative and the Corresponding Pd II Complexes: Triphos Ligand Derivative and Corresponding Pd II Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Deanna L.; Boro, Brian J.; Grubel, Katarzyna; Helm, Monte L.; Appel, Aaron M.

    2015-11-16

    The synthesis of the new bis(2-(diphenylphosphino)ethyl)methylhydroxyphosphine tridentate phosphine ligand, LCH2OH/Ph, is reported. The ligand reacts with [Pd(Cl)2(PhCN)2 to form [Pd(LCH2OH/Ph)Cl]Cl. Exchange of the chloride ions for triflate (OTf–) using AgOTf yielded pure [Pd(LCH2OH/Ph)OTf]OTf. In addition to spectral characterization the free ligand, LCH2OH/Ph, and Pd(II) complex, [Pd(LCH2OH/Ph)OTf]OTf, are structurally characterized. This research was supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences, and Geosciences. Pacific Northwest National Laboratory is a multiprogram national laboratory operated by Battelle for DOE.

  1. Binary and ternary copper(II) complexes of a new Schiff base ligand derived from 4-acetyl-5,6-diphenyl-3(2H)-pyridazinone: Synthesis, spectral, thermal, antimicrobial and antitumor studies

    Science.gov (United States)

    Shebl, Magdy; Adly, Omima M. I.; Abdelrhman, Ebtesam M.; El-Shetary, B. A.

    2017-10-01

    A new Schiff base ligand was synthesized by the reaction of 4-acetyl-5,6-diphenyl-3(2H)-pyridazinone with ethylenediamine. A series of binary copper(II) Schiff base complexes have been synthesized by using various copper(II) salts; AcO-, NO3-, ClO4-, Cl- and Br-. Ternary complexes were synthesized by using auxiliary ligands (L‧) [N,O-donor; 8-hydroxyquinoline and glycine or N,N-donor; 1,10-phenanthroline, bipyridyl and 2-aminopyridine]. The structures of the Schiff base and its complexes were characterized by elemental and thermal analyses, IR, electronic, mass, 1H NMR and ESR spectra in addition to conductivity and magnetic susceptibility measurements. The obtained complexes include neutral binuclear complexes as well as neutral and cationic mononuclear complexes according to the anion used and the experimental conditions. The ESR spin Hamiltonian parameters of some complexes were calculated and discussed. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. Kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of the thermal decomposition stages were evaluated using Coats-Redfern equations. The antimicrobial activity of the Schiff base and its complexes was screened against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus). The antitumor activity of the Schiff base and some of its Cu(II) complexes was investigated against HepG-2 cell line.

  2. Synthesis and Spectral Investigations of Manganese(II, Cobalt(II, Nickel(II, Copper(II and Zinc(II Complexes of New Polydentate Ligands Containing a 1,8-Naphthyridine Moiety

    Directory of Open Access Journals (Sweden)

    Sunkari Jyothi

    2006-12-01

    Full Text Available 2-(o-Hydroxyphenyl-1,8-naphthyridine (HN, 2-(4-hydroxy-6-methylpyran-2-one-3-yl-1,8-naphthyridine (HMPN and 2-(benzimidazol-2-yl-1,8-naphthyridine(BN react with acetates of Mn(II, Co(II, Ni(II, Cu(II and Zn(II to yield metal ioncomplexes of definite composition. These compounds were characterized by elementalanalyses, molar conductivity, magnetic susceptibility measurements, thermal studies, IR,UV-visible, NMR and mass spectral investigations. The complexes are found to have theformulae [M(HN2(H2O2], [M(HMPN2(H2O2] and [M(BN2(OAc2], respectively.

  3. Synthesis, spectral and electrochemical studies of Cu(II) and Ni(II) complexes with new N2O2 ligands: a new precursor capable of depositing copper nanoparticles using thermal reduction.

    Science.gov (United States)

    Habibi, Mohammad Hossein; Mokhtari, Reza; Mikhak, Maryam; Amirnasr, Mehdi; Amiri, Ahmad

    2011-09-01

    Cu(II) and Ni(II) complexes of the general type [M(N2O2)] are described. The N2O2 ligands used are [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,3-diamine] (HOMeSalpn) and [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,2-diamine (HOMeSalpr). These complexes have been characterized by IR, UV-vis, CV, TG-DTA and 1H NMR spectroscopy. The electrochemical behavior of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Cu(II)-Cu(I) and Ni(II)-Ni(I) is electrochemically irreversible. The new copper complexes have been applied for the preparation of copper nanoparticles using non-ionic surfactant (Triton X-100) by thermal reduction. The copper nanoparticles with average size of 48nm were formed by thermal reduction of [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,3-diamine]copper(II) in the presence of triphenylphosphine thus releasing the reduced copper and affording the high-purity copper nanoparticles.

  4. Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II, Co(II, Ni(II, Cu(II, and Zn(II] metals

    Directory of Open Access Journals (Sweden)

    Nahid Nishat

    2016-09-01

    Full Text Available A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II. All the polymeric compounds were characterized by (FT-IR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA and antibacterial activities. Polymer complexes of Mn(II, Co(II and Ni(II show octahedral geometry, while polymer complexes of Cu(II and Zn(II show square planar and tetrahedral geometry, respectively. The TGA revealed that all the polymer metal complexes are more thermally stable than their parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM-D-5338-93 standards of biodegradable polymers by CO2 evolution method which says that coordination decreases biodegradability. The antibacterial activity was screened with the agar well diffusion method against some selected microorganisms. Among all the complexes, the antibacterial activity of the Cu(II polymer–metal complex showed the highest zone of inhibition because of its higher stability constant.

  5. Synthesis of Copper Nanoparticles Coated with Nitrogen Ligands

    Directory of Open Access Journals (Sweden)

    Rubén Sierra-Ávila

    2014-01-01

    Full Text Available The synthesis of copper nanoparticles was studied by wet chemical methods using copper sulfate pentahydrate (CuSO4·5H2O and nitrogen ligands allylamine (AAm and polyallylamine (PAAm as stabilizers. The results suggest that the use of these ligands leads to the exclusive formation of metallic copper nanoparticles (Cu-NPs. The use of partially crosslinked polyallylamine (PAAmc leads to nanoparticles (NPs with low yields and high coating content, while linear PAAm leads to NPs with high yields and low coating content. The chemical composition of the particles was determined by XRD and average particle diameters were determined by the Debye-Scherrer equation. TGA analysis provided evidence of the content and thermal stability of the coating on the nanoparticles and PAAm. The morphology, particle size distribution, and presence of PAAm coating were observed through TEM. The use of AAm in the synthesis of NPs could be a good alternative to reduce costs. By using TGA, TEM, and DSC techniques, it was determined that synthesized NPs with AAm presented a coating with similar characteristics to NPs with PAAm, suggesting that AAm underwent polymerization during the synthesis.

  6. Chemistry of HIV-1 virucidal Pt complexes having neglected bidentate sp2 N-donor carrier ligands with linked triazine and pyridine rings. synthesis, NMR spectral features, structure, and reaction with guanosine.

    Science.gov (United States)

    Maheshwari, Vidhi; Bhattacharyya, Debadeep; Fronczek, Frank R; Marzilli, Patricia A; Marzilli, Luigi G

    2006-09-04

    Complexes of the types LPtCl2 and [L2Pt]X2 [L = substituted 3-(pyridin-2'-yl)-1,2,4-triazine] were synthesized and characterized by NMR spectroscopy and, for the first time, by X-ray crystallography in an effort to determine the coordination properties of this novel class of inorganic medicinal agents possessing HIV-1 virucidal activity. The agents containing either one or two sp2 N-donor bidentate ligands are referred to as ptt (platinum triazine) agents. The X-ray structures of three LPtCl2 compounds revealed the expected pseudo-square-planar geometry. The X-ray structure of [(pyPh2t)2Pt](BF4)2 [pyPh2t = 3-(pyridin-2'-yl)-5,6-diphenyl-1,2,4-triazine] has the expected trans relationship of the unsymmetrical L and is essentially planar, an unusual property for a Pt(II) complex with two bidentate sp2 N donors. HIV-1 is an RNA virus; the guanosine ribonucleoside (Guo) binds (MepyMe2t)PtCl2 at both (inequivalent) available coordination sites to form [(MepyMe2t)Pt(Guo)2]2+ [MepyMe2t = 3-(4'-methylpyridin-2'-yl)-5,6-dimethyl-1,2,4-triazine]. This adduct has four nearly equally intense Guo H8 signals attributed to two pairs of head-to-tail (HT) and head-to-head (HH) conformers, which interchange rapidly within each pair. However, equilibration between pairs requires rotation of the Guo cis to the MepyMe2t pyridyl ring, and the H6' proton on this ring projects toward the Guo and hinders Guo rotation about the Pt-N7 bond. Thus, the HT/HH pairs do not interchange; such behavior is rare. Guo did not add to [(MepyMe2t)2Pt]2+, a result suggesting the possibility that the virucidal activity of LPtCl2 and [L2Pt]2+ ptt agents arises respectively from covalent and noncovalent (possibly intercalative interactions favored by [L2Pt]2+ planarity) binding to biomolecular targets.

  7. Microwave assisted synthesis, spectral, magnetic and bioevolution of few Mn (II)-amide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Gaurav [Department of Chemistry, Govt. Engineering College, Bikaner (India); Verma, K. K.; Gudesaria, D. D.; Bhojak, N., E-mail: drbhojak@rediffmail.com [GCRC, Department of Chemistry, Govt Dungar College, Bikaner-334003, Rajasthan (India)

    2016-05-06

    The importance and versatility of amide group containing ligands have promoted the selection of this class of ligands and their complexes for the study. The present work describes the synthesis, spectral and biological investigations on the complexes of amides derived from heterocyclic amines with Mn (II) ions. Four ligands derived 2-aminopyridine and their complexes with Mn (II) have been synthesized. A method for the synthesis of complexes has been developed by the use of microwave irradiation which is in agreement to Green chemistry approach. The complexes have been characterized on the basis of elemental analysis, infrared, electronic, ESR spectra and magnetic susceptibility studies. The diffuse reflectance spectrum of the complexes show bands in the region 20,000 cm{sup −1} to 26,000 cm{sup −1} assignable to {sup 6}A{sub 1g} → {sup 4}T{sub 2g} and {sup 6}A{sub 1g} → {sup 4}E{sub 1g} transitions. These are also typical of tetrahedral environment around the manganese. The magnetic moment (5.80 BM) of the complex indicates high spin tetrahedral environment. The microwave method of synthesis of complexes have been found easier, convenient and ecofriendly. Antimicrobial activities of compounds were also carried out against bacteria and fungi. Further minimal inhibitory concentration (MIC) was also determined for each compound.

  8. Microwave assisted synthesis, spectral, magnetic and bioevolution of few Mn (II)-amide complexes

    Science.gov (United States)

    Joshi, Gaurav; Verma, K. K.; Gudesaria, D. D.; Bhojak, N.

    2016-05-01

    The importance and versatility of amide group containing ligands have promoted the selection of this class of ligands and their complexes for the study. The present work describes the synthesis, spectral and biological investigations on the complexes of amides derived from heterocyclic amines with Mn (II) ions. Four ligands derived 2-aminopyridine and their complexes with Mn (II) have been synthesized. A method for the synthesis of complexes has been developed by the use of microwave irradiation which is in agreement to Green chemistry approach. The complexes have been characterized on the basis of elemental analysis, infrared, electronic, ESR spectra and magnetic susceptibility studies. The diffuse reflectance spectrum of the complexes show bands in the region 20,000 cm-1 to 26,000 cm-1 assignable to 6A1g → 4T2g and 6A1g → 4E1g transitions. These are also typical of tetrahedral environment around the manganese. The magnetic moment (5.80 BM) of the complex indicates high spin tetrahedral environment. The microwave method of synthesis of complexes have been found easier, convenient and ecofriendly. Antimicrobial activities of compounds were also carried out against bacteria and fungi. Further minimal inhibitory concentration (MIC) was also determined for each compound.

  9. Microwave Synthesis, Basic Spectral and Biological Evaluation of Some Copper (II) Mesoporphyrinic Complexes

    OpenAIRE

    Rica Boscencu; Mihaela Ilie; Radu Socoteanu; Anabela Sousa Oliveira; Carolina Constantin; Monica Neagu; Gina Manda; Luis Filipe Vieira Ferreira

    2010-01-01

    Cu(II) complexes with asymmetrical and symmetrical porphyrinic ligands were synthesized with superior yields using microwave irradiation. The paper presents the synthesis of 5-(3-hydroxyphenyl)-10,15,20-tris-(4-carboxymethylphenyl)-21,23-Cu(II)-porphine in comparison to its symmetrical complex 5,10,15,20-meso-tetrakis-(4-carboxy-methylphenyl)-21,23-Cu(II) porphine. The two compounds were characterized by FT-IR, UV–Vis and EPR spectroscopy, which fully confirmed the structures. The spectral mo...

  10. Synthesis, spectroscopic, thermogravimetric and antimicrobial studies of mixed ligands complexes

    Science.gov (United States)

    Mahmoud, Walaa H.; Mahmoud, Nessma F.; Mohamed, Gehad G.; El-Sonbati, Adel Z.; El-Bindary, Ashraf A.

    2015-09-01

    An interesting series of mixed ligand complexes have been synthesized by the reaction of metal chloride with guaifenesin (GFS) in the presence of 2-aminoacetic acid (HGly) (1:1:1 molar ratio). The elemental analysis, magnetic moments, molar conductance, spectral (UV-Vis, IR, 1H NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structure of GFS is optimized theoretically and the quantum chemical parameters are calculated. The IR showed that the ligand (GFS) acts as monobasic tridentate through the hydroxyl, phenoxy etheric and methoxy oxygen atoms and co-ligand (HGly) as monobasic bidentate through the deprotonated carboxylate oxygen atom and nitrogen atom of amino group. The molar conductivities showed that all the complexes are non-electrolytes except Cr(III) complex is electrolyte. Electronic and magnetic data proposed the octahedral structure for all complexes under investigation. ESR spectrum for Cu(II) revealed data which confirm the proposed structure. Antibacterial screening of the compounds were carried out in vitro on gram positive (Bacillus subtilis and Staphylococcus aureus), gram negative (Escherichia coli and Neisseria gonorrhoeae) bacteria and for in vitro antifungal activity against Candida albicans organism. However, some complexes showed more chemotherapeutic efficiency than the parent GFS drug. The complexes were also screened for their in vitro anticancer activity against the breast cell line (MFC7) and the results obtained showed that they exhibit a considerable anticancer activity.

  11. On spectral synthesis on element-wise compact Abelian groups

    Science.gov (United States)

    Platonov, S. S.

    2015-08-01

    Let G be an arbitrary locally compact Abelian group and let C(G) be the space of all continuous complex-valued functions on G. A closed linear subspace \\mathscr H\\subseteq C(G) is referred to as an invariant subspace if it is invariant with respect to the shifts τ_y\\colon f(x)\\mapsto f(xy), y\\in G. By definition, an invariant subspace \\mathscr H\\subseteq C(G) admits strict spectral synthesis if \\mathscr H coincides with the closure in C(G) of the linear span of all characters of G belonging to \\mathscr H. We say that strict spectral synthesis holds in the space C(G) on G if every invariant subspace \\mathscr H\\subseteq C(G) admits strict spectral synthesis. An element x of a topological group G is said to be compact if x is contained in some compact subgroup of G. A group G is said to be element-wise compact if all elements of G are compact. The main result of the paper is the proof of the fact that strict spectral synthesis holds in C(G) for a locally compact Abelian group G if and only if G is element-wise compact. Bibliography: 14 titles.

  12. Bridging ligands in organometallic chemistry. II. Synthesis and reactivity of the green dimer of molybdenocene containing a bridging fulvalene ligand

    Energy Technology Data Exchange (ETDEWEB)

    Smart, J.C.; Curtis, C.J.

    1978-11-01

    Synthesis, precipitation, and isolation of dicyclopentadienyl(fulvalene)dihydridomolybdenum are described. The compound was used in reaction studies involving the addition of carbon monoxide and deprotonation with n-butyllithium. Data for elemental analysis, ir spectral and NMR(in toluene-d) spectral analysis are reported for the title compound and its reaction products.

  13. Ligand-protected gold clusters: the structure, synthesis and applications

    Science.gov (United States)

    Pichugina, D. A.; Kuz'menko, N. E.; Shestakov, A. F.

    2015-11-01

    Modern concepts of the structure and properties of atomic gold clusters protected by thiolate, selenolate, phosphine and phenylacetylene ligands are analyzed. Within the framework of the superatom theory, the 'divide and protect' approach and the structure rule, the stability and composition of a cluster are determined by the structure of the cluster core, the type of ligands and the total number of valence electrons. Methods of selective synthesis of gold clusters in solution and on the surface of inorganic composites based, in particular, on the reaction of Aun with RS, RSe, PhC≡C, Hal ligands or functional groups of proteins, on stabilization of clusters in cavities of the α-, β and γ-cyclodextrin molecules (Au15 and Au25) and on anchorage to a support surface (Au25/SiO2, Au20/C, Au10/FeOx) are reviewed. Problems in this field are also discussed. Among the methods for cluster structure prediction, particular attention is given to the theoretical approaches based on the density functional theory (DFT). The structures of a number of synthesized clusters are described using the results obtained by X-ray diffraction analysis and DFT calculations. A possible mechanism of formation of the SR(AuSR)n 'staple' units in the cluster shell is proposed. The structure and properties of bimetallic clusters MxAunLm (M=Pd, Pt, Ag, Cu) are discussed. The Pd or Pt atom is located at the centre of the cluster, whereas Ag and Cu atoms form bimetallic compounds in which the heteroatom is located on the surface of the cluster core or in the 'staple' units. The optical properties, fluorescence and luminescence of ligand-protected gold clusters originate from the quantum effects of the Au atoms in the cluster core and in the oligomeric SR(AuSR)x units in the cluster shell. Homogeneous and heterogeneous reactions catalyzed by atomic gold clusters are discussed in the context of the reaction mechanism and the nature of the active sites. The bibliography includes 345 references.

  14. Synthesis and characterization of mixed ligand chiral nanoclusters

    KAUST Repository

    Guven, Zekiye P.

    2016-06-22

    Chiral mixed ligand silver nanoclusters were synthesized in the presence of a chiral and an achiral ligand. While the chiral ligand led mostly to the formation of nanoparticles, the presence of the achiral ligand drastically increased the yield of nanoclusters with enhanced chiral properties. © 2016 The Royal Society of Chemistry.

  15. Synthesis, Characterisation, and Biological Evaluation of Zn(II Complex with Tridentate (NNO Donor Schiff Base Ligand

    Directory of Open Access Journals (Sweden)

    Nayaz Ahmed

    2015-01-01

    Full Text Available The present paper deals with the synthesis and characterization of metal complex of tridentate Schiff base ligand derived from the inserted condensation of 2-aminobenzimidazole (1H-benzimidazol-2-amine with salicylaldehyde (2-hydroxybenzaldehyde in a 1 : 1 molar ratio. Using this tridentate ligand, complex of Zn(II with general formula ML has been synthesized. The synthesized complex was characterized by several techniques using molar conductance, elemental analysis, FT-IR, and mass and 1HNMR spectroscopy. The elemental analysis data suggest the stoichiometry to be 1 : 1 [M : L]. The complex is nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen, imidazole nitrogen of benzimidazole ring, and azomethine nitrogen atom. Spectral studies suggest tetrahedral geometry for the complex. The pure compound, synthesized ligand, and metal complex were screened for their antimicrobial activity.

  16. Spectral, XRD, SEM and biological activities of transition metal complexes of polydentate ligands containing thiazole moiety

    Science.gov (United States)

    Neelakantan, M. A.; Marriappan, S. S.; Dharmaraja, J.; Jeyakumar, T.; Muthukumaran, K.

    2008-11-01

    Metal complexes of o-vanillidene-2-aminobenzothiazole have been prepared and characterized by elemental and spectral (vibrational, electronic, 1H NMR and EPR) data as well as magnetic susceptibility measurements and thermo gravimetric analysis (TG/DTA). The low molar conductance values reveal the non-electrolytic nature of these complexes. The elemental analysis suggests that the stoichiometry to be 1:2 (metal:ligand). Magnetic susceptibility data coupled with electronic spectra suggest that two ligands coordinate to each metal atom by phenolic oxygen and imino nitrogen to form high spin octahedral complex with Co(II), Mn(II) and Ni(II). The fifth and sixth position of metal ion is satisfied with water molecules. The thermal behaviour (TG/DTA) of the synthesised complexes shows that the complexes loss water molecules in the first step followed by decomposition of the ligand. Spin Hamiltonian parameters predict a distorted tetrahedral geometry for the copper complex. XRD and SEM analysis provide the crystalline nature and the morphology of the metal complexes. The in vitro biological activity of the metal chelates is tested against the Gram positive bacteria ( Bacillus amyloliquifacians) and gram negative bacteria ( Pseudomonas species), fungus ( Aspergillus niger) and yeast ( Sacchromyces cereviaceae). Most of the metal chelates exhibited higher biological activities.

  17. Synthesis, XRD, TEM, EPR, and Optical Absorption Spectral Studies of CuZnO2 Nanocompound

    Directory of Open Access Journals (Sweden)

    T. Ravindra Reddy

    2014-01-01

    Full Text Available Synthesis of nano CuZnO2 compound is carried out by thermal decomposition method. The crystalline phase of the material is characterized by XRD. The calculated unit cell constants are a=3.1 Å and c=3.4786 Å and are of tetragonal structure. The unit cell constants are different from wurtzite (hexagonal which indicate that a nanocompound is formed. Further TEM images reveal that the metal ion is in tetragonal structure with oxygen ligands. The prepared CuZnO2 is then characterized for crystallite size analysis by employing transmission electron microscopy (TEM. The size is found to be 100 nm. Uniform bright rings are noticed in the TEM picture suggesting that the nanocrystals have preferential instead of random orientations. The selected-area electron diffraction (SAED pattern clearly indicates the formation of CuO-ZnO nanocompound. The nature of bonding is studied by electron paramagnetic resonance (EPR. The covalency character is about 0.74 and thus the compound is electrically less conductive. Optical absorption spectral studies suggest that Cu(II is placed in tetragonal elongation crystal field. The spin-orbit coupling constant, λ, is calculated using the EPR and optical absorption spectral results suggest some covalent bond between metal and ligand. Near infrared (NIR spectra are due to hydroxyl and water fundamentals.

  18. Species-specific kinetics and zonation of hepatic DNA synthesis induced by ligands of PPARalpha.

    Science.gov (United States)

    Al Kholaifi, Abdullah; Amer, Abeer; Jeffery, Brett; Gray, Tim J B; Roberts, Ruth A; Bell, David R

    2008-07-01

    Peroxisome proliferator-activated receptor alpha (PPARalpha) ligands evoke a profound mitogenic response in rodent liver, and the aim of this study was to characterize the kinetics of induction of DNA synthesis. The CAR ligand, 1,4-bis[2-(3,5-dichoropyridyloxy)]benzene, caused induction of hepatocyte DNA synthesis within 48 h in 129S4/SvJae mice, but the potent PPARalpha ligand, ciprofibrate, induced hepatocyte DNA synthesis only after 3 or 4 days dosing; higher or lower doses did not hasten the DNA synthesis response. This contrasted with the rapid induction (24 h) reported by Styles et al., 1988, Carcinogenesis 9, 1647-1655. C57BL/6 and DBA/2J mice showed significant induction of DNA synthesis after 4, but not 2, days ciprofibrate treatment. Alderley Park and 129S4/SvJae mice dosed with methylclofenapate induced hepatocyte DNA synthesis at 4, but not 2, days after dosing and proved that inconsistency with prior work was not due to a difference in mouse strain or PPARalpha ligand. Ciprofibrate-induced liver DNA synthesis and growth was absent in PPARalpha-null mice and are PPARalpha dependent. In the Fisher344 rat, hepatocyte DNA synthesis was induced at 24 h after dosing, with a second peak at 48 h. Lobular localization of hepatocyte DNA synthesis showed preferential periportal induction of DNA synthesis in rat but panlobular zonation of hepatocyte DNA synthesis in mouse. These results characterize a markedly later hepatic induction of panlobular DNA synthesis by PPARalpha ligands in mouse, compared to rapid induction of periportal DNA synthesis in rat.

  19. A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

    Science.gov (United States)

    Blasius, Clemens K; Intorp, Sebastian N; Wadepohl, Hubert

    2016-01-01

    Summary We report the modular synthesis of three different types of neutral κ2-P,N-ligands comprising an imine and a phosphine binding site. These ligands were reacted with rhodium, iridium and palladium metal precursors and the structures of the resulting complexes were elucidated by means of X-ray crystallography. We observed that subtle changes of the ligand backbone have a significant influence on the binding geometry und coordination properties of these bidentate P,N-donors. PMID:27340475

  20. Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers

    Directory of Open Access Journals (Sweden)

    Nicola Otto

    2012-07-01

    Full Text Available In the search for new ligands for the Ullmann diaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could be identified.

  1. A convenient microwave-assisted synthesis of cinchona alkaloid-derived ligands

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An efficient synthesis of cinchona alkaloid-derived ligands based on solvent-free microwave-assisted reaction was described. The coupling of 1,4-dichlorophthalazine or 3,6-dichloropyridazine with quinine, cinchonine or cinchonidine provide bis- or mono-cinchona alkaloid-derived ligands in moderate to good yields (52-89%) within 15 rain under optimum microwave conditions.

  2. STIR: Redox-Switchable Olefin Polymerization Catalysis: Electronically Tunable Ligands for Controlled Polymer Synthesis

    Science.gov (United States)

    2013-03-28

    frameworks and metallated using organometallic reagents so as to produce precatalysts that could be activated using methylaluminoxane, borane, or...capable functionalities were incorporated into specifically chosen ligand frameworks and metallated using organometallic reagents so as to produce...Polymerization Catalysis: Electronically Tunable Ligands for Controlled Polymer Synthesis Brian K. Long Department of Chemistry University of Tennessee

  3. Synthesis and Spectral Evaluation of Some Unsymmetrical Mesoporphyrinic Complexes

    Directory of Open Access Journals (Sweden)

    Rica Boscencu

    2012-06-01

    Full Text Available Synthesis and spectral evaluation of new zinc and copper unsymmetrical mesoporphyrinic complexes are reported. Zn(II-5-(4-acetoxy-3-methoxyphenyl-10,15,20-tris-(4-carboxymethylphenylporphyrin, Zn(II-5-[(3,4-methylenedioxyphenyl]-10,15,20-tris-(4-carboxymethylphenylporphyrin, Cu(II-5-(4-acetoxy-3-methoxyphenyl-10,15,20-tris-(4-carboxymethylphenylporphyrin and Cu(II-5-[(3,4-methylenedioxyphenyl]-10,15,20-tris-(4-carboxymethylphenylporphyrin were synthesized using microwave-assisted synthesis. The complexes were characterized by elemental analysis, FT-IR, UV-Vis, EPR and NMR spectroscopy, which fully confirmed their structure. The spectral absorption properties of the porphyrinic complexes were studied in solvents with different polarities. Fluorescence emission and singlet oxygen formation quantum yields were evaluated for the compounds under study, revealing high yields for the zinc derivatives. The copper complexes are not emissive and only display residual capacity for singlet oxygen formation.

  4. Synthesis and spectral evaluation of some unsymmetrical mesoporphyrinic complexes.

    Science.gov (United States)

    Boscencu, Rica; Oliveira, Anabela Sousa; Ferreira, Diana P; Ferreira, Luís Filipe Vieira

    2012-01-01

    Synthesis and spectral evaluation of new zinc and copper unsymmetrical mesoporphyrinic complexes are reported. Zn(II)-5-(4-acetoxy-3-methoxyphenyl)-10,15,20- tris-(4-carboxymethylphenyl)porphyrin, Zn(II)-5-[(3,4-methylenedioxy)phenyl]-10,15,20- tris-(4-carboxymethylphenyl)porphyrin, Cu(II)-5-(4-acetoxy-3-methoxyphenyl)-10,15,20- tris-(4-carboxymethylphenyl)porphyrin and Cu(II)-5-[(3,4-methylenedioxy)phenyl]-10,15,20- tris-(4-carboxymethylphenyl)porphyrin were synthesized using microwave-assisted synthesis. The complexes were characterized by elemental analysis, FT-IR, UV-Vis, EPR and NMR spectroscopy, which fully confirmed their structure. The spectral absorption properties of the porphyrinic complexes were studied in solvents with different polarities. Fluorescence emission and singlet oxygen formation quantum yields were evaluated for the compounds under study, revealing high yields for the zinc derivatives. The copper complexes are not emissive and only display residual capacity for singlet oxygen formation.

  5. SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON MIXED LIGAND COMPLEXES OF CO (II, NI (II AND CU (II WITH ISOXAZOLE SCHIFF BASE AND 1, 10-PHENANTHROLINE/ 2, 2' -BIPYRIDINE LIGANDS Synthese, Charakterisierung und antimikrobiellen STUDIES ON MIXED Ligand-Komplexe von Co (II, Ni (II und Cu (II MIT Isoxazol SCHIFF BASE AND 1, 10-Phenanthrolin / 2, 2 '-Bipyridin-Liganden

    Directory of Open Access Journals (Sweden)

    R.Shakru, N.J.P.Subhashini, Shivaraj

    2011-08-01

    Full Text Available Synthesis, Characterization and antimicrobial studies of Cobalt (II, Nickel (II and Copper (II ternary complexes of mixed ligands with Schiff base derived from 3-amino 5-methyl isoxazole with 2-hydroxy 1-naphthaldehyde and 1, 10-phenanthroline/ 2, 2' bipyridine. The micro analytical, magnetic moment, IR and electronic spectral data analysis have been used to confirm the structure of these complexes, their lower electrical conductance values indicates that all the complexes are non- electrolytes. The magnetic moment values and electronics spectral data of the Co (II and Ni (II complexes further indicates the octahedral geometry and Cu (II complexes are tetragonal geometry. The synthesized compounds have been tested against microorganisms such as (bacillus and pseudomonas bacteria and (R.Saloni and A. niger fungi. A comparative study of the MIC (minimum inhibitory concentration values of the ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligand and control.

  6. Synthesis and Catalytic Activity of Two New Cyclic Tetraaza Ligands

    Directory of Open Access Journals (Sweden)

    Burkhard König

    2003-05-01

    Full Text Available Two new chiral cyclic tetraaza ligands were synthesized and characterized. Their catalytic activity was tested in the asymmetric addition of diethylzinc to benzaldehyde. The expected secondary alcohol was obtained in moderate yields, but with very low enantioselectivity.

  7. A proline-based aminophenol ligand: synthesis, iron complexation, magnetic, electronic and redox investigation.

    Science.gov (United States)

    Sheykhi, Hamid; Safaei, Elham

    2014-01-24

    A new proline-based aminophenol ligand was synthesized by a convenient procedure. The ligand was characterized by (1)H NMR, (13)C NMR and IR spectroscopies, elemental analysis and optical activity measurements. Mononuclear iron(III) complex (FeL(Pro)) of this ligand was synthesized and characterized by IR, UV-vis, ESI-MS, magnetic susceptibility studies and cyclic voltammetry techniques. The equilibrium formation constant of FeL(Pro) and the pure UV-vis spectral profile of the complex was determined by multivariate hard modeling method. The molecular structure of FeL(Pro) determined by ESI-MS consist of two aminophenolate ligands. The variation of magnetic susceptibility with temperature indicates paramagnetic iron(III) in the monomeric complex. FeL(Pro) complex undergo metal-centered reduction, and ligand-centered oxidation. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Synthesis, Spectral, and In Vitro Antibacterial Studies of Organosilicon(IV) Complexes with Schiff Bases Derived from Amino Acids.

    Science.gov (United States)

    Singh, Har Lal; Singh, Jangbhadur; Mukherjee, A

    2013-01-01

    The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR ((1)H, (13)C, and (29)Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Bacillus cereus, Nocardia spp., E. aerogenes, Escherichia coli, Klebsiella spp., and Staphylococcus spp.). The complexes were found to be more potent as compared to the ligands.

  9. Synthesis and enzymatic cleavage of dual-ligand quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Sewell, Sarah L. [Department of Biomedical Engineering, Vanderbilt University, Nashville, TN (United States); Giorgio, Todd D., E-mail: todd.d.giorgio@vanderbilt.edu [Department of Biomedical Engineering, Vanderbilt University, Nashville, TN (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN (United States)

    2009-05-05

    Site directed therapy promises to minimize treatment-limiting systemic effects associated with cytotoxic agents that have no specificity for pathologic tissues. One general strategy is to target cell surface receptors uniquely presented on particular tissues. Highly specific in vivo targeting of an emerging neoplasm through a single molecular recognition mechanism has not generally been successful. Nonspecific binding and specific binding to non-target cells compromise the therapeutic index of small molecule, ubiquitous cancer targeting ligands. In this work, we have designed and fabricated a nanoparticle (NP) construct that could potentially overcome the current limitations of targeted in vivo delivery. Quantum dots (QDs) were functionalized with a poly(ethylene glycol) (PEG) modified to enable specific cleavage by matrix metalloprotease-7 (MMP-7). The QDs were further functionalized with folic acid, a ligand for a cell surface receptor that is overexpressed in many tumors, but also expressed in some normal tissues. The nanomolecular construct is designed so that the PEG initially conceals the folate ligand and construct binding to cells is inhibited. MMP-7 activated peptide cleavage and subsequent unmasking of the folate ligand occurs only near tumor tissue, resulting in a proximity activated (PA) targeting system. QDs functionalized with both the MMP-7 cleavable substrate and folic acid were successfully synthesized and characterized. The proteolytic capability of the dual ligand QD construct was quantitatively assessed by fluorometric analysis and compared to a QD construct functionalized with only the PA ligand. The dual ligand PA nanoparticles studied here exhibit significant susceptibility to cleavage by MMP-7 at physiologically relevant conditions. The capacity to autonomously convert a biopassivated nanostructure to a tissue-specific targeted delivery agent in vivo represents a paradigm change for site-directed therapies.

  10. Synthesis of heterocycles: Indolo (2,1-a) isoquinolines, renewables, and aptamer ligands for cellular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, Jonathan [Ames Laboratory (AMES), Ames, IA (United States)

    2013-01-01

    In this thesis, we explore both total syntheses and methodologies of several aromatic heterocyclic molecules. Extensions of the Kraus indole synthesis toward 2-substituted and 2,3-disubstituted indoles, as well as biologically attractive indolo[2,1-a]isoquinolines are described. Recent renewable efforts directed to commodity maleic acid and the first reported furan-based ionic liquids are described. Our total synthesis of mRNA aptamer ligand PDC-Gly, and its dye coupled forms, plus aminoglycoside dye coupled ligands used in molecular imaging, are described.

  11. Design, Synthesis, and Structural Analysis of Divalent N(I) Compounds and Identification of a New Electron-Donating Ligand.

    Science.gov (United States)

    Bharatam, Prasad V; Arfeen, Minhajul; Patel, Neha; Jain, Priyanka; Bhatia, Sonam; Chakraborti, Asit K; Khullar, Sadhika; Gupta, Vijay; Mandal, Sanjay K

    2016-01-18

    The dative-bond representation (L→E) in compounds with main group elements (E) has triggered extensive debate in the recent past. The scope and limits of this nonclassical coordination bond warrant comprehensive exploration. Particularly compounds with (L→N←L')(+) arrangement are of special interest because of their therapeutic importance. This work reports the design and synthesis of novel chemical species with the general structural formula (L→N←L')(+) carrying the unusual ligand cyclohexa-2,5-diene-4-(diaminomethynyl)-1-ylidene. Four species belonging to the (L→N←L')(+) class carrying this unconventional ligand were synthesized. Quantum chemical and X-ray diffraction analyses showed that the electronic and geometric parameters are consistent with those of already reported divalent N(I) compounds. The molecular orbital analysis, geometric parameters, and spectral data clearly support the L→N and N←L' interactions in these species. The newly identified ligand has the properties of a reactive carbene and high nucleophilicity.

  12. Synthesis, spectroscopic and thermal studies of some IIB group complexes with a new N2-Schiff base ligand.

    Science.gov (United States)

    Montazerozohori, Morteza; Khani, Sara; Tavakol, Hosein; Hojjati, Ahmad; Kazemi, Mostafa

    2011-10-15

    Synthesis, spectroscopic and thermal studies of some complexes of a new N(2)-Schiff base ligand of N(1),N(2)-bis((E)-2-methyl-3-phenylallylidene)ethane-1,2-diamine (L) with a general formula of MLX(2) (M = Zn(II), Cd(II) and Hg(II); X = Cl(-), Br(-), I(-), SCN(-) and N(3)(-)) are described. The ligand and its complexes were characterized by elemental analysis, molar conductance, UV-vis spectra, FT-IR spectra, MS, (1)H NMR and (13)C NMR spectra. The conductivity measurement as well as spectral data indicated that the complexes are non-electrolyte. (1)H and (13)C NMR spectra have been studied in DMSO-d(6) and/or CDCl(3). The thermal behavior of the complexes shows weight loss by decomposition of the anions and ligand segments in the subsequent steps. Activation thermodynamic parameters of decomposition such as E*, ΔH*, ΔS* and ΔG* were calculated from TG curves.

  13. Synthesis and Characterization of Heteropoly Coordination Compounds Containing Optical Ligands

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Introduction   The heteropolyanion phase transfer chemistry created by Pope M. T. In 1984 has opened up a new field for heteropoly compound research[1-3]. But substituting coordination water molecules by organic optically active ligand has not been reported in literatures until 1997[4].

  14. Design, synthesis and evaluation of multivalent glycodendrimers as multivalent ligands

    NARCIS (Netherlands)

    Branderhorst, H.M.

    2008-01-01

    Carbohydrates are more and more of interest in drug design as they are important mediators in a whole range of biological processes. Because of the low affinity of carbohydrates for their receptors, multivalent ligand presentation was introduced. Multivalent compounds were shown to improve the affin

  15. Synthesis and Characterization of Metal Complexes with Schiff Base Ligands

    Science.gov (United States)

    Wilkinson, Shane M.; Sheedy, Timothy M.; New, Elizabeth J.

    2016-01-01

    In order for undergraduate laboratory experiments to reflect modern research practice, it is essential that they include a range of elements, and that synthetic tasks are accompanied by characterization and analysis. This intermediate general chemistry laboratory exercise runs over 2 weeks, and involves the preparation of a Schiff base ligand and…

  16. Synthesis and Structure Elucidation of Cr(III Complexes of Polydentate Hydroxamic Acid Ligands

    Directory of Open Access Journals (Sweden)

    K.P. SRIVASTAVA

    2013-06-01

    Full Text Available The ligands α-mercaptobenzacetohydroxamic acid (MBAHA-H and 2-amino-α-mercaptobenzacetohydroxamic acid (AMBAHA-H and their different mixed ligand novel complexes with CrIII having specific formulae have been synthesized and characterised by elemental analyses, magnetic and conductance measurements, IR and electronic spectral studies. The ligands were found to behave as monobasic tridentate (SO’O donor and tetradentate (SO’ ON donor manner respectively. All the synthesized CrIII complexes were non-electrolyte with magnetic moment ranging from 3.79 to 3.87 BM. The structural assessment of the complexes has been carried out based on spectral studies (electronic&infrared and molar conductivity values. All the complexes were found to be of octahedral geometry.

  17. Synthesis of ligand-free CZTS nanoparticles via a facile hot injection route

    DEFF Research Database (Denmark)

    Mirbagheri, Naghmehalsadat; Engberg, Sara Lena Josefin; Crovetto, Andrea

    2016-01-01

    and toxic solvents that otherwise could hinder grain growth and limit the deposition techniques. In addition the synthesis route presented here results in nanoparticles of a large size compared to other ligand-free CZTS nanoparticles, due to the high boiling point of the solvents selected. Large particle...

  18. A multistep continuous-flow system for rapid on-demand synthesis of receptor ligands

    DEFF Research Database (Denmark)

    Petersen, Trine P; Ritzén, Andreas; Ulven, Trond

    2009-01-01

    A multistep continuous-flow system for synthesis of receptor ligands by assembly of three variable building blocks in a single unbroken flow is described. The sequence consists of three reactions and two scavenger steps, where a Cbz-protected diamine is reacted with an isocyanate, deprotected, an...

  19. Spectral studies on mixed ligand complexes of sodium dinitro-bis(acetylacetonato) cobaltate(iii) with imida-zole ligands

    Science.gov (United States)

    Roychaudhury, Goutam; Dash, Kailash C.

    1980-11-01

    A number of mixed ligand complexes, nitro(imidazole) bis(acetylacetonato) cobaltate(III), [Co(acac) 2 (NO 2 ) 2 (L)] (L = imidazole or substituted imidazole) have been synthesised and characterised on the basis of chemical analyses, IR, electronic, mass and nuclear ( 1H and 13C) magnetic resonance spectra as well as TGA and DTA data. All complexes are non-electrolytic and possess a trans octahedral structure. The NO 2- group is coordinated through the N atom. Though the 1H NMR data of fresh CDCl 3 solutions of complexes confirm the trans structure, slow isomerisation to the cis configuration is observed at room temperature.

  20. Silver, Gold, Palladium Nanoparticles: Ligand Design, Synthesis and Polymer Composites

    Science.gov (United States)

    Iqbal, Muhammad

    Metal nanoparticles, especially gold nanoparticles (AuNPs), have been extensively studied due to their interesting optical properties and potential applications in emerging technologies like drug delivery, cancer therapy, catalysis, chemical and bio-sensing and microelectronics devices. Alkyl thiol ligands in the form of self assembled monolayers are often used to stabilize and functionalize the gold nanoparticles while other types of ligands have been rarely employed and the properties of AuNPs protected by different types of ligands have not been studied comprehensively and comparatively. This dissertation reports the first comparative studies on the thermal and chemical stability of AuNPs protected by alkyl thiolates, alkyl selenolates, dialkyl dithiophosphinates, and dialkyl dithiophosphates (Chapters 2 and 3). AuNPs protected by dialkyl dithiophosphinates and dialkyl dithiophosphates are unprecedented. All AuNPs were prepared from amine protected precursor AuNPs by ligand exchange to ensure similar size, size distribution, and chemical composition. They were extensively characterized by solution 1H-NMR and UV-VIS spectroscopy, transmission electron microscopy (TEM), thermal analysis, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. For the first time, thermal stability was investigated by differential scanning calorimetry (DSC) that provided more accurate decomposition temperatures and enthalpies, whereas chemical stability was tested as the availability of the gold surface towards etching with cyanide in different solvents. Surprisingly, alkyl selenolate protected AuNPs are thermally less stable than alkyl thiolate protected AuNPs despite their proposed stronger binding to the gold surface and a much more crystalline monolayer, which suggests that different decomposition mechanisms apply to alkyl thiolate and alkyl selenolate protected AuNPs. Dialkyl dithiophosphinates and dialkyl dithiophosphates protected AuNPs are thermally

  1. Synthesis and vibrational study of some polydentate ligands

    Science.gov (United States)

    Esteban, M. F. Gargallo; Serrano, R. Vilaplana; Vilchez, F. González

    Sodium salts of iminodiacetic acid (IDA), ethylenediaminetetraacetic acid (EDTA), 1,2-propylenediaminetetraacetic acid (PDTA) and 1,2-diaminocyclohexanetetraacetic acid (DCTA) were prepared by modification of the literature methods and their i.r. and Raman spectra were studied. The results obtained by application of both techniques allowed a better characterization of these polydentate ligands. Raman spectroscopy was specially useful in elucidating structural aspects in compounds containing acetate groups.

  2. Synthesis, spectral, computational and thermal analysis studies of metallocefotaxime antibiotics.

    Science.gov (United States)

    Masoud, Mamdouh S; Ali, Alaa E; Elasala, Gehan S

    2015-01-01

    Cefotaxime metal complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and two mixed metals complexes of (Fe,Cu) and (Fe,Ni) were synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility and ESR spectra. The studies proved that cefotaxime may act as mono, bi, tri and tetra-dentate ligand through oxygen atoms of lactam carbonyl, carboxylic or amide carbonyl groups and nitrogen atom of thiazole ring. From the magnetic measurements and electronic spectral data, octahedral structures were proposed for all complexes. Quantum chemical methods have been performed for cefotaxime to calculate charges, bond lengths, bond angles, dihedral angles, electronegativity (χ), chemical potential (μ), global hardness (η), softness (σ) and the electrophilicity index (ω). The thermal decomposition of the prepared metals complexes was studied by TGA, DTA and DSC techniques. Thermogravimetric studies revealed the presence of lattice or coordinated water molecules in all the prepared complexes. The decomposition mechanisms were suggested. The thermal decomposition of the complexes ended with the formation of metal oxides and carbon residue as a final product except in case of Hg complex, sublimation occur at the temperature range 376.5-575.0 °C so, only carbon residue was produced during thermal decomposition. The orders of chemical reactions (n) were calculated via the peak symmetry method and the activation parameters were computed from the thermal decomposition data. The geometries of complexes may be converted from Oh to Td during the thermal decomposition steps.

  3. Synthesis and Characterization of Dinuclear Metal Complexes Stabilized by Tetradentate Schiff Base Ligands

    Directory of Open Access Journals (Sweden)

    Eid A. Abdalrazaq

    2010-01-01

    Full Text Available Problem statement: The synthesis, spectroscopic properties and theoretical calculations of acetylacetonimine and acetylacetanilidimine Schiff-base ligands, L1H and L2H, respectively and their dinuclear complexes of the type [M2LnCl2(H2O2], where n = 1 or 2, M = Co(II, Ni(II, Cu(II, Zn(II and Cd(II are described. Approach: The new tetradentate dianion Schiff base ligand which was used as stabilizers for the complexes were prepared by condensation of hydrazine with acetylacetone or acetylacetanilide. The dinuclear complexes of theses ligands were synthesized by treating an ethanolic solution of the prepared ligand with hydrated metal salts in molar ratio of 1:2 (L:M. Results: The ligand and their dinuclear metal complexes were characterized by CHN elemental analysis, FT-IR, UV-Vis, 1HNMR (for the ligands, conductivity, magnetic susceptibility and theoretical calculation by using MM2 modeling program. Conclusion: The reaction of these ligands in a 1:2 (L:M afford dinuclear M(II metal complexes with tetrahedral arrangement around Co(II, Zn(II and Cd(II and square planar around Ni(II and Cu(II.

  4. Synthesis of meta-substituted monodentate phosphinite ligands and implication in hydroformylation

    Indian Academy of Sciences (India)

    SATEJ S DESHMUKH; SHAHAJI R GAIKWAD; SWECHCHHA PANDEY; PRAMOD S MALI; SAMIR H CHIKKALI

    2017-08-01

    Synthesis of meta-substituted phosphinite ligands 3,3' (methoxyphosphanediyl) bis (N,Ndiethylaniline) (4a) and methoxybis(3-methoxyphenyl)phosphane (4b), in high yields, has been demonstrated. Typical phosphorus chemical shift between 110–120 ppm, appearance of methoxy protons and corresponding carbon, as well as ESI-MS spectra unambiguously confirmed the existence of phosphinite ligands 4a and 4b. To demonstrate the synthetic usefulness of 4a and 4b, these ligands were tested in the rhodium catalyzed hydroformylation of 1-octene. The diethylamine substituted ligand 4a was found to be highly active, whereas4bwas less reactive but revealed slightly better regioselectivity of 62% under optimized conditions.Additionally, 4a and 4b were found to catalyze the hydroformylation of styrene, 1-undecenol and 1,1-disubstituted functionalolefin, methyl methacrylate. Both the ligands displayed excellent conversion of styrene, and 4b revealed an excellent branch selectivity of 75%. Although 1-undecenol proved to be amenable to hydroformylation (85–90% conversion to aldehyde), both the ligands failed to discriminate between the linear and branched products. Substrate methyl methacrylate proved to be highly challenging and reduced conversion (between 33–42%) was observed under optimized conditions. Ligand 4a was found to be highly selective towards linear aldehyde (81% linear selectivity).

  5. Synthesis and radiofluorination of putative NMDA receptor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberg, U.

    2011-01-15

    In the course of this work on the synthesis of radioligands for the NMDA receptor the authentic standards and labeling precursors of four compounds with an amidine structure was performed. Synthesis of the precursors followed reaction conditions given in the literature and was successful. The imidoesters used for the synthesis were obtained from their nitriles in a Pinner synthesis, while 2-hydroxybenzylamine was synthesized in a reduction of 2-hydroxybenzonitrile using borane as a reducing agent. After a coupling reaction of the amine and the imidoester in DMF using triethylamine as base the precursors were obtained in good yields and purified by crystallization from methanol. The cyclic standard compound was synthesized directly from 2-(bromomethyl)- benzonitrile and 2-hydroxybenzylamine in a ring closing reaction. Similar to the other precursors, crystallization from methanol produced a pure compound. The authentic standards were synthesized starting from salicylaldehyde. In a four step synthesis the desired ortho-fluoroethoxybenzylamine was obtained in good yield. Coupling of the amine with the respective imidoester or in the case of the cyclic compound 2-(bromomethyl)-benzonitrile gave the desired product which was then purified by column chromatography or by crystallization from ethanol and water. For the labeling procedure 1-bromo-2-[{sub 18}F]fluoroethane was synthesized following a previously published pathway starting from 1,2-dibromoethane. An alternative route of radiosynthesis for this prosthetic group was tested using ethyleneglycole- 1,2-ditosylate. The labeling reaction was performed on one of the precursors testing both DMF and DMSO as solvents and using NaOH as base. Yields of N-(2-fluoroethoxybenzyl)- cinnamamidine were about 78 % at 80 C after 30 minutes in DMSO. The desired product can now be synthesized in sufficient yields for in vitro and in vivo evaluation studies. Labeling on the cyclic precursor was attempted utilizing DMSO as solvent

  6. Synthesis, Characterization and Thermal Analysis of New Cu(II) Complexes with Hydrazide Ligands

    OpenAIRE

    Saber Rajaei; Shahriare Ghammamy; Kheyrollah Mehrani; Hajar Sahebalzamani

    2010-01-01

    A number of new complexes have been synthesized by reaction of novel ligands acetic acid(4-methyl-benzylidene)hydrazide (L1) and acetic acid(naphthalen-1-ylmethylene)hydrazide (L2) with copper(II) nitrate. These new compounds were characterized by elemental analysis, TG, DTA, IR spectroscopy, UV spectral techniques. The changes observed between the FT-IR and UV-Vis spectra of the ligands and of the complexes allowed us to establish the coordination mode of the metal in complexes. The results ...

  7. Ligand-exchange synthesis of selenophenolate-capped Au25 nanoclusters.

    Science.gov (United States)

    Meng, Xiangming; Xu, Qian; Wang, Shuxin; Zhu, Manzhou

    2012-07-21

    We report the synthesis and characterization of selenophenolate-capped 25-gold-atom nanoclusters via a ligand-exchange approach. In this method, phenylethanethiolate (PhCH(2)CH(2)S) capped Au(25) nanoclusters are utilized as the starting material, which is subject to ligand-exchange with selenophenol (PhSeH). The as-obtained cluster product is confirmed to be selenophenolate-protected Au(25) nanoclusters through characterization by electrospray ionization (ESI) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), thermogravimetric analysis (TGA), elemental analysis (EA), UV-Vis and (1)H/(13)C NMR spectroscopies. The ligand-exchange synthesis of [Au(25)(SePh)(18)](-)[(C(8)H(17))(4)N](+) nanoclusters demonstrates that the core size of gold nanoclusters is retained in the thiolate-to-selenolate exchange process and that the 18 surface thiolate ligands can be completely exchanged by selenophenolate, rather than giving rise to a mixed ligand shell on the cluster. The two types of Au(25)L(18) (L = thiolate or selenolate) nanoclusters also show some differences in stability and optical properties.

  8. Synthesis, Spectral Characterization and Computational Studies of Metal Chelates of 4-N-(2-Thienylideneaminoantipyrine

    Directory of Open Access Journals (Sweden)

    Sherifa Rahim

    2015-12-01

    Full Text Available Metal chelates of Schiff base derived from thiophene-2-aldehyde with 4-aminoantipyrine have been synthesized. The ligand and the complexes have been characterized by IR, molar conductance, magnetic moments, EPR, cyclic voltammetry, XRD and SEM measurements. Computational studies were also carried out. The geometry of the complexes was investigated by electronic spectral data and magnetic moment measurements. The metal complexes exhibit higher antibacterial activity than the free ligand.

  9. Synthesis, Spectral Characterization and Computational Studies of Metal Chelates of 4-N-(2-Thienylidene)aminoantipyrine

    OpenAIRE

    Sherifa Rahim; Arsha Antony; George Lukose; K. Mohanan; I. Hubert Joe; R. Selwin Joseyphus

    2015-01-01

    Metal chelates of Schiff base derived from thiophene-2-aldehyde with 4-aminoantipyrine have been synthesized. The ligand and the complexes have been characterized by IR, molar conductance, magnetic moments, EPR, cyclic voltammetry, XRD and SEM measurements. Computational studies were also carried out. The geometry of the complexes was investigated by electronic spectral data and magnetic moment measurements. The metal complexes exhibit higher antibacterial activity than the free ligand.

  10. A New Method of Synthesis of Azo Schiff Base Ligands with Azo and Azomethine Donors: Synthesis of N-4-Methoxybenzylidene-2-(3-hydroxyphenylazo)-5-hydroxyaniline and Its Nickel(Ⅱ) Complex

    Institute of Scientific and Technical Information of China (English)

    OFORKA, N. C; MKPENIE, V. N.

    2007-01-01

    A new method for the synthesis of azo Schiff an base ligand in which the azo and azomethine groups are coordination sites was developed through a Schiff base precursor. The precursor, A'-4-methoxybenzylidene-3-hydroxy-phenylamine (SB) derived from 3-aminophenol was regioselectively coupled with a diazonium ion para to the hydroxyl group of the amine component of the Schiff base. The para selectivity was controlled by the directing effect of the hydroxyl group. The ligand and its nickel(Ⅱ) complex were characterized by elemental analyses, IR and UV-Vis spectroscopy. The analytical and spectral data supported the mononuclear formulation of the complex with metal to ligand ratio (M : L= 1 : 2) and suggested a square planar geometry for the complex.

  11. Photocontrol of Anthocyanin Synthesis: VII. Factors Affecting the Spectral Sensitivity of Anthocyanin Synthesis in Young Seedlings.

    Science.gov (United States)

    Mancinelli, A L; Walsh, L

    1979-05-01

    Light-dependent anthocyanin synthesis is a typical high irradiance response (HIR) of plant photomorphogenesis. The spectral sensitivity of this response in young seedlings of cabbage and tomato is strongly affected by the length and mode of application of the light treatments. This observation suggests that the different experimental conditions, used in different action spectroscopy studies, might have been responsible, at least in part, for some of the reported differences in the characteristics of the HIR action spectra of different response-system combinations. In both cabbage and tomato, the values of the far red/blue, far red/red, and blue/red action ratios increase with increasing durations of the light treatments; this finding is in agreement with hypotheses of K. M. Hartmann (1966, 1967) and E. Schäfer (1975) for phytochrome action in the HIR. The similarity in the trend of change of the values of the action ratios suggests the possibility that the photomorphogenic pigment system, involved in the photoregulation of anthocyanin synthesis, may be the same in cabbage and tomato, even though there are some differences in the spectral sensitivity of the response between the two species.

  12. Microwave Synthesis, Basic Spectral and Biological Evaluation of Some Copper (II Mesoporphyrinic Complexes

    Directory of Open Access Journals (Sweden)

    Rica Boscencu

    2010-05-01

    Full Text Available Cu(II complexes with asymmetrical and symmetrical porphyrinic ligands were synthesized with superior yields using microwave irradiation. The paper presents the synthesis of 5-(3-hydroxyphenyl-10,15,20-tris-(4-carboxymethylphenyl-21,23-Cu(II-porphine in comparison to its symmetrical complex 5,10,15,20-meso-tetrakis-(4-carboxy-methylphenyl-21,23-Cu(II porphine. The two compounds were characterized by FT-IR, UV–Vis and EPR spectroscopy, which fully confirmed the structures. The spectral molecular absorption properties of the porphyrinic complexes were studied in organic solvents (methanol, ethanol, iso-propanol, dimethyl sulfoxide, dimethylformamide and methylene chloride, and the influence of the solvent polarity on the absorbance maxima is described. In order to establish their future potential in biomedical applications preliminary toxicological studies consisting of viability and proliferation of standard tumor cell lines (MCF7 and B16 testing was performed. The obtained results indicate a low toxicity for both compounds and further recommends them for testing in light activation protocols.

  13. Microwave synthesis, basic spectral and biological evaluation of some copper (II) mesoporphyrinic complexes.

    Science.gov (United States)

    Boscencu, Rica; Ilie, Mihaela; Socoteanu, Radu; Oliveira, Anabela Sousa; Constantin, Carolina; Neagu, Monica; Manda, Gina; Ferreira, Luis Filipe Vieira

    2010-05-25

    Cu(II) complexes with asymmetrical and symmetrical porphyrinic ligands were synthesized with superior yields using microwave irradiation. The paper presents the synthesis of 5-(3-hydroxyphenyl)-10,15,20-tris-(4-carboxymethylphenyl)-21,23-Cu(II)-porphine in comparison to its symmetrical complex 5,10,15,20-meso-tetrakis-(4-carboxy-methylphenyl)-21,23-Cu(II) porphine. The two compounds were characterized by FT-IR, UV-Vis and EPR spectroscopy, which fully confirmed the structures. The spectral molecular absorption properties of the porphyrinic complexes were studied in organic solvents (methanol, ethanol, iso-propanol, dimethyl sulfoxide, dimethylformamide and methylene chloride), and the influence of the solvent polarity on the absorbance maxima is described. In order to establish their future potential in biomedical applications preliminary toxicological studies consisting of viability and proliferation of standard tumor cell lines (MCF7 and B16) testing was performed. The obtained results indicate a low toxicity for both compounds and further recommends them for testing in light activation protocols.

  14. Synthesis, Characterization and Solvatochromism Investigation of Mixed Ligand Chelate Copper(Ⅱ) Complexes with Acetyleacetonate and Three Diamine Ligands

    Institute of Scientific and Technical Information of China (English)

    Golchoubian Hamid; Afshar Zahra Mohseni; Moayyedi Golasa; Bruno Giuseppe; Rudbari Hadi Amiri

    2012-01-01

    The syntheses of three mixed ligand chelate copper(II) complexes of the type [Cu(L)(acac)(H2O)]BPh4 where acac=acetyleacetonate; L=N,N-dimethyl,N′-benzylethane-1,2-diamine (L1), N,N-dimethyl, N′-2-methylbenzylethane-1,2-diamine (L2) or N,N-dimethyl,N′-2-chlorobenzylethane-1,2-diamine (L3) are reported and characterized by elemental analyses, spectroscopic and molar conductance measurements. The X-ray structure of complex 1 shows that the central copper atom is placed in a distorted square pyramidal geometry made by acac and diamine chelate in the base and a H2O molecule on the apex. The prepared complexes are fairly soluble in a large number of organic solvents and show positive solvatochromism. Calculations of SMLR (stepwise multiple linear regression) method was utilized to find the best model explaining the observed solvatochromic behavior and showed that among different solvent parameters, donor number (DN) is a dominant factor responsible for the shift in the d-d absorption band of the complexes to the lower wavenumber with increasing its values. The importance of substituent effect in diamine ligand on the spectral and SMLR measurements is also discussed.

  15. Design and Synthesis of a Novel Ganglioside Ligand for Influenza A Viruses

    Directory of Open Access Journals (Sweden)

    Tomohiro Nohara

    2012-08-01

    Full Text Available A novel ganglioside bearing Neua2-3Gal and Neua2-6Gal structures as distal sequences was designed as a ligand for influenza A viruses. The efficient synthesis of the designed ganglioside was accomplished by employing the cassette coupling approach as a key reaction, which was executed between the non-reducing end of the oligosaccharide and the cyclic glucosylceramide moiety. Examination of its binding activity to influenza A viruses revealed that the new ligand is recognized by Neua2-3 and 2-6 type viruses.

  16. Organometallic chemistry of chiral diphosphazane ligands: Synthesis and structural characterisation

    Indian Academy of Sciences (India)

    Kannan Raghuraman; Swadhin K Mandal; T S Venkatakrishnan; Setharampattu S Krishnamurthy; Munirathinam Nethaji

    2002-08-01

    The diphosphazane ligands of the type, (C20H12O2)PN(R)P(E)Y2 (R = CHMe2 or ()-∗CHMePh; E = lone pair or S; Y2 = O2C20H12 or Y = OC6H5 or OC6H4Me-4 or OC6H4OMe-4 or OC6H4Bu-4 or C6H5) bearing axially chiral 1,1'-binaphthyl-2,2'-dioxy moiety have been synthesised. The structure and absolute configuration of a diastereomeric palladium complex, [PdCl2{2-((O2C20H12)PN(()-∗CHMePh)PPh2}] has been determined by X-ray crystallography. The reactions of [CpRu(PPh3)2Cl] with various symmetrical and unsymmetrical diphosphazanes of the type, X2PN(R)PYY' (R = CHMe2 or ()-∗CHMePh; X = C6H5 or X2 = O2C20H12; Y = Y' = C6H5 or Y = C6H5, Y' = OC6H4Me-4 or OC6H3Me2-3,5 or N2C3HMe2-3,5) yield several diastereomeric neutral or cationic half-sandwich ruthenium complexes which contain a stereogenic metal center. In one case, the absolute configuration of a trichiral ruthenium complex, viz. [Cp∗Ru{2-Ph2PN(()-∗CHMePh)∗PPh (N2C3HMe2-3,5)}Cl] is established by X-ray diffraction. The reactions of Ru3(CO)12 with the diphosphazanes (C20H12O2)PN(R)PY2 (R = CHMe2 or Me; Y2=O2C20H12 or Y = OC6H5 or OC6H4Me-4 or OC6H4OMe-4 or OC6H4Bu-4 or C6H5) yield the triruthenium clusters [Ru3(CO)10{-(O2C20H12)PN(R)PY2}], in which the diphosphazane ligand bridges two metal centres. Palladium allyl chemistry of some of these chiral ligands has been investigated. The structures of isomeric 3-allyl palladium complexes, [Pd(3-1,3-R'2-C3H3){2-(rac)-(O2C20H12)PN(CHMe2)PY2}](PF6) (R' = Me or Ph; Y = C6H5 or OC6H5) have been elucidated by high field twodimensional NMR spectroscopic and X-ray crystallographic studies.

  17. Spectral, NLO, Fluorescence, and Biological Activity of Knoevenagel Condensate of β-Diketone Ligands and Their Metal(II Complexes

    Directory of Open Access Journals (Sweden)

    S. Sumathi

    2011-01-01

    Full Text Available Transition metal complexes of various acetylacetone-based ligands of the type ML (where M=  Cu(II, Ni(II, Co(II; L=  3-(aryl-pentane-2,4-dione have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, H1NMR, mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are nonelectrolytic in nature. Spectroscopic and other analytical data of the complexes suggest square planar geometry for copper(II, cobalt(II, and nickel(II complexes of 3-(3-phenylallylidenepentane-2,4-dione and octahedral geometry for other metal(II complexes. The redox behaviors of the copper(II complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against bacteria and fungus. The metal(II complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG efficiency of the ligands was found to have considerable effect compared to that of urea and KDP.

  18. Ruthenium(II) complexes containing quinone based ligands: Synthesis, characterization, catalytic applications and DNA interaction

    Science.gov (United States)

    Anitha, P.; Manikandan, R.; Endo, A.; Hashimoto, T.; Viswanathamurthi, P.

    2012-12-01

    1,2-Naphthaquinone reacts with amines such as semicarbazide, isonicotinylhydrazide and thiosemicarbazide in high yield procedure with the formation of tridentate ligands HLn (n = 1-3). By reaction of ruthenium(II) starting complexes and quinone based ligands HLn (n = 1-3), a series of ruthenium complexes were synthesized and characterized by elemental and spectroscopic methods (FT-IR, electronic, 1H, 13C, 31P NMR and ESI-MS). The ligands were coordinated to ruthenium through quinone oxygen, imine nitrogen and enolate oxygen/thiolato sulfur. On the basis of spectral studies an octahedral geometry may be assigned for all the complexes. Further, the catalytic oxidation of primary, secondary alcohol and transfer hydrogenation of ketone was carried out. The DNA cleavage efficiency of new complexes has also been tested.

  19. Synthesis, characterization and biological activity of symmetric dinuclear complexes derived from a novel macrocyclic compartmental ligand

    Energy Technology Data Exchange (ETDEWEB)

    Mruthyunjayaswamy, B.H.M.; Ijare, Omkar B.; Jadegoud, Y. [Gulbarga University (India). Dept. of Chemistry]. E-mail: bhmmswamy53@rediffmail.com

    2005-07-15

    A phenol based novel macrocyclic binucleating compartmental ligand N,N-bis(2,6-diiminomethyl-4-methyl-1-hydroxyphenyl)malonoyldicarboxamide was prepared. The complexes were prepared by template method by reacting 2,6-diformyl-4-methylphenol, malonoyl dihydrazide and the metal chlorides of Cu(II), Ni(II), Co(II), Cd(II), Zn(II) and Hg(II) in methanol to get a series of dinuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, ESR, NMR and FAB mass spectral data. The dinuclear nature of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, ESR and FAB mass spectral data. The ligand as well as Cu(II), Ni(II), Co(II) and Zn(II) complexes were tested for their antibacterial and antifungal properties against Escherichia coli, Staphyloccocus aureus, Aspergillus niger and Fusarium oxysporum. Magnetic susceptibility measurements of Cu(II), Ni(II) and Co(II) complexes reveal that these complexes exhibit antiferromagnetic coupling behavior due to the presence of two metal ions in close proximity. FAB mass spectrum of the Cu(II) complex gave a clear evidence for the dinuclear nature. The ligand and the complexes were found to be less active against the tested bacteria, but the ligand alone was found active against the fungus Fusarium oxysporum. (author)

  20. Lanthanide complexes derived from hexadentate macrocyclic ligand: synthesis, spectroscopic and thermal investigation.

    Science.gov (United States)

    Chandra, Sulekh; Tyagi, Monika; Rani, Soni; Kumar, Sumit

    2010-02-01

    The lanthanide complexes derived from (3,5,13,15-tetramethyl 2,6,12,16,21-22-hexaazatricyclo[15.3.I(1-17)I(7-11)]cosa-1(21),2,5,7,9,11(22),12,15,17,19-decane) were synthesized. The complexes were found to have general composition [Ln(L)X(2).H(2)O]X, where Ln=La(3+), Ce(3+), Nd(3+), Sm(3+) and Eu(3+) and X=NO(3)(-) and Cl(-). The ligand was characterized by elemental analyses, IR, Mass, and (1)H NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral techniques and thermal studies. The ligand acts as a hexadentate and coordinates through four nitrogen atoms of azomethine groups and two nitrogen of pyridine ring. The lanthanum complexes are diamagnetic while the other Ln(III) complexes are paramagnetic. The spectral parameters i.e. nephelauxetic ratio (beta), covalency factor (b(1/2)), Sinha parameter (delta%) and covalency angular overlap parameter (eta) have been calculated from absorption spectra of Nd(III) and Sm(III) complexes. These parameters suggest the metal-ligand covalent bonding. In the present study, the complexes were found to have coordination number nine.

  1. Synthesis, structure characterization and biological activity of selected metal complexes of sulfonamide Schiff base as a primary ligand and some mixed ligand complexes with glycine as a secondary ligand

    Science.gov (United States)

    Sharaby, Carmen M.; Amine, Mona F.; Hamed, Asmaa A.

    2017-04-01

    The current work reports synthesis of metal complexes and mixed ligand complexes of a novel sulfonamide Schiff base ligand (HL) resulted from the condensation of sulfametrole [N‧-(4-methoxy-1,2,5-thiadiazol-3-yl]sulfanilamide and acetyl-acetone as a primary ligand and glycine as a secondary ligand. The metal complexes and mixed ligand complexes of HL Schiff base ligand were synthesized and characterized using different physicochemical studies as elemental analyses, mass spectra, conductivity measurement, IR spectra, 1H NMR spectra, UV-vis Spectra, solid reflectance, magnetic susceptibility, thermal analyses (TGA and DTA) and their microbial and anticancer activities. The spectroscopic data of the complexes suggest their 1:2(L1:M) complex structures and 1:2:2(L1:L2:M) mixed ligand complex structures, where L1 = HL and L2 = glycine. Also, the spectroscopic studies suggested the octahedral structure for all complexes. The synthesized Schiff base, its metal and mixed ligand complexes were screened for their bacterial, antifungal and anticancer activity. The activity data show that the metal complexes and mixed ligand complexes exhibited promising microbial and anticancer activities than their parent HL Schiff base ligand, also the data show that the mixed ligand complexes more effective than the metal complexes.

  2. Rational design and asymmetric synthesis of potent and neurotrophic ligands for FK506-binding proteins (FKBPs).

    Science.gov (United States)

    Pomplun, Sebastian; Wang, Yansong; Kirschner, Alexander; Kozany, Christian; Bracher, Andreas; Hausch, Felix

    2015-01-01

    To create highly efficient inhibitors for FK506-binding proteins, a new asymmetric synthesis for pro-(S)-C(5) -branched [4.3.1] aza-amide bicycles was developed. The key step of the synthesis is an HF-driven N-acyliminium cyclization. Functionalization of the C(5)  moiety resulted in novel protein contacts with the psychiatric risk factor FKBP51, which led to a more than 280-fold enhancement in affinity. The most potent ligands facilitated the differentiation of N2a neuroblastoma cells with low nanomolar potency.

  3. Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

    Science.gov (United States)

    Brahma, Sanjaya; Shivashankar, S. A.

    2015-12-01

    We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.

  4. Synthesis and biological activity of novel small peptides with aminophosphonates moiety as NOP receptor ligands.

    Science.gov (United States)

    Naydenova, Emilia D; Todorov, Petar T; Mateeva, Polina I; Zamfirova, Rositza N; Pavlov, Nikola D; Todorov, Simeon B

    2010-11-01

    The aim of the present study was the synthesis and the biological screening of new analogs of Ac-RYYRWK-NH2, modified at the N-terminal with 1-[(methoxyphosphono)methylamino]cycloalkanecarboxylic acids. The four newly synthesized ligands for the nociceptin/orphanin FQ (N/OFQ) receptor (NOP) have been prepared by solid-phase peptide synthesis--Fmoc-strategy. These compounds were tested for agonistic activity in vitro on electrically stimulated smooth-muscle preparations isolated from vas deferens of Wistar rats. Our data showed that substitution of Arg at position 1 with aminophosphonates moiety decreased significantly the affinity of ligands to the NOP receptor. Furthermore, the enlargement of the cycle (with 5-8 carbon atoms) additionally diminished both the activity and the selectivity for NOP-receptor.

  5. Room-temperature sol–gel synthesis of organic ligand-capped ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zobel, Mirijam, E-mail: mirijam.zobel@fau.de; Chatterjee, Haimantee [Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Physics, Lehrstuhl für Kristallographie und Strukturphysik (Germany); Matveeva, Galina; Kolb, Ute [Johannes Gutenberg-Universität, Institut für Physikalische Chemie (Germany); Neder, Reinhard B., E-mail: reinhard.neder@fau.de [Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Physics, Lehrstuhl für Kristallographie und Strukturphysik (Germany)

    2015-05-15

    Powders of zinc oxide nanoparticles with individual particle sizes below 10 nm in diameter are readily produced in base-induced sol–gel processes from ethanolic solutions of zinc acetate dihydrate. These particles are covered with acetate molecules and without further stabilization, they grow when stored as a powder. Here, we present three organic ligands, which reproducibly stabilize individual particle sizes <5 nm within the agglomerated powders for extended periods of time, up to months. Citric acid and 1,5-diphenyl-1,3,5-pentanetrione result in average diameters of 3 nm, whereas dimethyl-L-tartrate stabilizes 2.1 nm. X-ray diffraction and pair distribution function analysis were used to investigate the structural properties of the particles. TEM data confirm the individual particle size and crystallinity and show that the particles are agglomerated without structural coherence. Besides the introduction of these novel ligands for ZnO nanoparticles, we investigated, in particular, the influence of each synthesis step onto the final nanoparticle size in the powder. Previous studies often reported the employed synthesis parameters, but did not motivate the reasoning for their choice based on detailed experimental observations. Herein, we regard separately the steps of (i) the synthesis of the colloids, (ii) their precipitation, and (iii) the drying of the resulting gel to understand the role of the ligands therein. ZnO particles only covered with acetate grow to 5 nm during the drying process, whereas particles with any of the additional ligands retain their colloidal size of 2–3 nm. This clearly shows the efficient binding and effect of the presented ligands.

  6. Synthesis of Phthalimide Derivatives as Potential PPAR-γ Ligands

    Directory of Open Access Journals (Sweden)

    So Hyeon Eom

    2016-06-01

    Full Text Available Paecilocin A, a phthalide derivative isolated from the jellyfish-derived fungus Paecilomyces variotii, activates PPAR-γ (Peroxisome proliferator-activated receptor gamma in rat liver Ac2F cells. Based on a SAR (Structure-activity relationships study and in silico analysis of paecilocin A-mimetic derivatives, additional N-substituted phthalimide derivatives were synthesized and evaluated for PPAR-γ agonistic activity in both murine liver Ac2F cells and in human liver HepG2 cells by luciferase assay, and for adipogenic activity in 3T3-L1 cells. Docking simulation indicated PD6 was likely to bind most strongly to the ligand binding domain of PPAR-γ by establishing crucial H-bonds with key amino acid residues. However, in in vitro assays, PD1 and PD2 consistently displayed significant PPAR-γ activation in Ac2F and HepG2 cells, and adipogenic activity in 3T3-L1 preadipocytes.

  7. Selective nonpeptidic fluorescent ligands for oxytocin receptor: design, synthesis, and application to time-resolved FRET binding assay.

    Science.gov (United States)

    Karpenko, Iuliia A; Margathe, Jean-François; Rodriguez, Thiéric; Pflimlin, Elsa; Dupuis, Elodie; Hibert, Marcel; Durroux, Thierry; Bonnet, Dominique

    2015-03-12

    The design and the synthesis of the first high-affinity fluorescent ligands for oxytocin receptor (OTR) are described. These compounds enabled the development of a TR-FRET based assay for OTR, readily amenable to high throughput screening. The validation of the assay was achieved by competition experiments with both peptide and nonpeptide OTR ligands as competitors. These probes represent the first selective fluorescent ligands for the oxytocin G protein-coupled receptor.

  8. A one pot organic/CdSe nanoparticle hybrid material synthesis with in situ π-conjugated ligand functionalization.

    Science.gov (United States)

    Mazzio, Katherine A; Okamoto, Ken; Li, Zhi; Gutmann, Sebastian; Strein, Elisabeth; Ginger, David S; Schlaf, Rudy; Luscombe, Christine K

    2013-02-14

    A one pot method for organic/colloidal CdSe nanoparticle hybrid material synthesis is presented. Relative to traditional ligand exchange processes, these materials require smaller amounts of the desired capping ligand, shorter syntheses and fewer processing steps, while maintaining nanoparticle morphology.

  9. Photochemical Synthesis and Ligand Exchange Reactions of Ru(CO)[subscript 4] (Eta[superscript 2]-Alkene) Compounds

    Science.gov (United States)

    Cooke, Jason; Berry, David E.; Fawkes, Kelli L.

    2007-01-01

    The photochemical synthesis and subsequent ligand exchange reactions of Ru(CO)[subscript 4] (eta[superscript2]-alkene) compounds has provided a novel experiment for upper-level inorganic chemistry laboratory courses. The experiment is designed to provide a system in which the changing electronic properties of the alkene ligands could be easily…

  10. Metal complexes with oxygen-functionalized NHC ligands: synthesis and applications.

    Science.gov (United States)

    Hameury, Sophie; de Frémont, Pierre; Braunstein, Pierre

    2017-02-06

    Ligand design has met with considerable success with both categories of hybrid ligands, which are characterized by chemically different donor groups, and of N-heterocyclic carbenes (NHCs). Their spectacular development and diversity are attracting worldwide interest and offers almost unlimited diversity and potential in e.g. coordination/organometallic main group and transition metal chemistry, catalysis, medicinal chemistry and materials science. This review aims at providing a comprehensive update on a specific class of ligands that has enjoyed much attention in the past few years, at the intersection between the two categories mentioned above, that of hybrid NHC ligands in which the functionality associated with the carbene donor is of the oxygen-donor type. For each type of oxygen-donor present in such chelating (Section 1) or bridging (Section 2) hybrid ligands, we will examine the synthesis, structures and reactivity of their metal complexes and their applications, with a special focus on homogeneous catalysis (Section 3). Thus, hydrogenation, C-H bond activation, C-C, C-N, C-O bond formation, hydrolysis of silanes, oligomerization, polymerization, metathesis, hydrosilylation, C-C bond cleavage, acceptorless dehydrogenation, dehalogenation/hydrogen transfer, oxidation and reduction reactions will be successively presented in a tabular manner, to facilitate an overview and a rapid identification of the relevant publications describing which metals associated with a given oxygen functionality are most suitable. The literature coverage includes the year 2015.

  11. Design, synthesis, and biological evaluation of CXCR4 ligands.

    Science.gov (United States)

    Mona, Christine E; Besserer-Offroy, Élie; Cabana, Jérôme; Leduc, Richard; Lavigne, Pierre; Heveker, Nikolaus; Marsault, Éric; Escher, Emanuel

    2016-11-02

    A combination of the CXCR4 inverse agonist T140 with N-terminal CXCL12 oligopeptides has produced the first nanomolar synthetic CXCR4 agonists. In these agonists, the inverse agonistic portion provides affinity whereas the N-terminal CXCL12 sequence induces receptor activation. Several CXCR4 crystal structures exist with either CVX15, an inverse agonist closely related to T140 and IT1t, a small molecule; we therefore attempted to produce another CXCL12 oligopeptide combination with IT1t. For this purpose, a primary amino group was introduced by total synthesis into one of the methyl groups of IT1t, serving as an anchoring point for the oligopeptide graft. The introduction of the oligopeptides on this analog however yielded antagonists, one compound displaying high affinity. On the other hand, the amino-substituted analogue itself proved to be an inverse agonist with a binding affinity of 2.6 nM compared to 11.5 nM for IT1t. This IT1t-like analog is hitherto one of the most potent non-peptidic CXCR4 inverse agonists reported.

  12. Synthesis, Spectroscopy, Theoretical, and Electrochemical Studies of Zn(II, Cd(II, and Hg(II Azide and Thiocyanate Complexes of a New Symmetric Schiff-Base Ligand

    Directory of Open Access Journals (Sweden)

    Morteza Montazerozohori

    2013-01-01

    Full Text Available Synthesis of zinc(II/cadmium(II/mercury(II thiocyanate and azide complexes of a new bidentate Schiff-base ligand (L with general formula of MLX2 (M = Zn(II, Cd(II, and Hg(II in ethanol solution at room temperature is reported. The ligand and metal complexes were characterized by using ultraviolet-visible (UV-visible, Fourier transform infrared (FT-IR, 1H- and 13C-NMR spectroscopy and physical characterization, CHN analysis, and molar conductivity. 1H- and 13C-NMR spectra have been studied in DMSO-d6. The reasonable shifts of FT-IR and NMR spectral signals of the complexes with respect to the free ligand confirm well coordination of Schiff-base ligand and anions in an inner sphere coordination space. The conductivity measurements as well as spectral data indicated that the complexes are nonelectrolyte. Theoretical optimization on the structure of ligand and its complexes was performed at the Becke’s three-parameter hybrid functional (B3 with the nonlocal correlation of Lee-Yang-Parr (LYP level of theory with double-zeta valence (LANL2DZ basis set using GAUSSIAN 03 suite of program, and then some theoretical structural parameters such as bond lengths, bond angles, and torsion angles were obtained. Finally, electrochemical behavior of ligand and its complexes was investigated. Cyclic voltammograms of metal complexes showed considerable changes with respect to free ligand.

  13. Spectral Synthesis via Mean Field approach Independent Component Analysis

    CERN Document Server

    Hu, Ning; Kong, Xu

    2015-01-01

    In this paper, we apply a new statistical analysis technique, Mean Field approach to Bayesian Independent Component Analysis (MF-ICA), on galaxy spectral analysis. This algorithm can compress the stellar spectral library into a few Independent Components (ICs), and galaxy spectrum can be reconstructed by these ICs. Comparing to other algorithms which decompose a galaxy spectrum into a combination of several simple stellar populations, MF-ICA approach offers a large improvement in the efficiency. To check the reliability of this spectral analysis method, three different methods are used: (1) parameter-recover for simulated galaxies, (2) comparison with parameters estimated by other methods, and (3) consistency test of parameters from the Sloan Digital Sky Survey galaxies. We find that our MF-ICA method not only can fit the observed galaxy spectra efficiently, but also can recover the physical parameters of galaxies accurately. We also apply our spectral analysis method to the DEEP2 spectroscopic data, and find...

  14. Synthesis and biological activities of simplified analogs of the natural PKC ligands, bryostatin-1 and aplysiatoxin.

    Science.gov (United States)

    Irie, Kazuhiro; Yanagita, Ryo C

    2014-04-01

    Protein kinase C (PKC) isozymes play central roles in signal transduction on the cell surface and could serve as promising therapeutic targets of intractable diseases like cancer, Alzheimer's disease, and acquired immunodeficiency syndrome (AIDS). Although natural PKC ligands like phorbol esters, ingenol esters, and teleocidins have the potential to become therapeutic leads, most of them are potent tumor promoters in mouse skin. By contrast, bryostatin-1 (bryo-1) isolated from marine bryozoan is a potent PKC activator with little tumor-promoting activity. Numerous investigations have suggested bryo-1 to be a promising therapeutic candidate for the above intractable diseases. However, there is a supply problem of bryo-1 both from natural sources and by organic synthesis. Recent approaches on the synthesis of bryo-1 have focused on its simplification, without decreasing the ability to activate PKC isozymes, to develop new medicinal leads. Another approach is to use the skeleton of natural PKC ligands to develop bryo-1 surrogates. We have recently identified 10-methyl-aplog-1 (26), a simplified analog of tumor-promoting aplysiatoxin (ATX), as a possible therapeutic lead for cancer. This review summarizes recent investigations on the simplification of natural PKC ligands, bryo-1 and ATX, to develop potential medicinal leads. Copyright © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Design and Synthesis of Bis-thioureas Ligands for Pd-Catalyzed Heck Reaction

    Institute of Scientific and Technical Information of China (English)

    CHEN Wei; CHEN Ying-Chun; WU Yong

    2004-01-01

    The palladium-catalyzed arylation of olefins (the Heck reaction) is one of the most versatile tools for C-C bond formation in organic synthesis. Phosphine ligands are generally used to stabilize the reactive palladium intermediates, the air-sensitivity of phosphine ligands, however,places significant limits on their synthetic applications. Recently, Yang1 and we2 have reported Heck and Suzuki reactions of highly active arenediazonium salts and halides catalyzed by air-stable monothiourea-Pd complexes.In this presentation, we disclose our results on the design and synthesis of novel bis-thiourea ligands. We report that the bis-thiourea-Pd(0) complexes are highly air-, moisture- and thermally stable catalysts for Heck reactions of aryl halides. We tested the catalytic activity of their complexes with Pd (0) in the Heck reaction between iodobenzene and n-butyl acrylate. Our work shows that in NMP at 180℃, quantitative yield was achieved within 0.5h when 0.001mol% Pd was used (TOF up to 200,000). Furthermore, solvent-free condition can be applied in our catalytic system and very high TON (up to 1,000,000) is obtained within 12h.Further investigations aimed at clarification of the reaction scope are currently in progress.

  16. Synthesis, Characterization and Biological Evaluation of Transition Metal Complexes Derived from N, S Bidentate Ligands

    Directory of Open Access Journals (Sweden)

    Enis Nadia Md Yusof

    2015-05-01

    Full Text Available Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC with 2-methoxybenzaldehyde (2MB and 3-methoxybenzaldehyde (3MB. The ligands were reacted separately with acetates of Cu(II, Ni(II and Zn(II yielding 1:2 (metal:ligand complexes. The metal complexes formed were expected to have a general formula of [M(NS2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1 and S2M3MBH (2 were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7 and estrogen receptor-negative (MDA-MB-231 breast cancer cell lines. Only the Cu(II complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II complexes have a strong DNA binding affinity.

  17. Synthesis, Characterization and Thermal Analysis of New Cu(II Complexes with Hydrazide Ligands

    Directory of Open Access Journals (Sweden)

    Saber Rajaei

    2010-01-01

    Full Text Available A number of new complexes have been synthesized by reaction of novel ligands acetic acid(4-methyl-benzylidenehydrazide (L1 and acetic acid(naphthalen-1-ylmethylenehydrazide (L2 with copper(II nitrate. These new compounds were characterized by elemental analysis, TG, DTA, IR spectroscopy, UV spectral techniques. The changes observed between the FT-IR and UV-Vis spectra of the ligands and of the complexes allowed us to establish the coordination mode of the metal in complexes. The results suggest that the Schiff bases L1 and L2 coordinate as univalent anions with their bidentate N,O donors derived from the carbonyl and azomethine nitrogen. Also the probing of thermal analysis complexes can detect which complex has excellent thermal stability.

  18. Half-sandwich ruthenium, rhodium and iridium complexes of triazolopyridine ligand: Synthesis and structural studies

    Indian Academy of Sciences (India)

    NARASINGA RAO PALEPU; RAO MOHAN KOLLIPARA

    2017-02-01

    Triazolopyridine ligand, {3-(2-pyridyl)-[1,2,3]triazolo[1,5-a]-pyridine}, L was synthesized by reaction of p-toulenesulphonyl hydrazine and dipyridyl ketone in the presence of acetic acid. Half-sandwich ruthenium, rhodium and iridium complexes [1–4] have been synthesized by reaction of [{(arene)MCl₂}₂] (arene= p-cymene/benzene/Cp* and M = Ru/Rh/Ir) with ligand L in methanol. The reaction in 1:2 (M:L) ratio has yielded all mononuclear cationic complexes such as [(arene)MLκ²N∩N Cl]PF₆, where {(arene)M} = (p-cym)Ru(1), (benz)Ru (2), Cp*Rh (3) and Cp*Ir (4). All the complexes were characterized by spectral studies and the solid state structures of complexes, 1 and 3 were unambiguously determined by crystallographic studies.

  19. Direct synthesis of thiolate-protected gold nanoparticles using Bunte salts as ligand precursors: investigations of ligand shell formation and core growth

    Science.gov (United States)

    Lohse, Samuel E.

    2011-12-01

    Applications of ligand-protected nanoparticles have increased markedly in recent years, yet their controlled synthesis remains an under-developed field. Nanoparticle syntheses are highly specialized in their execution and often possess significant limitations. For example, the synthesis of thiol-stabilized gold nanoparticles (AuNPs) with core diameters greater than 5.0 nm is difficult to achieve using existing methods. This dissertation describes the development of a synthetic strategy for thiolate-stabilized AuNPs over a wide range of core sizes using alkyl thiosulfates (Bunte salts) as ligand precursors. The use of Bunte salts permits the synthesis of larger AuNPs than can be achieved using thiols by allowing the AuNP cores to grow to larger diameters before the formation of the thiolate ligand shell. Chapter II details the development of a direct synthesis strategy using Bunte salts as ligand precursors that produces AuNPs with diameters up to 20 nm. Chapter III describes an investigation of the ligand shell formation that occurs during these syntheses. The ligand shell formation involves the adsorption of the Bunte salt to the AuNP surface, where it is converted to the thiolate. This conversion requires an excess of sodium borohydride in the synthesis of >5 nm AuNPs, but not for the synthesis of smaller AuNPs. This synthetic strategy was adapted for use in flow reactors to attain simultaneous AuNP synthesis and characterization. Chapter IV demonstrates that thiol-stabilized AuNPs can be synthesized in a microfluidic device with product monitoring provided by UV-vis absorbance spectroscopy. The development of a capillary flow reactor that permits the incorporation of new monitoring techniques is presented in Chapter V. The incorporation of Small-Angle X-ray Scattering (SAXS) analysis provides quantitative in situ determinations of AuNP diameter. The combination of synthetic control and monitoring makes capillary flow reactors powerful tools for optimization of

  20. [Enzyme-catalyzed synthesis of ASGPR ligand-targeted modifier in non-aqueous medium].

    Science.gov (United States)

    Cheng, Yi; Wu, Wei; Zhang, Dong-qing; Mai, Yan-zhen

    2010-09-01

    The asialoglycoprotein receptor (ASGPR) was used to mediate drug carrier for hepatic targeted drug delivery, this article showed the enzyme-catalyzed esterification of galactose and vinyl stearate and a kind of ASGPR ligand-targeted which was used to insert the surface of liposome has been synthesized. The structure of product has been confirmed by TLC, ESI-MS and 1H NMR. The factors of types and quantity of enzyme, organic solvents, molar ratio of substrate, temperature and time of reaction have been studied. Results showed when using acetone as reaction medium, the quantity of Novozym 435 immobilized lipase was 30 mg mL(-1), molar ratio of galactose to vinyl stearate was 1:5, and reacted at 60 degrees C for 12 h, the transformation of vinyl stearate reached more than 70%. This study provides a novel and efficient route to the synthesis of ligand-targeted modifier.

  1. Synthesis and Doping of Ligand-Protected Atomically-Precise Metal Nanoclusters

    KAUST Repository

    Aljuhani, Maha A.

    2016-05-01

    Rapidly expanding research in nanotechnology has led to exciting progress in a versatile array of applications from medical diagnostics to catalysis. This success resulted from the manipulation of the desired properties of nanomaterials by controlling their size, shape, and composition. Among the most thriving areas of research about nanoparticle is the synthesis and doping of the ligand-protected atomically-precise metal nanoclusters. In this thesis, we developed three different novel metal nanoclusters, such as doped Ag29 with five gold (Au) atoms leading to enhance its quantum yield with remarkable stability. We also developed half-doped (alloyed) cluster of Ni6 nanocluster with molybdenum (Mo). This enabled enhanced stability and better catalytic activity. The third metal nanocluster that we synthesized was Au28 nanocluster by using di-thiolate as the ligand stabilizer instead of mono-thiolate. The new metal clusters obtained have been characterized by spectroscopic, electrochemical and crystallographic methods.

  2. Spectral Synthesis via Mean Field approach to Independent Component Analysis

    Science.gov (United States)

    Hu, Ning; Su, Shan-Shan; Kong, Xu

    2016-03-01

    We apply a new statistical analysis technique, the Mean Field approach to Independent Component Analysis (MF-ICA) in a Bayseian framework, to galaxy spectral analysis. This algorithm can compress a stellar spectral library into a few Independent Components (ICs), and the galaxy spectrum can be reconstructed by these ICs. Compared to other algorithms which decompose a galaxy spectrum into a combination of several simple stellar populations, the MF-ICA approach offers a large improvement in efficiency. To check the reliability of this spectral analysis method, three different methods are used: (1) parameter recovery for simulated galaxies, (2) comparison with parameters estimated by other methods, and (3) consistency test of parameters derived with galaxies from the Sloan Digital Sky Survey. We find that our MF-ICA method can not only fit the observed galaxy spectra efficiently, but can also accurately recover the physical parameters of galaxies. We also apply our spectral analysis method to the DEEP2 spectroscopic data, and find it can provide excellent fitting results for low signal-to-noise spectra.

  3. Synthesis, spectral characterization, structural investigation and antimicrobial studies of mononuclear Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) complexes of a new potentially hexadentate N2O4 Schiff base ligand derived from salicylaldehyde

    Science.gov (United States)

    Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Elerman, Yalcin; Buyukgungor, Orhan

    2013-01-01

    A new potentially hexadentate N2O4 Schiff base ligand, H2L derived from condensation reaction of an aromatic diamine and salicylaldehyde, and its metal complexes were characterized by elemental analyses, IR, UV-Vis, EI-MS, 1H and 13C NMR spectra, as well as conductance measurements. It has been originated that the Schiff base ligand with Cu(II), Ni(II), Co(II), Cd(II) and Zn(II) ions form mononuclear complexes on 1:1 (metal:ligand) stoichiometry. The conductivity data confirm the non-electrolytic nature of the complexes. Also the crystal structures of the complexes [ZnL] and [CoL] have also been determined by using X-ray crystallographic technique. The Zn(II) and Co(II) complexes show a tetrahedral configuration. Electronic absorption spectra of the Cu(II) and Ni(II) complexes suggest a square-planar geometry around the central metal ion. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Bacillus cereus, Enterococcus faecalis and Listeria monocytogenes and also against the three Gram-negative bacteria: Salmonella paraB, Citrobacter freundii and Enterobacter aerogenes. The results showed that in some cases the antibacterial activity of complexes were more than nalidixic acid and amoxicillin as standards.

  4. Poly(ethylene glycol)s as Ligands in Calcium-Catalyzed Cyclic Carbonate Synthesis.

    Science.gov (United States)

    Steinbauer, Johannes; Werner, Thomas

    2017-08-10

    Herein the use of CaI2 in combination with poly(ethylene glycol) dimethyl ether (PEG DME 500) as an efficient catalyst system for the addition of CO2 to epoxides is reported. This protocol is based on a nontoxic and abundant metal in conjunction with a polymeric ligand. Fifteen terminal epoxides were converted at room temperature to give the desired products in yields up to 99 %. Notably, this system was also effective for the synthesis of twelve challenging internal carbonates in yields up to 98 %. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Gold(I)-selenolate complexes: Synthesis, characterization and ligand exchange reactions

    Indian Academy of Sciences (India)

    Krishna P Bhabak; Govindasamy Mugesh

    2011-11-01

    In this paper, the synthesis and characterization of some imidazole-based gold-selenolates are described. This study indicates that the nature of selenolate plays an important role in ligand exchange reactions in gold(I) selenolates. Furthermore, the reactivity of imidazole-based gold(I) selenolates toward nucleophiles such as selenols and phosphines is strikingly different from that of the ,-dimethylaminobenzylamine-based gold(I) complexes. The presence of Se$\\cdots$N non-bonded interactions in ,-dimethylaminobenzylamine-based gold(I) complexes modulates the reactivity of Au(I) centre towards incoming nucleophiles.

  6. Synthesis and coordination chemistry of tridentate (PNN) amine enamido phosphine ligands with ruthenium.

    Science.gov (United States)

    Wambach, T C; Lenczyk, C; Patrick, B O; Fryzuk, M D

    2016-04-07

    Tridentate amine-imine-phosphine ligands, R2PC5H7NC2H4NEt2 [(R)PNN(H)], where R = Pr(i) or Bu(t) are synthesized using a straightforward protocol of condensation, deprotonation, and addition of a chlorodialkylphosphine. Multinuclear NMR spectroscopy shows the ligands exist exclusively in the enamine tautomeric form in solution. Treating these ligands with RuHCl(PPr(i)3)2(CO) forms the desired coordination compounds, RuHCl[(R)PNN(H)](CO), where the imine tautomeric form of the ligands coordinates to ruthenium. Deuterium labelling experiments show Ru-H/N-D scrambling occurs during ligand coordination. Treating the RuHCl[(R)PNN(H)](CO) precursors with potassium tert-butoxide allows for the synthesis of two new ruthenium enamido-phosphine complexes, RuH[(R)PNN](CO), which were fully characterized. The structure of one of the derivatives was confirmed by X-ray crystallography (R = Pr(i)). The reactivity of the enamido-phosphine complexes with H2 and benzyl alcohol is also reported. For the enamido phosphine complex where R = Pr(i), the reaction with H2 is reversible and forms (RuH(CO)[(Pri)PNN(H)])2(μ-H)2, a hydride-bridged dimer that results from cooperative activation of H2. The reactivity of both amine-enamido-phosphine ruthenium compounds with benzyl alcohol establishes that the complexes are catalyst precursors for acceptorless dehydrogenation (AD), although the turnover frequencies measured using both catalyst precursors are modest.

  7. Synthesis, characterization and anti-proliferative activity of Cd(II) complexes with NNN type pyrazole-based ligand and pseudohalide ligands as coligand

    Science.gov (United States)

    Hopa, Cigdem; Yildirim, Hatice; Kara, Hulya; Kurtaran, Raif; Alkan, Mahir

    2014-03-01

    Cd(II) complexes of tridentate nitrogen donor ligand, 2,6-bis(3,4,5-trimethylpyrazolyl)pyridine (btmpp), Cd(btmpp)X2 (X:Cl, ONO or N(CN)2) have been synthesized and characterized by elemental and spectral (FT-IR, 1H NMR, 13C NMR, UV-Vis) analyses, differential thermal analysis and single crystal X-ray diffraction studies. The molecular structure of reported complex 1, revealed distorted square-pyramidal geometry around Cadmium. Complexes 1-3 and corresponding ligand were tested for cytotoxic activity against the human carcinoma cell lines HEP3B (hepatocellular carcinoma), PC3 (prostate adenocarcinoma), MCF7 (breast adenocarcinoma) and Saos2 (osteosarcoma). The results show that, complexes are more cytotoxic than the free ligand and complex 2 is the most cytotoxic complex for PC3.

  8. The Effect of Precursor Ligands and Oxidation State in the Synthesis of Bimetallic Nano-Alloys

    KAUST Repository

    LaGrow, Alec P.

    2015-05-12

    The characteristics of bimetallic nanomaterials are dictated by their size, shape and elemental distribution. Solution synthesis is widely utilized to form nanomaterials, such as nanoparticles, with controlled size and shape. However, the effects of variables on the characteristics of bimetallic nanomaterials are not completely understood. In this study, we used a continuous-flow synthetic strategy to explore the effects of the ligands and the oxidation state of a metal precursor in a shape-controlled synthesis on the final shape of the nanomaterials and the elemental distribution within the alloy. We demonstrate that this strategy can tune the size of monodisperse PtM (M=Ni or Cu) alloy nanocrystals ranging from 3 to 16 nm with an octahedral shape using acetylacetonate or halide precursors of Pt(II), Pt(IV) and Ni or Cu (II). The nanoparticles formed from halide precursors showed an enrichment of platinum on their surfaces, and the bromides could oxidatively etch the nanoparticles during synthesis with the O2/Br- pair. The two nanocrystal precursors can be uti-lized independently and can control the size with a trend of Pt(acac)2ligand shell of a precursor during the synthesis of alloy nanoparticles as well as to control, in a scalable manner, the nanomaterial size and surface chemistry.

  9. Mixed ligand Cu(II)N2O2 complexes: biomimetic synthesis, activities in vitro and biological models, theoretical calculations.

    Science.gov (United States)

    Li, Chen; Yin, Bing; Kang, Yifan; Liu, Ping; Chen, Liang; Wang, Yaoyu; Li, Jianli

    2014-12-15

    Three new mixed ligand Cu(II)N2O2 complexes, namely, [Cu(II)(2-A-6-MBT)2(m-NB)2] (1), [Cu(II)(2-ABT)2(m-NB)2] (2), and [Cu(II)(2-ABT)2(o-NB)2] (3), (2-A-6-MBT = 2-amino-6-methoxybenzothiazole, m-NB = m-nitrobenzoate, 2-ABT = 2-aminobenzothiazole, and o-NB = o-nitrobenzoate), have been prepared by the biomimetic synthesis strategy, and their structures were determined by X-ray crystallography studies and spectral methods. These complexes exhibited the effective superoxide dismutase (SOD) activity and catecholase activity. On the basis of the experimental data and computational studies, the structure-activity relationship for these complexes was investigated. The results reveal that electron-accepting abilities of these complexes and coordination geometries have significant effects on the SOD activity and catecholase activity. Then, we found that 1 and 2 exerted potent intracellular antioxidant capacity in the model of H2O2-induced oxidative stress based on HeLa cervical cancer cells, which were screened out by the cytotoxicity assays of different kinds of cells. Furthermore, 1-3 showed the favorable biocompatibility in two different biological models: Saccharomyces cerevisiae and human vascular endothelial cells. These biological experimental data are indicative of the promising application potential of these complexes in biology and pharmacology.

  10. Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fausthon Fred da; Fernandes de Oliveira, Carlos Alberto; Lago Falcão, Eduardo Henrique [Laboratório de Terras Raras, Departamento de Química Fundamental, Universidade Federal de Pernambuco (DQF-UFPE), 50590-470 Recife, PE (Brazil); Gatto, Claudia Cristina [Laboratório de Síntese Inorgânica e Cristalografia, Instituto de Química, Universidade de Brasília (IQ-UnB), 70904-970 Brasilia, DF (Brazil); Bezerra da Costa, Nivan; Oliveira Freire, Ricardo [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Chojnacki, Jarosław [Department of Inorganic Chemistry, Gdansk University of Technology, 80-233 Gdansk (Poland); Alves Júnior, Severino, E-mail: salvesjr@ufpe.br [Laboratório de Terras Raras, Departamento de Química Fundamental, Universidade Federal de Pernambuco (DQF-UFPE), 50590-470 Recife, PE (Brazil)

    2013-11-15

    The organic ligand 2,5-piperazinedione-1,4-diacetic acid (H{sub 2}PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P2{sub 1}/c monoclinic system as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric analysis. Two new coordination networks based on lanthanide ions were obtained with this ligand using hydrothermal reaction. In addition to single-crystal X-ray diffraction, the compounds were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis. Single-crystal XRD showed that the compounds are isostructural, crystallizing in P2{sub 1}/n monoclinic system with chemical formula [Ln(PDA){sub 1.5}(H{sub 2}O)](H{sub 2}O){sub 3} (Ln=Gd{sup 3+}(1) and Eu{sup 3+}(2)).The luminescence properties of both compounds were studied. In the compound (1), a broad emission band was observed at 479 nm, redshifted by 70 nm in comparison of the free ligand. In (2), the typical f–f transition was observed with a maximum peak at 618 nm, related with the red emission of the europium ions. Computational methods were performed to simulate the crystal structure of (2). The theoretical calculations of the intensity parameters are in good agreement with the experimental values. - Graphical abstract: Scheme of obtaining the ligand 2,5-piperazinedione-1,4-diacetic acid (H{sub 2}PDA) and two new isostructural 3D-coordination polymers [Ln(PDA){sub 1.5}(H{sub 2}O)](H{sub 2}O){sub 3} (Ln=Gd{sup 3+} and Eu{sup 3+}) by hydrothermal synthesis. Display Omitted - Highlights: • The ligand 2,5-piperazinedione-1,4-diacetic acid was synthetized using the hydrothermic method and characterized. • Two new 3D-coordination polymers with this ligand containing Gd{sup 3+} and Eu{sup 3+} ions

  11. Synthesis and Studies on S-Triazine-Based Ligand and Its Metal Complexes

    Directory of Open Access Journals (Sweden)

    R. Shanmugakala

    2012-01-01

    Full Text Available Tridentate chelate complexes of ML type (where M = Cu(II, Ni(II, and Co(II have been synthesized from triazine-based ligand 4,6-bis(5-mercapto-1,3,4-thiadiazol-amine2-phenylamino-1,3,5-triazine (BMTDT. Microanalytical data, magnetic susceptibility measurements, IR, 1H NMR, UV-vis, mass, and EPR spectral techniques were used to characterise the structure of chelates. The electronic absorption spectra and magnetic susceptibility measurements suggest that metal complexes show square pyramidal geometry. The electrochemical behavior of copper(II complex is studied by cyclic voltammetry. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation efficiency (SHG of the ligand and metal complexes has been found to be higher than that of urea and KDP. The antimicrobial activity of the ligand and metal(II complexes against the species Shigella, Chromobacterium, Staphylococcus aureus, Candida albicans, and Aspergillus niger has been carried out and compared with the standard one.

  12. Synthesis, Spectral and Thermal Studies of New Rutin Vanadyl Complexes

    Directory of Open Access Journals (Sweden)

    Rodica Olar

    2010-03-01

    Full Text Available Complexes between oxovanadium (IV cation and flavonoid derivatives were developed recently in order to increase the intestinal absorption and to reduce the toxicity of vanadium compounds. For these reasons, is interesting to investigate the complexation process between flavonoid rutin (Rut and vanadyl cation in order to isolate new complexes. Two new complexes [VO(Rut(H2O2](SO40.5×2H2O and [VO(Rut2]×4H2O have been obtained and characterized by elemental and thermal analyses and several spectroscopic techniques (ESI-MS, IR, UV-Vis, fluorescence. The studies concerning complex formation between vanadyl and rutin (Rut performed in different solutions show the formation of mononuclear complexes with 1:1 and 1:2 metal to ligand stoichiometry.

  13. Synthesis, spectral studies, antimicrobial and insect antifeedant potent keto oxiranes

    Directory of Open Access Journals (Sweden)

    Ganesamoorthy Thirunarayanan

    2016-09-01

    Full Text Available A series of ee (αS, βR biphenyl keto oxiranes (biphenyl-4-yl[3-(substituted phenyloxiran-2-yl]methanones have been synthesized by phase transfer catalysed epoxidation of biphenyl 2E-chalcones. The yields of oxiranes are more than 95%. The synthesized oxiranes have been characterized by IR, 1H, 13C and GC–MS spectra. The spectral data are correlated with Hammett substituent constants and Swain–Lupton parameters. From the regression analyses, the effect of substituent on the group frequencies has been predicted. The antimicrobial and insect antifeedant activities of all synthesized oxiranes have been evaluated.

  14. Synthesis, Characterization, and in Vitro Evaluation of a New TSPO-Selective Bifunctional Chelate Ligand.

    Science.gov (United States)

    Denora, Nunzio; Margiotta, Nicola; Laquintana, Valentino; Lopedota, Angela; Cutrignelli, Annalisa; Losacco, Maurizio; Franco, Massimo; Natile, Giovanni

    2014-06-12

    The 18-kDa translocator protein (TSPO) is overexpressed in many types of cancers and is also abundant in activated microglial cells occurring in inflammatory neurodegenerative diseases. Thus, TSPO has become an extremely attractive subcellular target not only for imaging disease states overexpressing this protein, but also for a selective mitochondrial drug delivery. In this work we report the synthesis, the characterization, and the in vitro evaluation of a new TSPO-selective ligand, 2-(8-(2-(bis(pyridin-2-yl)methyl)amino)acetamido)-2-(4-chlorophenyl)H-imidazo[1,2-a]pyridin-3-yl)-N,N-dipropylacetamide (CB256), which fulfils the requirements for a bifunctional chelate approach. The goal was to provide a new TSPO ligand that could be used further to prepare coordination complexes of a metallo drug to be used in diagnosis and therapy. However, the ligand itself proved to be a potent tumor cell growth inhibitor and DNA double-strand breaker.

  15. Novel Zinc(II) Complexes of Heterocyclic Ligands as Antimicrobial Agents: Synthesis, Characterisation, and Antimicrobial Studies

    Science.gov (United States)

    Yamgar, Ramesh S.; Nivid, Y.; Nalawade, Satish; Mandewale, Mustapha; Atram, R. G.; Sawant, Sudhir S.

    2014-01-01

    The synthesis and antimicrobial activity of novel Zn(II) metal complexes derived from three novel heterocyclic Schiff base ligands 8-[(Z)-{[3-(N-methylamino)propyl]imino}methyl]-7-hydroxy-4-methyl-2H-chromen-2-one, 2-[(E)-{[4-(1H-1,2,4-triazol-1-ylmethyl)phenyl]imino}methyl]phenol, and (4S)-4-{4-[(E)-(2-hydroxybenzylidene)amino]benzyl}-1,3-oxazolidin-2-one have been described. These Schiff base ligands and metal complexes are characterised by spectroscopic techniques. According to these data, we propose an octahedral geometry to all the metal complexes. Antimicrobial activity of the Schiff base ligand and its metal complexes was studied against Gram negative bacteria: E. coli and Pseudomonas fluorescens, Gram positive bacteria: Staphylococcus aureus, and also against fungi, that is, C. albicans and A. niger. Some of the metal complexes show significant antifungal activity (MIC < 0.2 μg/mL). The “in vitro” data has identified [Zn(NMAPIMHMC)2]·2H2O, [Zn(TMPIMP)2]·2H2O, and [Zn(HBABO)2]·2H2O as potential therapeutic antifungal agents against C. albicans and A. niger. PMID:24707242

  16. Synthesis and Structural Characterization of Schiff Base Ligand and their Metal Complexes

    Directory of Open Access Journals (Sweden)

    Amit Kumar Gautam

    2016-05-01

    Full Text Available In the present work, the synthesis and structural characterization of a 2-phenyl- 3(benzamido propyl quinazoline (3H -4- one semicarbazone/ thiosemicarbazone hydrochloride and its metal complexes have been reported. All the synthesized compounds were characterized by using various physico-chemical techniques such as Infrared spectra, electronic spectra, molar conductivity and magnetic susceptibility measurements. The ligand and metal ions reacted to form in the 2:1 ratio as found from the elemental analyses and general stiochiometry was determined, [M(PBPQS2X2] and [M(PBPQT2X2]; where M = Co(II, Ni(II and Cu(II; PBPQS = 2-phenyl- 3 (benzamido propyl quinazoline (3H -4- one semicarbazone and PBPQT = 2- phenyl- 3 (benzamido propyl quinazoline (3H -4- one thiosemicarbazone. On the basis of analytical data, a proposed structure for the Cu(II complexes are distorted octahedral and those for Co(II and Ni(II complexes are octahedral. Ligands PBPQS/ PBPQT have been proposed to act in a bidentate manner co-ordinating to the metal ions though azomethine nitrogen and oxygen/ sulphur atom of either semicarbazone/ thiosemicarbazone moiety. The remaining co-ordination sites are occupied by negative ions such as Cl-, Br-, I- or NO3-. The ligands and its metal complexes were tested for their possible antimicrobial potentials.

  17. Synthesis of ligand-free CZTS nanoparticles via a facile hot injection route

    Science.gov (United States)

    Mirbagheri, N.; Engberg, S.; Crovetto, A.; Simonsen, S. B.; Hansen, O.; Lam, Y. M.; Schou, J.

    2016-05-01

    Single-phase, ligand-free Cu2ZnSnS4 (CZTS) nanoparticles that can be dispersed in polar solvents are desirable for thin film solar cell fabrication, since water can be used as the solvent for the nanoparticle ink. In this work, ligand-free nanoparticles were synthesized using a simple hot injection method and the precursor concentration in the reaction medium was tuned to control the final product. The as-synthesized nanoparticles were characterized using various techniques, and were found to have a near-stoichiometric composition and a phase-pure kesterite crystal structure. No secondary phases were detected with Raman spectroscopy or scanning transmission electron microscopy energy dispersive x-ray spectroscopy. Furthermore, high resolution transmission electron microscopy showed large-sized nanoparticles with an average diameter of 23 nm ± 11 nm. This approach avoids all organic materials and toxic solvents that otherwise could hinder grain growth and limit the deposition techniques. In addition the synthesis route presented here results in nanoparticles of a large size compared to other ligand-free CZTS nanoparticles, due to the high boiling point of the solvents selected. Large particle size in CZTS nanoparticle solar cells may lead to a promising device performance. The results obtained demonstrate the suitability of the synthesized nanoparticles for application in low cost thin film solar cells.

  18. Synthesis and characterisation of novel o-xylene-based P,E ligands.

    Science.gov (United States)

    Allan, Kathryn M; Spencer, John L

    2014-02-14

    A range of novel hybrid ligands of the type, o-C6H4(CH2PBu(t)2)(CH2E) (E = P(C6F5)2, SBu(t), SPh, S(O)Bu(t), NR2, SiPh2H), have been synthesised in two or three steps from the common substrate, o-C6H4{CH2PBu(t)2(BH3)}(CH2Cl). The initial step involved treatment of the substrate with the appropriate nucleophilic reagent, or preparation of a Grignard reagent from o-C6H4{CH2PBu(t)2(BH3)}(CH2Cl) and reaction with the appropriate electrophile. In most cases, this versatile strategy produced air-stable crystalline ligand precursors. Phosphine deprotection was achieved via one of three methods, dependent upon the properties of the second functional group. An alternative synthesis of the known ligand, o-C6H4(CH2PBu(t)2)(CH2PPh2), is also presented.

  19. Synthesis, structural and spectral studies of five- and six-coordinate adducts of organotin(IV) halides containing dibenzylsulfoxide (DBSO) as ligand. The crystal structures of fac-[MeSnCl{sub 3}(dbso){sub 2}] and trans-[Ph{sub 2}SnCl{sub 2}(dbso){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Gerimario F. de [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Quimica], e-mail: gfreitas@unb.br; Sabino, Jose R.; Vencato, Ivo [Universidade Federal do Goias (UFGO), Goiania, GO (Brazil). Inst. de Fisica; Filgueiras, Carlos A. L. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Ardisson, Jose D. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Fisica Aplicada

    2009-07-01

    The reaction of the ambidentate ligand dibenzylsulfoxide (dbso) with Me{sub 2}SnCl{sub 2} in 1:1 molar ratio leads to the formation of the five-coordinate adduct [Me{sub 2}SnCl{sub 2}(dbso)], whereas the same reaction conditions with Ph{sub 2}SnCl{sub 2} provide the six-coordinate adduct trans-[Ph{sub 2}SnCl{sub 2}(dbso){sub 2}]. On the other hand, the reaction with {sup {pi}}Bu{sub 2}SnCl{sub 2} forms the dimeric adduct [{l_brace}{sup {pi}}Bu{sub 2}SnCl{sub 2}(dbso){r_brace}{sub 2}], which probably possesses octahedral tin(IV) nuclei and bridging chlorides. The adducts [MeSnCl{sub 3}(dbso){sub 2}] and [Ph{sub 3}SnCl(dbso)] were also prepared and included in the study. All complexes were studied by microanalysis and IR, NMR ({sup 1}H, {sup 13}C and {sup 119}Sn) and Moessbauer spectroscopies to investigate their structural properties. The six-coordinate species fac-[MeSnCl{sub 3}(dbso){sub 2}] and trans-[Ph{sub 2}SnCl{sub 2}(dbso){sub 2}] were also studied by single crystal X-ray diffractometry. These compounds crystallize in the orthorhombic, Pbcn, and monoclinic space group P2{sub 1}/c, respectively, as discrete neutral molecules with the tin(IV) atom in a distorted octahedral geometry and the two dbso ligands in cis and trans positions, respectively. (author)

  20. Synthesis and Spectral Study of Novel Norfloxacin Derivatives

    Directory of Open Access Journals (Sweden)

    Pradeep Yadav

    2008-01-01

    Full Text Available Reaction of [1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl-quinolone-3-carboxylic acid (norfloxacin with thiazole / benzothiazole diazonium chloride to get new piperazine substituted norfloxacin derivative. These norfloxacin derivatives were further condensed with various β-diketone to get novel acid derivatives of 1-Ethyl-6-fluoro-4-oxo-7- [4 (thiazol-2-yldiazenyl-piperzin-1-yl]-1,4-dihydro-quinoline-3-carboxylic acid (6a-e and 7-(4-(benzo[d]thiazol-2-yldiazenylpiperazin-1-yl-1-ethyl-6-fluoro-4-oxo-1, 4-dihydroquinoline-3-carboxylic acid (6 f-j. Structures of these compounds were established on the basis of spectral studies viz. IR, 1H NMR etc.

  1. Synthesis, spectral, computational and thermal analysis studies of metalloceftriaxone antibiotic

    Science.gov (United States)

    Masoud, Mamdouh S.; Ali, Alaa E.; Elasala, Gehan S.

    2015-03-01

    Binary ceftriaxone metal complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and six mixed metals complexes of (Fe, Cu), (Fe, Co), (Co, Ni), (Co, Cu), (Ni, Cu) and (Fe, Ni) were synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility and ESR spectra. The studies proved that the ligand has different combination modes and all complexes were of octahedral geometry. Molecular modeling techniques and quantum chemical methods have been performed for ceftriaxone to calculate charges, bond lengths, bond angles, dihedral angles, electronegativity (χ), chemical potential (μ), global hardness (η), softness (σ) and the electrophilicity index (ω). The thermal decomposition of the prepared metals complexes was studied by TGA, DTA and DSC techniques. The kinetic parameters and the reaction orders were estimated. The thermal decomposition of all the complexes ended with the formation of metal oxides and carbon residue as a final product except in case of Hg complex, sublimation occurs at the temperature range 297.7-413.7 °C so, only carbon residue was produced during thermal decomposition. The geometries of complexes may be altered from Oh to Td during the thermal decomposition steps. Decomposition mechanisms were suggested.

  2. Self assembled homodinuclear dithiocarbamates: One pot synthesis and spectral characterization

    Science.gov (United States)

    Nami, Shahab A. A.; Husain, Ahmad; Ullah, Irfan

    2014-01-01

    Several self assembled homodinuclear complexes of the type [M2(Ldtc)2·4H2O] derived from quadridentate ligand (Ldtc), where Ldtc = 2-aminobenzoylhydrazidebis(dithiocarbamate) and M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) have been reported. The in situ procedure gives high yield with the formation of single product as evident by TLC and various other physicochemical techniques. Elemental analysis, TGA, 1H NMR, 13C NMR, ESI mass spectrometry, EPR, UV-vis. and IR spectroscopy were used to characterize the homodinuclear complexes. The spectroscopic evidences and room temperature magnetic moment values suggest that all the complexes have octahedral geometry around the transition metal atom. A symmetrical bidentate coordination of the dithiocarbamato moiety has been observed in all the complexes. The energy-minimized structure of the molecule also showed that each metal atom acquires a distorted octahedral geometry. The complexes exhibit a three-step thermolytic pattern and are non-electrolyte in nature.

  3. Synthesis, Physico-Chemical and Antimicrobial Properties of Co(II, Ni(II, and Cu(II Mixed-Ligand Complexes of Dimethylglyoxime

    Directory of Open Access Journals (Sweden)

    A.A. Osunlaja

    2011-11-01

    Full Text Available The synthesis of non-electrolyte mixed-ligand complexes of the general formula [M(HdmgB], where M = Co(II, Ni(II or Cu(II Hdmg = dimethylglyoximato monoanion, B = 2- aminophenol(2-aph, diethylamine (dea or malonic acid (MOH are described. Metal analysis, melting points, solubility, conductivity, IR and UV/Visible electronic spectra were used in determining their physico-chemical properties. The antimicrobial activities of the complexes were tested against Esherichia coli, Staphylococcus aureus, Aspergillus niger and Aspergillus flavus. The complexes melted/decomposed at 120-306ºC and, most of them dissolved only in polar solvents. The colours of the complexes are mostly dark - brown or red. The spectral results suggest the binding of Hdmg, 2-amino phenol or malonic acid through the N atom and O atoms respectively to the metal ion In the electronic spectra of the complexes, the absorption bands observed in the UV/Visible region are presumed to be either due to charge transfer or intra-ligand transitions from the ligands or d-d transitions from the metal ions. The complexes showed marked antimicrobial activity against the tested microbes at 10 mg/mL. The possible use of the complexes as chemotherapeutic agents is hereby suggested.

  4. New Synthesis and Tritium Labeling of a Selective Ligand for Studying High-affinity γ-Hydroxybutyrate (GHB) Binding Sites

    OpenAIRE

    Vogensen, Stine B.; Marek, Aleš; Bay, Tina; Wellendorph, Petrine; Kehler, Jan; Bundgaard, Christoffer; Frølund, Bente; Pedersen, Martin H. F.; Clausen, Rasmus P.

    2013-01-01

    3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [3H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide. Screening of 1 against different CNS targets establishes a high selectivity and we demonstrate in vivo brain penetration. In vitro characterization of [3H]-1 binding shows high specificity to the high-affin...

  5. Mixed ligand complexation of some transition metal ions in solution and solid state: Spectral characterization, antimicrobial, antioxidant, DNA cleavage activities and molecular modeling

    Science.gov (United States)

    Shobana, Sutha; Dharmaraja, Jeyaprakash; Selvaraj, Shanmugaperumal

    2013-04-01

    Equilibrium studies of Ni(II), Cu(II) and Zn(II) mixed ligand complexes involving a primary ligand 5-fluorouracil (5-FU; A) and imidazoles viz., imidazole (him), benzimidazole (bim), histamine (hist) and L-histidine (his) as co-ligands(B) were carried out pH-metrically in aqueous medium at 310 ± 0.1 K with I = 0.15 M (NaClO4). In solution state, the stoichiometry of MABH, MAB and MAB2 species have been detected. The primary ligand(A) binds the central M(II) ions in a monodentate manner whereas him, bim, hist and his co-ligands(B) bind in mono, mono, bi and tridentate modes respectively. The calculated Δ log K, log X and log X' values indicate higher stability of the mixed ligand complexes in comparison to binary species. Stability of the mixed ligand complex equilibria follows the Irving-Williams order of stability. In vitro biological evaluations of the free ligand(A) and their metal complexes by well diffusion technique show moderate activities against common bacterial and fungal strains. Oxidative cleavage interaction of ligand(A) and their copper complexes with CT DNA is also studied by gel electrophoresis method in the presence of oxidant. In vitro antioxidant evaluations of the primary ligand(A), CuA and CuAB complexes by DPPH free radical scavenging model were carried out. In solid, the MAB type of M(II)sbnd 5-FU(A)sbnd his(B) complexes were isolated and characterized by various physico-chemical and spectral techniques. Both the magnetic susceptibility and electronic spectral analysis suggest distorted octahedral geometry. Thermal studies on the synthesized mixed ligand complexes show loss of coordinated water molecule in the first step followed by decomposition of the organic residues subsequently. XRD and SEM analysis suggest that the microcrystalline nature and homogeneous morphology of MAB complexes. Further, the 3D molecular modeling and analysis for the mixed ligand MAB complexes have also been carried out.

  6. A spectral synthesis code for rapid modelling of supernovae

    CERN Document Server

    Kerzendorf, Wolfgang E

    2014-01-01

    We present TARDIS - an open-source code for rapid spectral modelling of supernovae (SNe). Our goal is to develop a tool that is sufficiently fast to allow exploration of the complex parameter spaces of models for SN ejecta. This can be used to analyse the growing number of high-quality SN spectra being obtained by transient surveys. The code uses Monte Carlo methods to obtain a self-consistent description of the plasma state and to compute a synthetic spectrum. It has a modular design to facilitate the implementation of a range of physical approximations that can be compared to asses both accuracy and computational expediency. This will allow users to choose a level of sophistication appropriate for their application. Here, we describe the operation of the code and make comparisons with alternative radiative transfer codes of differing levels of complexity (SYN++, PYTHON, and ARTIS). We then explore the consequence of adopting simple prescriptions for the calculation of atomic excitation, focussing on four sp...

  7. UV/EUV spectral synthesis in spherical symmetry

    Science.gov (United States)

    Haberreiter, M.; Fontenla, J.

    2009-04-01

    The Sun's varying output in the UV/EUV has strong effect on the Earth's ionosphere and e.g. satellite positioning. We present latest progress in modeling the solar UV/EUV irradiance spectrum based on physical principles. We use the Solar Radiation Physical Modeling (SRPM) system to calculate the solar UV/EUV spectrum for the wavelength range from 10 to 180 nm. We solve the full NLTE for the most abundant elements from H to Fe up to ion charge 2. For the higher ionization states we solve the statistical equation with an optically thin approach, i.e. using the collision strengths and spontaneous emission. Currently we account for a total number of 14 000 atomic levels and 170 000 spectral lines. For computing the optically thin coronal spectrum we use line of sight calculation in spherical symmetry, which allows us to correctly calculate the contribution of the corona to the irradiance spectrum. Inputs to our calculations are 1D atmosphere structures for the chromosphere and transition region for different solar surface features and different sets of coronal temperature structures for coronal features. We discuss the differences of the coronal structures and compare the synthetic UV/EUV spectra with observations such as the spectrum taken with the EVE rocket instrument on April 14, 2008 and the EUV spectrum taken with the SOLAR platform on the ISS.

  8. Synthesis and characterization of divalent metal complexes with ligand derived from the reaction of 3-aminopyridine and biacetyl

    Directory of Open Access Journals (Sweden)

    RAMESH KUMAR

    2006-09-01

    Full Text Available Divalent cobalt, nickel and copper salts reacted in situ with 3-aminopyridine and biacetyl to form complexes of the type: [M(Ap2biac2X2], where Ap2biac is the ligand and X=Cl, Br, NO3 or NCS. The complexes were analysed and characterized as distorted octahedral by conductance, molecular weight, magnetic, electronic and IR spectral studies. The electronic spectra were interpreted and tentative aassignments made. The infrared spectral studies revealed that two molecules of 3-aminopyridine were joined by molecules of biacetyl through a two carbon atom bridge and that the ligand coordinated through azomethine nitrogen atoms, whereas the pyridine nitrogen does not participate in the coordination. In the far infrared spectra, various metal–ligand vibrations were observed and are discussed.

  9. Metal complexes of ONO donor Schiff base ligand as a new class of bioactive compounds: synthesis, characterization and biological evolution.

    Science.gov (United States)

    Kumar Naik, K H; Selvaraj, S; Naik, Nagaraja

    2014-10-15

    Present work reviews that, the synthesis of (E)-N'-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide [L] ligand and their metal complexes. The colored complexes were prepared of type [M(2+)L]X2, where M(2+)=Mn, Co, Ni, Cu, Sr and Cd, L=(7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide, X=Cl(-). Ligand derived from the condensation of 8-formyl-7-hydroxy-4-methylcoumarin and benzohydrazide in the molar ratio 1:1 and in the molar ratio 1:2 for metal complexes have been prepared. The chelation of the ligand to metal ions occurs through the both oxygen groups, as well as the nitrogen atoms of the azomethine group of the ligand. Reactions of the Schiff base ligand with Manganese(II), Cobalt(II), Nickel(II), Copper(II), Strontium(II), and Cadmium(II) afforded the corresponding metal complexes. The structures of the obtained ligand and their respective metal complexes were elucidated by infra-red, elemental analysis, Double beam UV-visible spectra, conductometric measurements, magnetic susceptibility measurements and also thermochemical studies. The metal complex exhibits octahedral coordination geometrical arrangement. Schiff base ligand and their metal complexes were tested against antioxidants, antidiabetic and antimicrobial activities have been studied. The Schiff base metal complexes emerges effective α-glucosidase inhibitory activity than free Schiff base ligand.

  10. Metal complexes of ONO donor Schiff base ligand as a new class of bioactive compounds; Synthesis, characterization and biological evolution

    Science.gov (United States)

    Kumar Naik, K. H.; Selvaraj, S.; Naik, Nagaraja

    2014-10-01

    Present work reviews that, the synthesis of (E)-N";-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide [L] ligand and their metal complexes. The colored complexes were prepared of type [M2+L]X2, where M2+ = Mn, Co, Ni, Cu, Sr and Cd, L = (7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide, X = Cl-. Ligand derived from the condensation of 8-formyl-7-hydroxy-4-methylcoumarin and benzohydrazide in the molar ratio 1:1 and in the molar ratio 1:2 for metal complexes have been prepared. The chelation of the ligand to metal ions occurs through the both oxygen groups, as well as the nitrogen atoms of the azomethine group of the ligand. Reactions of the Schiff base ligand with Manganese(II), Cobalt(II), Nickel(II), Copper(II), Strontium(II), and Cadmium(II) afforded the corresponding metal complexes. The structures of the obtained ligand and their respective metal complexes were elucidated by infra-red, elemental analysis, Double beam UV-visible spectra, conductometric measurements, magnetic susceptibility measurements and also thermochemical studies. The metal complex exhibits octahedral coordination geometrical arrangement. Schiff base ligand and their metal complexes were tested against antioxidants, antidiabetic and antimicrobial activities have been studied. The Schiff base metal complexes emerges effective α-glucosidase inhibitory activity than free Schiff base ligand.

  11. Synthesis and spectral properties of near-infrared aminophenyl-, hydroxyphenyl-, and phenyl-substituted heptamethine cyanines.

    Science.gov (United States)

    Lee, Hyeran; Mason, J Christian; Achilefu, Samuel

    2008-01-18

    Diverse meso-aminophenyl-, hydroxyphenyl-, and phenyl-substituted heptamethine cyanine dyes were prepared by a modified Suzuki--Miyaura method in good yields. In addition, direct Suzuki coupling of Vilsmeier--Haack reagent extends the procedure to the synthesis of otherwise difficult cyanine dyes containing multiple heteroatoms in the indolium ring. The new compounds possess excellent spectral properties and can be used to label bioactive molecules and nanoparticles. The one-pot synthesis procedure eliminates the cumbersome steps of protecting/deprotecting amino or hydroxy groups.

  12. Synthesis, structures, and dearomatization by deprotonation of iron complexes featuring bipyridine-based PNN pincer ligands.

    Science.gov (United States)

    Zell, Thomas; Langer, Robert; Iron, Mark A; Konstantinovski, Leonid; Shimon, Linda J W; Diskin-Posner, Yael; Leitus, Gregory; Balaraman, Ekambaram; Ben-David, Yehoshoa; Milstein, David

    2013-08-19

    The synthesis and characterization of new iron pincer complexes bearing bipyridine-based PNN ligands is reported. Three phosphine-substituted pincer ligands, namely, the known (t)Bu-PNN (6-((di-tert-butylphosphino)methyl)-2,2'-bipyridine) and the two new (i)Pr-PNN (6-((di-iso-propylphosphino)methyl)-2,2'-bipyridine) and Ph-PNN (6-((diphenylphosphino)methyl)-2,2'-bipyridine) ligands were synthesized and studied in ligation reactions with iron(II) chloride and bromide. These reactions lead to the formation of two types of complexes: mono-chelated neutral complexes of the type [(R-PNN)Fe(X)2] and bis-chelated dicationic complexes of the type [(R-PNN)2Fe](2+). The complexes [(R-PNN)Fe(X)2] (1: R = (t)Bu, X = Cl, 2: R = (t)Bu, X = Br, 3: R = (i)Pr, X = Cl, and 4: R = (i)Pr, X = Br) are readily prepared from reactions of FeX2 with the free R-PNN ligand in a 1:1 ratio. Magnetic susceptibility measurements show that these complexes have a high-spin ground state (S = 2) at room temperature. Employing a 2-fold or higher excess of (i)Pr-PNN, diamagnetic hexacoordinated dicationic complexes of the type [((i)Pr-PNN)2Fe](X)2 (5: X = Cl, and 6: X = Br) are formed. The reactions of Ph-PNN with FeX2 in a 1:1 ratio lead to similar complexes of the type [(Ph-PNN)2Fe](FeX4) (7: X = Cl, and 8: X = Br). Single crystal X-ray studies of 1, 2, 4, 6, and 8 do not indicate electron transfer from the Fe(II) centers to the neutral bipyridine unit based on the determined bond lengths. Density functional theory (DFT) calculations were performed to compare the relative energies of the mono- and bis-chelated complexes. The doubly deprotonated complexes [(R-PNN*)2Fe] (9: R = (i)Pr, and 10: R = Ph) were synthesized by reactions of the dicationic complexes 6 and 8 with KO(t)Bu. The dearomatized nature of the central pyridine of the pincer ligand was established by X-ray diffraction analysis of single crystals of 10. Reactivity studies show that 9 and 10 have a slightly different behavior in

  13. Dynamic corner frequency in source spectral model for stochastic synthesis of ground motion

    Institute of Scientific and Technical Information of China (English)

    Xiaodan Sun; Xiaxin Tao; Guoxin Wang; Taojun Liu

    2009-01-01

    The static corner frequency and dynamic corner frequency in stochastic synthesis of ground motion from finite-fault modeling are introduced, and conceptual disadvantages of the two are discussed in this paper. Furthermore, the non-uniform radiation of seismic wave on the fault plane, as well as the trend of the larger rupture area, the lower corner frequency, can be described by the source spectral model developed by the authors. A new dynamic corner frequency can be developed directly from the model. The dependence of ground motion on the size of subfault can be eliminated if this source spectral model is adopted in the synthesis. Finally, the approach presented is validated from the comparison between the synthesized and observed ground motions at six rock stations during the Northridge earthquake in 1994.

  14. Noncommutative spectral synthesis for the involutive Banach algebra associated with a topological dynamical system

    CERN Document Server

    de Jeu, Marcel

    2012-01-01

    If X is a compact Hausdorff space, supplied with a homeomorphism, then a crossed product involutive Banach algebra is naturally associated with these data. If X consists of one point, then this algebra is the group algebra of the integers. In this paper, we study spectral synthesis for the closed ideals of this associated algebra in two versions, one modeled after C(X), and one modeled after the group algebra of the integers. We identify the closed ideals which are equal to (what is the analogue of) the kernel of their hull, and determine when this holds for all closed ideals, i.e., when spectral synthesis holds. In both models, this is the case precisely when the homeomorphism has no periodic points.

  15. Ligand-controlled Co-reduction versus electroless Co-deposition: synthesis of nanodendrites with spatially defined bimetallic distributions.

    Science.gov (United States)

    Ortiz, Nancy; Weiner, Rebecca G; Skrabalak, Sara E

    2014-12-23

    The predictable synthesis of bimetallic nanostructures via co-reduction of two metal precursors is challenging due to our limited understanding of precursor ligand effects. Here, the influence of different metal-ligand environments is systematically examined in the synthesis of Pd-Pt nanostructures as a model bimetallic system. Nanodendrites with different spatially defined Pd-Pt compositions are achieved, where the local ligand environments of metal precursors dictate if temporally separated co-reduction dominates to achieve core-shell nanostructures or whether electroless co-deposition proceeds to facilitate alloyed nanostructure formation. As the properties of bimetallic nanomaterials depend on crystal ordering and composition, chemical routes to structurally defined bimetallic nanomaterials are critically needed. The approaches reported here should be applicable to other bimetallic compositions given the established reactivity of coordination complexes available for use as precursors.

  16. Fast synthesis of dopamine-coated Fe3O4 nanoparticles through ligand-exchange method

    Institute of Scientific and Technical Information of China (English)

    Peng An; Fang Zuo; Yuan Peng Wu; Jun Hua Zhang; Zhao Hui Zheng; Xiao Bin Ding; Yu Xing Peng

    2012-01-01

    A fast approach was described for the synthesis of water-dispersible monodisperse dopamine-coated Fe3O4 nanoparticles (DA-Fe3O4) with uniform size and shape via ligand-exchange of oleic acid on Fe3O4 using only 2 min.The prepared DA-Fe3O4 nanoparticles were characterized by transmission electron microscopy,Fourier transform infrared spectrometry,and vibrating sample magnetometer.The results indicated that the resulting DA-Fe3O4 nanoparticles had an average diameter of about 19.2 nm.The magnetic saturation value of the prepared DA-Fe3O4 nanoparticles was determined to be 72.87 emu/g,which indicating a wellestablished superparamagnetic property.

  17. Synthesis and biological evaluation of new opioid agonist and neurokinin-1 antagonist bivalent ligands.

    Science.gov (United States)

    Vardanyan, Ruben; Kumirov, Vlad K; Nichol, Gary S; Davis, Peg; Liktor-Busa, Erika; Rankin, David; Varga, Eva; Vanderah, Todd; Porreca, Frank; Lai, Josephine; Hruby, Victor J

    2011-10-15

    Newly designed bivalent ligands-opioid agonist/NK1-antagonists have been synthesized. The synthesis of new starting materials-carboxy-derivatives of Fentanyl (1a-1c) was developed. These products have been transformed to 'isoimidium perchlorates' (2a-c). The new isoimidium perchlorates have been successfully implemented in nucleophilic addition reactions, with l-tryptophan 3,5-bis(trifluoromethyl)benzyl ester to give the target compounds-amides (3a-c). Perchlorates (2a-c) successfully undergo reactions with other nucleophiles such as alcohols, amines or hydrazines. The obtained compound 3b exhibited μ-opioid agonist activity and NK1-antagonist activity and may serve as a useful lead compound for the further design of a new series of opioid agonist/NK1-antagonist compounds.

  18. Synthesis of the sup 11 C-labelled. beta. -adrenergic receptor ligands atenolol, metoprolol and propanolol

    Energy Technology Data Exchange (ETDEWEB)

    Antoni, G.; Ulin, J.; Laangstroem, B. (Uppsala Univ. (Sweden). Dept. of Organic Chemistry)

    1989-01-01

    The {sup 11}C-labelled {beta}-adrenergic receptor ligands atenolol 1, metoprolol 2 and propranolol 3 have been synthesized by an N-alkylation reaction using (2-{sup 11}C)isopropyl iodide. The labelled isopropyl iodide was prepared in a one-pot reactor system from ({sup 11}C)carbon dioxide and obtained in 40% radiochemical yield within 14 min reaction time. The total reaction times for compounds 1-3, counted from the start of the isopropyl iodide synthesis and including purification were 45-55 min. The products were obtained in 5-15% radiochemical yields and with radiochemical purities higher than 98%. The specific activity ranged from 0.4 to 4 GBq/{mu}mol. In a typical experiment starting with 4 GBq around 75 MBq of product was obtained. (author).

  19. Single-molecule synthesis and characterization of metal-ligand complexes by low-temperature STM.

    Science.gov (United States)

    Liljeroth, Peter; Swart, Ingmar; Paavilainen, Sami; Repp, Jascha; Meyer, Gerhard

    2010-07-14

    We present scanning tunneling microscopy (STM)-based single-molecule synthesis of linear metal-ligand complexes starting from individual metal atoms (iron or nickel) and organic molecules (9,10-dicyanoanthracene) deposited on an ultrathin insulating film. We directly visualize the frontier molecular orbitals by STM orbital imaging, from which, in conjunction with detailed density functional theory calculations, the electronic structure of the complexes is inferred. Our studies show how the order of the molecular orbitals and the spin-state of the complex can be engineered through the choice of the metal atom. The high-spin iron complex has a singly occupied delocalized orbital with a large spin-splitting that points to the use of these engineered complexes as modular building blocks in molecular spintronics.

  20. Synthesis, Crystal Structures and Spectral Properties of Two New Cobalt Complexes of Tripodal Ligand with Oxalate and Thiocyanate%两个含草酸根及硫氰酸根的新型三脚架钴(Ⅱ)配合物的合成、晶体结构及光谱性质

    Institute of Scientific and Technical Information of China (English)

    张智慧; 陆艳春; 杨海龙; 汤宇

    2005-01-01

    本文合成了两个新型Co(Ⅱ)配合物,[LCo(μ-C2O4)CoL]·(ClO4)2·2CH3CN(1)和[CoL(SCN)]·ClO4(2),其中,L即三(3,5-二甲基吡唑甲基)胺.在配合物1中,Co与来自三脚架配体的4个氮和草酸根桥联配体的2个氧原子配位,处于扭曲八面体配位环境.由草酸根桥联两套LCo,构成了一个双核结构.在单核配合物2中,Co(Ⅱ)处于三角双锥配位构型,SCN-通过N配位与中心离子Co(Ⅱ)键联.在同一晶胞中有两个构型略微不同的分子,两个分子之间通过SCN的S原子有弱相互作用.对化合物1和2在溶液中的光谱性质做了进一步的研究和讨论.%Two novel cobalt complexes, [LCo(μ-oxalate)CoL)·(ClO4)2· 2CH3CN (1) and [CoL(SCN)]·ClO4 (2) havebeen synthesized, and their structures have been determined by X-ray crystallography, where L is tris[(3,5-dimethylpyrazol-l-yl)methyl]amine. In compound 1, Co(Ⅱ) is in a distorted octahedron environment with four nitro-gen atoms from the tripodal ligand and two oxygen atoms from the bridged oxalate, and the molecule is a dimmer-ic structure consisting of two LCo unites linked by bridging oxalate. In the monomer 2, Co(Ⅱ) center is in trigonalbipyrimad coordination configuration, a thiocyanate group is bonded to the metal center through the nitrogenatom. There are two somewhat different configurations of 2 in the unit cell, and there is a weaker interaction be-tween two molecules of 2 at sulphur atoms. The title complexes were generated by a precursor mononuclear cobaltCCDC: 244798, 1; 244799, 2.

  1. Synthesis and spectroscopic behavior of highly luminescent trinuclear europium complexes with tris-β-diketone ligand

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dunjia, E-mail: dunjiawang@163.com; Pi, Yan; Liu, Hua; Wei, Xianhong; Hu, Yanjun; Zheng, Jing

    2014-11-15

    Highlights: • Synthesis of the tris-β-diketone ligand and its trinuclear europium complexes. • Photoluminescence behavior of trinuclear europium complexes. • Analysis of the Judd–Ofelt intensity parameters (Ω{sub t}), lifetime (τ) and quantum yield (η). - Abstract: A new tris-β-diketone ligand, 2-[4,6-bis-(1-benzoyl-2-oxo-2-phenyl-ethyl)-[1,3,5]triazin-2-yl] -1,3-diphenyl-propane-1,3-dione (H{sub 3}L), and its trinuclear europium complexes, Eu{sub 3}(DBM){sub 6}L (C1), Eu{sub 3}(DBM){sub 6}(Bipy){sub 3}L (C2) and Eu{sub 3}(DBM){sub 6}(Phen){sub 3}L (C3) were synthesized and their spectroscopic behaviors were studied by FT-IR, {sup 1}H NMR, UV–vis and photoluminescence spectroscopic techniques. These europium complexes exhibited the characteristic emission bands that arise from the {sup 5}D{sub 0} → {sup 7}F{sub J} (J = 0–4) transitions of the europium ion in solid state. The Ω{sub 2} and Ω{sub 4} intensity parameters, lifetime (τ) and luminescence quantum yield (η) were calculated according to the emission spectra and luminescence decay curves in solid state. The results indicated that these trinuclear europium complexes displayed a longer lifetime (τ) and higher luminescence quantum efficiency (η), especially complexes C2 (τ = 0.820 ms, η = 46.5%) and C3 (τ = 0.804 ms, η = 47.4%), which due to the effect of two additional europium ion lumophors and the introduction of the third ligands, Bipy or Phen in trinuclear complexes. Their Ω{sub 2} values demonstrated that the europium ion in these complexes is in a highly polarizable chemical environment.

  2. Ligand-induced fate of embryonic species in the shape-controlled synthesis of rhodium nanoparticles.

    Science.gov (United States)

    Biacchi, Adam J; Schaak, Raymond E

    2015-02-24

    The shapes of noble metal nanoparticles directly impact their properties and applications, including in catalysis and plasmonics, and it is therefore important to understand how multiple distinct morphologies can be controllably synthesized. Solution routes offer powerful capabilities for shape-controlled nanoparticle synthesis, but the earliest stages of the reaction are difficult to interrogate experimentally and much remains unknown about how metal nanoparticle morphologies emerge and evolve. Here, we use a well-established polyol process to synthesize uniform rhodium nanoparticle cubes, icosahedra, and triangular plates using bromide, trifluoroacetate, and chloride ligands, respectively. In all of these systems, we identified rhodium clusters with diameters of 1-2 nm that form early in the reactions. The colloidally stable metal cluster intermediates served as a stock solution of embryonic species that could be transformed predictably into each type of nanoparticle morphology. The anionic ligands that were added to the embryonic species determined their eventual fate, e.g., the morphologies into which they would ultimately evolve. Extensive high-resolution transmission electron microscopy experiments revealed that the growth pathway-monomer addition, coalescence, or a combination of the two-was different for each of the morphologies, and was likely controlled by the interactions of each specific anionic adsorbate with the embryonic species. Similar phenomena were observed for related palladium and platinum nanoparticle systems. These studies provide important insights into how noble metal nanoparticles nucleate, the pathways by which they grow into several distinct morphologies, and the imperative role of the anonic ligand in controlling which route predominates in a particular system.

  3. Laser synthesis of ligand-free bimetallic nanoparticles for plasmonic applications.

    Science.gov (United States)

    Intartaglia, R; Das, G; Bagga, K; Gopalakrishnan, A; Genovese, A; Povia, M; Di Fabrizio, E; Cingolani, R; Diaspro, A; Brandi, F

    2013-03-07

    A picosecond laser ablation approach has been developed for the synthesis of ligand-free AuAg bimetallic NPs where the relative amount of Ag is controlled in situ through a laser shielding effect. Various measurements, such as optical spectroscopy, transmission electron microscopy combined with energy dispersive X-ray spectroscopy and inductively coupled plasma optical emission spectrometry, revealed the generation of homogenous 15 nm average size bimetallic NPs with different compositions and tunable localized surface plasmon resonance. Furthermore, ligand-free metallic nanoparticles with respect to chemically synthesized nanoparticles display outstanding properties, i.e. featureless Raman background spectrum, which is a basic requirement in many plasmonic applications such as Surface Enhanced Raman Spectroscopy. Various molecules were chemisorbed on the nanoparticle and SERS investigations were carried out, by varying the laser wavelength. The SERS enhancement factor for AuAg bimetallic NPs shows an enhancement factor of about 5.7 × 10(5) with respect to the flat AuAg surface.

  4. Polarisation Spectral Synthesis For Type Ia Supernova Explosion Models

    Science.gov (United States)

    Bulla, Mattia

    2017-02-01

    provide a clear distinction. In particular, we find that one model is too strongly asymmetric and produces polarisation levels that are too high and clearly inconsistent with those detected for the bulk of Type Ia supernovae. Polarisation signals – and their time evolution – extracted for the remaining two models are instead in good agreement with the currently available spectropolarimetry data. Providing a powerful way to connect hydrodynamic explosion models to observed data, the study presented in this thesis is an important step towards a better understanding of Type Ia supernovae from a synthesis of theory and observations.

  5. Semi-empirical analysis of SDSS galaxies: I. Spectral synthesis method

    CERN Document Server

    Fernandes, R C; Sodré, L; Stasinska, G; Gomes, J M

    2004-01-01

    In this paper we investigate the power of spectral synthesis as a mean to estimate physical properties of galaxies. Spectral synthesis is nothing more than the decomposition of an observed spectrum in terms of a superposition of a base of simple stellar populations of various ages and metallicities, producing as output the star-formation and chemical histories of a galaxy, its extinction and velocity dispersion. Our implementation of this method uses the Bruzual & Charlot (2003) models and observed spectra in the 3650--8000 \\AA range. The reliability of this approach is studied by three different means: (1) simulations, (2) comparison with previous work based on a different technique, and (3) analysis of the consistency of results obtained for a sample of galaxies from the SDSS. We find that spectral synthesis provides reliable physical parameters as long as one does not attempt a very detailed description of the star-formation and chemical histories. We show that besides providing excellent fits to obser...

  6. 一些含杂环配体的过渡金属配合物的微波合成、光谱、热化学性质和生物活性%Microwave Synthesis, Spectral, Thermal and Biological Significance of Some Transition Metal Complexes Containing Heterocyclic Ligands

    Institute of Scientific and Technical Information of China (English)

    Jain Rajendra K; Mishra A P

    2012-01-01

    Some new Schiff base complexes of Cr(Ⅲ),Co(Ⅱ),Ni(Ⅱ) and Cu(Ⅱ) derived from 5-chlorosalicylaldehyde with 2-amino-5-nitrothiazole (L1H) and 4-chlorobenzaldehyde with 2-amino-3-hydroxypyridine (L2H) have been synthesized by conventional as well as microwave methods.These compounds have been characterized by elemental analysis,FTIR,FAB-mass,molar conductance,electronic spectra,1H-NMR,ESR,magnetic susceptibility,thermal,electrical conductivity and XRD analysis.The complexes are coloured and stable in air.Analytical data reveal that all the complexes exhibit 1∶2 (metal∶ligand) ratio with coordination number of 4 or 6.FAB-mass and thermal data show degradation pattern of the complexes.XRD patterns indicate crystalline nature for the complexes.The Schiff base and metal complexes show a good activity against the Gram-positive bacteria:Staphylococcus aureus and Gramnegative bacteria:Escherichia coli and fungi:Aspergillus niger and Candida albicans.%用5-氯邻羟苯甲醛与2-氨基-5-硝基噻唑(L1H)和4-氯苯甲醛与2-氨基-3-羟基吡啶(L2H)的反应,再用传统和微波方法将生成物与Cr(Ⅲ),Co(Ⅱ),Ni(Ⅱ)和Cu(Ⅱ)合成了一些席夫碱配合物.用元素分析,FTIR,快原子轰击质谱,摩尔电导率,电子光谱,1H-NMR,ESR,磁化率,热分析,电导率和XRD等对这些化合物进行了表征.这些配合物在空气中稳定并有颜色.分析数据表明所有配合物金属与配体的比均为1∶2,配位数为4或6.原子轰击质谱和热分析数据说明了这些配合物的降解方式.XRD图给出了这些配合物的结晶情况.席夫碱的上述金属配合物对革兰氏阳性菌:金黄色葡萄球菌和革兰氏阴性菌:大肠埃希菌(大肠杆菌)和真菌:黑曲霉和白色念珠菌显示出良好的抗菌活性.

  7. Synthesis, Characterisation, Spectral and Microbial Studies of Transition Metal Complexes of the Drug, Secnidazole

    Directory of Open Access Journals (Sweden)

    Aradhana Verma

    2010-01-01

    Full Text Available 5-Chloromethyl-8-quinolinol hydrochloride was condensed with 1-(2-methyl-5-nitro-1H-imidazol-1-ylpropan-2-ol in presence of potassium carbonate. The resulting 5-((1-(2-methyl-5-nitro-1H-imidazol-1-ylpropan-2-yloxymethylquinolin-8-ol was characterized by elemental analysis and spectral studies. The transition metal chelates of the same were prepared with Cu2+, Ni2+, Co2+, Mn2+ and Zn2+ and characterized by IR and electronic spectral studies and magnetic properties. The antimicrobial activity of ligand and its metal chelates were screened against various gram positive and gram negative organisms. The results show that all these samples are more or less active agents against various organisms.

  8. Synthesis, structure, photophysical and catalytic properties of CuI-Iodide complexes of di-imine ligands

    Science.gov (United States)

    Mondal, Jahangir; Ghorai, Anupam; Singh, Sunil K.; Saha, Rajat; Patra, Goutam K.

    2016-03-01

    Two new multifunctional CuII based complexes [CuI(L1)] (1) and [Cu2(μ-I)2(L2)] (2) with bidentate N-N donor ligands L1 and imino-pyridyl ligand L2 have been synthesized and characterized by elemental analysis, IR, UV-Vis, NMR and single crystal X-ray crystallography. The bidentate di-imine ligand (L1) forms monomeric CuI complex (1) whereas the bis-bidentate di-imine ligand (L2) favours the formation of dimeric CuI complex (2) in association with two bridging iodides. Structural analysis reveals that in complex 1 each monomeric units are connected by π⋯π and C-H⋯π interactions to form 3D supramolecular structure whereas in complex 2 each molecules are connected by only π⋯π interactions to form 3D supramolecular structure. The photoluminescence properties of the complexes have been studied at room temperature. Theoretical analysis shows that HOMO is focused on the Cu and iodides while LUMO is focused on di-imine ligands and the luminescence behaviour arises due to metal to ligand charge transfer (MLCT) and halide to ligand charge transfer (XLCT). The complexes 1 and 2 are effective catalysts for the synthesis of 2-substituted benzoxazoles.

  9. Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: Spectral, thermal, molecular modelling and mycological studies

    Science.gov (United States)

    Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

    2014-01-01

    Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L = 2-acetyl thiophene thiosemicarbazone and X = Cl- and NO3-]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum.

  10. Synthesis and ligand-based reduction chemistry of boron difluoride complexes with redox-active formazanate ligands

    NARCIS (Netherlands)

    Chang, M. -C.; Otten, E.

    2014-01-01

    Mono(formazanate) boron difluoride complexes (LBF2), which show remarkably facile and reversible ligand-based redox-chemistry, were synthesized by transmetallation of bis(formazanate) zinc complexes with boron trifluoride. The one-electron reduction product [LBF2](-)[Cp2Co](+) and a key intermediate

  11. Synthesis, characterization, and photophysical and electroluminescent properties of blue-emitting cationic iridium(III) complexes bearing nonconjugated ligands.

    Science.gov (United States)

    Zhang, Fuli; Ma, Dongxin; Duan, Lian; Qiao, Juan; Dong, Guifang; Wang, Liduo; Qiu, Yong

    2014-07-07

    The development of pure-blue-to-deep-blue-emitting ionic phosphors is an ultimate challenge for full-color displays and white-light sources. Herein we report two series of short-wavelength light-emitting cationic iridium(III) complexes with nonconjugated ancillary and cyclometalating ligands, respectively. In the first series, nonconjugated 1-[(diphenylphosphino)methyl]-3-methylimidazolin-2-ylidene-C,C2' (dppmmi) is used as the ancillary ligand and 2-phenylpyridine (ppy), 2-(2,4-difluorophenyl)pyridine (dfppy), and 1-(2,4-difluorophenyl)-1H-pyrazole (dfppz) are used as cyclometalating ligands. In the second one, nonconjugated 2,4-difluorobenzyl-N-pyrazole (dfbpz) is used as the cyclometalating ligand and 3-methyl-1-(2-pyridyl)benzimidazolin-2-ylidene-C,C(2)' (pymbi) as the ancillary ligand. The synthesis and photophysical and electrochemical properties, together with the X-ray crystal structures of these complexes, have been investigated. At room temperature, blue-emitting complexes [Ir(ppy)2(dppmmi)]PF6 (1) and [Ir(dfppy)2(dppmmi)]PF6 (2; PF6(-) is hexafluorophosphate) show much larger photoluminescence quantum yields of 24% and 46%, respectively. On the contrary, for complexes [Ir(dfppz)2(dppmmi)]PF6 (3) and [Ir(dfbpz)2(pymbi)]PF6 (4), deep-blue luminescence is only observed at low temperature (77 K). Density functional theory calculations are used to rationalize the differences in the photophysical behavior observed upon changes of the ligands. It is shown that the electronic transition dipoles of cationic iridium complexes 1 and 2 are mainly confined to cyclometalated ligands ((3)MLCT and LC (3)π-π*) and those of complex 3 are confined to all of the ligands ((3)MLCT, LC (3)π-π*, and (3)LLCT) because of the high LUMO energy level of dfppz. The emission of 4 mainly originates from the central iridium(III) ion and cyclometalated ligand to ancillary ligand charge transfer ((3)MLCT and (3)LLCT), in contrast to commonly designed cationic complexes using carbene

  12. Combining on-chip synthesis of a focused combinatorial library with computational target prediction reveals imidazopyridine GPCR ligands.

    Science.gov (United States)

    Reutlinger, Michael; Rodrigues, Tiago; Schneider, Petra; Schneider, Gisbert

    2014-01-07

    Using the example of the Ugi three-component reaction we report a fast and efficient microfluidic-assisted entry into the imidazopyridine scaffold, where building block prioritization was coupled to a new computational method for predicting ligand-target associations. We identified an innovative GPCR-modulating combinatorial chemotype featuring ligand-efficient adenosine A1/2B and adrenergic α1A/B receptor antagonists. Our results suggest the tight integration of microfluidics-assisted synthesis with computer-based target prediction as a viable approach to rapidly generate bioactivity-focused combinatorial compound libraries with high success rates.

  13. Pt(II) diimine complexes bearing carbazolyl-capped acetylide ligands: synthesis, tunable photophysics and nonlinear absorption.

    Science.gov (United States)

    Liu, Rui; Chen, Hongbin; Chang, Jin; Li, Yuhao; Zhu, Hongjun; Sun, Wenfang

    2013-01-01

    A series of new Pt(II) diimine complexes with different carbazolyl-capped acetylide ligands (Pt-1–Pt-5) were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. All complexes exhibit ligand-centered 1π,π* transitions in the UV region, and broad, structureless metal-to-ligand charge transfer (1MLCT)/ligand-to-ligand charge transfer (1LLCT) absorption bands in the visible spectral region. All complexes are emissive in solution at room temperature, with the emitting state being tentatively assigned to the 3MLCT/3LLCT states for Pt-1–Pt-4, and the emitting state of Pt-5 exhibiting a switch from the 3π,π* state in high-polarity solvents to the 3MLCT state in low-polarity solvents. Complexes Pt-1–Pt-5 all exhibit moderate triplet transient absorption (TA) from the visible to the NIR region, where reverse saturable absorption (RSA) could occur. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these Pt complexes can be tuned drastically by the carbazolyl-capped acetylide ligand, which would be useful for rational design of transition-metal complexes with high emission quantum yield, long excited-state lifetime, broadband excited-state absorption, and strong nonlinear transmittance for organic light-emitting and/or broadband nonlinear transmission applications.

  14. Mixed-ligand complexes of ruthenium(II) incorporating a diazo ligand: Synthesis, characterization and DNA binding

    Indian Academy of Sciences (India)

    Megha S Deshpande; Avinash S Kumbhar

    2005-03-01

    Mixed-ligand complexes of the type [Ru(N-N)2(dzdf)]Cl2, where N-N is 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen) and 9-diazo-4,5-diazafluorene (dzdf), have been synthesized and characterized by elemental analysis, UV-Vis, IR and NMR spectroscopy. Binding of these complexes with calf thymus DNA (CT-DNA) has been investigated by absorption spectroscopy, steady-state emission spectroscopy and viscosity measurements. The experimental results indicate that the size and shape of the intercalating ligands have marked effect on the binding affinity of the complexes to CT-DNA. The complex [Ru(phen)2(dzdf)]Cl2 binds with CT-DNA through an intercalative binding mode, while the complex [Ru(bpy)2(dzdf)]Cl2 binds electrostatically.

  15. Synthesis of nanoparticle/ligand composite thin films by sequential ligand self assembly and surface complex reduction.

    Science.gov (United States)

    Muench, Falk; Fuchs, Anne; Mankel, Eric; Rauber, Markus; Lauterbach, Stefan; Kleebe, Hans-Joachim; Ensinger, Wolfgang

    2013-01-01

    Nanocomposite thin films consisting of ligand-connected metal nanoparticles were deposited by iteration of ligand assembly, surface complex formation and reduction. This novel and convenient approach combines characteristics of the layer-by-layer (LbL) and the successive ion layer adsorption and reaction (SILAR) techniques. In contrast to classical LbL assembly, the nanoparticle formation is performed in situ, avoiding separate reduction, protection and attachment steps. To demonstrate the versatility of the approach, different metal precursors (Pd, Ag and Au salts) and linkers (1,2-ethanedithiol, 1,4-benzenedithiol and polythiol) were applied. The formation of dithiol-linked nanoparticle films was confirmed by TEM and XPS. By combining the deposition protocol with ion track etched polycarbonate templates, nanotubes and nanowires with high aspect ratios of up to 300 could be fabricated.

  16. Resolving galaxies in time and space: II: Uncertainties in the spectral synthesis of datacubes

    CERN Document Server

    Fernandes, R Cid; Benito, R Garcia; Perez, E; de Amorim, A L; Sanchez, S F; Husemann, B; Barroso, J Falcon; Lopez-Fernandez, R; Sanchez-Blazquez, P; Asari, N Vale; Vazdekis, A; Walcher, C J; Mast, D

    2013-01-01

    In a companion paper we have presented many products derived from the application of the spectral synthesis code STARLIGHT to datacubes from the CALIFA survey, including 2D maps of stellar population properties and 1D averages in the temporal and spatial dimensions. Here we evaluate the uncertainties in these products. Uncertainties due to noise and spectral shape calibration errors and to the synthesis method are investigated by means of a suite of simulations based on 1638 CALIFA spectra for NGC 2916, with perturbations amplitudes gauged in terms of the expected errors. A separate study was conducted to assess uncertainties related to the choice of evolutionary synthesis models. We compare results obtained with the Bruzual & Charlot models, a preliminary update of them, and a combination of spectra derived from the Granada and MILES models. About 100k CALIFA spectra are used in this comparison. Noise and shape-related errors at the level expected for CALIFA propagate to 0.10-0.15 dex uncertainties in st...

  17. Oxygen spectral line synthesis: 3D non-LTE with CO5BOLD hydrodynamical model atmospheres

    CERN Document Server

    Prakapavicius, D; Kucinskas, A; Ludwig, H -G; Freytag, B; Caffau, E; Cayrel, R

    2013-01-01

    In this work we present first results of our current project aimed at combining the 3D hydrodynamical stellar atmosphere approach with non-LTE (NLTE) spectral line synthesis for a number of key chemical species. We carried out a full 3D-NLTE spectrum synthesis of the oxygen IR 777 nm triplet, using a modified and improved version of our NLTE3D package to calculate departure coefficients for the atomic levels of oxygen in a CO5BOLD 3D hydrodynamical solar model atmosphere. Spectral line synthesis was subsequently performed with the Linfor 3D code. In agreement with previous studies, we find that the lines of the oxygen triplet produce deeper cores under NLTE conditions, due to the diminished line source function in the line forming region. This means that the solar oxygen IR 777 nm lines should be stronger in NLTE, leading to negative 3D NLTE-LTE abundance corrections. Qualitatively this result would support previous claims for a relatively low solar oxygen abundance. Finally, we outline several further steps ...

  18. Synthesis and Optical Characterization of Mixed Ligands Beryllium Complexes for Display Device Applications

    Directory of Open Access Journals (Sweden)

    Vandna Nishal

    2015-01-01

    Full Text Available Synthesis and photoluminescent behaviour of mixed ligand based beryllium complexes with 2-(2-hydroxyphenylbenzoxazole (HPB and 5-chloro-8-hydroxyquinoline (Clq or 5,7-dichloro-8-hydroxyquinoline (Cl2q or 2-methyl-8-hydroxyquinoline (Meq or 8-hydroxyquinoline (q are reported in this work. These complexes, that is, [BeHPB(Clq], [BeHPB(Cl2q], [BeHPB(Meq], and [BeHPB(q], were prepared and their structures were confirmed by elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and thermal analysis. The beryllium complexes exhibited good thermal stability up to ~300°C temperature. The photophysical properties of beryllium complexes were studied using ultraviolet-visible absorption and photoluminescence emission spectroscopy. The complexes showed absorption peaks due to π-π∗ and n-π∗ electronic transitions. The complexes emitted greenish blue light with peak wavelength at 496 nm, 510 nm, 490 nm, and 505 nm, respectively, consisting of high intensity. Color tuning was observed with changing the substituents in quinoline ring ligand in metal complexes. The emitted light had Commission Internationale d’Eclairage color coordinates values at x=0.15 and y=0.43 for [BeHPB(Clq], x=0.21 and y=0.56 for [BeHPB(Cl2q], x=0.14 and y=0.38 for [BeHPB(Meq], x=0.17 and y=0.41 for [BeHPB(q]. Theoretical calculations using DFT/B3LYP/6-31G(d,p method were performed to reveal the three-dimensional geometries and the frontier molecular orbital energy levels of these synthesized metal complexes.

  19. Discrete and polymeric Cu(II) complexes featuring substituted indazole ligands: their synthesis and structural chemistry.

    Science.gov (United States)

    Hawes, Chris S; Kruger, Paul E

    2014-11-21

    Reported here are the syntheses of four indazole-based ligands and the structural characterisation of four Cu(II) complexes derived from them. The ligands 1-(2-pyridyl)-1H-indazole, L1, and 2-(2-pyridyl)-2H-indazole, L2, have been characterised by single crystal X-ray diffraction methods for the first time. The intramolecular structural changes within L1 and L2 that result from the transition from the 1H to the 2H electronic configuration have been delineated. The synthesis of 1H-indazole-6-carboxylic acid, H2L3, and 1H-indazole-7-carboxylic acid, H2L4, is fully described and the structure of H2L4·H2O determined. The structures of two discrete mononuclear complexes {[Cu(L1)2(NO3)]·NO3·1.5H2O}, 1, and {[Cu(L2)2(NO3)]·NO3}, 2, have been determined and their molecular compositions corroborated by solution-based methods. Reaction of Cu(II) with H2L3 generates a 2D coordination polymer, [Cu3(HL3)4(NO3)2(EtOH)2]·3(C6H6)·2(H2O), 3, that features the archetypal [Cu2(OAc)4] paddlewheel motif and 1D channels; whereas reaction with H2L4 gives a discrete complex [Cu(HL4)2]·H2O·MeOH, 4, in which hydrogen bonding interactions link indazole dimers via a water molecule to yield a 1D network.

  20. Spectrum synthesis for a spectrally tunable light source based on a DMD-convex grating Offner configuration

    Science.gov (United States)

    Ma, Suodong; Pan, Qiao; Shen, Weimin

    2016-09-01

    As one kind of light source simulation devices, spectrally tunable light sources are able to generate specific spectral shape and radiant intensity outputs according to different application requirements, which have urgent demands in many fields of the national economy and the national defense industry. Compared with the LED-type spectrally tunable light source, the one based on a DMD-convex grating Offner configuration has advantages of high spectral resolution, strong digital controllability, high spectrum synthesis accuracy, etc. As a key link of the above type light source to achieve target spectrum outputs, spectrum synthesis algorithm based on spectrum matching is therefore very important. An improved spectrum synthesis algorithm based on linear least square initialization and Levenberg-Marquardt iterative optimization is proposed in this paper on the basis of in-depth study of the spectrum matching principle. The effectiveness of the proposed method is verified by a series of simulations and experimental works.

  1. Nonlinear inverse synthesis for high spectral efficiency transmission in optical fibers

    CERN Document Server

    Le, Son Thai; Turitsyn, Sergei K

    2014-01-01

    In linear communication channels, spectral components (modes) defined by the Fourier transform of the signal propagate without interactions with each other. In certain nonlinear channels, such as the one modelled by the classical nonlinear Schr\\"odinger equation, there are nonlinear modes (nonlinear signal spectrum) that also propagate without interacting with each other and without corresponding nonlinear cross talk; effectively, in a linear manner. Here, we describe in a constructive way how to introduce such nonlinear modes for a given input signal. We investigate the performance of the nonlinear inverse synthesis (NIS) method, in which the information is encoded directly onto the continuous part of the nonlinear signal spectrum. This transmission technique, combined with the appropriate distributed Raman amplification, can provide an effective eigenvalue division multiplexing with high spectral efficiency, thanks to highly suppressed channel cross talk. The proposed NIS approach can be integrated with any...

  2. New Synthesis and Tritium Labeling of a Selective Ligand for Studying High-affinity γ-Hydroxybutyrate (GHB) Binding Sites

    Science.gov (United States)

    Vogensen, Stine B.; Marek, Aleš; Bay, Tina; Wellendorph, Petrine; Kehler, Jan; Bundgaard, Christoffer; Frølund, Bente; Pedersen, Martin H.F.; Clausen, Rasmus P.

    2013-01-01

    3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [3H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide. Screening of 1 against different CNS targets establishes a high selectivity and we demonstrate in vivo brain penetration. In vitro characterization of [3H]-1 binding shows high specificity to the high-affinity GHB binding sites. PMID:24053696

  3. New synthesis and tritium labeling of a selective ligand for studying high-affinity γ-hydroxybutyrate (GHB) binding sites.

    Science.gov (United States)

    Vogensen, Stine B; Marek, Aleš; Bay, Tina; Wellendorph, Petrine; Kehler, Jan; Bundgaard, Christoffer; Frølund, Bente; Pedersen, Martin H F; Clausen, Rasmus P

    2013-10-24

    3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [(3)H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide. Screening of 1 against different CNS targets establishes a high selectivity, and we demonstrate in vivo brain penetration. In vitro characterization of [(3)H]-1 binding shows high specificity to the high-affinity GHB binding sites.

  4. New Synthesis and Tritium Labeling of a Selective Ligand for Studying High-Affinity γ-Hydroxybutyrate (GHB) Binding Sites

    DEFF Research Database (Denmark)

    Vogensen, Stine B.; Marek, Ales; Bay, Tina

    2013-01-01

    3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [3H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide....... Screening of 1 against different CNS targets establishes a high selectivity, and we demonstrate in vivo brain penetration. In vitro characterization of [3H]-1 binding shows high specificity to the high-affinity GHB binding sites....

  5. Multistep continuous-flow synthesis in medicinal chemistry: discovery and preliminary structure-activity relationships of CCR8 ligands.

    Science.gov (United States)

    Petersen, Trine P; Mirsharghi, Sahar; Rummel, Pia C; Thiele, Stefanie; Rosenkilde, Mette M; Ritzén, Andreas; Ulven, Trond

    2013-07-08

    A three-step continuous-flow synthesis system and its application to the assembly of a new series of chemokine receptor ligands directly from commercial building blocks is reported. No scavenger columns or solvent switches are necessary to recover the desired test compounds, which were obtained in overall yields of 49-94%. The system is modular and flexible, and the individual steps of the sequence can be interchanged with similar outcome, extending the scope of the chemistry. Biological evaluation confirmed activity on the chemokine CCR8 receptor and provided initial structure-activity-relationship (SAR) information for this new ligand series, with the most potent member displaying full agonist activity with single-digit nanomolar potency. To the best of our knowledge, this represents the first published example of efficient use of multistep flow synthesis combined with biological testing and SAR studies in medicinal chemistry.

  6. Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.-F., E-mail: wgf1979@126.com, E-mail: s-shuwen@163.com [Yuncheng University, Department of Applied Chemistry (China); Zhang, X., E-mail: zhangx@hit.edu.cn [Harbin Institute of Technology, Academy of Fundamental and Interdisciplinary Science (China); Sun, S.-W.; Sun, H.; Ma, H.-X. [Yuncheng University, Department of Applied Chemistry (China)

    2015-12-15

    The synthesis and characterization of two new halfsandwich mononuclear nickel(II) complexes with the scorpionate ligands, [k{sup 3}-N, N',N''-Tp{sup t-Bu}, {sup Me}NiI] (1) and [k{sup 3}-N,N',N''-Tp{sup t-Bu}, {sup Me}NiNO{sub 3}] (2), are reported. These complexes have been fully characterized by elemental analyses and infrared spectra. Their molecular structures were determined by single crystal X-ray diffraction. The nickel(II) ion of complex 1 is in a four-coordinate environment, in which the donor atoms are provided by three nitrogen atoms of a hydrotris(pyrazolyl) borate ligand and one iodide atom, while that of complex 2 is in a five-coordinate environment with three nitrogen atoms from a hydrotris(pyrazolyl)borate ligand and two oxygen atoms from a nitrate ion.

  7. Spectral analysis of natural solar ultraviolet B to promote synthesis of vitamin D

    Science.gov (United States)

    Hung, Min-Wei; Lin, Yu-Hsuan; Chang, Han-Chao; Huang, Kuo-Cheng

    2016-10-01

    This paper presents a spectral analysis system for the measurement of solar ultraviolet B over long durations. The proposed system provides high resolution at low cost in a highly robust and flexible format. We obtained information pertaining to the absolute irradiance of sunlight in a fixed location with the aim of identifying the best period in which to seek exposure to the sun with regard to maximizing the synthesis of vitamin D while minimizing damage to the skin. This study also provides a means of establishing a database for the development of healthy lamp technology.

  8. Spectral analysis of natural solar ultraviolet B to promote synthesis of vitamin D

    Science.gov (United States)

    Hung, Min-Wei; Lin, Yu-Hsuan; Chang, Han-Chao; Huang, Kuo-Cheng

    2016-06-01

    This paper presents a spectral analysis system for the measurement of solar ultraviolet B over long durations. The proposed system provides high resolution at low cost in a highly robust and flexible format. We obtained information pertaining to the absolute irradiance of sunlight in a fixed location with the aim of identifying the best period in which to seek exposure to the sun with regard to maximizing the synthesis of vitamin D while minimizing damage to the skin. This study also provides a means of establishing a database for the development of healthy lamp technology.

  9. Ligand Design for Rh(III)-Catalyzed C–H Activation: An Unsymmetrical Cyclopentadienyl Enables a Regioselective Synthesis of Dihydroisoquinolones

    Science.gov (United States)

    Hyster, Todd K.; Dalton, Derek M.

    2014-01-01

    We report the regioselective synthesis of dihydroisoquinolones from aliphatic alkenes and O-pivaloyl benzhydroxamic acids mediated by a Rh(III) precatalyst bearing sterically bulky substituents. While the prototypical Cp* ligand provides product with low selectivity, sterically bulky Cpt affords product with excellent regioselectivity for a range of benzhydroxamic acids and alkenes. Crystallographic evidence offers insight as to the source of the increased regioselectivity. PMID:25489470

  10. Synthesis and Crystal Structures of Ni(II)/(III) and Zn(II) Complexes with Schiff Base Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Bon Kweon [Catholic Univ., of Daegu, Daegu (Korea, Republic of)

    2013-12-15

    Coordination polymers are of great interest due to their intriguing structural motifs and potential applications in optical, electronic, magnetic, and porous materials. The most commonly used strategy for designing such materials relies on the utilization of multidentate N- or Odonor ligands which have the capacity to bridge between metal centers to form polymeric structures. The Schiff bases with N,O,S donor atoms are an useful source as they are readily available and easily form stable complexes with most transition metal ions. Schiff bases are also important intermediates in synthesis of some bioactive compounds and are potent anti-bacterial, anti-fungal, anticancer and antiviral compounds. In this work, the Schiff bases, Hapb and Hbpb, derived from 2-acetylpyridene or 2-benzoylpyridine and benzhydrazide were taken as trifunctional (N,N,O) monobasic ligand (Scheme 1). This ligand is of important because the π-delocalization of charge and the configurational flexibility of their molecular chain can give rise to a great variety of coordination modes. Although many metal.Schiff base complexes have been reported, the 1D, 2D, and 3D networks of coordination polymers linked through the bridging of ligands such as dicyanamide, N(CN){sub 2}{sup -} as coligand have been little published. In the process of working to extend the dimensionality of the metal-Schiff base complexes using benzilic acid as a bridging ligand, we obtained three simple metal (II)/(III) complexes of acetylpyridine/2-benzoyl pyridine based benzhydrazide ligand. Therefore, we report here the synthesis and crystal structures of the complexes.

  11. Synthesis of solution-phase phosphoramidite and phosphite ligand libraries and their in situ screening in the rhodium-catalyzed asymmetric addition of arylboronic acids

    NARCIS (Netherlands)

    Jagt, Richard B. C.; Toullec, Patrick Y.; Schudde, Ebe P.; de Vries, Johannes G.; Feringa, Ben L.; Minnaard, Adriaan J.

    2007-01-01

    Herein, we report the automated parallel synthesis of solution-phase libraries of phosphoramidite ligands for the development of enantioselective catalysts. The ligand libraries are screened in situ in the asymmetric rhodium-catalyzed addition of arylboronic acids to aldehydes and imines. It is show

  12. Synthesis, Characterization and Antibacterial Activity of New Ln( Ⅲ) Complexes with an Unsymmetrical Schiff Base Ligand

    Institute of Scientific and Technical Information of China (English)

    BI Caifeng; YAN Liangliang; FAN Yuhua; ZHANG Xia; WANG Aidong

    2006-01-01

    A new unsymmetrical Schiff base ligand (H2LLi) was synthesized using L-lysine, salicylaldehyde and 2-hydroxyprepared and characterized by elemental analyses, IR spectra, UV spectra, TG-DTG and molar conductance.The antibacterial activities of the ligand and its complexes are also studied.The antibacterial experiments indicate that the ligand and its complexes possess antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis and that the complexes have higher activity than those of the ligand.

  13. Synthesis, characterization and thermal study of some transition metal complexes of an asymmetrical tetradentate Schiff base ligand

    Directory of Open Access Journals (Sweden)

    ACHUT S. MUNDE

    2010-03-01

    Full Text Available Complexes of Cu(II, Ni(II, Co(II, Mn(II and Fe(III with an asymmetric tetradentate Schiff base ligand derived from dehydroacetic acid, 4-methyl-o-phenylenediamine and salicylic aldehyde were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV–Vis, IR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a dibasic tetadentate ligand towards the central metal ion with an ONNO donor atoms sequence. From the microanalytical data, the stoichiometry of the complexes 1:1 (metal:ligand was found. The physico-chemical data suggested square planar geometry for the Cu(II and Ni(II complexes and octahedral geometry for the Co(II, Mn(II and Fe(III complexes. The thermal behaviour (TGA/DTA of the complexes was studied and kinetic parameters were determined by Horowitz–Metzger and Coats–Redfern methods. The powder X-ray diffraction data suggested a monoclinic crystal system for the Co(II, Mn(II and Fe(III complexes. The ligand and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli and fungicidal activity against Aspergillus niger and Trichoderma viride.

  14. Synthesis and Reactivity of Chiral, Wide-Bite-Angle, Hybrid Diphosphorus Ligands

    NARCIS (Netherlands)

    C.F. Czauderna; D.B. Cordes; A.M.Z. Slawin; C. Müller; J.I. van der Vlugt; D. Vogt; P.C.J. Kamer

    2014-01-01

    Effective and modular synthetic approaches toward phosphine-phosphite ligands and phosphine-phosphonite ligands featuring a diphenyl ether backbone have been developed. The phosphine-phosphite ligands are obtained by a two-step protocol from 2-bromo-2-methoxydiphenyl ether. The phosphine-phosphonite

  15. Metal–organic coordination architectures of tetrazole heterocycle ligands bearing acetate groups: Synthesis, characterization and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Bo-Wen, E-mail: bowenhu@hit.edu.cn; Zheng, Xiang-Yu; Ding, Cheng

    2015-12-15

    Two new coordination complexes with tetrazole heterocycle ligands bearing acetate groups, [Co(L){sub 2}]{sub n} (1) and [Co{sub 3}(L){sub 4}(N{sub 3}){sub 2}·2MeOH]{sub n} (2) (L=tetrazole-1-acetate) have been synthesized and structurally characterized. Single crystal structure analysis shows that the cobalt-complex 1 has the 3D 3,6-connected (4{sup 2}.6){sub 2}(4{sup 4}.6{sup 2}.8{sup 8}.10)-ant topology. By introducing azide in this system, complex 2 forms the 2D network containing the [Co{sub 3}] units. And the magnetic properties of 1 and 2 have been studied. - Graphical abstract: The synthesis, crystal structure, and magnetic properties of the new coordination complexes with tetrazole heterocycle ligands bearing acetate groups are reported. - Highlights: • Two novel Cobalt(II) complexes with tetrazole acetate ligands were synthesized. • The magnetic properties of two complexes were studied. • Azide as co-ligand resulted in different structures and magnetic properties. • The new coordination mode of tetrazole acetate ligand was obtained.

  16. Synthesis, spectral characterization and eukaryotic DNA degradation of thiosemicarbazones and their platinum(IV) complexes

    Science.gov (United States)

    Al-Hazmi, G. A.; El-Metwally, N. M.; El-Gammal, O. A.; El-Asmy, A. A.

    2008-01-01

    The condensation products of acetophenone (or its derivatives), salicylaldehyde and o-hydroxy- p-methoxybenzophenone with thiosemicarbazide and ethyl- or phenyl-thiosemicarbazide are the investigated thiosemicarbazones. Their reactions with H 2PtCl 6 produced Pt(IV) complexes characterized by elemental, thermal, mass, IR and electronic spectral studies. The coordination modes were found mononegative bidentate in the acetophenone derivatives and binegative tridentate in the salicylaldehyde derivatives. The complexes were analyzed thermogravimetrically and found highly stable. Some ligands and their complexes were screened against Sarcina sp. and E. coli using the cup-diffusion technique. [Pt( oHAT)(OH)Cl] shows higher activity against E. coli than the other compounds. The degradation power of the tested compounds on the calf thymus DNA supports their selectivity against bacteria and not against the human or related eukaryotic organisms.

  17. Synthesis, spectral, thermal and antimicrobial studies of some new tri metallic biologically active ceftriaxone complexes.

    Science.gov (United States)

    Ali, Alaa E

    2011-01-01

    Iron, cobalt, nickel and copper complexes of ceftriaxone were prepared in 1:3 ligand:metal ratio to examine the ligating properties of the different moieties of the drug. The complexes were found to have high percentages of coordinated water molecules. The modes of bonding were discussed depending on the infrared spectral absorption peaks of the different allowed vibrations. The Nujol mull electronic absorption spectra and the magnetic moment values indicated the Oh geometry of the metal ions in the complexes. The ESR spectra of the iron, cobalt, and copper complexes were determined and discussed. The thermal behaviors of the complexes were studied by TG and DTA techniques. The antimicrobial activities of the complexes were examined and compared to that of the ceftriaxone itself.

  18. A series of novel oxovanadium(IV) complexes: Synthesis, spectral characterization and antimicrobial study

    Science.gov (United States)

    Sahani, M. K.; Pandey, S. K.; Pandey, O. P.; Sengupta, S. K.

    2014-09-01

    Oxovanadium(IV) complexes have been synthesized by reacting vanadyl sulfate with Schiff bases derived from 4-amino-5-(substitutedphenoxyacetic acid)-1,2,4-triazole-3-thiol and benzil. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non-electrolytes and characterized by elemental analysis, spectral techniques (UV-Vis, IR, EPR and XRD) and magnetic moment measurements. The EPR spectra indicate that the free electron is in dxy orbital. In vitro antifungal activity of ligands and synthesized compounds was determined against fungi Aspergillus niger, Colletotrichum falcatum and Colletotrichum pallescence and in vitro antibacterial activity was determined by screening the compounds against Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains. The antimicrobial activities have shown that the activity increases upon complexation.

  19. Photocontrol of Anthocyanin Synthesis: VI. Spectral Sensitivity, Irradiance Dependence, and Reciprocity Relationships.

    Science.gov (United States)

    Rabino, I; Mancinelli, A L; Kuzmanoff, K M

    1977-04-01

    The spectral sensitivity and the irradiance dependence of anthocyanin synthesis, a "high irradiance response," in cabbage (Brassica oleracea, cv. Red Acre) and tomato (Lycopersicon esculentum, cv. Beefsteak) seedlings exposed to continuous irradiation depend upon the length of the exposure. In cabbage, blue and red are more effective than far red when the irradiations are shorter than 12 hours and less effective than far red when the irradiations are longer than 12 hours. The irradiance dependence is negligible under red and becomes evident under blue and far red red only for exposures longer than 12 hours. Anthocyanin synthesis under intermittent light treatments, of efficiency comparable to that of continuous treatments, obeys the Bunsen-Roscoe reciprocity law and is a function of the dose (irradiance x time), rather than of the irradiance alone. The validity of the reciprocity relationships suggests that only one photoreceptor is responsible for the photocontrol of the response in the blue, red, and far red spectral regions. The characteristics of the response suggest that the photoreceptor is phytochrome, at least in cabbage.

  20. Ruthenium(II) hydrazone Schiff base complexes: synthesis, spectral study and catalytic applications.

    Science.gov (United States)

    Manikandan, R; Viswanathamurthi, P; Muthukumar, M

    2011-12-01

    Ruthenium(II) hydrazone Schiff base complexes of the type [RuCl(CO)(B)(L)] (were B=PPh(3), AsPh(3) or Py; L=hydrazone Schiff base ligands) were synthesized from the reactions of hydrazone Schiff base ligand (obtained from isonicotinoylhydrazide and different hydroxy aldehydes) with [RuHCl(CO)(EPh(3))(2)(B)] (where E=P or As; B=PPh(3), AsPh(3) or Py) in 1:1 molar ratio. All the new complexes have been characterized by analytical and spectral (FT-IR, electronic, (1)H, (13)C and (31)P NMR) data. They have been tentatively assigned an octahedral structure. The synthesized complexes have exhibited catalytic activity for oxidation of benzyl alcohol to benzaldehyde and cyclohexanol to cyclohexanone in the presence of N-methyl morpholine N-oxide (NMO) as co-oxidant. They were also found to catalyze the transfer hydrogenation of aliphatic and aromatic ketones to alcohols in KOH/Isopropanol.

  1. Synthesis and spectral characterization of a new blue fluorescent tripod for detecting metal cations and protons

    Energy Technology Data Exchange (ETDEWEB)

    Staneva, Desislava [University of Chemical Technology and Metallurgy, 1756 Sofia (Bulgaria); Makki, Mohammad S.I.; Sobahi, Tariq R. [Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Bosch, Paula [Institute of Science and Technology of Polymers, CSIC, Juan de la Cierva 3, 28006, Madrid (Spain); Abdel-Rahman, Reda M. [Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Asiri, Abdullah [Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Grabchev, Ivo, E-mail: i.grabchev@chem.uni-sofia.bg [Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Sofia University “St. Kliment Ohridski”, Faculty of Medicine, 1407 Sofia (Bulgaria)

    2015-06-15

    A new symmetrical blue fluorescent tripod containing three 1,8-naphtalimide fragments has been synthesized. Its spectral properties have been investigated in organic solvents of different polarity. Its basic photophysical characteristics depend strongly on the polarity of the organic solvents. In nonpolar solvents (diethyl ether, chloroform and toluene) the new tripod emits eximer fluorescence. The new tripod has been investigated as a ligand for detection of metal ions (Ag{sup +}, Co{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, Ni{sup 2+}, and Cu{sup 2+}) in acetonitrile and acetonitrile/H{sub 2}O (1:4, v/v). The influence of protons in an ethanol–water (1:4, v/v) solution and in toluene and diethyl ether solvents on the tripod fluorescence intensity has been investigated and it has been shown that the protons destroy the excimer formations recovering the monomer fluorescence. - Highlights: • New blue fluorescent tripod containing three 1,8-naphtalimide fragments was described. • In nonpolar solvents the new tripod emits eximer fluorescence. • The new tripod has been investigated as a ligand for metal ions and protons.

  2. Synthesis, complexation, spectral, antibacterial and antifungal activity of 2,4-dihydroxy-5-[(E-phenyldiazenyl]benzaldehyde oxime

    Directory of Open Access Journals (Sweden)

    MÜKERREM KURTOGLU

    2010-09-01

    Full Text Available A new substituted salicylaldoxime ligand containing an azo (–N=N– group, 2,4-dihydroxy-5-[(E-phenyldiazenyl]benzaldehyde oxime (H3salox (2, was synthesized by the reaction of 2,4-dihydroxy-5-[(E-phenyldiazenyl]benzaldehyde (1 with hydroxylamine in ethanolic solution at room temperature. Mononuclear complexes of (H3salox (2, a bidentate hydroxyaldoxime ligand, were synthesized by reaction with nickel(II, cobalt(II and copper(II chloride salts. The complexes, [Ni(H2salox2] (3, [Cu(H2salox2] (4 and [Co(H2salox2] (5 were characterized by elemental analyses (C, H, N, conductivity measurements and infrared and electronic spectral studies. The 1H-NMR spectrum of the H3salox (2 ligand was also recorded. The mononuclear Ni(II, Co(II and Cu(II complexes of the ligand, (H3salox, have a metal:ligand ratio of 1:2 and the ligand coordinates through the N and O atoms, as is the case with most hydroxyaldoximes. The molar conductivities in DMF solution indicate the non-electrolytic nature of the metal chelates. The antimicrobial activities of the ligand and its metal complexes were estimated for eight bacteria, i.e., Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium smegmatis, Pseudomonas aeruginosa, Enterococcus cloacae, Bacillus megaterium and Micrococcus luteus and three fungi, i.e., Kluyveromyces fragilis, Rhodotorula rubra and Saccharomyces cerevisiae.

  3. Design, synthesis and biological evaluation of bivalent ligands against A1-D1 receptor heteromers

    Institute of Scientific and Technical Information of China (English)

    Jian SHEN; Lei ZHANG; Wan-ling SONG; Tao MENG; Xin WANG; Lin CHEN; Lin-yin FENG

    2013-01-01

    Aim:To design and synthesize bivalent ligands for adenosine A1-dopamine D1 receptor heteromers (A1-D1R),and evaluate their pharmacological activities.Methods:Bivalent ligands and their corresponding A1R monovalent ligands were designed and synthesized.The affinities of the bivalent ligands for A1R and D1R in rat brain membrane preparation were examined using radiolabeled binding assays.To demonstrate the formation of A1-D1R,fluorescence resonance energy transfer (FRET) was conducted in HEK293 cells transfected with D1-CFP and A1-YFP.Molecular modeling was used to analyze the possible mode of protein-protein and protein-ligand interactions.Results:Two bivalent ligands for A1R and D1R (20a,20b),as well as the corresponding A1R monovalent ligands (21a,21b) were synthesized.In radiolabeled binding assays,the bivalent ligands showed affinities for A1R 10-100 times higher than those of the corresponding monovalent ligands.In FRET experiments,the bivalent ligands significantly increased the heterodimerization of A1R and D1R compared with the corresponding monovalent ligands.A heterodimer model with the interface of helixes 3,4,5 of A1R and helixes 1,6,7 from D1R was established with molecular modeling.The distance between the two ligand binding sites in the heterodimer model was approximately 48.4 (A),which was shorter than the length of the bivalent ligands.Conclusion:This study demonstrates the existence of A1-D1R in situ and a simultaneous interaction of bivalent ligands with both the receptors.

  4. Microwave Synthesis, Spectral, Thermal and Electrical Properties of Some Metal Complexes Involving 5-Bromosalicylaldehyde

    Directory of Open Access Journals (Sweden)

    Rajendra K. Jain

    2012-01-01

    Full Text Available Microwave-assisted synthesis is a branch of green chemistry. The salient features of microwave approach are shorter reaction times, simple reaction conditions and enhancements in yields. Some new Schiff base complexes of Cr(III, Co(II, Ni(II and Cu(II derived from 5-bromosalicylaldehyde with 4-nitro-1,2-phenylenediamine (H2L1 have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility and thermal analysis. The complexes exhibit coordination number 4 or 6. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:1 (metal: ligand ratio. FAB-mass and thermal data show degradation pattern of the complexes. The thermal behavior of metal complexes shows that the hydrated complexes loses water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes.

  5. Synthesis, characterization and coordination properties of bis(alkyl)selenosalen ligands.

    Science.gov (United States)

    Panda, Snigdha; Krishna, G Rama; Reddy, C Malla; Zade, Sanjio S

    2011-07-07

    New bis (alkyl) selenosalen podand ligands having Se2N2 donor sites have been synthesized by the condensation of unsymmetrical o-formylphenyl alkyl selenide (1-3) with ethylenediamine. The reaction of bis(alkyl)selenosalen podands with Pd(II) and Pt(II) afforded selenoether-selenolate coordination complexes 7-10via cleavage of one of the two Se-C(alkyl) bonds of bis(alkyl)selenosalen podands upon complexation. DFT calculations revealed that the cleavage of Se-C(alkyl) bonds occurred possibly via S(N)2 mechanism instead of a sequence of oxidative addition and reductive elimination reactions. The spectral data and elemental analyses confirmed the formation of selenoether-selenolate complexes. The structures of the podands N,N'-bis[(2-methylseleno)phenylmethylene]-1,2-ethanediamine (4), N,N'-bis[(2-decylseleno)phenylmethylene]-1,2-ethanediamine (5) and the selenoether-selenolate complex 8 have been determined by single crystal X-ray diffraction analysis. The crystal structure of 5 showed SeH interaction with a ladder like 3D supramolecular arrangement via interdigitation of long alkyl chains. Comparison of crystal packing of podands 4 and 5 indicates that the alkyl chain length has significant impact on the crystal packing. The platinum selenolate complex 8 shows a square planar arrangement around the Pt centre, where the Se atoms in the selenolate and the selenoether have nearly equal Pt-Se bond length. This journal is © The Royal Society of Chemistry 2011

  6. Synthesis, spectral characterization of Schiff base transition metal complexes: DNA cleavage and antimicrobial activity studies

    Indian Academy of Sciences (India)

    N Raman; J Dhaveethu Raja; A Sakthivel

    2007-07-01

    A new series of transition metal complexes of Cu(II), Ni(II), Co(II), Mn(II), Zn(II), VO(IV), Hg(II) and Cd(II) have been synthesized from the Schiff base (L) derived from 4-aminoantipyrine, 3-hydroxy-4-nitrobenzaldehyde and -phenylenediamine. Structural features were obtained from their elemental analyses, magnetic susceptibility, molar conductance, mass, IR, UV-Vis, 1H NMR and ESR spectral studies. The data show that these complexes have composition of ML type. The UV-Vis, magnetic susceptibility and ESR spectral data of the complexes suggest a square-planar geometry around the central metal ion except VO(IV) complex which has square-pyramidal geometry. The redox behaviour of copper and vanadyl complexes was studied by cyclic voltammetry. Antimicrobial screening tests gave good results in the presence of metal ion in the ligand system. The nuclease activity of the above metal complexes shows that Cu, Ni and Co complexes cleave DNA through redox chemistry whereas other complexes are not effective.

  7. Synthesis and transition metal coordination chemistry of a novel hexadentate bispidine ligand.

    Science.gov (United States)

    Comba, Peter; Rudolf, Henning; Wadepohl, Hubert

    2015-02-14

    Reported is the new bispidine-derived hexadentate ligand (L = 3-(2-methylpyridyl)-7-(bis-2-methylpyridyl)-3,7-diazabicyclo[3.3.1]nonane) with two tertiary amine and four pyridine donor groups. This ligand can form heterodinuclear and mononuclear complexes and, in the mononuclear compounds discussed here, the ligand may coordinate as a pentadentate ligand, with one of the bispyridinemethane-based pyridine groups un- or semi-coordinated, or as a hexadentate ligand, leading to a pentagonal pyramidal coordination geometry or, with an additional monodentate ligand, to a heptacoordinate pentagonal bipyramidal structure. The solution and solid state data presented here indicate that, with the relatively small Cu(II) and high-spin Fe(II) ions the fourth pyridine group is only semi-coordinated for steric reasons and, with the larger high-spin Mn(II) ion genuine heptacoordination is observed but with a relatively large distortion in the pentagonal equatorial plane.

  8. Synthesis, characterization and cytotoxic activity of gallium(III) complexes anchored by tridentate pyrazole-based ligands.

    Science.gov (United States)

    Silva, Francisco; Marques, Fernanda; Santos, I C; Paulo, António; Rodrigues, António Sebastião; Rueff, José; Santos, Isabel

    2010-05-01

    Reactions of GaCl(3) with pyrazole-containing ligands of the pyrazole-imine-phenol (HL(1)-HL(3)) or pyrazole-amine-phenol (HL(4)-HL(6)) types led to the synthesis of well-defined [GaL(2)](+) homoleptic complexes (1-6). Complexes 1-6 were characterized by elemental analysis, ESI-MS (electrospray ionization-mass spectrometry), IR and NMR spectroscopies, and in the case of Complex 1 also by X-ray diffraction analysis. In complexes 1-3, the pyrazole-imine-phenolate ligands act as monoanionic chelators that coordinate to the metal in a meridional fashion, while 4-6 contain monoanionic and facially coordinated pyrazole-amine-phenolate ligands. Complexes 1-3 have a greater stability in solution compared to 4-6, which have shown a more pronounced tendency to release the respective ancillary ligands. The cytotoxicity of 1-6 and of the respective ligands (HL(1)-HL(6)) was evaluated against human prostate cancer cells PC-3 and human breast cancer cells MCF-7. The substituents of the phenolate rings strongly influenced the cytotoxicity of the compounds. Complexes 3 and 6 that contain chloride substituents at the phenolate rings have shown the highest cytotoxicity, including in the cisplatin-resistant PC-3 cell line. The cytotoxic profile of 3 and 6 is very similar to the one displayed by the respective anchor ligands, respectively HL(1) and HL(6). The cytotoxic activity of 3 and 6 is slightly increased by the presence of transferrin, and both complexes provoke cell death mainly by induction of apoptotic pathways.

  9. Synthesis and studies on Cu(II), Co(II), Ni(II) complexes of Knoevenagel β-diketone ligands

    Science.gov (United States)

    Sumathi, S.; Tharmaraj, P.; Sheela, C. D.; Anitha, C.

    2012-11-01

    Transition metal complexes of various acetylacetone based ligands of the type ML [where M = Cu(II), Ni(II), Co(II); L = 3-(aryl)-pentane-2,4-dione] have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, 1H NMR, Mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are non-electrolytic in nature. Spectroscopic and other analytical data of the complexes suggest octahedral geometry for other metal(II) complexes. The redox behavior of the copper(II) complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus as well as the fungus Candida albicans by well diffusion method. The zone of inhibition value indicates that the most of the metal(II) complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligands (L1-L3) was found to be considerable effect than that of urea and KDP (potassium dihydrogen phosphate).

  10. Preparation of New Chiral Ferroceny Phosphine Ligands and Their Application to Organic Synthesis

    Institute of Scientific and Technical Information of China (English)

    S.Fukuzawa

    2007-01-01

    1 Results The unique structure of chiral ferrocenes allows one to design a variety of chiral phosphine ligands,which are useful tools for metal catalyzed asymmetric reactions.Although some useful chiral ferrocenyl phosphine ligands have already been reported,it is still an challenging subject tocreate new ferrocenyl phosphine ligands in order to cover asymmetric reactions in which conventional ligands do not effectively work[1].We happned to discover that 1,5-dilithiation of o-TMS blocked ferrocene 1 pr...

  11. Synthesis, Spectroscopic, and Magnetic Studies of Mono- and Polynuclear Schiff Base Metal Complexes Containing Salicylidene-Cefotaxime Ligand

    Directory of Open Access Journals (Sweden)

    J. R. Anacona

    2013-01-01

    Full Text Available Metal complexes of a Schiff base ligand derived from cefotaxime and salicylaldehyde were prepared. The salicilydene-cefotaxime ligand (H2L and mononuclear [M(L] (M(II = Co, Ni and Cu, dinuclear [Ag2(L(OAc2], and tetranuclear metal complexes [M4(L(OH6] (M(II = Ni, Cu were characterized on the basis of analytical, thermal, magnetic, and spectral studies (IR, UV-visible, 1H NMR, 13C NMR, and EPR. The electronic spectra of the complexes and their magnetic moments suggesttetrahedral geometry for the isolated complexes. The complexes are nonelectrolytes and insoluble in water and common organic solvents but soluble in DMSO.

  12. Ruthenium complexes of chelating amido-functionalized N-heterocyclic carbene ligands: Synthesis, structure and DFT studies

    Indian Academy of Sciences (India)

    Sachin Kumar; Anantha Narayanan; Mitta Nageswar Rao; Mobin M Shaikh; Prasenjit Ghosh

    2011-11-01

    Synthesis, structure and density functional theory (DFT) studies of a series of new ruthenium complexes, [1-(R)-3--(benzylacetamido)imidazol-2-ylidene]RuCl(-cymene) [R = Me (1c), -Pr (2c), CH2Ph (3c); -cymene = 4--propyltoluene] supported over /-functionalized N-heterocyclic carbene (NHC) ligands are reported. In particular, the ruthenium (1-3)c complexes were synthesized from the respective silver complexes, [1-(R)-3--(benzylacetamido)imidazol-2-ylidene]2Ag+Cl− [R = Me (1b), -Pr (2b), CH2Ph (3b)] by the treatment with [Ru(-cymene)Cl2]2 in 65-76% yields. The molecular structures of (1-3)c revealed the chelation of the N-heterocylic carbene ligand through the carbene center and an amido sidearm of the ligand in all of the three complexes. The density functional theory studies on the ruthenium (1-3)c complexes indicated strong binding of the NHC ligand to the metal center as was observed from the deeply buried NHC-Ru -bonding molecular orbitals.

  13. Designing ancillary ligands for heteroleptic/homoleptic zinc complex formation: synthesis, structures and application in ROP of lactides.

    Science.gov (United States)

    Jędrzkiewicz, D; Ejfler, J; Gulia, N; John, Ł; Szafert, S

    2015-08-14

    Synthesis and characterization of a series of new amino-phenol/naphthol ligands (L(1,2)-H) have been developed and their respective zinc complexes ( 1 and 2-Zn ) have been synthesized. The molecular structures of L(1)-H and 1, 2-Zn were explored in detail by NMR, single-crystal X-ray studies and DFT calculations, which confirmed the existence of complexes as stabile dimers both in a solution and in the solid state. All complexes mediate the ring-opening polymerization (ROP) of lactide highly efficiently, at room temperature, in a controlled fashion. The influence of the architecture of the ligand on the desired homo/heteroleptic complex formation, as well as the relationship between the initiator design and the catalytic activity have been investigated.

  14. New approach to the synthesis of an organopolymolybdate polymer in aqueous media by linkage of multicarboxylic ligands.

    Science.gov (United States)

    Gao, Guang-Gang; Xu, Lin; Qu, Xiao-Shu; Liu, Hong; Yang, Yan-Yan

    2008-04-21

    The reaction of molybdates with multicarboxylic ligands resulted in the crystalline materials of [Na 8(Mo (VI) 10O 32EDTA)(H 2O) 35] n ( 1) and (NH 4) 8 n [Mo (VI) 10O 32PDTA] n (H 2O) 30 n ( 2) (EDTA = 1,2-diaminoethanetetraacetate; PDTA = 1,3-diaminopropanetetraacetate). In the two compounds, decamolybdate clusters are covalently linked by multicarboxylic ligands to form unusual meso-helical chains. For the first time, the synthesis of an organopolyoxometalate polymer is realized in aqueous media, which opens a green chemical approach to the fabrication of polyoxometalate-based polymers. The photochromic properties of 1 in the poly(vinyl alcohol) film displayed reddish-brown coloration upon UV irradiation, providing a new coloration material for photochromic films.

  15. Ligand mediated synthesis of AgInSe{sub 2} nanoparticles with tetragonal/orthorhombic crystal phases

    Energy Technology Data Exchange (ETDEWEB)

    Abazovic, Nadica D., E-mail: kiki@vinca.rs; Comor, Mirjana I.; Mitric, Miodrag N. [University of Belgrade, Vinca Institute of Nuclear Sciences (Serbia); Piscopiello, Emanuela [ENEA, Department of Advanced Physics Technology and New Materials (FIM) (Italy); Radetic, Tamara [Lawrence Berkeley National Laboratory (United States); Jankovic, Ivana A.; Nedeljkovic, Jovan M. [University of Belgrade, Vinca Institute of Nuclear Sciences (Serbia)

    2012-03-15

    Nanosized AgInSe{sub 2} particles (d {approx} 7-25 nm) were synthesized using colloidal chemistry method at 270 Degree-Sign C. As solvents/surface ligands 1-octadecene, trioctylphosphine, and oleylamine were used. It was shown that choice of ligand has crucial impact not only on final crystal phase of nanoparticles, but also at mechanism of crystal growth. X-ray diffraction and TEM/HRTEM techniques were used to identify obtained crystal phases and to measure average size and shape of nanoparticles. UV/Vis data were used to estimate band-gap energies of obtained samples. It was shown that presented routes can provide synthesis of nanoparticles with desired crystal phase (tetragonal and/or orthorhombic), with band-gap energies in the range from 1.25 to 1.53 eV.

  16. Synthesis of Novel Bisoxazoline Ligands for the Enantioselective Diels-Alder Reaction

    Institute of Scientific and Technical Information of China (English)

    Qing Hua BIAN; Jun LIU; Ming Ming YIN; Min WANG

    2006-01-01

    Four novel bisoxazoline ligands 8a-d were synthesized from (S)-amino alcohols and could be formed effective catalysts (up to 77% ee for endo isomer) with Cu(OTf)2 for enantioselective Diels-Alder addition. The facility of the reaction was dependent on the nature of the substituent R in the bisoxazoline ligand.

  17. Synthesis, Spectral and Anthelmintic Activity Studies on Some Novel Imidazole Derivatives

    Directory of Open Access Journals (Sweden)

    Rajiv Dahiya

    2008-01-01

    Full Text Available Present study describes the synthesis of a novel series of 3,5-diiodo-4-(5-nitro-1H-2-imidazolylbenzoyl amino acids and di/tri/tetrapeptides using diisopropylcarbodiimide/dicyclohexylcarbodiimide (DIPC/DCC as coupling agents and N-methylmorpholine/triethylamine (NMM/TEA as bases. Structure elucidation of all the newly synthesized compounds was done by elemental analysis and IR, 1H NMR, 13C NMR and mass spectral data. Synthesized imidazolopeptides were screened for their anthelmintic activity and found to possess moderate to good bioactivity against earthworms Megascoplex konkanensis, Pontoscotex corethruses and Eudrilus eugeniea when compared to reference drugs - albendazole and mebendazole at dose level of 2 mg mL−1.

  18. Template synthesis, characterization and antimicrobial activity of some new complexes with isonicotinoyl hydrazone ligands

    Directory of Open Access Journals (Sweden)

    LIVIU MITU

    2009-09-01

    Full Text Available Complexes of Cu(II, Ni(II, Co(II with the 9-anthraldehyde iso-nicotinoyl hydrazone ligand (HL1 and the 3,5-di-tert-butyl-4-hydroxy-benzaldehyde isonicotinoyl hydrazone ligand (H2L2 were synthesized by the template method. The complexes were characterized by analytical analysis, IR, UV-Vis and ESR spectroscopy, magnetic measurements, conductometry and thermal analysis and the two ligands by 1H-NMR spectroscopy. From the elemental analysis, 1:2 (metal:ligand stoichiometry for the complexes of Cu(II, Ni(II with the ligands HL1 and H2L2 and 1:1 (metal:ligand stoichiometry for the complex of Co(II with the ligand HL1 are proposed. The molar conductance data showed that the complexes are non-electrolytes. The magnetic susceptibility results coupled with the electronic and ESR spectra suggested a distorted octahedral geometry for the complexes Ni(II/HL1, Ni(II/H2L2 and Cu(II/H2L2, a tetrahedral stereochemistry for the complex Cu/HL1 and a square-planar geometry for the complex Co/HL1. The IR spectra demonstrated the bidentate coordination of the ligands HL1 and H2L2 by the O=C amide oxygen and the azomethine nitrogen, as well as monodentate coordination of the ligand HL1 by the azomethine nitrogen in the Cu(IIcomplex. The antibacterial activity of the ligands and their metallic complexes were tested against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.

  19. Synthesis, spectral and extended spectrum beta-lactamase studies of transition metal tetraaza macrocyclic complexes.

    Science.gov (United States)

    Kumar, Dinesh; Sharma, Nutan; Nair, Manjula

    2017-01-18

    Urinary tract infections commonly occur in humans due to microbial pathogens invading the urinary tract, which can bring about a range of clinical symptoms and potentially fatal sequelae. The present study is aimed at addressing the development of a new antimicrobial agent against extended spectrum beta lactamase (ESBL) producing E. coli bacteria. We have synthesised some biologically potent (NNNN) donor macrocycles (L 1  = dibenzo[f,n]dipyrido[3,4-b:4',3'-j][1,4,9,12]tetraazacyclohexadecine-6,11,18,23(5H,12H, 7H, 24H)-tetraone, and L 2  = 6,12,19,25-tetraoxo-4,6,11,12,16,18,23,24-octahydrotetrabenzo [b,g,k,p][1,5,10,14]tetra azacyclooctadecine-2,13-dicarboxylic acid) and their Ti and Zr metal complexes in alcoholic media using microwave protocol. Macrocyclic ligands were synthesised by incorporating of 3,5-diaminobenzoic acid, phthalic acid and 3,4-diaminopyridine in 1:1:1 molar ratio. The macrocyclic ligands and their metal complexes have been characterised by elemental analysis, conductance measurement, magnetic measurement and their structure configurations have been determined by various spectroscopic (FTIR, (1)H/(13)C NMR, UV-Vis, LC-MS mass, XRD and TGA) techniques. [ZrL2Cl2]Cl2 metal complex shows excellent antibacterial activity against ESBLs. A zone of inhibition and minimum inhibitory concentration was determined by McFarland and the dilution method, respectively. The spectral studies confirm the binding sites of the nitrogen atom of the macrocycles. An octahedral geometry has been assigned to the metal complexes based on the findings.

  20. New Mn(II, Ni(II, Cd(II, Pb(II complexes with 2-methylbenzimidazole and other ligands. Synthesis, spectroscopic characterization, crystal structure, magnetic susceptibility and biological activity studies

    Directory of Open Access Journals (Sweden)

    Shayma A. Shaker

    2016-11-01

    Full Text Available Synthesis and characterization of Mn(II, Ni(II, Cd(II and Pb(II mixed ligand complexes of 2-methylbenzimidazole with other ligands have been reported. The structure of the ligands and their complexes was investigated using elemental analysis, IR, UV–Vis, (1H, 13C NMR spectroscopy, molar conductivity and magnetic susceptibility measurements. In all the studies of complexes, the 2-methylbenzimidazole behaves as a neutral monodentate ligand which is coordinated with the metal ions through the N atom. While benzotriazole behaves as a neutral bidentate ligand which is coordinated with the Ni(II ion through the two N atoms. Moreover, the N-acetylglycine behaves as a bidentate ligand which is coordinated with the Mn(II, Ni(II and Pb(II ions through the N atom and the terminal carboxyl oxygen atom. The magnetic and spectral data indicate the tetrahedral geometry for Mn(II complex, irregular tetrahedral geometry for Pb(II complex and octahedral geometry for Ni(II complex. The X-ray single crystal diffraction method was used to confirm a centrosymmetric dinuclear Cd(II complex as each two metal ions are linked by a pair of thiocyanate N = S bridge. Two 2-methylbenzimidazole N-atom donors and one terminal thiocyanate N atom complete a highly distorted square pyramid geometry around the Cd atom. Besides, different cell types were used to determine the inhibitory effect of Mn(II, Ni(II, Cd(II and Pb(II complexes on cell growth using MTT assay. Cd(II complex showed cytotoxic effect on various types of cancer cell lines with different EC50 values.

  1. The synthesis and pH-dependent behaviour of Re(CO)3 conjugates with diimine phenolic ligands

    OpenAIRE

    Chanawanno, Kullapa; James T. Engle; Le, Kevin X.; Herrick, Richard S.; Ziegler, Christopher J.

    2013-01-01

    In this report we present a study of a series of Re(CO)3 pyridineimine complexes with pendant phenol groups. We investigated the effects of the position of the phenol hydroxyl group (para, meta or ortho to the imine) on the steric and electronic characteristics of a series of Re(CO)3X(pyca-C6H4OH) compounds, where X = Cl, Br and pyca = pyridine-2-carbaldehyde imine. These compounds can be generated either via ligand synthesis followed by metal chelation (compound 4) or via a one-pot method (c...

  2. The Effects of Magnesium Ions on the Enzymatic Synthesis of Ligand-Bearing Artificial DNA by Template-Independent Polymerase

    Directory of Open Access Journals (Sweden)

    Yusuke Takezawa

    2016-06-01

    Full Text Available A metal-mediated base pair, composed of two ligand-bearing nucleotides and a bridging metal ion, is one of the most promising components for developing DNA-based functional molecules. We have recently reported an enzymatic method to synthesize hydroxypyridone (H-type ligand-bearing artificial DNA strands. Terminal deoxynucleotidyl transferase (TdT, a template-independent DNA polymerase, was found to oligomerize H nucleotides to afford ligand-bearing DNAs, which were subsequently hybridized through copper-mediated base pairing (H–CuII–H. In this study, we investigated the effects of a metal cofactor, MgII ion, on the TdT-catalyzed polymerization of H nucleotides. At a high MgII concentration (10 mM, the reaction was halted after several H nucleotides were appended. In contrast, at lower MgII concentrations, H nucleotides were further appended to the H-tailed product to afford longer ligand-bearing DNA strands. An electrophoresis mobility shift assay revealed that the binding affinity of TdT to the H-tailed DNAs depends on the MgII concentration. In the presence of excess MgII ions, TdT did not bind to the H-tailed strands; thus, further elongation was impeded. This is possibly because the interaction with MgII ions caused folding of the H-tailed strands into unfavorable secondary structures. This finding provides an insight into the enzymatic synthesis of longer ligand-bearing DNA strands.

  3. Synthesis and Structure of a Ternary Copper(II) Complex with Mixed Ligands of Diethylenetriamine and Picrate: DNA/Protein-Binding Property and In Vitro Anticancer Activity Studies.

    Science.gov (United States)

    Shi, Ya-Ning; Zheng, Kang; Zhu, Ling; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2015-05-01

    Based on the importance of the design and synthesis of transition metal complexes with noncovalent DNA/protein-binding abilities in the field of metallo pharmaceuticals, a new mononuclear ternary copper(II) complex with mixed ligands of diethylenetriamine (dien) and picrate anion (pic), identified as [Cu(dien)(pic)](pic), was synthesized and characterized by elemental analysis, molar conductivity measurement, infrared spectrum, electronic spectral studies, and single-crystal X-ray diffractometry. The structure analysis reveals that the copper(II) complex crystallizes in the monoclinic space group P21 /c, and the copper(II) ion has a distorted square pyramidal coordination geometry. A two-dimensional supramolecular structure is formed through hydrogen bonds. The DNA/bovine serum albumin (BSA)-binding properties of the complex are explored, indicating that the complex can interact with herring sperm DNA via intercalation mode and bind to BSA responsible for quenching of tryptophan fluorescence by static quenching mechanism. The in vitro anticancer activity shows that the copper(II) complex is active against the selected tumor cell lines.

  4. Microwave-assisted synthesis, characterization and biological screening of nitrogen-sulphur and nitrogen-oxygen donor ligands and their organotin(IV) complexes.

    Science.gov (United States)

    Singh, R V; Chaudhary, Pratibha; Poonia, Kavita; Chauhan, Shikha

    2008-08-01

    Series of new trigonal bipyramidal and octahedral complexes of tin(IV) have been synthesized by the reaction of dimethyltin(IV) dichloride with 4-nitro-benzanilidethiosemicarbazone (L(1)H), 4-chlorobenzanilidethiosemicarbazone (L(2)H), 4-nitrobenzanilidesemicarbazone (L(3)H) and 4-chlorobenzanilidesemicarbazone (L(4)H). The unimolecular and bimolecular reactions of dimethyltin(IV) dichloride and monobasic bidentate ligands were carried out using microwave irradiations as the thermal energy source and the complexes so formed were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data, viz. IR, UV-vis, (1)H and (13)C NMR. The complexes have also been prepared by the general thermal methods for comparison purposes. The comparison data support the synthesis using the microwave route, i.e. green chemistry route. The tin(IV) complexes show penta-coordinated structure for 1:1 complexes and hexa-coordinated for 1:2 complexes. The antifungal, antibacterial and antifertility activities have been examined and the results were indeed very encouraging.

  5. Design and synthesis of dual 5-HT1A and 5-HT7 receptor ligands.

    Science.gov (United States)

    Ofori, Edward; Zhu, Xue Y; Etukala, Jagan R; Peprah, Kwakye; Jordan, Kamanski R; Adkins, Adia A; Bricker, Barbara A; Kang, Hye J; Huang, Xi-Ping; Roth, Bryan L; Ablordeppey, Seth Y

    2016-08-15

    5-HT1A and 5-HT7 receptors have been at the center of discussions recently due in part to their major role in the etiology of major central nervous system diseases such as depression, sleep disorders, and schizophrenia. As part of our search to identify dual targeting ligands for these receptors, we have carried out a systematic modification of a selective 5HT7 receptor ligand culminating in the identification of several dual 5-HT1A and 5-HT7 receptor ligands. Compound 16, a butyrophenone derivative of tetrahydroisoquinoline (THIQ), was identified as the most potent agent with low nanomolar binding affinities to both receptors. Interestingly, compound 16 also displayed moderate affinity to other clinically relevant dopamine receptors. Thus, it is anticipated that compound 16 may serve as a lead for further exploitation in our quest to identify new ligands with the potential to treat diseases of CNS origin.

  6. Synthesis and Photoluminescence of Three Europium (Ⅲ) Ternary Complexes with New Secondary Ligands of Different Structure

    Institute of Scientific and Technical Information of China (English)

    袁继兵; 李嘉航; 梁万里; 苏树江; 石建新; 龚孟濂

    2004-01-01

    Three new 1,10-phenanthroline derivatives, dipyrido (3,2-f: 2,3-h) quinoxaline (DPQN), imidazo (5,6-f)-(1,10)-phenanthroline (IP) and 3-phenyl-imidazo (5,6-f)-(1,10)-phenanthroline (PIP) were designed and synthesized as a secondary ligand to coordinate with europium (Ⅲ) ion while dibenzoylmethane (DBM) was used as the first ligand. The compositions of the ligands and the europium (Ⅲ) ternary complexes were confirmed by elementary analysis, IR and 1H-NMR spectroscopy. The UV-visible absorption spectra, thermal stability, photoluminescence spectra, quantum yield and fluorescence life time of the Eu(Ⅲ) complexes were investigated. The effect of the structure of the secondary ligand on the photoluminescence of the complexes was discussed. The results show that the synthesized Eu(Ⅲ) complexes are good red-emitiing materials for potential application in fabrication of organic electroluminescence devices.

  7. New Cu(I)-ethylene complexes based on tridentate imine ligands: synthesis and structure.

    Science.gov (United States)

    Ebrahimpour, Parisa; Haddow, Mairi F; Wass, Duncan F

    2013-04-01

    A new bulky facially coordinating N3-donor tach-based ligand (tach: cis,cis-1,3,5-triaminocyclohexane) [1: cis,cis-1,3,5-tris(2-fluoro-6-(trifluoromethyl)benzylideneamino)cyclohexane] has been obtained from the condensation of tach with 3 equiv of the appropriate benzaldehyde. Reaction of 1 with [Cu(NCMe)4][PF6] gave the complex [(1)Cu(NCMe)][PF6]. Displacement of the acetonitrile ligand is possible with CO and C2H4 (3-5 bar). Cu(I)-ethylene complexes of ligands 1 and 2 [2: cis,cis-1,3,5-(mesitylideneamino)cyclohexane] were prepared successfully by treatment of the ligands with CuBr and AgSbF6 in the presence of ethylene. These complexes display reversible complexation of the ethylene molecule under mild changes to pressure, suggesting possible application in olefin separation and extraction.

  8. Dimeric ligands for GPCRs involved in human reproduction : synthesis and biological evaluation

    NARCIS (Netherlands)

    Bonger, Kimberly Michelle

    2008-01-01

    Dimeric ligands for G-protein coupled receptors that are involved in human reproduction, namely the gonadotropin releasing hormone receptor, the luteinizing hormone receptor and the follicle-stimulating hormone receptor, were synthesized and biologically evaluated.

  9. Synthesis, Spectroscopic Characterisation, and Biopotential and DNA Cleavage Applications of Mixed Ligand 4-N,N-Dimethylaminopyridine Metal Complexes

    Directory of Open Access Journals (Sweden)

    C. Surendra Dilip

    2013-01-01

    Full Text Available The mixed ligand transition metal complexes of 4-N,N-dimethylaminopyridine (DP and chloride as primary and secondary ligands with the general formula [M(DP3Cl3]; M = Cr(III and Fe(III; [M′(DP4Cl2]M′ = Co(II, Ni(II, Cu(II, and Cd(II were synthesized in a microwave oven. The complexes were characterized by FT-IR and UV, 1HNMR, 13CNMR spectra, TG/DTG, and various physicoanalytical techniques. From the magnetic moment measurements and the electronic spectral data, a distorted octahedral geometry was proposed for the complexes. The complexes express similar trend of thermal behaviour such that they lose water of hydration initially with the subsequent emission of organic and inorganic fragments and leave left the metal oxides as residue. The activation thermodynamic parameters, such as , , , and of the metal complexes, illustrate the spontaneous formation of the complexes. The antimicrobial studies against various pathogenic bacterial and fungal serums insist on that the enhanced potential of the complexes over their ligand and their biopotential properties increases with concentration. The DNA interaction of the synthesized complexes on CT-DNA was investigated by UV-Vis spectroscopy, viscosity, thermal denaturation, and electroanalytical experiments and their binding constants ( were also calculated.

  10. Synthesis of New Chiral Bis(BINOL) Substituted 2,2'-Bipyridine Ligands

    Institute of Scientific and Technical Information of China (English)

    BAI,Xiao-Li; GAO,Lian-Xun

    2004-01-01

    @@ Chiral 2,2'-bipyridines have been reported to be highly efficient catalysts and useful building blocks of supramolecular.[1,2] Chirality of bipyridines was introduced by chiral substituents. Because 1,1'-binaphthyl (BINOL) and its derivatives belong to the most important components of asymmetric catalysts, we would like to synthesize 5,5'-and 6,6'-positions substituted chiral bipyridine-type ligands, the chiral moieties of ligands originate from enationpure 1, 1'-binapthyl units.

  11. Synthesis and Characterisation of a Novel Phosphonate Ligand and Its Palladium(II Coordination Compound

    Directory of Open Access Journals (Sweden)

    Olesea Cuzan

    2017-06-01

    Full Text Available The novel N-(methylene-2-pyridine-N,N-bis(diethoxyphosphorylmethylamine ligand (L was obtained through a double Kabachnik-Fields reaction, starting from 2-aminomethyl pyridine (2-picolylamine. Based on the L ligand, a new palladium(II coordination compound [Pd(L2Cl2] has been synthetized and comprehensively characterized by spectroscopic methods (1H NMR, UV-Vis, ESI mass spectrometry and X-ray crystallography.

  12. Synthesis, spectral characterization, thermal and biological studies of lanthanide(III) complexes of oxyphenbutazone

    Institute of Scientific and Technical Information of China (English)

    PS Binil; MR Anoop; KR Jisha; S Suma; MR Sudarsanakumar

    2014-01-01

    Lanthanide(III) complexes of 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione (OPB) were prepared by ho-mogeneous precipitation. The solid complexes were characterized by elemental analysis, magnetic susceptibility data, molar conduc-tivity measurements and IR, UV-Vis, mass, 1H NMR and 13C NMR spectral methods. The thermal decomposition of the complexes under static air atmosphere was investigated by simultaneous TG/DTG at a heating rate of 10 °C/min. The final decomposition prod-ucts were found to be metal oxides. The spectroscopic data suggested that OPB acted as a bidentate, mono-ionic ligand coordinating through two carbonyl oxygens of the pyrazolidinedione ring. The kinetic and thermodynamic parameters such as activation energy, pre-exponential factor and entropy of activation for each step of the decomposition reactions were evaluated using Coats-Redfern and MacCallum-Tanner equations. The negative entropy values of the complexes indicated that the activated complexes had a more or-dered structure than the reactant and that the reactions were slower than normal. Investigations of antimicrobial activity of the com-pounds were carried out by the disk diffusion technique.

  13. Synthesis and spectral characterization of ternary mixed-vanadyl β-diketonate complexes with Schiff bases.

    Science.gov (United States)

    Baranwal, Balram Prasad; Tripathi, Kiran; Singh, Alok Kumar; Tripathi, Saurabh

    2012-06-01

    A new method to synthesize some mononuclear ternary oxovanadium(IV) complexes of the general formula [VO(β-dike)(SB)] (where Hβ-dike=acetylacetone; benzoylacetone or dibenzoylmethane, HSB=Schiff bases) has been explored by stepwise substitutions of acetylacetonate ion of VO(acac)(2) with Schiff bases. The substituted acetylacetone could be fractionated out with p-xylene as an azeotrope. The complexes were characterized by elemental analyses, molecular weight determinations, spectral (electronic, infrared, (1)H NMR, EPR and powder XRD) studies, magnetic susceptibility measurements and cyclic voltammetry. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bidentate chelating nature of β-diketones and Schiff base anions in the complexes was established by infrared and NMR spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. The EPR spectra illustrated coupling of the unpaired electron with (51)V nucleus (I=7/2). Cyclic voltammograms of all the complexes displayed two-step oxidation processes. The oxidation peak potential corresponded to the quasireversible one-electron oxidation process of the metal center, yielding V(V) species. Transmission electron microscopy (TEM) indicated spherical particles of ∼200 nm diameter. The synthesized complexes are mixed-ligand complexes showing a considerable hydrolytic stability in which vanadium is having coordination number 5. A square pyramidal geometry around vanadium has been assigned in all the complexes.

  14. Highly luminescent lanthanide complexes with novel bis-β-diketone ligand: synthesis, characterization and photoluminescent properties.

    Science.gov (United States)

    Li, Hong-Feng; Li, Guang-Ming; Chen, Peng; Sun, Wen-Bin; Yan, Peng-Fei

    2012-11-01

    A biphenyl-linked bis-β-diketone ligand, 3,3'-bis(3-phenyl-3-oxopropanol)biphenyl (BPB) has been prepared for the syntheses of a series of dinuclear lanthanide complexes. The ligand bears two benzoyl β-diketonate sites linked by a 3,3'-biphenyl spacer. Reaction of the doubly negatively charged bis-bidenate ligand with lanthanide ions forms triple-stranded dinuclear complexes Ln(2)(BPB)(3) (Ln=Nd (1), Sm (2), Eu (3), Yb (4) and Gd (5)). Electrospray mass spectrometry is used to identify the formation of the triple-stranded dinuclear complexes 1-5, which have been further characterized by various spectroscopic techniques. The complexes display strong visible and NIR luminescence upon excitation at ligands bands around 360 nm, depending on the choice of the lanthanides, and the emission quantum yields and luminescence lifetimes of 2-3 have been determined. It shows that the biphenyl-linked ligand BPB is a more efficient sensitizer than the monodiketone ligand DBM (dibenzoylmethane), through the comparisons of Ln(2)(BPB)(3) and Ln(DBM)(3) on their photoluminescent properties.

  15. Highly luminescent lanthanide complexes with novel bis-β-diketone ligand: Synthesis, characterization and photoluminescent properties

    Science.gov (United States)

    Li, Hong-Feng; Li, Guang-Ming; Chen, Peng; Sun, Wen-Bin; Yan, Peng-Fei

    2012-11-01

    A biphenyl-linked bis-β-diketone ligand, 3,3'-bis(3-phenyl-3-oxopropanol)biphenyl (BPB) has been prepared for the syntheses of a series of dinuclear lanthanide complexes. The ligand bears two benzoyl β-diketonate sites linked by a 3,3'-biphenyl spacer. Reaction of the doubly negatively charged bis-bidenate ligand with lanthanide ions forms triple-stranded dinuclear complexes Ln2(BPB)3 (Ln = Nd (1), Sm (2), Eu (3), Yb (4) and Gd (5)). Electrospray mass spectrometry is used to identify the formation of the triple-stranded dinuclear complexes 1-5, which have been further characterized by various spectroscopic techniques. The complexes display strong visible and NIR luminescence upon excitation at ligands bands around 360 nm, depending on the choice of the lanthanides, and the emission quantum yields and luminescence lifetimes of 2-3 have been determined. It shows that the biphenyl-linked ligand BPB is a more efficient sensitizer than the monodiketone ligand DBM (dibenzoylmethane), through the comparisons of Ln2(BPB)3 and Ln(DBM)3 on their photoluminescent properties.

  16. Cu(II), Ni(II), and Zn(II) Complexes of Salan-Type Ligand Containing Ester Groups: Synthesis, Characterization, Electrochemical Properties, and In Vitro Biological Activities

    OpenAIRE

    Jeslin Kanaga Inba, P.; B. Annaraj; Thalamuthu, S.; Neelakantan, M.A.

    2013-01-01

    A salen ligand on reduction and N-alkylation affords a novel [N2O2] chelating ligand containing ester groups [L = diethyl-2,2′-(propane-1,3-diylbis((2-hydroxy-3-methoxy benzyl)azanediyl))diacetate]. The purity of the ligand was confirmed by NMR and HPLC chromatograms. Its Cu(II), Ni(II), and Zn(II) complexes were synthesized and characterized by a combination of elemental analysis, IR, NMR, UV-Vis, and mass spectral data, and thermogravimetric analysis (TG/DTA). The magnetic moments, UV-Vis, ...

  17. Phosphine-free synthesis of CdSe quantum dots in a new co-capping ligand system.

    Science.gov (United States)

    Wang, Chun; Jiang, Yang; Zhang, Zhongping; Li, Guohua; Chen, Lanlan; Jie, Jiansheng

    2009-08-01

    High-quality CdSe quantum dots with zinc blende structure were successfully synthesized via a new cheaper, greener phosphine-free route, using environmentally friendly N,N-dimethyl-oleoyl amide as the solvent of Se. The process eliminates trioctylphoshine from the synthesis, using oleic acid (OA) as a primary capping ligand and benzophenone (BP) as a secondary ligand in the noncoordinating solvent. It has been found that the addition of BP can improve the size distribution (below 10%) of as-synthesized CdSe quantum dots greatly, and the nucleation and growth process can also be well-separated. Moreover, a comprehensive examination on the control of particle size and size distribution was performed by systematically varying the BP/OA molar ratio. The phosphine-free route enables us to obtain high-quality CdSe quantum dots with sharp UV-vis absorption peak, size ranging from 2.8 to 6.8 nm, and narrow full width of half-maximum between 27 and 35 nm with purely band-edge luminescence, and without any post-synthesis processing.

  18. Quaternary Cu2ZnSnS4 quantum dot-sensitized solar cells: Synthesis, passivation and ligand exchange

    Science.gov (United States)

    Bai, Bing; Kou, Dongxing; Zhou, Wenhui; Zhou, Zhengji; Tian, Qingwen; Meng, Yuena; Wu, Sixin

    2016-06-01

    The quaternary Cu2ZnSnS4 (CZTS) QDs had been successfully introduced into quantum dot-sensitized solar cells (QDSC) via hydrolysis approach in our previous work [Green Chem. 2015, vol. 17, p. 4377], but the obtained cell efficiency was still limited by low open-circuit voltage and fill factor. Herein, we use 1-dodecanethiol (DDT) as capping ligand for fairly small-sized CZTS QDs synthesis to improve their intrinsic properties. Since this strong bonded capping ligand can not be replaced by 3-mercaptopropionic acid (MPA) directly, the nature cation (Cu, Zn or Sn)-DDT units of QDs are first exchanged by the preconjugated Cd-oleate via successive ionic layer adsorption and reaction (SILAR) procedure accompanied with the formation of a core/shell structure. The weak bonded oleic acid (OA) can be finally replaced by MPA and the constructed water soluble CZTS/CdSe QDSC achieves an impressive conversion efficiency of 4.70%. The electron transport and recombination dynamic processes are confirmed by intensity-modulated photocurrent spectroscopy (IMPS)/intensity-modulated photovoltage spectroscopy (IMVS) measurements. It is found that the removal of long alkyl chain is conducive to improve the electron transport process and the type-II core/shell structure is beneficial to accelerate electron transport and retard charge recombination. This effective ligand removal strategy is proved to be more convenient for the applying of quaternary QDs in QDSC and would boost a more powerful efficiency in the future work.

  19. Copper(I) complexes with trispyrazolylmethane ligands: synthesis, characterization, and catalytic activity in cross-coupling reactions.

    Science.gov (United States)

    Haldón, Estela; Álvarez, Eleuterio; Nicasio, M Carmen; Pérez, Pedro J

    2012-08-01

    Three novel Cu(I) complexes bearing tris(pyrazolyl)methane ligands, Tpm(x), have been prepared from reactions of equimolar amounts of CuI and the ligands Tpm, (HC(pz)(3)), Tpm*, (HC(3,5-Me(2)-pz)(3)), and Tpm(Ms), (HC(3-Ms-pz)(3)). X-ray diffraction studies have shown that the Tpm and Tpm(Ms) derivatives exhibit a 2:1 Cu:ligand ratio, whereas the Tpm* complex is a mononuclear species in nature. The latter has been employed as a precatalyst in the arylation of amides and aromatic thiols with good activity. The synthesis of a Tpm*Cu(I)-phthalimidate, a feasible intermediate in this catalytic process, has also been performed. Low temperature (1)H NMR studies in CDCl(3) have indicated that this complex exists in solution as a mixture of two, neutral and ionic forms. Conductivity measurements have reinforced this proposal, the ionic form predominating in a very polar solvent such as DMSO. The reaction of Tpm*Cu(I)-phthalimidate with iodobenzene afforded the expected C-N coupling product in 76% yield accounting for its role as an intermediate in this transformation.

  20. Multimetallic ruthenium(II) complexes based on biimidazole and bibenzimidazole: Effect of dianionic bridging ligands on Redox and spectral properties

    Energy Technology Data Exchange (ETDEWEB)

    Rillema, D.P.; Sahai, R.; Matthews, P.; Edwards, A.K.; Shaver, R.J.; Morgan, L. (Univ. of North Carolina, Charlotte (USA))

    1990-01-24

    The preparation and properties of ruthenium(II) complexes containing the ligands 2,2{prime}-biimidazole (BiImH{sub 2}), 2,2{prime}-bibenzimidazole (BiBzImH{sub 2}), and 2,2{prime}-bipyridine (bpy) are reported. The complexes described are ((Ru(bpy){sub 2}){sub 2}BiIm){sup 2+} and the series (Ru-(bpy){sub n}(BiImH{sub 2}){sub 3{minus}n}){sup 2+}, (Ru(bpy){sub n}(BiBzImH{sub 2}){sub 3{minus}n}){sup 2+}, and (Ru(bpy){sub n}(BiBzImRu(bpy){sub 2}){sub 3{minus}n}){sup 2+}, n = 0-2. The redox potential for the first Ru{sup 3+/2+} couple shifted negatively from 1.26 to {minus}0.26 V vs SSCE as bpy ligands were replaced by BiImH{sub 2}, BiBzImH{sub 2}, and BiBzImRu(bpy){sub 2} ligands. Reductions were found in the {minus}1.5- to {minus}1.6-V range for complexes containing bypyridine ligands, but none were observed out to {minus}2.0 V for (Ru(BiImH{sub 2}){sub 3}){sup 2+} or (Ru(BiBzImH{sub 2}){sub 3}){sup 2+}. The complexes absorbed energy in the visible and UV regions of the spectrum and emitted radiation, with the exception of the tetrametallic species, in the 600-800-nm region. Estimates of the excited-state redox potentials revealed that the excited-state species were powerful reductants, but were weak oxidants. The (Ru{sup III}-(BiBzImRu{sup II}(bpy){sub 2}){sub 3}){sup 3+} cation absorbed in the near-infrared region at 12.2 {times} 10{sup 3} cm{sup {minus}1} in acetonitrile, but the absorption disappeared upon reduction to (Ru{sup II}(BiBzImRu{sup II}(bpy){sub 2}){sub 3}){sup 2+}. The position of the absorption manifold maximum varied linearly with the static and optical dielectric constant of the solvent. 45 refs., 12 figs., 3 tabs.

  1. Synthesis, characterization and optical properties of low nuclearity liganded silver clusters: Ag31(SG)19 and Ag15(SG)11

    Science.gov (United States)

    Bertorelle, Franck; Hamouda, Ramzi; Rayane, Driss; Broyer, Michel; Antoine, Rodolphe; Dugourd, Philippe; Gell, Lars; Kulesza, Alexander; MitrićPresent Address: Institut Für Physikalische Und Theoretische Chemie, Julius-Maximilians Universität Würzburg, Emil-Fischer-Straße 42, 97074 Würzburg, Germany, Roland; Bonačić-Koutecký, Vlasta

    2013-05-01

    We report a simple synthesis of silver:glutathione (Ag:SG) clusters using a cyclic reduction under oxidative conditions. Two syntheses are described which lead to solutions containing well-defined Ag31(SG)19 and Ag15(SG)11 clusters that have been characterized by mass spectrometry. The optical properties of silver:glutathione (Ag:SG) cluster solutions have been investigated experimentally. In particular, the solution containing Ag15(SG)11 clusters shows a bright and photostable emission. For Ag31(SG)19 and Ag15(SG)11 clusters, the comparison of experimental findings with DFT and TDDFT calculations allowed us to reveal the structural and electronic properties of such low nuclearity liganded silver clusters.We report a simple synthesis of silver:glutathione (Ag:SG) clusters using a cyclic reduction under oxidative conditions. Two syntheses are described which lead to solutions containing well-defined Ag31(SG)19 and Ag15(SG)11 clusters that have been characterized by mass spectrometry. The optical properties of silver:glutathione (Ag:SG) cluster solutions have been investigated experimentally. In particular, the solution containing Ag15(SG)11 clusters shows a bright and photostable emission. For Ag31(SG)19 and Ag15(SG)11 clusters, the comparison of experimental findings with DFT and TDDFT calculations allowed us to reveal the structural and electronic properties of such low nuclearity liganded silver clusters. Electronic supplementary information (ESI) available: Optimal settings for the MS instrument; schematic diagrams for syntheses A and B; ESI mass spectra of silver clusters from ``synthesis A'' in different solvent mixtures, at different pH values and with different synthesis protocols; excitation and emission spectra of clusters from ``synthesis B'' in water and of the separated band after PAGE separation; lifetime measurements of silver clusters from a solution of ``synthesis B'' in water; the structure and absorption spectrum of the two lowest-energy isomers

  2. 80GHz waveform generator by optical Fourier synthesis of four spectral sidebands (Conference Presentation)

    Science.gov (United States)

    Fatome, Julien; Hammani, Kamal; Kibler, Bertrand; Finot, Christophe

    2016-04-01

    Versatile and easy to implement methods to generate arbitrary optical waveforms at high repetition rates are of considerable interest with applications in optical communications, all-optical signal processing, instrumentation systems and microwave signal manipulation. While shaping sinusoidal, Gaussian or hyperbolic secant intensity profiles is commonly achieved by means of modulators or mode-locked lasers, other pulse profiles such as parabolic, triangular or flat-top shapes still remain challenging to synthesize. In this context, several strategies were already explored. First, the linear pulse shaping is a common method to carve an initial ultrashort pulse train into the desired shape. The line-by-line shaping of a coherent frequency comb made of tens of spectral components was also investigated to generate more complex structures whereas Fourier synthesis of a few discrete frequencies spectrum was exploited to efficiently generate high-fidelity ultrafast periodic intensity profiles. Besides linear shaping techniques, several nonlinear methods were implemented to benefit from the adiabatic evolution of the intensity pulse profile upon propagation in optical fibers. Other examples of efficient methods are based on the photonic generation involving specific Mach-Zehnder modulators, microwave photonic filters as well as frequency-to-time conversion. In this contribution, we theoretically and experimentally demonstrate a new approach enabling the synthesis of periodic high-repetition rate pulses with various intensity profiles ranging from parabola to triangular and flat-top pulses. More precisely by linear phase and amplitude shaping of only four spectral lines is it possible to reach the targeted temporal profile. Indeed, tailoring the input symmetric spectrum only requires the determination of two physical parameters: the phase difference between the inner and outer spectral sidebands and the ratio between the amplitude of these sidebands. Therefore, a systematic

  3. Synthesis, structure, redox and spectra of green iridium complexes of tridentate azo-aromatic ligands

    Indian Academy of Sciences (India)

    Manashi Panda; Chayan Das; Chen-Hsiung Hung; Sreebrata Goswami

    2007-01-01

    Reactions of IrCl3$\\cdot$ H2O with the ligands, 2-[(phenylamino)phenylazo]pyridine (HL1a) and 2-[(-tolylamino)phenylazo]pyridine (HL1b) produce [Ir(L1)2]Cl (L1 = L1a, [1]Cl and L1 = L1b, [2]Cl) along with many unidentified products. The iridium complexes have been characterized by various techniques such as X-ray crystallography, mass spectrometry, 1H and 13C NMR, cyclic voltammetry and absorption studies. The complex [1]ClO4 crystallises in triclinic space group. The crystallographic data have been determined. Notably, the Ir-N (azo) lengths are short (av. 1.9875(4) Å) as compared to the remaining four Ir-N lengths (av. 2.052(5) Å). There is significant degree of ligand backbone conjugation in the coordinated ligands, which result in shortening of the C-N lengths on the other side of the middle phenyl ring and also in lengthening of the diazo (N=N) lengths. The complexes display multiple low energy transitions ranging between 1010 and 450 nm. These are electro active and show three reversible redox responses in the potential range, +1.5 V to -1.5 V. The cathodic potential responses are ascribed as ligand reductions, while the redox process at the anodic potential occurs at a mixed metal-ligand (HOMO) orbital.

  4. Tetradentate Schiff base ligands and their complexes: synthesis, structural characterization, thermal, electrochemical and alkane oxidation.

    Science.gov (United States)

    Ceyhan, Gökhan; Köse, Muhammet; McKee, Vickie; Uruş, Serhan; Gölcü, Ayşegül; Tümer, Mehmet

    2012-09-01

    Three Schiff base ligands (H(2)L(1)-H(2)L(3)) with N(2)O(2) donor sites were synthesized by condensation of 1,5-diaminonapthalene with benzaldehyde derivatives. A series of Cu(II), Co(II), Ni(II), Mn(II) and Cr(III) complexes were prepared and characterized by spectroscopic and analytical methods. Thermal, electrochemical and alkane oxidation reactions of the ligands and their metal complexes were investigated. Extensive application of 1D ((1)H, (13)C NMR) and 2D (COSY, HETCOR, HMBC and TOSCY) NMR techniques were used to characterize the structures of the ligands and establish the (1)H and (13)C resonance assignments of the three ligands. Ligands H(2)L(1) and H(2)L(3) were obtained as single crystals from THF solution and characterized by X-ray diffraction. Both molecules are centrosymmetric and asymmetric unit contains one half of the molecule. Catalytic alkane oxidation reactions with the transition metal complexes investigated using cyclohexane and cyclooctane as substrates. The Cu(II) and Cr(III) complexes showed good catalytic activity in the oxidation of cyclohexane and cyclooctane to desired oxidized products. Electrochemical and thermal properties of the compounds were also investigated.

  5. Coinage metal complexes with bridging hybrid phosphine-NHC ligands: synthesis of di- and tetra-nuclear complexes.

    Science.gov (United States)

    Simler, Thomas; Braunstein, Pierre; Danopoulos, Andreas A

    2016-03-28

    A series of P-NHC-type hybrid ligands containing both PR2 and N-heterocyclic carbene (NHC) donors on meta-bis-substituted phenylene backbones, L(Cy), L(tBu) and L(Ph) (R = Cy, tBu, Ph, respectively), was accessed through a modular synthesis from a common precursor, and their coordination chemistry with coinage metals was explored and compared. Metallation of L(Ph)·n(HBr) (n = 1, 2) with Ag2O gave the pseudo-cubane [Ag4Br4(L(Ph))2], isostructural to [Ag4Br4(L(R))2] (R = Cy, tBu) (T. Simler, P. Braunstein and A. A. Danopoulos, Angew. Chem., Int. Ed., 2015, 54, 13691), whereas metallation of ·HBF4 (R = Ph, tBu) led to the dinuclear complexes [Ag2(L(R))2](BF4)2 which, in the solid state, feature heteroleptic Ag centres and a 'head-to-tail' (HT) arrangement of the bridging ligands. In solution, interconversion with the homoleptic 'head-to-head' (HH) isomers is facilitated by ligand fluxionality. 'Head-to-tail' [Cu2Br2(L(R))2] (R = Cy, tBu) dinuclear complexes were obtained from L(R)·HBr and [Cu5(Mes)5], Mes = 2,4,6-trimethylphenyl, which also feature bridging ligands and heteroleptic Cu centres. Although the various ligands L(R)l ed to structurally analogous complexes for R = Cy, tBu and Ph, the rates of dynamic processes occurring in solution are dependent on R, with faster rates for R = Ph. Transmetallation of both NHC and P donor groups from [Ag4Br4(L(tBu))2] to AuI by reaction with [AuCl(THT)] (THT = tetrahydrothiophene) led to L(tBu) transfer and to the dinuclear complex [Au2Cl2L(tBu)] with one L(tBu) ligand bridging the two Au centres. Except for the silver pseudo-cubanes, all other complexes do not exhibit metallophilic interactions.

  6. Synthesis of Janus-like gold nanoparticles with hydrophilic/hydrophobic faces by surface ligand exchange and their self-assemblies in water.

    Science.gov (United States)

    Iida, Ryo; Kawamura, Hitoshi; Niikura, Kenichi; Kimura, Takashi; Sekiguchi, Shota; Joti, Yasumasa; Bessho, Yoshitaka; Mitomo, Hideyuki; Nishino, Yoshinori; Ijiro, Kuniharu

    2015-04-14

    This study aims at the synthesis of Janus gold nanoparticles (Janus GNPs) with hydrophilic/hydrophobic faces by a simple ligand exchange reaction in an homogeneous system and at the elucidation of the self-assembled structures of the Janus GNPs in water. As hydrophilic surface ligands, we synthesized hexaethylene glycol (E6)-terminated thiolate ligands with C3, C7, or C11 alkyl chains, referred to as E6C3, E6C7, and E6C11, respectively. As a hydrophobic ligand, a butyl-headed thiolate ligand C4-E6C11, in which a C4 alkyl was introduced on the E6C11 terminus, was synthesized. The degree of segregation between the two ligands on the GNPs (5 nm in diameter) was examined by matrix-assisted laser desorption/ionization time-of fright mass spectrometry (MALDI-TOF MS) analysis. We found that the choice of immobilization methods, one-step or two-step addition of the two ligands to the GNP solution, crucially affects the degree of segregation. The two-step addition of a hydrophilic ligand (E6C3) followed by a hydrophobic ligand (C4-E6C11) produced a large degree of segregation on the GNPs, providing Janus-like GNPs. When dispersed in water, these Janus-like GNPs formed assemblies of ∼160 nm in diameter, whereas Domain GNPs, in which the two ligands formed partial domains on the surface, were precipitated even when the molar ratio of the hydrophilic ligand and the hydrophobic ligand on the surface of the NPs was almost 1:1. The assembled structure of the Janus-like GNPs in water was directly observed by pulsed coherent X-ray solution scattering using an X-ray free-electron laser, revealing irregular spherical structures with uneven surfaces.

  7. Synthesis and luminescence properties of lanthanide complexes with a new tripodal ligands featuring salicylamide arms.

    Science.gov (United States)

    Song, Xue-Qin; Dong, Wen-Kui; Zhang, Yu-Jie; Liu, Wei-Sheng

    2010-01-01

    A series of luminescent lanthanide complexes with a new tripodal ligand featuring salicylamide arms, 2,2',2''-nitrilotris(2-furfurylaminoformylphenoxy)triethylamine (L), were synthesized and characterized by elemental analysis, IR and molar conductivity measurements. Photophysical properties of the complexes were studied by means of UV-vis absorption and steady-state luminescence spectroscopy. Excited-state luminescence lifetimes and quantum yield of the complexes were determined. Luminescence studies demonstrated that the tripodal ligand featuring salicylamide arms exhibits a good antennae effect with respect to the Tb(III) and Dy(III) ion due to efficient intersystem crossing and ligand to metal energy transfer. From a more general perspective, this work offers interesting perspectives for the development of efficient luminescent stains and enlarges the arsenal for developing novel luminescent lanthanide complexes of salicylamide derivatives.

  8. Imidazole-based Potential Bi- and Tridentate Nitrogen Ligands: Synthesis, Characterization and Application in Asymmetric Catalysis

    Directory of Open Access Journals (Sweden)

    Jiří Kulhánek

    2008-09-01

    Full Text Available Twelve new imidazole-based potential bi- and tridentate ligands were synthesized and characterized. Whereas in the first series the α-amino acid and imidazole moieties were linked by an amino bond, in the second series the tridentate ligands, containing two imidazole groups, were separated by an amide bond. The first series was obtained by the reductive amination of 2-phenylimidazole-4-carboxaldehyde with α-amino acid esters. The tridentate ligands were prepared from 2-phenylimidazole-4-carboxylic acid and chiral amines. In the Henry reaction, the amines were revealed as a more reactive species than the less nucleophilic amides, however the enantiomeric excesses were generally poor.

  9. Synthesis, characterization and luminescent properties of lanthanide complexes with a novel multipodal ligand.

    Science.gov (United States)

    Yan, Zhen-Zhong; Hou, Na; Wang, Cong-Min

    2015-02-25

    Solid complexes of lanthanide nitrates with an novel multipodal ligand, 1,2,4,5-tetramethyl-3,6-bis{N,N-bis[((2'-furfurylaminoformyl)phenoxyl)ethyl]-aminomethyl}-benzene (L) have been synthesized and characterized by elemental analysis, infrared spectra and molar conductivity measurements. At the same time, the luminescent properties of the Sm(III), Eu(III), Tb(III) and Dy(III) nitrate complexes in solid state were investigated. Under the excitation of UV light, these complexes exhibited characteristic emission of central metal ions. The lowest triplet state energy level of the ligand indicates that the triplet state energy level (T1) of the ligand matches better the resonance level of Tb(III) than other lanthanide ions.

  10. Synthesis and photophysical and electrochemical properties of new cyclometalated platinum complex containing oxadiazole ligand

    Institute of Scientific and Technical Information of China (English)

    DENG Ji-yong; LIU Yu; HU Zheng-yong; ZHU Mei-xiang; ZHU Wei-guo

    2007-01-01

    A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-y1)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated.A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about -5.69 and -3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.

  11. Rare Earth Metal Complexes of Bidentate Nitroxide Ligands: Synthesis and Electrochemistry.

    Science.gov (United States)

    Kim, Jee Eon; Bogart, Justin A; Carroll, Patrick J; Schelter, Eric J

    2016-01-19

    We report rare earth metal complexes with tri- and bidentate ligands including strongly electron-donating nitroxide groups. The tridentate ligand 1,3,5-tris(2'-tert-butylhydroxylaminoaryl)benzene (H3arene-triNOx) was complexed to cerium(IV) in a 2:1 ligand-to-metal stoichiometry as Ce(Harene-triNOx)2 (1). Cyclic voltammetry of this compound showed stabilization of the tetravalent cerium cation with a Ce(IV/III) couple at E1/2 = -1.82 V versus Fc/Fc(+). On the basis of the uninvolvement of the third nitroxide group in the coordination chemistry with the cerium(IV) cation, the ligand system was redesigned toward a simpler bidentate mode, and a series of rare earth metal-arene-diNOx complexes were prepared with La(III), Ce(IV), Pr(III), Tb(III), and Y(III), [RE(arene-diNOx)2](-) ([2-RE](-), RE = La, Pr, Y, Tb) and Ce(IV)(arene-diNOx)2, where H2arene-diNOx = 1,3-bis(2'-tert-butylhydroxylaminoaryl)benzene. The core structures were isostructural throughout the series, with three nitroxide groups in η(2) binding modes and one κ(1) nitroxide group coordinated to the metal center in the solid state. In all cases except Ce(IV)(arene-diNOx)2, electrochemical analysis described two subsequent, ligand-based, quasi-reversible redox waves, indicating that a stable [N-O•] group was generated on the electrochemical time scale. Chemical oxidation of the terbium complex was performed, and isolation of the resulting complex, Tb(arene-diNOx)2·CH2Cl2 (3·CH2Cl2), confirmed the assignment of the cyclic voltammograms. Magnetic data showed no evidence of mixing between the Tb(III) states and the states of the open-shell ligand.

  12. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang, E-mail: gfzhang@snnu.edu.cn; Gao, Ziwei, E-mail: zwgao@snnu.edu.cn

    2015-01-15

    A successive anchoring of Ti(NMe{sub 2}){sub 4}, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, {sup 13}C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, {sup 13}C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated.

  13. Synthesis of novel chiral tetraaza ligands and their application in enantioselective transfer hydrogenation of ketones

    Institute of Scientific and Technical Information of China (English)

    Shen Luan Yu; Yan Yun Li; Zhen Rong Dong; Jing Xing Gao

    2012-01-01

    Novel chiral tetraaza ligands (R)-N,N'-bis[2-(piperidin-l-yl)benzylidene]propane-1,2-diamine 6 and (S)-N-[2-(piperidin-1-yl)benzylidene]-3-{ [2-(piperidin-1-yl)benzylidene]amino}-alanine sodium salt 7 have been synthesized and fully characterized by NMR,IR,MS and CD spectra.The catalytic property of the ligands was investigated in Ir-catalyzed enantioselective transfer hydrogenation of ketones.The corresponding optical active alcohols were obtained with high yields and moderate ees under mild reaction conditions.

  14. Synthesis and in vitro evaluation of new diphenyl ether derivatives as serotonin transporter ligands

    Institute of Scientific and Technical Information of China (English)

    GUO YunHang; CHEN XiangJi; JIA HongMei; DEUTHER-CONRAD Winnie; BRUST Peter; STEINBACH Jorg; VERCOUILLIE Johnny; LIU BoLi

    2008-01-01

    For the development of new ligands as potential imaging agents for the serotonin transporter (SERT), a series of diphenyl ether derivatives have been synthesized, characterized, and evaluated for their in vitro binding affinities to the SERT. Among the above compounds, 2-(2-((dimethylamino)methyl)-4-fluoro-phenoxy)-5-bromobenzenamine (15) and 2-(2-((dimethylamino)methyl)-4-fluorophenoxy)-5-iodobenzene respectively. They can be further labeled with carbon-11, fluorine-18, iodine-123 or bromine-76, and evaluated as useful imaging agents for the SERT. Moreover, the study of the structure-activity relationship (SAR) provides some useful information for the future design of new ligands.

  15. Ti (IV complexes of some heterocyclic ligands. Synthesis, characterization and ethylene polymerization activity

    Directory of Open Access Journals (Sweden)

    Hamdi Ali Elagab

    2016-03-01

    Full Text Available 31 complexes of bis - (benzimidazole, benzothiazole and benzoxazole compounds with Ti (IV metal centers were synthesized, characterized, activated with methylalumoxane (MAO and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The highest activity was obtained with 39 / MAO (573 kg PE / mol cat. h. The produced polyethylenes showed high molecular weights (up to 1.5 ×106 g/mol and broad molecular weight distributions (PD = 65. This could result from different interactions of the MAO counterion with the heteroatoms of the catalyst ligand generating different active sites.

  16. Synthesis, spectroscopic characterization, solid state d.c. electrical conductivity and biological studies of some lanthanide(III chloride complexes with a heterocyclic Schiff base ligand

    Directory of Open Access Journals (Sweden)

    K. Mohanan

    2016-07-01

    Full Text Available Condensation of 2-hydroxy-1-naphthaldehyde with 2-amino-3-carboxyethyl-4,5-dimethylthiophene in 1:1 molar ratio, yielded a potentially tridentate Schiff base viz. 2-[N-(2′-hydroxy-1-naphthylideneamino]-3-carboxyethyl-4,5-dimethylthiophene (HNAT. This ligand formed complexes with lanthanum(III, cerium(III, praseodymium(III, neodymium(III, samarium(III, europium(III and gadolinium(III chloride under well defined conditions. These complexes were characterized through elemental analysis, molar conductance, magnetic moment measurements, IR, UV–Vis, FAB mass and 1H NMR spectral studies. Analytical data showed that all the metal complexes exhibited 1:1 metal–ligand ratio. Molar conductance values adequately confirmed the non-electrolytic nature of the metal complexes. The proton NMR spectral observations supplement the IR spectral assignments. The spectral data revealed that the ligand acted as neutral tridentate, coordinating to the metal ion through azomethine nitrogen, ester carbonyl and naphtholate oxygen without deprotonation. The ligand and its lanthanum(III chloride complex were subjected to XRD studies. The lanthanum(III chloride complex has undergone a facile transesterification reaction. The solid state d.c. electrical conductivity of some selected complexes were measured as a function of temperature, indicating the semiconducting nature of the metal complexes. The antimicrobial activities were examined by disk diffusion method against some pathogenic bacterial and fungal species.

  17. SimBAL: A Spectral Synthesis Approach to Analyzing Broad Absorption Line Quasar Spectra

    Science.gov (United States)

    Terndrup, Donald M.; Leighly, Karen; Gallagher, Sarah; Richards, Gordon T.

    2017-01-01

    Broad Absorption Line quasars (BALQSOs) show blueshifted absorption lines in their rest-UV spectra, indicating powerful winds emerging from the central engine. These winds are essential part of quasars: they can carry away angular momentum and thus facilitate accretion through a disk, they can distribute chemically-enriched gas through the intergalactic medium, and they may inject kinetic energy to the host galaxy, influencing its evolution. The traditional method of analyzing BALQSO spectra involves measuring myriad absorption lines, computing the inferred ionic column densities in each feature, and comparing with the output of photonionization models. This method is inefficient and does not handle line blending well. We introduce SimBAL, a spectral synthesis fitting method for BALQSOs, which compares synthetic spectra created from photoionization model results with continuum-normalized observed spectra using Bayesian model calibration. We find that we can obtain an excellent fit to the UV to near-IR spectrum of the low-redshift BALQSO SDSS J0850+4451, including lines from diverse ionization states such as PV, CIII*, SIII, Lyalpha, NV, SiIV, CIV, MgII, and HeI*.

  18. Synthesis, Characterization and Spectral Properties of Substituted Tetraphenylporphyrin Iron Chloride Complexes

    Directory of Open Access Journals (Sweden)

    Kai Li

    2011-04-01

    Full Text Available A series of substituted tetraphenylporphyrin iron chloride complexes [RTPPFe(IIICl, R=o/p-NO2, o/p-Cl, H, o/p-CH3, o/p-OCH3] were synthesized by a novel universal mixed-solvent method and the spectral properties of free base porphyrins and iron porphyrin compounds were compared with each other. The experimental results showed that the one-pot mixed solvent method was superior to the two-step method in the yields, reaction time and workup of reaction mixtures for the synthesis of iron porphyrin compounds. The highest yields (28.7%-40.4% of RTPPFe(IIICl were obtained in the mixed solvents propionic acid, glacial acetic acid and m-nitrotoluene under reflux for 2 h. A detailed analysis of ultraviolet-visible (UV-vis, infrared (IR and far-infrared (FIR spectra suggested the transformation from free base porphyrins to iron porphyrins. The red shift of the Soret band in ultraviolet-visible spectra due to the presence of p-nitrophenyl substituents and the blue shift of Fe-Cl bond of TPPFeCl in far-infrared spectra were further explained by the electron transfer and molecular planarity in the porphyrin ring.

  19. Successful spectral synthesis of Zeeman-split molecular bands in sunspot spectra

    Science.gov (United States)

    Berdyugina, S. V.; Frutiger, C.; Solanki, S. K.; Livingstone, W.

    2000-12-01

    We present the first spectral synthesis of Zeeman-split Stokes profiles of the MgH A2Pi -X2BLAigma green system and TiO gamma -system. The calculations involve different regimes of the molecular Zeeman effect, up to the complete Paschen-Back effect for individual lines. The synthetic spectra are compared with observations of Stokes I and V in sunspot umbrae. We find that although the Stokes I spectra are reasonably reproduced, some lines are obviously still missing from the employed line lists. The Stokes V spectra turn out to be much cleaner since the missing lines do not appear to be Zeeman-split. We thus provide the first good fit to Zeeman-split molecular lines, including profiles with unconventional Stokes V shapes, determined by the Paschen-Back effect. Based on observations from the Canada-France-Hawaii Telescope operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique de France and the University of Hawaii

  20. Instant Ligand Libraries. Parallel Synthesis of Monodentate Phosphoramidites and in Situ Screening in Asymmetric Hydrogenation

    NARCIS (Netherlands)

    Lefort, Laurent; Boogers, Jeroen A.F.; Vries, André H.M. de; Vries, Johannes G. de

    2004-01-01

    Chiral phosphoramidites have been identified as excellent ligands for various metal-catalyzed enantioselective transformations. Taking advantage of their easy preparation and modular nature, we designed a fully automated protocol for the parallel preparation of a library of 32 phosphoramidites and i

  1. Organo-gallium and indium complexes with dithiolate and oxo ligands: Synthesis, structures and applications

    Indian Academy of Sciences (India)

    Vimal K Jain; Amey Wadawale; Nisha P Kushwah; Manoj K Pal

    2011-03-01

    The chemistry of organo-gallium and indium complexes with dithiolate and internally functionalised oxo ligands has been explored. With 1,1-dithiolate ligands both classical and organometallic complexes of gallium and indium, [M(S$^\\cap$S)3], [RM(S$^\\cap$S)2] and [R2M(S$^\\cap$S)] (where R = Me or Et; M = Ga or In; S$^\\cap$S = RCS2, ROCS2, R2NCS2 and (RO)2PS2) have been isolated. Reactions of internally functionalised oxo ligands with R3MR$\\cdot$OEt2 afforded diorganometal complexes [R2ML]. Molecular structures of several of these complexes have been established by single crystal X-ray diffraction analyses. Complexes derived from oxo ligands showed photoluminescence. They have been used as alkylating agents for C-C coupling reactions of aryl bromides in the presence of PdCl2(PPh3)2. Indium dithiolate complexes have been used as molecular precursors for the preparation of mono dispersed ẞ-In2S3 nanoparticles.

  2. Synthesis of triple-stranded complexes using bis(dipyrromethene) ligands.

    Science.gov (United States)

    Zhang, Zhan; Dolphin, David

    2010-12-20

    The reaction of an α-free, β,β'-linked bis(dipyrromethene) ligand with Fe(3+) or Co(3+) led to noninterconvertible triple-stranded helicates and mesocates. In the present context, a stable α-free ligand 2 has been developed and complexation of ligands 1 and 2 with diamagnetic Co(3+), Ga(3+), and In(3+) has been studied. The triple-stranded M(2)1(3) (M = Ga, In) and M(2)2(3) (M = Co, Ga, In) complexes were characterized using matrix-assisted laser desorption ionization time-of-flight spectrometry, (1)H NMR and UV-vis spectroscopy, and X-ray crystallography. Again, the (1)H NMR analysis showed that both the triple-stranded helicates and mesocates were generated in this metal-directed assembly. Consistent with our previous finding on coordinatively inert Co(3+) complexes, variable-temperature NMR spectroscopy indicated that the triple-stranded helicate and mesocate of labile In(3+) did not interconvert in solution, either. However, the diastereoselectivity of the M(2)2(3) complexes was found to improve with an increase in the reaction temperature. Taken together, this study complements the coordination chemistry of poly(dipyrromethene) ligands and provides further insight into the formation of helicates versus mesocates.

  3. Synthesis and evaluation of peptide and nucleic acid based Toll-like receptor ligands

    NARCIS (Netherlands)

    Weterings, Josephus Johannes

    2008-01-01

    Toll-like receptors (TLRs) are receptors that continuously scour their direct surroundings for pathogen associated molecular patterns (PAMPs) of bacterial, viral or fungal origin. TLRs can be found at cells that play a role in the immune system. Binding of the TLR with its corresponding ligand

  4. Synthesis of Two Blue-light - emitting Complexes with Schiff Base Calixarene as the Ligand

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two new blue luminescent zinc and beryllium complexes with Schiff base calixarene derivative as the ligand were prepared. Their luminescent properties were determined, which indicated that they had strong blue fluorescent properties. They also had good solubility and film formation. These new complexes can be used as blue organic electroluminescent materials (OELMs) in organic electroluminescent devices.

  5. Synthesis and anti-fungicidal activity of some transition metal complexes with benzimidazole dithiocarbamate ligand

    Science.gov (United States)

    Mohamed, Gehad G.; Ibrahim, Nasser A.; Attia, Hanaa A. E.

    2009-04-01

    Seven transition metal complexes of benzimidazole ligand (HL) are reported and characterized based on elemental analyses, IR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TGA and DTA). From the obtained data, the complexes were proposed to have the general formulae [MX 2(HL)(H 2O)]· yH 2O, where M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cr(III); X = Cl -, SO 42- and y = 0-4. The molar conductance data revealed that all the metal chelates were non-electrolytes. From the magnetic and solid reflectance spectra, it was found that the geometrical structure of these complexes is octahedral. The thermal behaviour of these chelates showed that the hydrated complexes loss water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. Fungicidal activity of the prepared complexes and free ligand was evaluated against three soil borne fungi. Data obtained showed the higher biological activity of the prepared complexes than the parent Schiff base ligand. Formulation of the most potent complex was carried out in the form of 25% WP. Fungicidal activity of the new formulation was evaluated and compared with the standard fungicide Pencycuron (Monceren 25% WP). In most cases, the new formulation possessed higher fungicidal activity than the standard fungicide under the laboratory conditions.

  6. Synthesis, crystal structure and photoluminescence property of Eu/Tb MOFs with mixed polycarboxylate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lu; Zhang, Sheng; Qu, Xiaoni; Yang, Qi [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127 (China); Liu, Xiangyu [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127 (China); School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021 (China); Wei, Qing; Xie, Gang [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127 (China); Chen, Sanping, E-mail: sanpingchen@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127 (China)

    2015-11-15

    Lanthanide MOFs, [Eu(TCA)(NDC)·H{sub 2}O]{sub n} (1) and [Tb(TCA)(NDC)·H{sub 2}O]{sub n} (2), have been prepared with the mixed aromatic carboxylate ligands, namely, 4,4′,4″-tricarboxytriphenylamine (H{sub 3}TCA) and 1,4-naphthalenedicarboxylate (H{sub 2}NDC). Single-crystal X-ray diffraction analysis reveals that isomorphic 1 and 2 present pillar-layered 3D framework that Eu/Tb(III) bond with carboxylate in various coordination fashions. Optical investigation indicates that the as-prepared compounds feature characteristic luminescence emission bands of Eu/Tb ions in the visible regions at room temperature. Moreover, compound 2 shows a relatively longer luminescence lifetime (τ=0.342 ms) and significantly enhanced quantum yield (Φ{sub overall}=11%) comparing with those of 1 (τ=0.335 ms, Φ{sub overall}=0.06%). - Graphical abstract: Synoptic: Two Ln-MOFs (Ln=Eu{sup III}, Tb{sup III}) with mixed polycarboxylate ligands present different luminescent properties. - Highlights: • Two Eu/Tb-MOFs with H{sub 3}TCA and H{sub 2}NDC ligands have been obtained. • The ancillary ligand is employed to decrease water molecule coordinate numbers. • 2displays superior quantum yield and lifetime than those of 1.

  7. Synthesis and Base Hydrolysis of a Cobalt(III) Complex Coordinated by a Thioether Ligand

    Science.gov (United States)

    Roecker, Lee

    2008-01-01

    A two-week laboratory experiment for students in advanced inorganic chemistry is described. Students prepare and characterize a cobalt(III) complex coordinated by a thioether ligand during the first week of the experiment and then study the kinetics of Co-S bond cleavage in basic solution during the second week. The synthetic portion of the…

  8. Synthesis and pharmacological evaluation of benzofuran-acetamides as "antineophobic" mitochondrial DBI receptor complex ligands

    NARCIS (Netherlands)

    Liao, Y; Kozikowski, AP; Guidotti, A; Costa, E

    1998-01-01

    A series of novel benzofuran analogues of N,N-di-n-hexyl-2-phenylindole-3-acetamide (5, FGIN-1-27), a potent and highly specific mitochondrial DBI receptor complex ligand, were synthesized by a modified Fischer method and found in vitro and in vivo to be equally potent and selective as FGIN-1-27. (C

  9. Synthesis, Structures and Properties of Cobalt Thiocyanate Coordination Compounds with 4-(hydroxymethylpyridine as Co-ligand

    Directory of Open Access Journals (Sweden)

    Stefan Suckert

    2016-04-01

    Full Text Available Reaction of Co(NCS2 with 4-(hydroxymethylpyridine (hmpy leads to the formation of six new coordination compounds with the composition [Co(NCS2(hmpy4] (1, [Co(NCS2(hmpy4] × H2O (1-H2O, [Co(NCS2(hmpy2(EtOH2] (2, [Co(NCS2(hmpy2(H2O2] (3, [Co(NCS2(hmpy2]n∙4 H2O (4 and [Co(NCS2(hmpy2]n (5. They were characterized by single crystal and powder X-ray diffraction experiments, thermal and elemental analysis, IR and magnetic measurements. Compound 1 and 1-H2O form discrete complexes, in which the Co(II cations are octahedrally coordinated by two terminal thiocyanato anions and four 4-(hydroxymethylpyridine ligands. Discrete complexes were also observed for compounds 2 and 3 where two of the hmpy ligands were substituted by solvent, either water (3 or ethanol (2. In contrast, in compounds 4 and 5, the Co(II cations are linked into chains by bridging 4-(hydroxymethylpyridine ligands. The phase purity was checked with X-ray powder diffraction. Thermogravimetric measurements showed that compound 3 transforms into 5 upon heating, whereas the back transformation occurs upon resolvation. Magnetic measurements did not show any magnetic exchange via the hmpy ligand for compound 5.

  10. Synthesis and Characterization of Chiral Organogallium and Indium Complexes with Salen Ligands

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several new chiral organogallium and indium complexes with chiral Salen (1 and 2) as anxciliary ligands have been synthesized and characterized by elemental analysis, IR, 1H NMR and Mass spectroscopy. For the gallium, mono and bimetallic complexes were obtained, whereas ring closure complexes of indium were obtained.

  11. Synthesis, EPR and Fluorescence Properties of Quaternary Lanthanide Complexes with Chloroacetate and Phenanthroline Ligands

    Institute of Scientific and Technical Information of China (English)

    朱龙观; 肖洪平

    2002-01-01

    A series of novel quaternary mixed anion complexes of lanthanide containing 1,10-phenanthroline (phen) and chloroacetate ligands were synthesized from the water/ethanol solution with slightly acidic solution and characterized by elemental analysis, IR, UV and thermal analysis. The EPR and fluorescence properties also were studied.

  12. Synthesis, fluorescence properties of Eu(Ⅲ) complexes with novel carbazolefunctionalized β-diketone ligand

    Institute of Scientific and Technical Information of China (English)

    TANG Ruiren; ZHANG Wei; LUO Yiming; LI Jun

    2009-01-01

    A novel carbazole functionalized β-diketone, methyl 6-(9-ethylcarbazole-3-yl)-oxoacetyl-2-pyridinecarboxylate (MEP), and its Corresponding Corresponding binary Eu(Ⅲ) complexes Eu(MEP)32H2O and ternary complex Eu(MEP)3Phen with 1,10-Phenanthroline (Phen) were pre-pared. The ligand was characterized based on elemental analysis, FT-IR, and 1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis (TG-DTA). The investigation of fluorescence properties of the com-plexes Eu(MEP)32H2O and Eu(MEP)3Phen showed that the Eu(Ⅲ) ion could be sensitized efficiently by the ligand to some extent, in par-titular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the π-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.

  13. SYNTHESIS AND CATALYTIC ACTIVITY OF PLATINUM COMPLEX OF ACRYLATE TERPOLYMER WITH Se,N BIDENTATE LIGAND

    Institute of Scientific and Technical Information of China (English)

    MengLingzhi; QiLiangwei; 等

    1998-01-01

    Acrylate terpolymer-bound Se,N bidentate ligand was synthesized from the side chain chlorine of copolymer and β-dimethylamino-β′-hydroxyl-diethyl selenoether.The polymer-supported platinum complex exhibited high catalytic activity in the hydrosilylation of olefins with triethoxysilane.

  14. Synthesis and Base Hydrolysis of a Cobalt(III) Complex Coordinated by a Thioether Ligand

    Science.gov (United States)

    Roecker, Lee

    2008-01-01

    A two-week laboratory experiment for students in advanced inorganic chemistry is described. Students prepare and characterize a cobalt(III) complex coordinated by a thioether ligand during the first week of the experiment and then study the kinetics of Co-S bond cleavage in basic solution during the second week. The synthetic portion of the…

  15. Synthesis, spectral characterisation, morphology, biological activity and DNA cleavage studies of metal complexes with chromone Schiff base

    Directory of Open Access Journals (Sweden)

    P. Kavitha

    2016-07-01

    Full Text Available Cu(II, Co(II, Ni(II and Zn(II complexes have been synthesized using 3-((pyridine-2-yliminomethyl-4H-chromen-4-one as a ligand derived from 3-formyl chromone and 2-amino pyridine. All the complexes were characterised by analytical, conductivity, IR, electronic, magnetic, ESR, thermal, powder XRD and SEM studies. The analytical data revealed that the metal to ligand molar ratio is 1:2 in all the complexes. Molar conductivity data indicates that all the complexes are neutral in nature. On the basis of magnetic and electronic spectral data, octahedral geometry is proposed for all the complexes. Thermal behaviour of the synthesized complexes indicates the coordinated and lattice water molecules are present in the complexes. The X-ray diffraction data suggest a triclinic system for all compounds. Different surface morphologies were identified from SEM micrographs. All metal complexes exhibit fluorescence. The antimicrobial and nematicidal activity data show that metal complexes are more potent than the parent ligand. The DNA cleavage activity of the ligand and its metal complexes were observed in the presence of H2O2.

  16. Synthesis, spectral characterization and thermal aspects of coordination polymers of some transition metal ions with adipoyl bis(isonicotinoylhydrazone)

    Science.gov (United States)

    Haque, Mahejabeen Azizul; Paliwal, L. J.

    2017-04-01

    A series of metal coordination polymers of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), obtained by the reaction of metal acetate with newly synthesized adipoyl bis(isonicotinoylhydrazone) (ADBI) have been investigated. The ligand has been characterized by 1H NMR, 13C NMR, FTIR, and ESI mass spectra. Structural and spectroscopic characterization of the coordination polymers have been carried out using elemental analysis, XRD, SEM, infrared and diffused reflectance spectra, magnetic susceptibility measurements and thermogravimetric analytical techniques. Each metal ion is coordinated to the ligand through oxygen of carbonyl group and the nitrogen of azomethine group of ligand forming a stable 5-membered heterocyclic ring. The synthesized ligand coordinates in an octadentate manner. Magnetic and diffused reflectance spectral studies reveal octahedral geometry of Co(II), Cu(II), Fe(II) and Ni(II) coordination polymers and tetrahedral geometry of Mn(II) and Zn(II) coordination polymers. The thermal stability and decomposition steps of all coordination polymers have been studied using TG, DTG and DTA techniques. Moreover, the kinetic parameters such as activation energy (Ea*), order of reaction (n), Arrhenius factor (A), change in entropy (ΔS*), change in enthalpy (ΔH*) and free energy change (ΔG*) were evaluated at each stage of decomposition curve using Coats-Redfern method.

  17. Investigations into the synthesis and fluorescence properties of Tb(III) complexes of a novel bis-beta-diketone-type ligand and a novel bispyrazole ligand.

    Science.gov (United States)

    Xiao, Lin-Xiang; Luo, Yi-Ming; Chen, Zhe; Li, Jun; Tang, Rui-Ren

    2008-11-15

    A novel bis-beta-diketone organic ligand, 1,1'-(2,6-bispyridyl)bis-3-(p-methoxyphenyl)-1,3-propanedione (L1) and its derivatives, a novel bispyrazole ligand, 2,6-bis(5-(4-methoxyphenyl)-1H-pyrazol-3-yl)pyridine (L2) were designed and synthesized and their complexes with Tb(III) ion were successfully prepared. The ligands and the corresponding metal complexes were characterized by elemental analysis, infrared, proton nuclear magnetic resonance spectroscopy and TG-DTA. Analysis of the IR spectra suggested that the lanthanide metal ion Tb(III) coordinated to the ligands via the nitrogen atom of the pyridine ring and the carbonyl oxygen atoms for ligand L1 and the nitrogen atom of the pyrazole ring for ligand L2. The fluorescence properties of the two complexes in solid state were investigated and it was discovered that the Tb(III) ions could be sensitized by both the ligand (L1) and ligand (L2) to some extent. In particular, the complex of ligand (L2) is a better green luminescent material that could be used as a candidate material in organic light-emitting devices (OLEDs) since it could be much better sensitized by the ligand (L2), and the fluorescence intensity of Tb(III) complex of L2 are almost as twice strong as L1's.

  18. Investigations into the synthesis and fluorescence properties of Tb(III) complexes of a novel bis-β-diketone-type ligand and a novel bispyrazole ligand

    Science.gov (United States)

    Xiao, Lin-Xiang; Luo, Yi-Ming; Chen, Zhe; Li, Jun; Tang, Rui-Ren

    2008-11-01

    A novel bis-β-diketone organic ligand, 1,1'-(2,6-bispyridyl)bis-3-( p-methoxyphenyl)-1,3-propanedione (L 1) and its derivatives, a novel bispyrazole ligand, 2,6-bis(5-(4-methoxyphenyl)-1H-pyrazol-3-yl)pyridine (L 2) were designed and synthesized and their complexes with Tb(III) ion were successfully prepared. The ligands and the corresponding metal complexes were characterized by elemental analysis, infrared, proton nuclear magnetic resonance spectroscopy and TG-DTA. Analysis of the IR spectra suggested that the lanthanide metal ion Tb(III) coordinated to the ligands via the nitrogen atom of the pyridine ring and the carbonyl oxygen atoms for ligand L 1 and the nitrogen atom of the pyrazole ring for ligand L 2. The fluorescence properties of the two complexes in solid state were investigated and it was discovered that the Tb(III) ions could be sensitized by both the ligand (L 1) and ligand (L 2) to some extent. In particular, the complex of ligand (L 2) is a better green luminescent material that could be used as a candidate material in organic light-emitting devices (OLEDs) since it could be much better sensitized by the ligand (L 2), and the fluorescence intensity of Tb(III) complex of L 2 are almost as twice strong as L 1's.

  19. Design of HIV-1 protease inhibitors with pyrrolidinones and oxazolidinones as novel P1'-ligands to enhance backbone-binding interactions with protease: synthesis, biological evaluation, and protein-ligand X-ray studies

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Leshchenko-Yashchuk, Sofiya; Anderson, David D.; Baldridge, Abigail; Noetzel, Marcus; Miller, Heather B.; Tie, Yunfeng; Wang, Yuan-Fang; Koh, Yasuhiro; Weber, Irene T.; Mitsuya, Hiroaki; (GSU); (Purdue); (NCI); (Kumamoto University School of Medicine)

    2009-09-02

    Structure-based design, synthesis, and biological evaluation of a series of novel HIV-1 protease inhibitors are described. In an effort to enhance interactions with protease backbone atoms, we have incorporated stereochemically defined methyl-2-pyrrolidinone and methyl oxazolidinone as the P1{prime}-ligands. These ligands are designed to interact with Gly-27{prime} carbonyl and Arg-8 side chain in the S1{prime}-subsite of the HIV protease. We have investigated the potential of these ligands in combination with our previously developed bis-tetrahydrofuran (bis-THF) and cyclopentanyltetrahydrofuran (Cp-THF) as the P2-ligands. Inhibitor 19b with a (R)-aminomethyl-2-pyrrolidinone and a Cp-THF was shown to be the most potent compound. This inhibitor maintained near full potency against multi-PI-resistant clinical HIV-1 variants. A high resolution protein-ligand X-ray crystal structure of 19b-bound HIV-1 protease revealed that the P1{prime}-pyrrolidinone heterocycle and the P2-Cp-ligand are involved in several critical interactions with the backbone atoms in the S1{prime} and S2 subsites of HIV-1 protease.

  20. Five-coordinated oxovanadium(IV) complexes derived from amino acids and ciprofloxacin: synthesis, spectral, antimicrobial, and DNA interaction approach.

    Science.gov (United States)

    Patel, M N; Patel, S H; Chhasatia, M R; Parmar, P A

    2008-12-15

    Five-coordinated oxovanadium(IV) complexes with ciprofloxacin and various uninegative bidentate amino acids have been prepared. The structure of complexes has been investigated using spectral, physicochemical, mass spectroscopy, and elemental analyses. The antimicrobial activities (MIC) of the complexes, ligands, metal salt, and some standard drugs have been evaluated using the doubling dilution technique against Staphylococcus aureus, Bacillus subtilis, Serratia marcescens (gram-positive), and Pseudomonas aeruginosa, and Escherichia coli (gram-negative) bacteria. The result shows the significant increase in the antibacterial activity of the ligand, metal, and ciprofloxacin on complexation. The interaction of the complexes with pBR322 DNA has been investigated using spectroscopic, gel electrophoresis, and viscometric techniques. This shows that the complexes can bind to pBR322 DNA by the intercalative mode. The superoxide dismutase-like activity of the complexes has been determined.

  1. Synthesis of picosecond pulses by spectral compression and shaping of femtosecond pulses in engineered quadratic nonlinear media.

    Science.gov (United States)

    Marangoni, M; Brida, D; Conforti, M; Capobianco, A D; Manzoni, C; Baronio, F; Nalesso, G F; De Angelis, C; Ramponi, R; Cerullo, G

    2009-02-01

    Narrow-bandwidth picosecond pulses of predetermined spectral and temporal shapes are generated with high efficiency by frequency conversion of femtosecond pulses in lithium tantalate crystals with engineered quasi-phase-matching structures. We give examples of the synthesis of Gaussian and super-Gaussian picosecond pulses and also of a pair of synchronized phase-coherent picosecond pulses with a predetermined carrier-frequency difference.

  2. Mononuclear mercury(II) complexes containing bipyridine derivatives and thiocyanate ligands: Synthesis, characterization, crystal structure determination, and luminescent properties

    Science.gov (United States)

    Amani, Vahid; Alizadeh, Robabeh; Alavije, Hanieh Soleimani; Heydari, Samira Fadaei; Abafat, Marzieh

    2017-08-01

    A series of mercury(II) complexes, [Hg(Nsbnd N)(SCN)2] (Nsbnd N is 4,4‧-dimethyl-2,2‧-bipyridine in 1, 5,5‧-dimethyl-2,2‧-bipyridine in 2, 6,6‧-dimethyl-2,2‧-bipyridine in 3 and 6-methyl-2,2‧-bipyridine in 4), were prepared from the reactions of Hg(SCN)2 with mentioned ligands in methanol. Suitable crystals of these complexes were obtained for X-ray diffraction measurement by methanol diffusion into a DMSO solution. The four complexes were thoroughly characterized by spectral methods (IR, UV-Vis, 13C{1H}NMR, 1H NMR and luminescence), elemental analysis (CHNS) and single crystal X-ray diffraction. The X-ray structural analysis indicated that in the structures of these complexes, the mercury(II) cation is four-coordinated in a distorted tetrahedral configuration by two S atoms from two thiocyanate anions and two N atoms from one chelating 2,2‧-bipyridine derivative ligand. Also, in these complexes intermolecular interactions, for example Csbnd H⋯N hydrogen bonds (in 1-4), Csbnd H⋯S hydrogen bonds (in 1, 2 and 4), π … π interactions (in 2-4), Hg⋯N interactions (in 2) and S⋯S interactions (in 4), are effective in the stabilization of the crystal structures and the formation of the 3D supramolecular complexes. Furthermore, the luminescence spectra of the title complexes show that the intensity of their emission bands are stronger than the emission bands for the free bipyridine derivative ligands.

  3. The synthesis and pH-dependent behaviour of Re(CO)3 conjugates with diimine phenolic ligands.

    Science.gov (United States)

    Chanawanno, Kullapa; Engle, James T; Le, Kevin X; Herrick, Richard S; Ziegler, Christopher J

    2013-10-07

    In this report we present a study of a series of Re(CO)3 pyridine-imine complexes with pendant phenol groups. We investigated the effects of the position of the phenol hydroxyl group (para, meta or ortho to the imine) on the steric and electronic characteristics of a series of Re(CO)3X(pyca-C6H4OH) compounds, where X = Cl, Br and pyca = pyridine-2-carbaldehyde imine. These compounds can be generated either via ligand synthesis followed by metal chelation (compound 4) or via a one-pot method (compounds 2, 3, 5 and 6). All six compounds show striking differences in pH-dependent UV-visible absorption based on the position of the phenol hydroxyl group.

  4. Synthesis, physicochemical studies and biological evaluation of unimetallic and heterobimetallic complexes of hexadentate dihydrazone ligands

    Directory of Open Access Journals (Sweden)

    Fathy A. El Saied

    2017-03-01

    Full Text Available A new coordination unimetallic and heterobimetallic complexes of hexadentate N2O4 donor dihydrazone ligands were prepared by the condensation of 4-formyl antipyrine with adipic dihydrazide and succinic dihydrazide. The ligands (1 and (11 and their complexes thoroughly characterized using various analytical, physical and spectroscopic techniques, which indicate a distorted octahedral geometry around the metal ions. The ESR spectra of solid copper(II complexes (2–4 and (12–14 showed axial symmetry with g||>g⊥ > ge, indicating distorted octahedral structure and the presence of the unpaired electron in a d(x2−y2 orbital with significant covalent bond character. The antimicrobial activity results of the metal compounds (2–5, (7, (10, (12–15 and (17 show that, all these complexes exhibit inhibitory moderate to mild effects towards Bacillus subtilis, Escherichia coli and Aspergillus niger.

  5. Cytisine derivatives as high affinity nAChR ligands: synthesis and comparative molecular field analysis.

    Science.gov (United States)

    Nicolotti, O; Canu Boido, C; Sparatore, F; Carotti, A

    2002-06-01

    A number of new N-substituted cytisine derivatives were prepared and tested, along with similar compounds already described by us and others, as high affinity neuronal acetylcholine receptor ligands. Structure-affinity relationships were discussed in the light of our recently proposed pharmacophore model for nicotinic receptor agonists. The most significant physicochemical interactions modulating the receptor-ligand binding were detected at the three dimensional (3D) level by means of comparative molecular field analysis (CoMFA). The best predictive PLS model was a single-field steric model showing good statistical figures: n = 17, Q2 = 0.717, s(ev) = 0.566, r2 = 0.942, s = 0.275.

  6. Synthesis and in vitro evaluation of new diphenyl ether derivatives as serotonin transporter ligands

    Institute of Scientific and Technical Information of China (English)

    DEUTHER-CONRAD; Winnie; BRUST; Peter; STEINBACH; Jrg; VERCOUILLIE; Johnny

    2008-01-01

    For the development of new ligands as potential imaging agents for the serotonin transporter (SERT),a series of diphenyl ether derivatives have been synthesized,characterized,and evaluated for their in vitro binding affinities to the SERT. Among the above compounds,2-(2-((dimethylamino)methyl)-4-fluoro-phenoxy)-5-bromobenzenamine (15) and 2-(2-((dimethylamino)methyl)-4-fluorophenoxy)-5-iodobenzene amine (16) show high binding affinities for the SERT with Ki values of 0.28 and 0.20 nmol·L-1,respectively. They can be further labeled with carbon-11,fluorine-18,iodine-123 or bromine-76,and evaluated as useful imaging agents for the SERT. Moreover,the study of the structure-activity relationship (SAR) provides some useful information for the future design of new ligands.

  7. Synthesis, Structure and Characterization of a Series of Transition Metal Complexes with Tripodal Polyimidazole Ligand

    Institute of Scientific and Technical Information of China (English)

    任颜卫; 吴爱芝; 李珺; 张逢星; 张金花

    2005-01-01

    Five new metal transition metal complexes formed with tripodal polyimidazole ligand tri{2-[2-(1-methyl)imidazoly](methylimino)ethyl}amine ((min)3tren), [Zn(min)3tren](ClO4)2 (1) [Cu(min)3tren](ClO4)2 (2), [Ni(min)3tren]-(ClO4)2 (3), [Co(min)3tren](ClO4)2 (4), and [Mn(min)3tren](ClO4)2·CH3CN (5) were synthesized and characterized by elemental analysis, molar conductances, IR and electronic spectra. Analytical results show 1 : 1 metal-ligand stoichiometry and 2 : 1 type of electrolyte in all metal complexes. The crystal structures of 4 and 5 have been determined. The metal atoms in 4 and 5, being in distorted [MN6] octahedra, are coordinated with three imine nitrogen atoms and three imidazole nitrogen atoms.

  8. Synthesis of Ruthenium(III Phthalocyanine with Di-axial Bromo Ligands - A Promising Molecular Conductor with Giant Negative Magnetoresistance

    Directory of Open Access Journals (Sweden)

    Mario A.V. Gamboa

    2015-01-01

    Full Text Available The electron transport of Phthalocyanines (Pc with central metal and di-axial ligands (such as FeIII(PcL2; where L = CN, Cl, Br originates from its intermolecular Pc π-π orbital overlap while its giant negative magnetoresistance (GNMR arises from its intramolecular Pc-π(HOMO and Fe-d (s=1/2 interaction. However, the π-d interaction tends to localize itinerant electrons resulting in the decrease in the conductivity of the FeIII(PcL2 series compared to the non-magnetic CoIII(PcL2 where π-d interaction is absent. More so, the axial ligand field energy of the FeIII(PcL2 system is found to have the ability to proportionally modulate the π-d interaction. In reference thereof, theoretical calculations point that isostructural RuIII(PcBr2 would provide the best balance of π-d orbital energy interplay. That is, RuIII(PcBr2 is expected to be a molecule with high electrical conductivity and GNMR which would make it an ideal magnetic molecular conductor. This paper reports on the synthesis of RuIII(PcBr2.

  9. Hafnium(IV) chloride complexes with chelating β-ketiminate ligands: Synthesis, spectroscopic characterization and volatility study.

    Science.gov (United States)

    Patil, Siddappa A; Medina, Phillip A; Antic, Aleks; Ziller, Joseph W; Vohs, Jason K; Fahlman, Bradley D

    2015-09-05

    The synthesis and characterization of four new β-ketiminate hafnium(IV) chloride complexes dichloro-bis[4-(phenylamido)pent-3-en-2-one]-hafnium (4a), dichloro-bis[4-(4-methylphenylamido)pent-3-en-2-one]-hafnium (4b), dichloro-bis[4-(4-methoxyphenylamido)pent-3-en-2-one]-hafnium (4c), and dichloro-bis[4-(4-chlorophenylamido)pent-3-en-2-one]-hafnium (4d) are reported. All the complexes (4a-d) were characterized by spectroscopic methods ((1)H NMR, (13)C NMR, IR), and elemental analysis while the compound 4c was further examined by single-crystal X-ray diffraction, revealing that the complex is monomer with the hafnium center in octahedral coordination environment and oxygens of the chelating N-O ligands are trans to each other and the chloride ligands are in a cis arrangement. Volatile trends are established for four new β-ketiminate hafnium(IV) chloride complexes (4a-d). Sublimation enthalpies (ΔHsub) were calculated from thermogravimetric analysis (TGA) data, which show that, the dependence of ΔHsub on the molecular weight (4a-c) and inductive effects from chlorine (4d). Copyright © 2015 Elsevier B.V. All rights reserved.

  10. MiR-155 induction by microbes/microbial ligands requires NF-kB-dependent de novo protein synthesis

    Directory of Open Access Journals (Sweden)

    Susheela eTridandapani

    2012-06-01

    Full Text Available MiR-155 regulates numerous aspects of innate and adaptive immune function. This miR is induced in response to toll-like receptor ligands, cytokines, and microbial infection. We have previously shown that miR-155 is induced in monocytes/macrophages infected with Francisella tularensis and suppresses expression of the inositol phosphatase SHIP to enhance activation of the PI3K/Akt pathway, which in turn promotes favorable responses for the host. Here we examined how miR-155 expression is regulated during infection. First, our data demonstrate that miR-155 can be induced through soluble factors of bacterial origin and not the host. Second, miR-155 induction is not a direct effect of infection and it requires NF-κB signaling to up-regulate fos/jun transcription factors. Finally, we demonstrate that the requirement for NF-κB-dependent de novo protein synthesis is globally shared by microbial ligands and live bacteria. This study provides new insight into the complex regulation of miR-155 during microbial infection.

  11. Synthesis, structural characterization, and magnetic properties of a copper-gadolinium complex derived from a hydroxybenzohydrazide ligand.

    Science.gov (United States)

    Costes, Jean-Pierre; Duhayon, Carine; Vendier, Laure

    2014-02-17

    The reaction of hydroxybenzohydrazide with o-vanillin yields 2-hydroxy-N'-[(2-hydroxy-3-methoxyphenyl)methylidene]benzohydrazide (LH3), a ligand that is able to give mononuclear and tetranuclear copper complexes but also to associate copper and gadolinium ions in a Cu2-Gd2 heterotetranuclear complex. This synthesis is successful if the Gd ions, which are acidic in protic solvents, are introduced in a basic methanol solution of the mononuclear copper complex. In the absence of piperidine, the addition of Gd ions to a methanol solution of the mononuclear copper complex only yields a tetranuclear cubane-type copper complex. This work reports on the first structural characterization of a copper-gadolinium complex involving a benzohydrazide ligand. The resulting complex consists of two Cu-Gd pairs linked by a dihydroxo Gd-Gd bridge, in which the Cu and Gd ions are bridged by a nonsymmetric phenoxo-hydroxo bridge. The magnetostructural correlation between the ferromagnetic coupling constant and the hinge angle observed in symmetrical double-phenoxo Cu-Gd bridges remains valid for dissymmetric Cu-Gd bridges and confirms the preponderance of the structural factor over the nature of the bridge. This tetranuclear complex corresponds to two S = 4 units linked through a dihydroxo bridge introducing a weak antiferromagnetic Gd-Gd interaction and impeding the existence of a S = 8 ground state.

  12. Synthesis of Dendrimer-supported Chiral Bis(oxazoline) Ligands and Their Applications in Aldol Reaction via Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-min; YANG Bai-yuan; ZHANG Yi-li; QU Xue; FAN Qing-hua

    2004-01-01

    Chiral bis(oxazoline) ligands have been applied in many enatioselective reactions.Recently, studies of the immobilization of bis(oxazoline) on both soluble and insoluble supports have been of great interest. Among the different methods to anchor the homogeneous catadysts, a soluble, polymer-supported catalyst usually achieves higher stereoselectivity and activity because the catalysis can be separated and recycled via simple methods such as solvent precipitation.Dendrimers are highly branched macromolecules having precisely defined molecular structures with nano-scale size. Compared with soluble polymer supports, the dendrimer architecture may offer better control of the deposition of the catalytic species in soluble polymer-based catalysts. Therefore,such catalysts may fill the gap between homogeneous and heterogeneous catalysis and combine the advantages of both.In this paper, we report the synthesis of bis(oxazoline)-centered dendrimers and their application in Mukaiyama aldol reaction in aqueous media. It was found that the dendritic chiral bis(oxazolines)showed the similar reactivities and enantioselectivities in the asymmetric copper-catalyzed aldol reaction in aqueous media in comparison to the corresponding small molecular ligands.

  13. Synthesis of mixed silylene-carbene chelate ligands from N-heterocyclic silylcarbenes mediated by nickel.

    Science.gov (United States)

    Tan, Gengwen; Enthaler, Stephan; Inoue, Shigeyoshi; Blom, Burgert; Driess, Matthias

    2015-02-01

    The Ni(II) -mediated tautomerization of the N-heterocyclic hydrosilylcarbene L(2) Si(H)(CH2 )NHC 1, where L(2) =CH(CCH2 )(CMe)(NAr)2 , Ar=2,6-iPr2 C6 H3 ; NHC=3,4,5-trimethylimidazol-2-yliden-6-yl, leads to the first N-heterocyclic silylene (NHSi)-carbene (NHC) chelate ligand in the dibromo nickel(II) complex [L(1) Si:(CH2 )(NHC)NiBr2 ] 2 (L(1) =CH(MeCNAr)2 ). Reduction of 2 with KC8 in the presence of PMe3 as an auxiliary ligand afforded, depending on the reaction time, the N-heterocyclic silyl-NHC bromo Ni(II) complex [L(2) Si(CH2 )NHCNiBr(PMe3 )] 3 and the unique Ni(0) complex [η(2) (Si-H){L(2) Si(H)(CH2 )NHC}Ni(PMe3 )2 ] 4 featuring an agostic SiH→Ni bonding interaction. When 1,2-bis(dimethylphosphino)ethane (DMPE) was employed as an exogenous ligand, the first NHSi-NHC chelate-ligand-stabilized Ni(0) complex [L(1) Si:(CH2 )NHCNi(dmpe)] 5 could be isolated. Moreover, the dicarbonyl Ni(0) complex 6, [L(1) Si:(CH2 )NHCNi(CO)2 ], is easily accessible by the reduction of 2 with K(BHEt3 ) under a CO atmosphere. The complexes were spectroscopically and structurally characterized. Furthermore, complex 2 can serve as an efficient precatalyst for Kumada-Corriu-type cross-coupling reactions.

  14. Synthesis, structure and magnetic properties of two new coordination polymers with carboxylate-substituted benzoimidazole ligands

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper reports two new coordination polymers formed by carboxylate-substituted benzoimidazole and formate ligands: [Mn(L)·(HCO2)]n (1) and [Co(L)·(HCO2)]n (2) (L = benzoimidazol-1-yl-acetate). Com-plexes 1 and 2 are isomorphous and adopt a new 3,6-connected three-nodal topology showing inter-esting magnetic properties: spin canted antiferromagnetism for MnⅡ complex 1, but simple antiferro-magnetic coupling for CoⅡ complex 2.

  15. Synthesis, Spectroscopy and Crystal Structure of a New Copper Complex Builtup by Cationic (Dimethylphosphorylmethanaminium Ligands

    Directory of Open Access Journals (Sweden)

    Manuela E. Richert

    2014-05-01

    Full Text Available A new transition metal complex of the mono-protonated ligand (dimethylphosphorylmethanamine (dpmaH+ was obtained by equimolar reaction of copper(II chloride dihydrate and dpma in concentrated hydrochloric acid. The asymmetric unit of the title structure, [CuCl2(C3H11NOP4][CuCl4]2, consists of one half of a fourfold charged trans-dichloridotetrakis[(dimethylphosphorylmethanaminium]copper(II complex with the copper atom located on an inversion centre and one tetrachloridocuprate(II dianion found in a general position. The copper centre in the cationic complex shows a tetragonally distorted octahedral environment composed of four oxygen atoms in a square plane and two trans-coordinated chlorido ligands. This 4+2-coordination causes elongated Cu-Cl distances because of the Jahn-Teller effect. The geometry of the tetrachloridocuprate(II dianion is best described as a seriously distorted tetrahedron. Analysis of the hydrogen bonding scheme by graph-set theory shows three patterns of rings in the title compound. The cationic copper complex reveals intramolecular hydrogen bonds between two aminium groups and the two axial chlorido ligands. Further hydrogen bonding among the cations and anions, more precisely between four aminium groups and the chlorido ligands of four adjacent tetrachloridocuprate(II anions, lead to a chain-type structure. Comparing the coordination chemistry of the title structure with an analogue cobalt(II compound only disclose differences in hydrogen bonding pattern resulting in an unusual chain propagation. Besides the crystal structure received spectroscopic data are in accordance with appropriate literature.

  16. Synthesis, characterization luminiscence studies and microbial activity of ethylenediamine ruthenium (II) complexes with dipyridophenazine ligands.

    Science.gov (United States)

    Shilpa, Mynam; Nagababu, Penumaka; Kumar, Y Praveen; Latha, J Naveena Lavanya; Reddy, M Rajender; Karthikeyan, K S; Gabra, Nazar Md; Satyanarayana, Sirasani

    2011-05-01

    Three symmetric ligands 7-methyl dipyrido-[3,2-a;2',3'-c]phenazine (dppz-CH(3)), 7-nitro dipyrido-[3,2-a;2',3'-c]phenazine (dppz-NO(2)) and benzo[i]dipyrido-[3,2-a;2',3'-c]phenazine (dppn) and their ruthenium(II) complexes [Ru(en)(2)(L)][ClO(4)](2) (en= ethylenediamine), L= dppz-CH(3), dppz-NO(2) and dppn have been synthesized and characterized by IR, (1)H, (13)C NMR and Mass spectra. The interactions of these complexes with calf thymus DNA have been investigated by spectrophotometric, spectrofluorimetric, circular dichroism, viscosity and thermal denaturation studies. As the planar extension of the intercalative ligand increases, the interaction of the complex with DNA increases, indicating that the size and shape of the intercalalative ligand has a marked effect on the strength of interaction. The plot of log K versus log [Na(+)] yield a slope of -1.26, -1.53, -1.60 for the complexes 1, 2 and 3 respectively. These three complexes have been found to promote the cleavage of plasmid pBR 322 DNA upon irradiation.

  17. Synthesis and Characterization of New Bivalent Agents as Melatonin- and Histamine H3-Ligands

    Directory of Open Access Journals (Sweden)

    Daniele Pala

    2014-09-01

    Full Text Available Melatonin is an endogenous molecule involved in many pathophysiological processes. In addition to the control of circadian rhythms, its antioxidant and neuroprotective properties have been widely described. Thus far, different bivalent compounds composed by a melatonin molecule linked to another neuroprotective agent were synthesized and tested for their ability to block neurodegenerative processes in vitro and in vivo. To identify a novel class of potential neuroprotective compounds, we prepared a series of bivalent ligands, in which a prototypic melatonergic ligand is connected to an imidazole-based H3 receptor antagonist through a flexible linker. Four imidazolyl-alkyloxy-anilinoethylamide derivatives, characterized by linkers of different length, were synthesized and their binding affinity for human MT1, MT2 and H3 receptor subtypes was evaluated. Among the tested compounds, 14c and 14d, bearing a pentyl and a hexyl linker, respectively, were able to bind to all receptor subtypes at micromolar concentrations and represent the first bivalent melatonergic/histaminergic ligands reported so far. These preliminary results, based on binding affinity evaluation, pave the way for the future development of new dual-acting compounds targeting both melatonin and histamine receptors, which could represent promising therapeutic agents for the treatment of neurodegenerative pathologies.

  18. Synthesis and characterization of pseudo-affinity ligand for penicillin acylase purification.

    Science.gov (United States)

    Keçili, Rüstem; Say, Ridvan; Yavuz, Handan

    2006-11-15

    The aim of this work was to test a chromatographic affinity support containing methacryloyl antipyrine (MAAP) for penicillin acylase (PA) purification by using pure penicillin acylase and crude extract. First, MAAP as a pseudo-specific ligand was synthesized by using methacryloyl chloride and 4-aminoantipyrine. Polymer beads (average size diameter: 40-120 micro m) were prepared by suspension polymerization of ethylene glycol dimethacrylate (EGDMA) and MAAP. This approach for the preparation of adsorbent has several advantages over conventional preparation protocols. An expensive and time consuming step in the preparation of adsorbent is immobilization of a ligand to the adsorption matrix. In this procedure, affinity ligand MAAP acts as comonomer without further modification steps. Poly(EGDMA-MAAP) beads were characterized by FTIR, NMR and screen analysis. Elemental analysis of MAAP for nitrogen was estimated as 89.3 micro mol/g. The prepared adsorbent was then used for the capture of penicillin acylase in batch system. The maximum penicillin acylase adsorption capacity of the poly(EGDMA-MAAP) beads was found to be 82.2 mg/g at pH 5.0. Chromatography with crude feedstock resulted in 23.2-fold purification and 93% recovery with 1.0 M NaOH.

  19. Synthesis, spectral characterization, molecular modeling and antimicrobial activity of new potentially N2O2 Schiff base complexes

    Science.gov (United States)

    Adly, Omima M. I.; Taha, Ali; Fahmy, Shery A.

    2013-12-01

    Metal complexes of a new potentially tetradentate symmetrical Schiff base ligand (H2L) with Cu(II), Ni(II), Co(II), VO(IV), Zn(II), Cd(II), Ce(III), Fe(III) and UO2(VI) metal ions have been synthesized and characterized based on their elemental analyses, spectral (IR, UV-Vis, 1H NMR and mass spectra), magnetic and molar conductance studies as well as thermal gravimetric analysis (TGA). The synthesized complexes have the general formula [MHxL(H2O)yXn]: x = 0-1, y = 0-4 and n = 0-1; where: L = dianion of 6-hydroxy-5-[N-(2-{[(1E)-1-(6-hydroxy-2,4-dioxo-3,4-dihydro-2H-1,3-thiazin-5-yl)ethylidene]amino}ethyl) ethanimidoyl]-2H-1,3-thiazine-2,4(3H)-dione and X = nitrate or sulphate anion. The ligand behaves as diabasic tetradentate N2O2 sites, except in cases of Co(II), VO(IV) and UO2(VI) metal ions, it behaves as monobasic tetradentate Schiff base ligand. The metal complexes exhibited square planar, square-pyramidal and octahedral geometrical arrangements except for Ce(III) and UO2(VI) complexes, they are octa-coordinated. The Coats-Redfern equation was used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition stages of some complexes. Structural parameters of the ligand and its metal complexes have been theoretically computed on the basis of semiemperical PM3 level, and the results were correlated with their experimental data. The antimicrobial activities of the ligand and its metal complexes were tested against some Gram-positive and Gram-negative bacteria; and fungus strain and the results were discussed.

  20. Ruthenium(II) complexes bearing pyridine-functionalized N-heterocyclic carbene ligands: Synthesis, structure and catalytic application over amide synthesis

    Indian Academy of Sciences (India)

    MUTHUKUMARAN NIRMALA; PERIASAMY VISWANATHAMURTHI

    2016-11-01

    A series of four imidazolium salts was synthesized by the reaction of 2-bromopyridine with 1- substituted imidazoles. These imidazolium salts (1a–d) were successfully employed as ligand precursors for the syntheses of new ruthenium(II) complexes bearing neutral bidentate ligands of N-heterocyclic carbene and pyridine donor moiety. The NHC-ruthenium(II) complexes (3a–d) were synthesized by reacting the appropriately substituted pyridine-functionalized N-heterocyclic carbenes with Ag₂O forming the NHC–silver bromide in situ followed by transmetalation with [RuHCl(CO)(PPh₃)₃]. The new complexes were characterized by elemental analyses and spectroscopy (IR, UV-Vis, ¹H, ¹³C, ³¹P-NMR) as well as ESI mass spectrometry. Based on the spectral results, an octahedral geometry was assigned for all the complexes. The complexes were shown to be efficient catalysts for the one-pot conversion of various aldehydes to their corresponding primary amides with good to excellent isolated yields using NH₂OH.HCl and NaHCO₃. The effects of solvent, base, temperature, time and catalyst loading were also investigated. A broad range of amides were successfully synthesized with excellent isolated yields using the above optimized protocol. Notably, the complex 3a was found to be a very efficient and versatile catalyst towards amidation of a wide range of aldehydes.

  1. Synthesis and spectral studies on Pb(II) dithiocarbamate complexes containing benzyl and furfuryl groups and their use as precursors for PbS nanoparticles

    Science.gov (United States)

    Sathiyaraj, Ethiraj; Thirumaran, Subbiah

    2012-11-01

    Nine lead bis(dithiocarbamate) complexes based on benzyl and furfuryl groups have been prepared. The complexes were characterized using IR and NMR spectroscopy. All the complexes showed the expected signals in 1H and 13C NMR spectra associated with the dithiocarbamate ligands. IR and 13C NMR spectral studies indicate that the S2Cpdbdtd N double bond character increases with increase in length of alkyl chain bonded to nitrogen atom. Bis(N-benzyl-N-(2-phenylethyl)dithiocarbamato-S,S')lead(II) (3) and bis(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S')lead(II) (4) have been used as single source precursors for the synthesis of ethylenediamine capped PbS nanoparticles. Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), FTIR, UV-vis and fluorescence spectroscopy have been used to characterize the as-prepared lead sulfide nanoparticles. The PXRD measurements suggest that PbS nanoparticles are single phase with face-centered-cubic structure.

  2. The Impact of Surface Ligands and Synthesis Method on the Toxicity of Glutathione-Coated Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Bryan Harper

    2014-05-01

    Full Text Available Gold nanoparticles (AuNPs are increasingly used in biomedical applications, hence understanding the processes that affect their biocompatibility and stability are of significant interest. In this study, we assessed the stability of peptide-capped AuNPs and used the embryonic zebrafish (Danio rerio as a vertebrate system to investigate the impact of synthesis method and purity on their biocompatibility. Using glutathione (GSH as a stabilizer, Au-GSH nanoparticles with identical core sizes were terminally modified with Tryptophan (Trp, Histidine (His or Methionine (Met amino acids and purified by either dialysis or ultracentrifugation. Au-GSH-(Trp2 purified by dialysis elicited significant morbidity and mortality at 200 µg/mL, Au-GSH-(His2 induced morbidity and mortality after purification by either method at 20 and 200 µg/mL, and Au-GSH-(Met2 caused only sublethal responses at 200 µg/mL. Overall, toxicity was significantly reduced and ligand structure was improved by implementing ultracentrifugation purifications at several stages during the multi-step synthesis and surface modification of Au-GSH nanoparticles. When carefully synthesized at high purity, peptide-functionalized AuNPs showed high biocompatibility in biological systems.

  3. Ruthenium(II) arene complexes with oligocationic triarylphosphine ligands: synthesis, DNA interactions and in vitro properties

    NARCIS (Netherlands)

    Snelders, D.J.M.; Casini, A.; Edafe, F.; van Koten, G.; Klein Gebbink, R.J.M.; Dyson, P.J.

    2011-01-01

    The synthesis, DNA binding properties and cytotoxicity of a series of Ru(II)-arene complexes containing oligocationic ammonium-functionalized triarylphosphines, of the type Ru(p-cymene)Cl2(L) (L ¼ oligocationic phosphine), are reported. The complexes are highly charged (the overall charge states bei

  4. Fructose derived pyridyl alcohol ligands: synthesis and application in the asymmetric diethylzinc addition to aldehydes

    Institute of Scientific and Technical Information of China (English)

    ZHOU, Yong-Gui; DAI, Li-Xin; HOU, Xue-Long

    2000-01-01

    Easily available chiral ketones were employed for the synthesis of optically active pyridyl alcohols, which were applied in the asymmetric diethylzinc addition to aldehydes, up to 89.4%e.e. was obtained using D-fructose-derived pyridyl alcohol.

  5. Synthesis and characterization of crystalline structures based on phenylboronate ligands bound to alkaline earth cations.

    Science.gov (United States)

    Reinholdt, Marc; Croissant, Jonas; Di Carlo, Lidia; Granier, Dominique; Gaveau, Philippe; Bégu, Sylvie; Devoisselle, Jean-Marie; Mutin, P Hubert; Smith, Mark E; Bonhomme, Christian; Gervais, Christel; van der Lee, Arie; Laurencin, Danielle

    2011-08-15

    We describe the preparation of the first crystalline compounds based on arylboronate ligands PhB(OH)(3)(-) coordinated to metal cations: [Ca(PhB(OH)(3))(2)], [Sr(PhB(OH)(3))(2)]·H(2)O, and [Ba(PhB(OH)(3))(2)]. The calcium and strontium structures were solved using powder and single-crystal X-ray diffraction, respectively. In both cases, the structures are composed of chains of cations connected through phenylboronate ligands, which interact one with each other to form a 2D lamellar structure. The temperature and pH conditions necessary for the formation of phase-pure compounds were investigated: changes in temperature were found to mainly affect the morphology of the crystallites, whereas strong variations in pH were found to affect the formation of pure phases. All three compounds were characterized using a wide range of analytical techniques (TGA, IR, Raman, XRD, and high resolution (1)H, (11)B, and (13)C solid-state NMR), and the different coordination modes of phenylboronate ligands were analyzed. Two different kinds of hydroxyl groups were identified in the structures: those involved in hydrogen bonds, and those that are effectively "free" and not involved in hydrogen bonds of any significant strength. To position precisely the OH protons within the structures, an NMR-crystallography approach was used: the comparison of experimental and calculated NMR parameters (determined using the Gauge Including Projector Augmented Wave method, GIPAW) allowed the most accurate positions to be identified. In the case of the calcium compound, it was found that it is the (43)Ca NMR data that are critical to help identify the best model of the structure.

  6. Uranyl Sequestration: Synthesis and Structural Characterization of Uranyl Complexes with a Tetradentate Methylterephthalamide Ligand

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Chengbao; Shuh, David; Raymond, Kenneth

    2011-03-07

    Uranyl complexes of a bis(methylterephthalamide) ligand (LH{sub 4}) have been synthesized and characterized by X-ray crystallography. The structure is an unexpected [Me{sub 4}N]{sub 8}[L(UO{sub 2})]{sub 4} tetramer, formed via coordination of the two MeTAM units of L to two uranyl moieties. Addition of KOH to the tetramer gave the corresponding monomeric uranyl methoxide species [Me{sub 4}N]K{sub 2}[LUO{sub 2}(OMe)].

  7. Synthesis and computational studies of Mg complexes supported by 2,2':6,2''-terpyridine ligands.

    Science.gov (United States)

    Guard, Louise M; Palma, Julio L; Stratton, William P; Allen, Laura J; Brudvig, Gary W; Crabtree, Robert H; Batista, Victor S; Hazari, Nilay

    2012-07-14

    The reactions of the substituted 2,2':6,2''-terpyridine ligands, 4'-mesityl-2,2':6',2''-terpyridine (mesitylterpy) (1a), 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine (tri-(t)Buterpy) (1b) and 4'-phenyl-2,2':6',2''-terpyridine (phenylterpy) (1c) with Grignard reagents were investigated. When half an equivalent of mesitylterpy or tri-(t)Buterpy were treated with MeMgBr in diethyl ether, the only products were (R-terpy)MgBr(2) (R = mesityl (5a), or tri-(t)Bu (5b)) and Me(2)Mg and a similar reaction was observed in THF. Compounds 5a and 5b were characterized by X-ray crystallography. Changing the Grignard reagent to PhMgBr also generated 5a and 5b along with Ph(2)Mg, while the reaction between MeMgCl or PhMgCl and 1a or 1b generated (R-terpy)MgCl(2) (R = mesityl (6a), or tri-(t)Bu (6b)) and either Me(2)Mg or Ph(2)Mg, respectively. The products from reactions between phenylterpy (1c) and Grignard reagents were highly insoluble and could not be fully characterized but appeared to be the same as those from reactions with 1a and 1b. In contrast to other studies using tridentate nitrogen ligands, which formed either mixed halide alkyl species or dihalide and bis(alkyl) species depending on whether the Grignard reagent was reacted with the ligand in diethyl ether or THF, the formation of mixed halide, alkyl complexes of the type (R-terpy)MgR'X (R' = Me or Ph; X = Cl or Br) or dialkyl species such as (R-terpy)MgR'(2) (R' = Me or Ph) was not observed here, regardless of the reaction conditions. DFT studies were performed to complement the experimental studies. The experimental results could not be accurately reproduced unless π-stacking effects associated with free terpyridine were included in the model. When these effects were included, the calculations were consistent with the experimental results which indicated that the formation of the terpy Mg dihalide species and R'(2)Mg (R' = Me or Ph) is thermodynamically preferred over the formation of mixed alkyl halide Mg

  8. Synthesis and structural characterization of monomeric mercury(II) selenolate complexes derived from 2-phenylbenzamide ligands.

    Science.gov (United States)

    Patel, Saket; Meenakshi; Hodage, Ananda S; Verma, Ajay; Agrawal, Shailendra; Yadav, Abhimanyu; Kumar, Sangit

    2016-03-07

    Monomeric Hg(II) selenolate complexes derived from 2-phenylbenzamide ligands were prepared by oxidative addition of diselenides [{C6H4(CONR2)Se}2, R = Me, Et, iPr] to elemental Hg and reductive cleavage of the Se–N bond of isoselenazolone derivatives [(NO2)C6H3(CONSe)R, (R = allyl, nbutyl)] followed by the treatment with HgCl2. The complexes have been characterized by multinuclear NMR (1H, 13C and 77Se) spectroscopy and mass spectrometry which suggest the monomeric form of these in solution. The molecular structures of diselenides [C6H4(CONR2)Se]2 and mercury selenolates [Hg{(NO2)C6H3(CONH-C3H5) Se}2], [Hg{C6H4(CONiPr2)Se}2] and [Hg{C6H4(CONMe2)Se}2] were established by a single crystal X-ray diffraction study. Diselenides show strong intramolecular non-bonded Se⋯O interactions, which are influenced by the nature of C(O)NR̲2 and decrease with the sterically bulky alkyl substituent (Se⋯O =2.823 Å for R = di-Me, 2.760 Å for R = allyl, and 3.157 Å for R = di-iPr). Mercury complexes derived from less bulky 2-phenyl-N,N-dialkylbenzamide ligands associated with poor or no intramolecular nonbonded Hg⋯O interactions (4.91 Å for R = di-Me, 4.199 Å for R = allyl) and instead strong intermolecular Hg⋯O [2.792(3) and 2.820(4) Å] for di-Me and allyl and Hg⋯Se [3.3212(5) and 3.4076(8) Å] interactions were observed which lead to a dimeric form in the crystals. On the other hand, the mercury complex derived from the sterically bulky diisopropyl amide ligand shows a strong intramolecular non-bonded Hg⋯O (2.860 Å) interaction, adopts linear geometry and exists as a monomer. Thermogravimetric analysis (TGA) of the mercury selenolate complexes revealed two-step decomposition which leads to the formation of HgSe. The mercury selenolate complex 3c derived from the sterically bulky 2-phenyl-N,Ndiisopropylbenzamide ligand decomposed to give HgSe in the range of 220-300 °C.

  9. Synthesis and Electronic Structure Determination of Uranium(VI) Ligand Radical Complexes

    OpenAIRE

    Herasymchuk, Khrystyna; Chiang, Linus; Hayes, Cassandra E.; Brown, Matthew L; Ovens, Jeffrey S.; Patrick, Brian; Leznoff, Daniel B.; Storr, Tim

    2016-01-01

       Pentagonal bipyramidal uranyl complexes of salen ligands, N,N’-bis(3-tert-butyl-(5R)-salicylidene)-1,2-phenylenediamine, in which R = tBu (1a), OMe (1b), and NMe2 (1c), were prepared and the electronic structure of the one-electron oxidized species [1a-c]+ were investigated in solution. The solid-state structures of 1a and 1b were solved by X-ray crystallography, and in the case of 1b an asymmetric UO22+ unit was found due to an intermolecular hydrogen bonding interaction. Ele...

  10. Synthesis of Novel Chiral Biphenylamine Ligand 6,6′- Dimethoxy-2,2′- diaminobiphenyl

    Institute of Scientific and Technical Information of China (English)

    CHEN,Yi-Xin (陈亿新); LI,Yue-Ming(李月明); LAM,Kim-Hung(林剑虹); CHAN,Albers S.C. (陈新滋)

    2001-01-01

    A new chiral ligand 6,6′-dimethoxy-2,2′-diaminobiphenyl was successfully prepared from 3-nitrophenol via iodination, Ulmann coupling, and reduction. The resolving reagent (2R,3R)- or (2S,3S)-2,3-di(phenylaminocarbonyl)tartaric acid was prepared from commercially available tartaric acid in large scale and was used to resolve the racemic 6,6′- dimethoxy-2,2′-diaminobiphenyl. The chiral 6,6′- dimethoxy-2,2′-diaminobiphenyl obtained was proved to be enantiomerically pure.

  11. Uranyl Sequestration: Synthesis and Structural Characterization of Uranyl Complexes with a Tetradentate Methylterephthalamide Ligand

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Chengbao; Shuh, David; Raymond, Kenneth

    2011-03-07

    Uranyl complexes of a bis(methylterephthalamide) ligand (LH{sub 4}) have been synthesized and characterized by X-ray crystallography. The structure is an unexpected [Me{sub 4}N]{sub 8}[L(UO{sub 2})]{sub 4} tetramer, formed via coordination of the two MeTAM units of L to two uranyl moieties. Addition of KOH to the tetramer gave the corresponding monomeric uranyl methoxide species [Me{sub 4}N]K{sub 2}[LUO{sub 2}(OMe)].

  12. A novel terbium complex using oxadiazole derivative as a neutral ligand: Synthesis and properties

    Institute of Scientific and Technical Information of China (English)

    Yu Liu; Kong Qiang Xing; Ji Yong Deng; Mei Xiang Zhu; Xia Yu Wang; Wei Guo Zhu

    2007-01-01

    A novel terbium complex using 1,3,4-oxadiazole derivative as a neutral ligand was synthesized and characterized. Its thermal stability and photoluminescent properties were studied. The strong emission peaked at 546 nm with a full width at half maximum of 5 nm was observed in the pure terbium complex film under excitation of 328 nm light, which is attributed to the characteristic emission of terbium ion. The good thermal stability and intense sharp emission of this terbium complex display its potential application in electroluminescence devices.

  13. Synthesis of Aminophosphine Ligands with Binaphthyl Backbones for Silver(I)-catalyzed Enantioselective Allylation of Benzaldehyde

    Institute of Scientific and Technical Information of China (English)

    WANG,Yi(王以); JI,Bao-Ming(吉保明); DING,Kui-Ling(丁奎岭)

    2002-01-01

    A series of aminophosphine ligands was synthesized from 2amino-2′-hydroxy-1,1′-binaphthyl (NOBIN). Their asymmetric induction efficiency was examined for silver(I)catalyzed enantioselective allylation reaction of benzaldehyde with allyltributyltin.Under the optimized reaction conditions,quantitative yield as well as moderate ee value (54.5% ee)of product was achieved by the catalysis with silver(I)/3 complex. The effects of the binaphthyl backbone and the substituted situated at chelating N, Patoms on enantioselectivity of the reaction were also discussed.

  14. Flexible and Asymmetric Ligand in Constructing Coordinated Complexes: Synthesis, Crystal Structures and Fluorescent Characterization

    Directory of Open Access Journals (Sweden)

    Jianhua Lin

    2010-12-01

    Full Text Available Flexible and asymmetric ligand L [L = 1-((pyridin-3-ylmethyl-1H-benzotriazole], is used as a basic backbone to construct complicated metal-organic frameworks. Two new polymers, namely, [Ag2(L2(NO32]n (1 and [Ag(L(ClO4]n (2, were synthesized and characterized by X-ray structure analysis and fluorescent spectroscopy. The complex 1 gives an “S” type double helical conformation, whereas complex 2 exhibits a 1D zigzag configuration. Different anions affect the silver coordination geometry and crystal packing topology.

  15. Configuration Control in the Synthesis of Homo- and Heteroleptic Bis(oxazolinylphenolato/thiazolinylphenolato) Chelate Ligand Complexes of Oxorhenium(V): Isomer Effect on Ancillary Ligand Exchange Dynamics and Implications for Perchlorate Reduction Catalysis.

    Science.gov (United States)

    Liu, Jinyong; Wu, Dimao; Su, Xiaoge; Han, Mengwei; Kimura, Susana Y; Gray, Danielle L; Shapley, John R; Abu-Omar, Mahdi M; Werth, Charles J; Strathmann, Timothy J

    2016-03-01

    This study develops synthetic strategies for N,N-trans and N,N-cis Re(O)(LO-N)2Cl complexes and investigates the effects of the coordination spheres and ligand structures on ancillary ligand exchange dynamics and catalytic perchlorate reduction activities of the corresponding [Re(O)(LO-N)2](+) cations. The 2-(2'-hydroxyphenyl)-2-oxazoline (Hhoz) and 2-(2'-hydroxyphenyl)-2-thiazoline (Hhtz) ligands are used to prepare homoleptic N,N-trans and N,N-cis isomers of both Re(O)(hoz)2Cl and Re(O)(htz)2Cl and one heteroleptic N,N-trans Re(O)(hoz)(htz)Cl. Selection of hoz/htz ligands determines the preferred isomeric coordination sphere, and the use of substituted pyridine bases with varying degrees of steric hindrance during complex synthesis controls the rate of isomer interconversion. The five corresponding [Re(O)(LO-N)2](+) cations exhibit a wide range of solvent exchange rates (1.4 to 24,000 s(-1) at 25 °C) and different LO-N movement patterns, as influenced by the coordination sphere of Re (trans/cis), the noncoordinating heteroatom on LO-N ligands (O/S), and the combination of the two LO-N ligands (homoleptic/heteroleptic). Ligand exchange dynamics also correlate with the activity of catalytic reduction of aqueous ClO4(-) by H2 when the Re(O)(LO-N)2Cl complexes are immobilized onto Pd/C. Findings from this study provide novel synthetic strategies and mechanistic insights for innovations in catalytic, environmental, and biomedical research.

  16. Synthesis of highly luminescent and biocompatible CdTe/CdS/ZnS quantum dots using microwave irradiation: a comparative study of different ligands.

    Science.gov (United States)

    He, Hua; Sun, Xing; Wang, Xiaojuan; Xu, Hai

    2014-11-01

    We compared the effects of several ligands frequently used in aqueous synthesis, including L-cysteine, L-cysteine hydrochloride, N-acetyl-L-cysteine (NAC), glutathione and 3-mercaptopropionic acid, for microwave synthesis of CdTe quantum dots (QDs) in a sealed vessel with varied temperatures and times, and then developed a rapid microwave-assisted protocol for preparing highly luminescent, photostable and biocompatible CdTe/CdS/ZnS core-multishell QDs. The effects of molecular structures of these ligands on QD synthesis under high temperatures were explored. Among these ligands, NAC was found to be the optimal ligand in terms of the optical properties of resultant QDs and reaction conditions. The emission wavelength of NAC-capped CdTe QDs could reach 700 nm in 5 min by controlling the reaction temperature, and the resultant CdTe/CdS/ZnS core-multishell QDs could achieve the highest quantum yields up to 74% with robust photostability. In addition, the effects of temperature, growth time and shell-precursor ratio on shell growth were examined. Finally, cell culturing indicated the low cytotoxicity of CdTe/CdS/ZnS core-multishell QDs as compared to CdTe and CdTe/CdS QDs, suggesting their high potential for applications in biomedical imaging and diagnostics.

  17. Polynuclear Iron-Oxo/Hydroxy Complexes of Ketoacidoximate Ligands: Synthesis, Structures and Conversion to Ferric Oxide

    KAUST Repository

    Davaasuren, Bambar

    2017-06-13

    The polynuclear iron-oxo/hydroxy complexes containing ketoacidoximate ligands described in this report are [Fe3(μ3-O){O2C-C(C6H5)=NOCH3}6(py)3] (1) (py=pyridine), [Fe2(μ3-O){O2C-C(CH2-C6H5)=NO}2(H2O)(CH3OH)]2 (2) and [{Fe(μ2-OH)(O2C-C(CH3)=NO)}(dmso)]6 (3) (dmso=dimethyl sulfoxide). 1–3 are isolated from the reaction of Fe(NO3)3⋅9H2O and in situ generated anions of ketoacidoximate ligand [(HO2C-C(R1)=NOR2), where R1=CH3, C6H5 and CH2-C6H5; R2=H or CH3] in H2O, followed by crystallization in donor solvents. 1–3 undergo thermal decomposition above 200 °C and form crystalline α-Fe2O3 at 600 °C.

  18. Synthesis, characterization and anticancer studies of mixed ligand dithiocarbamate palladium(II) complexes.

    Science.gov (United States)

    Khan, Hizbullah; Badshah, Amin; Murtaz, Ghulam; Said, Muhammad; Rehman, Zia-ur-; Neuhausen, Christine; Todorova, Margarita; Jean-Claude, Bertrand J; Butler, Ian S

    2011-09-01

    Six mixed ligand dithiocarbamate Pd(II) complexes (1-6) of general formula [(DT)Pd(PR(3))Cl], where DT = dimethyldithiocarbamate (1, 5), diethyldithiocarbamate (2, 3), dicyclohexyldithiocarbamate (4), bis(2-methoxyethyl)dithiocarbamate (6); PR(3) = benzyldiphenylphosphine (1), diphenyl-2-methoxyphenylphosphine (2), diphenyl-p-tolylphosphine (3), diphenyl-m-tolylphosphine (4), tricyclohexylphosphine (5), diphenyl-2-pyridylphosphine (6) have been synthesized and characterised using Elemental analysis, FT-IR, Raman and multinuclear magnetic resonance (NMR) spectroscopy. Compounds 1 and 2 were also characterized by single crystal X-ray diffraction technique (XRD). The XRD study reveals that the Pd(II) moiety has a pseudo square-planar geometry, in which two positions are occupied by the dithiocarbamate ligand in a bidentate fashion, while at the remaining two positions organophosphine and chloride are present. The anticancer activity of the synthesized metallodrugs was checked against DU145 human prostate carcinoma (HTB-81) cells, the IC(50) values indicate that the compounds are highly active against these cells. These Pd(II) complexes also show moderate antibacterial activity against gram positive and gram negative bacteria.

  19. Monophthalocyanine complexes of samarium and terbium with axial ligands:synthesis, structure and optoelectronic properties

    Institute of Scientific and Technical Information of China (English)

    Alexander A Maleev; Mikhail N Bochkarev; Anatoly P Pushkarev; Vasily A Ilichev; Mikhail A Lopatin; Maxim A Samsonov; Georgy K Fukin; Georgy L Pakhomov; Vladislav V Travkin; Ivan D Grishin

    2014-01-01

    The monophthalocyanine complexes of samarium and terbium containing axial 2-mercaptobenzothiazole (PcSm(MBT) (1)), 2-(2-benzoxazol-2-yl) phenolate (PcTb(OON) (2)) or 2-(2-benzothiazol-2-yl)phenolate (PcTb(SON) (3)) ligands were synthe-sized and identified by elemental, LDI-TOF and X-ray (for 1) analysis. Photoluminescence (PL) and electroluminescence (EL) spec-tra of the compounds contained only emission bands of phthalocyanine and axial ligands but did not contain the bands of f-f transi-tions. It was found that among the complexes 1, 2, 3 the latter had highest photoconductivity (~10–7 S/cm) and photovoltaic properties. An organic photovoltaic device (OPV) of configuration of ITO/3/C60/Alq3/Al revealed open-circuit voltage (VOC) of 0.24 V and short current density (ISC) of 0.3μA/cm2 under illumination by a xenon lamp at 17 mW/cm2.

  20. Ligand exchange synthesis of organometallic Rh nanoparticles and application in explosive sensing

    Science.gov (United States)

    Srivastav, Amit K.; Agrawal, Bhavesh; Swami, Bhavya; Agrawal, Yadvendra K.; Maity, Prasenjit

    2017-06-01

    Alkyne {phenyl acetylene (PA) and 9-ethynylphenanthrene (EPT)}-ligated Rh nanoparticles ( 1 and 2, respectively) with mean diameter of 1.5 ± 0.2 nm were synthesized via a facile and high-yield biphasic ligand exchange protocol using similar sized ethylene glycol (EG)-stabilized Rh nanoparticles as precursors (EG:Rh). The synthesized organometallic Rh nanoparticles were convincingly characterized using several spectroscopic and microscopic techniques, e.g., Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), optical absorption spectroscopy (UV-Vis), photoluminescence spectroscopy (PL), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM). We propose that the syntheses mechanism relies on catalytic acetylenic (≡C-H, carbon-hydrogen) bond breaking by EG:Rh followed by strong metal-carbon bond formation with a vinyldiene (>C═C═M) motif. The obtained 1 and 2 showed luminescence property, which arises from ligand structure through intraparticle conjugation. Electron-rich phenanthrene-ligated Rh nanoparticles ( 2) showed good sensing performance for detection of electron deficient nitro-aromatic explosive molecules (NA) in solution phase through luminescence quenching method.

  1. Synthesis and Characterization of a New Bivalent Ligand Combining Caffeine and Docosahexaenoic Acid.

    Science.gov (United States)

    Fernández-Dueñas, Víctor; Azuaje, Jhonny; Morató, Xavier; Cordobilla, Begoña; Domingo, Joan Carles; Sotelo, Eddy; Ciruela, Francisco

    2017-02-27

    Caffeine is a promising drug for the management of neurodegenerative diseases such as Parkinson's disease (PD), demonstrating neuroprotective properties that have been attributed to its interaction with the basal ganglia adenosine A2A receptor (A2AR). However, the doses needed to exert these neuroprotective effects may be too high. Thus, it is important to design novel approaches that selectively deliver this natural compound to the desired target. Docosahexaenoic acid (DHA) is the major omega-3 fatty acid in the brain and can act as a specific carrier of caffeine. Furthermore, DHA displays properties that may lead to its use as a neuroprotective agent. In the present study, we constructed a novel bivalent ligand covalently linking caffeine and DHA and assessed its pharmacological activity and safety profile in a simple cellular model. Interestingly, the new bivalent ligand presented higher potency as an A2AR inverse agonist than caffeine alone. We also determined the range of concentrations inducing toxicity both in a heterologous system and in primary striatal cultures. The novel strategy presented here of attaching DHA to caffeine may enable increased effects of the drug at desired sites, which could be of interest for the treatment of PD.

  2. Insight into the Ligand-Mediated Synthesis of Colloidal CsPbBr3 Perovskite Nanocrystals: The Role of Organic Acid, Base, and Cesium Precursors.

    Science.gov (United States)

    Pan, Aizhao; He, Bo; Fan, Xiaoyun; Liu, Zeke; Urban, Jeffrey J; Alivisatos, A Paul; He, Ling; Liu, Yi

    2016-08-23

    While convenient solution-based procedures have been realized for the synthesis of colloidal perovskite nanocrystals, the impact of surfactant ligands on the shape, size, and surface properties still remains poorly understood, which calls for a more detailed structure-morphology study. Herein we have systematically varied the hydrocarbon chain composition of carboxylic acids and amines to investigate the surface chemistry and the independent impact of acid and amine on the size and shape of perovskite nanocrystals. Solution phase studies on purified nanocrystal samples by (1)H NMR and IR spectroscopies have confirmed the presence of both carboxylate and alkylammonium ligands on surfaces, with the alkylammonium ligand being much more mobile and susceptible to detachment from the nanocrystal surfaces during polar solvent washes. Moreover, the chain length variation of carboxylic acids and amines, ranging from 18 carbons down to two carbons, has shown independent correlation to the size and shape of nanocrystals in addition to the temperature effect. We have additionally demonstrated that employing a more soluble cesium acetate precursor in place of the universally used Cs2CO3 results in enhanced processability without sacrificing optical properties, thus offering a more versatile recipe for perovskite nanocrystal synthesis that allows the use of organic acids and amines bearing chains shorter than eight carbon atoms. Overall our studies have shed light on the influence of ligand chemistry on crystal growth and stabilization of the nanocrystals, which opens the door to functionalizable perovskite nanocrsytals through surface ligand manipulation.

  3. Total Synthesis of Verruculogen and Fumitremorgin A Enabled by Ligand-Controlled C-H Borylation.

    Science.gov (United States)

    Feng, Yu; Holte, Dane; Zoller, Jochen; Umemiya, Shigenobu; Simke, Leah R; Baran, Phil S

    2015-08-19

    Verruculogen and fumitremorgin A are bioactive alkaloids that contain a unique eight-membered endoperoxide. Although related natural products such as fumitremorgins B and C have been previously synthesized, we report the first synthesis of the more complex, endoperoxide-containing members of this family. A concise route to verruculogen and fumitremorgin A relied not only on a hydroperoxide/indole hemiaminal cyclization, but also on the ability to access the seemingly simple starting material, 6-methoxytryptophan. An iridium-catalyzed C-H borylation/Chan-Lam procedure guided by an N-TIPS group enabled the conversion of a tryptophan derivative into a 6-methoxytryptophan derivative, proving to be a general way to functionalize the C6 position of an N,C3-disubstituted indole for the synthesis of indole-containing natural products and pharmaceuticals.

  4. Synthesis and Characterization of Rhenium(V) Oxo Complexes Bearing PNP-Pincer Ligands

    NARCIS (Netherlands)

    Korstanje, Ties J.; Lutz, Martin; Jastrzebski, Johann T. B. H.; Klein Gebbink, Bert

    2014-01-01

    The synthesis of a series of pyridine-based PNP-pincer rhenium-oxo complexes, with phenyl (1, 3), tertbutyl (2), or cyclohexyl (4) groups on the phosphorus atoms and either a ReO2X (1, 2) or a ReCl2O (3, 4) core is reported. The structures of these compounds were characterized using H-1, C-13, and P

  5. Total Synthesis of Verruculogen and Fumitremorgin A Enabled by Ligand-controlled C–H Borylation

    OpenAIRE

    Feng, Yu; Holte, Dane; Zoller, Jochen; Umemiya, Shigenobu; Simke, Leah R.; Baran, Phil S.

    2015-01-01

    Verruculogen an fumitremorgin A are bioactive alkaloids that contain a unique eight-membered endoperoxide. Although related natural products such as fumitremorgins B and C have been previously synthesized, we report the first synthesis of the more complex, endoperoxide-containing members of this family. A concise route to verruculogen and fumitremorgin A relied not only on a hydroperoxide/indole hemiaminal cyclization, but also on the ability to access the seemingly simple starting material, ...

  6. Vanadium(iv and v) complexes of pyrazolone based ligands: Synthesis, structural characterization and catalytic applications.

    Science.gov (United States)

    Maurya, Mannar R; Sarkar, Bithika; Avecilla, Fernando; Correia, Isabel

    2016-11-01

    The ONO donor ligands obtained from the condensation of 4-benzoyl-3-methyl-1-phenyl-2-pyrazoline-5-one (Hbp) with benzoylhydrazide (H2bp-bhz I), furoylhydrazide (H2bp-fah II), nicotinoylhydrazide (H2bp-nah III) and isonicotinoylhydrazide (H2bp-inh IV), upon treatment with [V(IV)O(acac)2], lead to the formation of [V(IV)O(bp-bhz)(H2O)] 1, [V(IV)O(bp-fah)(H2O)] 2, [V(IV)O(bp-nah)(H2O)] 3 and [V(IV)O(bp-inh)(H2O)] 4, respectively. At neutral pH the in situ generated aqueous K[H2V(V)O4] reacts with ligands I and II, forming potassium salts, K(H2O)2[V(V)O2(bp-bhz)] 5 and K(H2O)2[V(V)O2(bp-fah)] 6, while ligands III and IV give neutral complexes, [V(V)O2(Hbp-nah)] 9 and [V(V)O2(Hbp-inh)] 10, respectively. Acidification of aqueous solutions of 5 and 6 with HCl also gives neutral complexes [V(V)O2(Hbp-bhz)] 7 and [V(V)O2(Hbp-fah)] 8, respectively. Complexes 1-4, upon slow aerial oxidation in methanol, convert into monooxidovanadium(v) complexes, [V(V)O(bp-bhz)(OMe)] 11, [V(V)O(bp-fah)(OMe)] 12, [V(V)O(bp-nah)(OMe)] 13 and [V(V)O(bp-inh)(OMe)] 14, respectively. All complexes were characterized by various spectroscopic techniques like FT-IR, UV-visible, EPR (for complexes 1-4) and NMR ((1)H, (13)C and (51)V), elemental analysis, thermogravimetry and single crystal X-ray diffraction (for complexes 5-10 and 12). In the solid state, all complexes characterized by X-ray diffraction show the metal ion 5-coordinated in a distorted square pyramidal geometry. Complexes 11-14 were tested as catalysts for the one-pot three-component (ethylacetoacetate, benzaldehyde and ammonium acetate) dynamic covalent assembly, via Hantzsch reaction, using hydrogen peroxide as oxidant in solution and under solvent-free conditions. The complexes are also active catalysts for the oxidation of tetralin to tetralone with H2O2 as oxidant. The influence of the amounts of catalyst and oxidant, and solvent, temperature and time on the catalyzed reactions was investigated.

  7. Synthesis, Characterization, Antimicrobial, DNA Cleavage, and In Vitro Cytotoxic Studies of Some Metal Complexes of Schiff Base Ligand Derived from Thiazole and Quinoline Moiety

    Directory of Open Access Journals (Sweden)

    Nagesh Gunvanthrao Yernale

    2014-01-01

    Full Text Available A novel Schiff base ligand N-(4-phenylthiazol-2yl-2-((2-thiaxo-1,2-dihydroquinolin-3-ylmethylenehydrazinecarboxamide (L obtained by the condensation of N-(4-phenylthiazol-2-ylhydrazinecarboxamide with 2-thioxo-1,2-dihydroquinoline-3-carbaldehyde and its newly synthesized Cu(II, Co(II, Ni(II, and Zn(II complexes have been characterized by elemental analysis and various spectral studies like FT-IR, 1H NMR, ESI mass, UV-Visible, ESR, TGA/DTA, and powder X-ray diffraction studies. The Schiff base ligand (L behaves as tridentate ONS donor and forms the complexes of type [ML(Cl2] with square pyramidal geometry. The Schiff base ligand (L and its metal complexes have been screened in vitro for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC method. The DNA cleavage activity of ligand and its metal complexes were studied using plasmid DNA pBR322 as a target molecule by gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties for the ligand and its metal complexes against Artemia salina. The results showed that the biological activities of the ligand were found to be increased on complexation.

  8. Synthesis, characterization and antimicrobial activities of mixed ligand transition metal complexes with isatin monohydrazone Schiff base ligands and heterocyclic nitrogen base

    Science.gov (United States)

    Devi, Jai; Batra, Nisha

    2015-01-01

    Mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with various uninegative tridentate ligands derived from isatin monohydrazone with 2-hydroxynapthaldehyde/substituted salicylaldehyde and heterocyclic nitrogen base 8-hydroxyquinoline have been synthesized and characterized by elemental analysis, conductometric studies, magnetic susceptibility and spectroscopic techniques (IR, UV-VIS, NMR, mass and ESR). On the basis of these characterizations, it was revealed that Schiff base ligands existed as monobasic tridentate ONO bonded to metal ion through oxygen of carbonyl group, azomethine nitrogen and deprotonated hydroxyl oxygen and heterocyclic nitrogen base 8-hydroxyquinoline existed as monobasic bidentate ON bonded through oxygen of hydroxyl group and nitrogen of quinoline ring with octahedral or distorted octahedral geometry around metal ion. All the compounds have been tested in vitro against various pathogenic Gram positive bacteria, Gram negative bacteria and fungi using different concentrations (25, 50, 100, 200 μg/mL) of ligands and their complexes. Comparative study of antimicrobial activity of ligands, and their mixed complexes indicated that complexes exhibit enhanced activity as compared to free ligands and copper(II) Cu(LIV)(Q)ṡH2O complex was found to be most potent antimicrobial agent.

  9. Synthesis of radioiodinated naltrindole analogues: Ligands for studies of delta opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    Kinter, Chris M.; Lever, John R

    1995-07-01

    Analogues of naltrindole and N1'-methylnaltrindole having radioiodine in the 7'-position of the indole ring have been prepared for evaluation as delta opioid receptor ligands. The no-carrier-added radiosyntheses were conducted by Cu(I) assisted nucleophilic exchange of radioiodide for bromide under reducing conditions at 190 deg. C. A combination of HPLC and solid-phase extraction gave the {sup 125}I- or {sup 123}I-labeled products in satisfactory yields (47%) with high radiochemical purities (>98%) and high specific activities ({sup 125}I: 43-68 GBq/{mu}mol, 1155-1833 mCi/{mu}mol; {sup 123}I: > 92 GBq/{mu}mol, 2500 mCi/{mu}mol)

  10. Synthesis of New Benzimidazole and Benzothiazole Disulfide Metal Complexes as G-quadruplex Binding Ligands.

    Science.gov (United States)

    Saour, Kawkab; Lafta, Dunya

    2016-01-01

    Compounds that can bind and stabilize non-canonical DNA structures are named quadruplex and are of interest in anticancer drug design due to their selective inhibitions of telomerase and consequent effects on cell proliferation. In this study, we report novel Co/Cu [II] complex compounds as G-quadruplex DNA binding ligands. The results from the preliminary assay indicated that the introduction of a positively charged 6-membered tail to the aromatic terminal group of benzimidazole significantly enhanced the binding affinity with the quadruplex and exhibited anti-telomerase activity. These derivatives showed significant selectivities for the telomeric quadruplex over duplex nucleic acids. The stabilization of non-canonical forms estimated with the FRET DNA technology using different sequences, such as F21T, c-kit1 and c-kit2, in cancer cell lines were assessed. Three members of this family showed to be very selective in stabilizing one particular G-quadruplex.

  11. Bis- and Tetrakis(carboxylato)platinum(IV) complexes with mixed axial ligands - synthesis, characterization, and cytotoxicity.

    Science.gov (United States)

    Hoffmeister, Björn R; Hejl, Michaela; Adib-Razavi, Mahsa S; Jakupec, Michael A; Galanski, Markus; Keppler, Bernhard K

    2015-04-01

    A series of twelve novel diamminetetrakis(carboxylato)platinum(IV) and 18 novel bis(carboxylato)dichlorido(ethane-1,2-diamine)platinum(IV) complexes with mixed axial carboxylato ligands was synthesized and characterized by multinuclear (1) H-, (13) C-, (15) N-, and (195) Pt-NMR spectroscopy. Their cytotoxic potential was evaluated (by MTT assay) against three human cancer cell lines derived from ovarian teratocarcinoma (CH1/PA-1), lung (A549), and colon carcinoma (SW480). In the cisplatin-sensitive CH1/PA-1 cancer cell line, diamminetetrakis(carboxylato)platinum(IV) complexes showed IC50 values in the low micromolar range, whereas, for the most lipophilic compounds of the bis(carboxylato)dichlorido(ethane-1,2-diamine)platinum(IV) series, IC50 values in the nanomolar range were found. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  12. Synthesis and characterization of titanium complex with a dithiolate ligand for green LCD color filter dyes.

    Science.gov (United States)

    Shin, Hwangyu; Park, Youngil; Kim, Seungho; An, Byeong-Kwan; Park, Jongwook

    2012-11-21

    Three green compounds for color filter dyes based on bis(cyclopentadienyl) titanium complexes including dithiolate ligand were synthesized. Physical properties by the change of the substitution groups of the synthesized materials were systematically examined. UV-visible absorption spectrum of the synthesized materials showed maximum absorbing wavelengths of 427 to 430 nm and 632 to 635 nm in solution state, and 434 to 438 nm and 637 to 651 nm in film state, indicating green and black colors. It was observed that the extinction coefficient values (log ε) of all the synthesized materials are very high at 4.0 or above. In addition, it was shown that since the Td values of three synthesized materials show thermal stability higher than 240°C, they possess high potential to be applied as dyes for LCD color filter and black matrix addictive.

  13. Ionotropic excitatory amino acid receptor ligands. Synthesis and pharmacology of a new amino acid AMPA antagonist

    DEFF Research Database (Denmark)

    Madsen, U; Sløk, F A; Stensbøl, T B;

    2000-01-01

    We have previously described the potent and selective (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor agonist, (RS)-2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA), and the AMPA receptor antagonist (RS)-2-amino-3-[3-(carboxymethoxy)-5-methyl-4......-isoxazolyl]propionic acid (AMOA). Using these AMPA receptor ligands as leads, a series of compounds have been developed as tools for further elucidation of the structural requirements for activation and blockade of AMPA receptors. The synthesized compounds have been tested for activity at ionotropic...... excitatory amino acid (EAA) receptors using receptor binding and electrophysiological techniques, and for activity at metabotropic EAA receptors using second messenger assays. Compounds 1 and 4 were essentially inactive. (RS)-2-Amino-3-[3-(2-carboxyethyl)-5-methyl-4-isoxazolyl]propionic acid (ACMP, 2...

  14. Synthesis, Optical Characterization, and Thermal Decomposition of Complexes Based on Biuret Ligand

    Directory of Open Access Journals (Sweden)

    Mei-Ling Wang

    2016-01-01

    Full Text Available Four complexes were synthesized in methanol solution using nickel acetate or nickel chloride, manganese acetate, manganese chloride, and biuret as raw materials. The complexes were characterized by elemental analyses, UV, FTIR, Raman spectra, X-ray powder diffraction, and thermogravimetric analysis. The compositions of the complexes were [Ni(bi2(H2O2](Ac2·H2O (1, [Ni(bi2Cl2] (2, [Mn(bi2(Ac2]·1.5H2O (3, and [Mn(bi2Cl2] (4 (bi = NH2CONHCONH2, respectively. In the complexes, every metal ion was coordinated by oxygen atoms or chlorine ions and even both. The nickel and manganese ions were all hexacoordinated. The thermal decomposition processes of the complexes under air included the loss of water molecule, the pyrolysis of ligands, and the decomposition of inorganic salts, and the final residues were nickel oxide and manganese oxide, respectively.

  15. Synthesis and Thermal Decomposition Kinetics of La(Ⅲ) Complex with Unsymmetrical Schiff Base Zwitterion Ligand

    Institute of Scientific and Technical Information of China (English)

    Bi Caifeng; Xiao Yan; Fan Yuhua; Xie Sitan; Xu Jiakun

    2007-01-01

    A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine. o-vanillin and 2-hydroxy-l-naph-thaldehyde. Solid La (Ⅲ) complex of this ligand [LaL(NO3)](NO3)·2H2O was prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage were studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt=A·e-E/RT·(1-α)2. The kinetic parameters (E, A), activation entropy ΔS≠ and activation free-energy ΔG≠ were also gained.

  16. Synthesis,structure and catalytic behavior of yttrium complexes bearing a diaminobis(phenolate) ligand

    Institute of Scientific and Technical Information of China (English)

    SONG FengKui; YAN ChunHui; SUN HongMei; YAO YingMing; SHEN Qi; ZHANG Yong

    2009-01-01

    Yttrium complexes stabilized by a diaminobis(phenolate) ligand were synthesized and their catalytic behavior was explored. Reaction of YCI3 with 1 equiv of LNa2 [L=Me2NCH2CH2N{CH2-(2-O-C6H2-tBu2-3,5)}2]gave the yttrium chloride LYCI(THF) (1) in 92% yield. Complex 1 can be used as starting material to prepare the yttrium amido derivative. Complex 1 reacted with 1 equiv of LiNPh2 in THF to afford the expected yttrium amido complex LYNPh2 (2) in high yield. Both of complexes 1 and 2 have been well detected by elemental analysis,NMR spectra and single-crystal X-ray analysis. It was found that complex 2 can efficiently initiate the ring-opening polymerization of L-lactide and ε-caprolactone,and a controlled manner is observed in the former case.

  17. Synthesis of a Bis(thiophenolate)pyridine Ligand and Its Titanium, Zirconium, and Tantalum Complexes

    KAUST Repository

    Lenton, Taylor N.

    2012-11-12

    A precursor to a new tridentate LX 2 type ligand, bis(thiophenol)pyridine ((SNS)H 2 = (2-C 6H 4SH) 2-2,6-C 5H 3N), was prepared. Bis(thiophenolate)pyridine complexes of Ti, Zr, and Ta having dialkylamido coligands were synthesized and structurally characterized. The zirconium complex (SNS)Zr(NMe 2) 2 (4) displays C 2 symmetry in the solid state, unlike a related bis(phenolate)pyridine compound, C s-symmetric (ONO)Ti(NMe 2) 2. This change is likely the result of strain about the sulfur atom in the six-membered chelate with longer metal-sulfur and carbon-sulfur bonds. Solid-state structures of tantalum complexes (SNS)Ta(NMe 2) 3 (5) and (SNS)TaCl(NEt 2) 2 (6) also display pronounced C 2 twisting of the SNS ligand. 1D and 2D NMR experiments show that 5 is fluxional, with rotation about the Ta-N(amide) bonds occurring on the NMR time scale that interchange the equatorial amide methyl groups (ΔG ‡ 393 = 25.0(3) kcal/mol). The fluxional behavior of 6 in solution was also studied by variable-temperature 1H NMR. Observation of separate signals for the diastereotopic protons of the methylene unit of the diethylamide indicates that the complex remains locked on the NMR time scale in one diastereomeric conformation at temperatures below -50 °C, fast rotation about the equatorial amide Ta-N bonds occurs at higher temperature (ΔG ‡ 393 = 13.4(3) kcal/mol), and exchange of diastereomeric methylene protons occurs via inversion at Ta that interconverts antipodes (ΔG ‡ 393 ≈ 14(1) kcal/mol). © 2012 American Chemical Society.

  18. Unsymmetrical tren-based ligands: synthesis and reactivity of rhenium complexes.

    Science.gov (United States)

    Mösch-Zanetti, Nadia C; Köpke, Sinje; Herbst-Irmer, Regine; Hewitt, Manuel

    2002-07-01

    Reaction of bis(2-aminoethyl)(3-aminopropyl)amine with C(6)F(6) and K(2)CO(3) in DMSO yields unsymmetrical [(C(6)F(5))HNCH(2)CH(2)](2)NCH(2)CH(2)CH(2)NH(C(6)F(5)) ([N(3)N]H(3)). The tetraamine acts as a tridentate ligand in complexes of the type H[N(3)N]Re(O)X (X = Cl 1, Br 2) prepared by reacting Re(O)X(3)(PPh(3))(2) with [N(3)N]H(3) and an excess of NEt(3) in THF. Addition of 1 equiv of TaCH(CMe(2)Ph)Br(3)(THF)(2) to 1 gives the dimeric compound H[N(3)N]ClReOReBrCl[N(3)N]H (3) in quantitative yield that contains a Re(V)[double bond]O[bond]Re(IV) core with uncoordinated aminopropyl groups in each ligand. Addition of 2 equiv of TaCH(CMe(2)Ph)Cl(3)(THF)(2) to 1 leads to the chloro complex [N(3)N]ReCl (4) with all three amido groups coordinated to the metal, whereas by addition of 2 equiv of TaCH(CMe(2)Ph)Br(3)(THF)(2) to 2 the dibromo species H[N(3)N]ReBr(2) (5) with one uncoordinated amino group is isolated. Reduction of 4 under an atmosphere of dinitrogen with sodium amalgam gives the dinitrogen complex [N(3)N]Re(N(2)) (6). Single-crystal X-ray structure determinations have been carried out on complexes 1, 3, 5, and 6.

  19. Synthesis, characterization, DFT calculations and biological studies of Mn(II), Fe(II), Co(II) and Cd(II) complexes based on a tetradentate ONNO donor Schiff base ligand

    Science.gov (United States)

    Abdel-Rahman, Laila H.; Ismail, Nabawia M.; Ismael, Mohamed; Abu-Dief, Ahmed M.; Ahmed, Ebtehal Abdel-Hameed

    2017-04-01

    This study highlights synthesis and characterization of a tetradentate ONNO Schiff base ligand namely (1, 1‧- (pyridine-2, 3-dimethyliminomethyl) naphthalene-2, 2‧-diol) and hereafter denotes as "HNDAP″ and selected metal complexes including Mn(II), Fe(II), Co(II) and Cd(II) as a central metal. HNDAP was synthesized from 1:2 M ratio condensation of 2, 3-diaminopyridine and 2- hydroxy-1-naphthaldhyde, respectively. The stoichiometric ratios of the prepared complexes were estimated using complementary techniques such as; elemental analyses (-C, H, N), FT-IR, magnetic measurements and molar conductivity. Furthermore, their physicochemical studies were carried out using thermal TGA, DTA and kinetic-thermodynamic studies along with DFT calculations. The results of elemental analyses showed that these complexes are present in a 1:1 metal-to- ligand molar ratio. Moreover, the magnetic susceptibilities values at room temperature revealed that Mn(II), Fe(II) and Co(II) complexes are paramagnetic in nature and have an octahedral (Oh) geometry. In contrast, Cd(II) is diamagnetic and stabilizes in square planar sites. The molar conductivity measurements indicated that all complexes are nonelectrolytes in dimethyl formamide. Spectral data suggested that the ligand is as tetradentate and coordinated with Co(II) ion through two phenolic OH and two azomethine nitrogen. However, for Mn(II), Fe(II) and Cd(II) complexes, the coordination occurred through two phenolic oxygen and two azomethine nitrogen with deprotonation of OH groups. The proposed chemical structures have been validated by quantum mechanics calculations. Antimicrobial activities of both the HNDAP Schiff base ligand and its metal complexes were tested against strains of Gram (-ve) E. coli and Gram (+ve) B. subtilis and S. aureus bacteria and C. albicans, A. flavus and T. rubrum fungi. All the prepared compounds showed good results of inhibition against the selected pathogenic microorganisms. The investigated

  20. Designing, synthesis and spectral characterization of Schiff base transition metal complexes: DNA cleavage and antimicrobial activity studies

    Directory of Open Access Journals (Sweden)

    N. RAMAN

    2008-10-01

    Full Text Available A new series of transition metal complexes of Cu(II, Ni(II, Co(II and Zn(II have been designed and synthesized using a Schiff base (L derived from 4-aminoantipyrine, benzaldehyde and o-phenylenediamine. The structural features were derived from their elemental analyses, magnetic susceptibility and molar conductivity, as well as from mass, IR, UV–Vis, 1H-NMR and ESR spectral studies. The FAB mass spectral data and elemental analyses showed that the complexes had a composition of the ML type. The UV–Vis and ESR spectral data of the complexes suggested a square-planar geometry around the central metal ion. The magnetic susceptibility values of the complexes indicated that they were monomeric in nature. Antimicrobial screening tests were also performed against four bacteria, viz. Salmonella typhi, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis and three fungi, viz. Aspergillus niger, Aspergillus flavus and Rhizoctonia bataicola. These data gave good results in the presence of metal ion in the ligand system. The nuclease activity of the above metal complexes shows that only the copper complex cleaves CT DNA in the presence of an oxidant.

  1. Semi-empirical AGN detection threshold in spectral synthesis studies of Lyman-continuum-leaking early-type galaxies

    CERN Document Server

    Cardoso, Leandro S M; Papaderos, Polychronis

    2016-01-01

    Various lines of evidence suggest that the cores of a large portion of early-type galaxies (ETGs) are virtually evacuated of warm ionised gas. This implies that the Lyman-continuum (LyC) radiation produced by an assumed active galactic nucleus (AGN) can escape from the nuclei of these systems without being locally reprocessed into nebular emission, which would prevent their reliable spectroscopic classification as Seyfert galaxies with standard diagnostic emission-line ratios. The spectral energy distribution (SED) of these ETGs would then lack nebular emission and be essentially composed of an old stellar component and the featureless power-law (PL) continuum from the AGN. A question that arises in this context is whether the AGN component can be detected with current spectral population synthesis in the optical, specifically, whether these techniques effectively place an AGN detection threshold in LyC-leaking galaxies. To quantitatively address this question, we took a combined approach that involves spectr...

  2. Synthesis of triated N1`-alkyl derivatives of the delta opioid receptor ligand naltrindole

    Energy Technology Data Exchange (ETDEWEB)

    Lever, J.R.; Johnson, S.M. [Johns Hopkins Univ. School of Hygiene and Public Health, Environmental Health Sciences Dept., Baltimore, MD (United States)

    1997-02-01

    Tritiated N1`-methyl and N1`-ethyl analogues of naltrindole (NTI) have been synthesized for evaluation as radioligands for studies of delta opioid receptors. The two N1`-alkyl-5`,7`-dibromoNTI precursors for radiolabeling were prepared by base-promoted alkylation of 2,4-dibromophenylhydrazine with either iodomethane or iodoethane followed by condensation with naltrexone using the Fischer indole synthesis. Catalytic debromotritiation followed by HPLC purification afforded [{sup 3}H]MeNTI (17.3 Ci/mmol) and [{sup 3}H]EtNTI (22.5 Ci/mmol) with high chemical and radiochemical purities ({>=} 99.8%). (author).

  3. Synthesis and CD Spectra of Chiral Molybdenum-fullerenyl Complexes with Pineno-bipyridine Ligands

    Institute of Scientific and Technical Information of China (English)

    Hui ZHANG; Cai Fei ZHU; Li LI; Wei ZOU; Yong Qing HUANG; Jing Xing GAO

    2004-01-01

    The synthesis and characterization of two chiral fullerene complexes (+) CD430- [Mo(η2-C60)(CO)3(LRR)] 1 and (-)CD430-[Mo(η2-C60)(CO)3(LSS)] 2 were described. The CD spectra of 1 and 2 in the visible range show weak Cotton effects, which are approximately of mirror image, indicating that the appended pineno-groups with opposite chirality in bipyridines can perturb the fullerene chromophores through the molybdenum centers and lead to induced CD effects.

  4. N-alkylphenothiazines - synthesis, structure and application as ligands in metal complexes

    Directory of Open Access Journals (Sweden)

    Krstić Milena

    2016-01-01

    Full Text Available Phenothiazines are a large group of heterocyclic, aromatic molecules with nitrogen and sulphur between two benzene rings. Their derivatives, N-alkylphenothiazines have supstitutient on heterocyclic nitrogen atom which gives them different properties. Also, a series of these molecules have substitution on carbon atom at place 2 of phenothiazine benzene ring. Alkylphenothiazines contain aminoalkyl substituent and their alkyl, acyl and sulphonil derivatives, as well as monocyclic and bicyclic heterocycles attached at thiazine nitrogen atom or directly linked to benzene ring. The N-alkylphenothiazines have been known as antipsychotic drugs, but they also possess antibacterial, antifungal, anticancer activity, and ability to react with macromolecules and to coordinate to the metals. Metal complexes with N-alkylphenothiazines are biological active compounds with different antimicrobial activities and cytotoxic effect against tumor cell lines. Their large field of application of N-alkylphenothiazines is very attractive in terms of synthesis of new related derivatives, metal complexes, studying their properties and applications. This article presents a review of the literature and a contemporary view at N-alkylphenothiazines - their synthesis and application, as well as their metal complexes which have promising biological effects. [Projekat Ministarstva nauke Republike Srbije, br. 172014

  5. Bio-sensitive activities of coordination compounds containing 1,10-phenanthroline as co-ligand: Synthesis, structural elucidation and DNA binding properties of metal(II) complexes

    Science.gov (United States)

    Raman, Natarajan; Mahalakshmi, Rajkumar; Mitu, Liviu

    2014-10-01

    Present work reports the DNA binding and cleavage characteristics of a series of mixed-ligand complexes having the composition [M(L)(phen)2]Cl2 (where M = Cu(II), Ni(II), Co(II) and Zn(II) and phen as co-ligand) in detail. Their structural features and other properties have been deduced from their elemental analyses, magnetic susceptibility and molar conductivity as well as from IR, UV-Vis, 1H NMR and EPR spectral studies. The UV-Vis, magnetic susceptibility and EPR spectral data of metal complexes suggest an octahedral geometry. The binding properties of these complexes with calf thymus DNA (CT-DNA) have been explored using electronic absorption spectroscopy, viscosity measurement, cyclic voltammetry and differential pulse voltammetry. The DNA-binding constants for Cu(II), Ni(II), Co(II), and Zn(II) complexes are 6.14 × 105 M-1, 1.8 × 105 M-1, 6.7 × 104 M-1 and 2.5 × 104 M-1 respectively. Detailed analysis reveals that these complexes interact with DNA through intercalation binding. Nuclease activity has also been investigated by gel electrophoresis. Moreover, the synthesized Schiff base and its mixed-ligand complexes have been screened for antibacterial and antifungal activities. The data reveal that the complexes exhibit higher activity than the parent ligand.

  6. Synthesis and Spectroscopic Studies of Mixed Ligand Complexes of Pt(II and Pd(II with Ethyl-α-Isonitrosoacetoacetate and Dienes

    Directory of Open Access Journals (Sweden)

    Anita Krishankant Taksande

    2015-12-01

    Full Text Available The mixed ligand complexes of the kind [M(L1 (L2] where M= Pt(II, Pd(II.L1 = primary ligand ethyl-α-isonitrosoacetoacetate derived from reaction between ethyl acetoacetate, acetic acid and sodium nitrite and L2=secondary ligand para-phenyldiamine (PPD are synthesized. All the prepared complexes were identified and confirmed by elemental analysis, molar conductance measurements, and infrared electronic absorption. Their complexes has been made based on elemental analysis, molar conductivity, UV-Vis, FT-IR and 1HNMR spectroscopy and magnetic moment measurements as well as thermal analysis (TGA and DTA. The elemental analysis information recommends that the stoichiometry of the complexes to be 1:2:1. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral information showed the coordination sites of the free ligand with the central metal particle. The electronic absorption spectral information disclosed the existence of an octahedral geometry for Pt(II and Pd(II complexes. DOI: http://dx.doi.org/10.17807/orbital.v7i4.633 

  7. Synthesis, characterization and biological evaluation of novel Ru(II)-arene complexes containing intercalating ligands.

    Science.gov (United States)

    Nikolić, Stefan; Rangasamy, Loganathan; Gligorijević, Nevenka; Aranđelović, Sandra; Radulović, Siniša; Gasser, Gilles; Grgurić-Šipka, Sanja

    2016-07-01

    Three new ruthenium(II)-arene complexes, namely [(η(6)-p-cymene)Ru(Me2dppz)Cl]PF6 (1), [(η(6)-benzene)Ru(Me2dppz)Cl]PF6 (2) and [(η(6)-p-cymene)Ru(aip)Cl]PF6 (3) (Me2dppz=11,12-dimethyldipyrido[3,2-a:2',3'-c]phenazine; aip=2-(9-anthryl)-1H-imidazo[4,5-f] [1,10] phenanthroline) have been synthesized and characterized using different spectroscopic techniques including elemental analysis. The complexes were found to be well soluble and stable in DMSO. The biological activity of the three complexes was tested in three different human cancer cell lines (A549, MDA-MB-231 and HeLa) and in one human non-cancerous cell line (MRC-5). Complexes 1 and 3, carrying η(6)-p-cymene as the arene ligand, were shown to be toxic in all cell lines in the low micromolar/subnanomolar range, with complex 1 being the most cytotoxic complex of the series. Flow cytometry analysis revealed that complex 1 caused concentration- and time-dependent arrest of the cell cycle in G2-M and S phases in HeLa cells. This event is followed by the accumulation of the sub-G1 DNA content after 48h, in levels higher than cisplatin and in the absence of phosphatidylserine externalization. Fluorescent microscopy and acridine orange/ethidium bromide staining revealed that complex 1 induced both apoptotic and necrotic cell morphology characteristics. Drug-accumulation and DNA-binding studies performed by inductively coupled plasma mass spectrometry in HeLa cells showed that the total ruthenium uptake increased in a time- and concentration-dependent manner, and that complex 1 accumulated more efficiently than cisplatin at equimolar concentrations. The introduction of a Me2dppz ligand into the ruthenium(II)-p-cymene scaffold was found to allow the discovery of a strongly cytotoxic complex with significantly higher cellular uptake and DNA-binding properties than cisplatin. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Synthesis and characterization of two polyoxometalates consisting of different Cu-ligand hydrogen phosphate units

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jinshuang; Zhao, Xiaofang; Huang, Jiao; Gong, Kaining; Han, Zhangang, E-mail: hanzg116@126.com; Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn

    2014-03-15

    Two polyoxometalates [(Cu-mbpy){sub 4}(HPO{sub 4}){sub 2}(H{sub 2}O){sub 2}][PMo{sub 12}O{sub 40}]·H{sub 2}O (1) and [(Cu-mbpy){sub 6}(HPO{sub 4}){sub 4}][PW{sub 12}O{sub 40}]·4H{sub 2}O (2) (mbpy=4,4'-dimethyl-2,2'-dipyridyl in 1; 5,5″-dimethyl-2,2'-dipyridyl in 2) have been synthesized and characterized by IR, X-ray powder diffraction, TG analysis and electrochemical property. The structural features of 1–2 are in their cationic moieties consisting of different linkages of [Cu-mbpy]{sup 2+} and HPO{sub 4}{sup 2−} groups. In 1 four Cu-mbpy bridged by two HPO{sub 4}{sup 2−} ions form a discrete cluster with an interesting octahedron of (Cu{sub 4}P{sub 2}), while in 2 Cu-mbpy fragments are bridged by HPO{sub 4}{sup 2−} ions into 1D structure consisting of trigonal bipyramidal polyhedra of (Cu{sub 3}P{sub 2}). Photocatalytic experiments indicate that compounds 1 and 2 are actively photocatalytic for degradation of methyl orange in the presence of H{sub 2}O{sub 2} under UV light irradiation. -- Graphical abstract: Two polyoxometalate-based supramolecular compounds consisting of different linkages based on Cu-ligand and HPO{sub 4}{sup 2−} groups have been synthesized and characterized. The photocatalytic activity are studied. Highlights: • Two polyoxometalate-based supramolecular compounds consisting of different linkages based on Cu-ligand and HPO{sub 4}{sup 2−} groups have been synthesized. • Hydrogen bonding and π…π interactions play important roles in constructing crystal supramolecular frameworks. • Two compounds represent a high photocatalytic activity in the degradation of methyl orange.

  9. Pseudohalide copper(II) complexes derived from polypyridyl ligands: Synthesis and characterization

    Science.gov (United States)

    Mautner, Franz A.; Louka, Febee R.; LeGuet, Thibaut; Massoud, Salah S.

    2009-02-01

    A novel series of pseudohalide- ( N3- NCS -) and perchlorato-Cu(II) complexes possessing a series of ligands with pyridyl-containing donors have been investigated. These include [Cu(pmap)ClO 4)]ClO 4 ( 1), [Cu(pmap)(N 3)]ClO 4 ( 2), [Cu(pmea)(N 3)]ClO 4·H 2O ( 3), [Cu(dp-pa)(N 3)]ClO 4·½H 2O ( 4), [Cu(pzdepy)ClO 4]ClO 4 ( 5), [Cu(pzdepy)(NCS)]ClO 4 ( 6) and [Cu 2(L)(NCS) 4]·2CH 3CN ( 7) where pmap = bis[2-(2-pyridylethyl)]-(2-pyridylmethyl)amine, pmea = bis(2-pyridylmethyl)-2-(2-pyridylethyl)amine, dp-pa = N-propanamide- N, N-bis(2-pyridylmethyl)amine, pzdepy = N, N'-bis[2-(2-pyridylethyl)]piperazine and L = 3,5-bis[bis(2-pyridylmethyl)aminomethyl]-toluene. All complexes were characterized by elemental analyses, IR and UV-Visible spectroscopy. The visible spectra of all complexes reveal the square-pyramidal geometries (SP) around the central Cu 2+ ion. IR spectra confirmed the coordination of the ClO4- group in 1 and 5 and the N-donor thiocyanate group in complexes 6 and 7. The X-ray structure determination of the pseudohalide complexes 2, 6 and 7 confirmed the monodentate coordination nature of N3- and NCS - ions. The structure of 2 or 6 consists of isolated [Cu(pmap)(N 3)] + or [Cu(pzdepy)(NCS)] + cations and perchlorate counter anions. The copper centers are penta-coordinated by the four N atoms of the pmap or pzdepy and N(5) atom of the azide group in 2 and the thiocyanate group in 6. In the dinuclear unit [Cu 2(L)(NCS) 4] of 7, each copper atom forms bonds to three nitrogen atoms of the ligand L, [Cu sbnd N bonds from 2.013(2) to 2.054(2) Å], and to N(4) and N(5) atoms of the two terminal thiocyanato groups [Cu(1) sbnd N(4) = 1.954(2) Å; Cu(1) sbnd N(5) = 2.178(2) Å]. The intradimer Cu(1)...Cu(1A) distance is 5.7010(14) Å. An intramolecular π-π stacking with a ring-ring separation of 3.5991(14) Å is observed between the central benzene ring and the pyridyl rings. In the three complexes ( 2, 6 and 7), the CuN 5 chromophore may be described as an

  10. Copper(I) cyanide networks: synthesis, structure, and luminescence behavior. Part 2. Piperazine ligands and hexamethylenetetramine.

    Science.gov (United States)

    Lim, Mi Jung; Murray, Courtney A; Tronic, Tristan A; deKrafft, Kathryn E; Ley, Amanda N; deButts, Jordan C; Pike, Robert D; Lu, Haiyan; Patterson, Howard H

    2008-08-04

    A variety of photoluminescent, and in some cases thermochromic, metal-organic networks of CuCN were self-assembled in aqueous reactions with amine ligands: (CuCN) 2(Pip) ( 1a), (CuCN) 20(Pip) 7 ( 1b), (CuCN) 7(MePip) 2 ( 2), (CuCN) 2(Me 2Pip) ( 3a), (CuCN) 4(Me 2Pip) ( 3b), (CuCN) 7(EtPip) 2 ( 4), (CuCN) 4(Et 2Pip) ( 5), (CuCN) 3(BzPip) 2 ( 6a), (CuCN) 5(BzPip) 2 ( 6b), (CuCN) 7(BzPip) 2 ( 6c), (CuCN) 4(BzPip) ( 6d), (CuCN) 2(Bz 2Pip) ( 7), (CuCN)(Ph 2CHPip) ( 8a), (CuCN) 2(Ph 2CHPip) ( 8b), (CuCN) 3(HMTA) 2 ( 9a), (CuCN) 5(HMTA) 2 ( 9b), and (CuCN) 5(HMTA) ( 9c) (Pip = piperazine, MePip = N-methylpiperazine, Me 2Pip = N, N'-dimethylpiperazine, EtPip = N-ethylpiperazine, Et 2Pip = N, N'-diethylpiperazine, BzPip = N-benzylpiperazine, Bz 2Pip = N, N'-dibenzylpiperazine, Ph 2CHPip = N-(diphenylmethyl)piperazine, and HMTA = hexamethylenetetramine). New X-ray structures are reported for 1b, 2, 3b, 4, 5, 6a, 6d, 7, 8b, 9b, and 9c. An important structural theme is the formation of (6,3) (CuCN) 2(piperazine) sheets with or without threading of independent CuCN chains. Strong luminescence at ambient temperature is observed for all but complexes 6 and 7. All luminescent compounds show a broad emission band in the blue region at about 450 nm attributable to metal-to-ligand charge transfer behavior based on the large Stokes shift between excitation and emission maxima. 3, 8, and 9 are thermochromic due to an additional lower energy emission band, which is absent at 77 K.

  11. Synthesis and characterization of two new types of oxovanadium complexes with pyrazole as ligand

    Institute of Scientific and Technical Information of China (English)

    XING Yongheng; ZHANG Yuanhong; XU Yongting; ZHANG Baoli; NIU Shuyun; BAI Fengying

    2006-01-01

    At room temperature, two new different oxovanadium complexes with simple pyrazole (C3H4N2) as ligand were synthesized. VO(pz)4(SO4).H2O (1) (pz: pyrazole) is a mono-nuclear oxovanadium complex with pyrazole as terminal ligands. V2O2(μ-pz)(μ-OOSO2)(μ-OCH3)(pz)4 (2) is bi-nuclear oxovanadium complex containing three different bridges, which are pyrazolate, sulphate and methoxy, respectively. The two complexes were characterized by IR, elemental analyses, thermal analyses and X-ray diffraction. The crystal structural data of the complexes 1 and 2 are given as follows: Complex 1, orthorhombic, Pna21, a = 14.547(2)(°A), b =10.895(2)(°A), c =11.835(2)(°A); α=β=γ=90°, V=1875.8(5)(°A)3, Z = 4, R1 = 0.0485, WR2 = 0.1092. Complex 2, triclinic, , a =8.377(2)(°A), b =9.928(2)(°A), c = 16.527(3)(°A), α= 85.54(3)°, β = 80.92(3)°, γ= 87.92(3)°, R1 = 0.1461, WR2 = 0.4444. The study of non-thermal kinetic decomposition shows that, for complex 1, the possible reaction mechanisms of the two steps are nucleation and growth n=1/3, and three-dimensional pervasion n=2, respectively, and the kinetic equations may be expressed as dα/dT = (A/β)exp(-E/RT){1/3(1-α) [-In(1-α)]-2} and dα/dT = (A/β)exp(-E/RT){3/2(1-α)2/3 [1–(1-α)1/3]-1}, respectively; for complex 2, the possible reaction mechanisms of the two steps are chemical reaction, and three-dimensional pervasion n=2, respectively; the kinetic equations may be expressed as dα/dT = (A/β)exp(-E/RT)[(1-α)2], and dα/dT = (A/β)exp(-E/RT){3/2(1-α)2/3[1-(1-α)1/3]-1}, respectively.

  12. Mixed ligand ruthenium(III) complexes of benzaldehyde 4-methyl-3-thiosemicarbazones with triphenylphosphine/triphenylarsine co-ligands: Synthesis, DNA binding, DNA cleavage, antioxidative and cytotoxic activity

    Science.gov (United States)

    Sampath, K.; Sathiyaraj, S.; Raja, G.; Jayabalakrishnan, C.

    2013-08-01

    The new ruthenium(III) complexes with 4-methyl-3-thiosemicarbazone ligands, (E)-2-(2-chlorobenzylidene)-N-methylhydrazinecarbothioamide (HL1) and (E)-2-(2-nitrobenzylidene)-N-methylhydrazinecarbothioamide (HL2), were prepared and characterized by various physico-chemical and spectroscopic methods. The title compounds act as bidentate, monobasic chelating ligands with S and N as the donor sites and are preferably found in the thiol form in all the complexes studied. The molecular structure of HL1 and HL2 were determined by single crystal X-ray diffraction method. DNA binding of the ligands and complexes were investigated by absorption spectroscopy and IR spectroscopy. It reveals that the compounds bind to nitrogenous bases of DNA via intercalation. The oxidative cleavage of the complexes with CT-DNA inferred that the effects of cleavage are dose dependent. Antioxidant study of the ligands and complexes showed the significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of the ligands and complexes against MCF-7 cell line was assayed which showed higher cytotoxic activity with the lower IC50 values indicating their efficiency in killing the cancer cells even at low concentrations.

  13. A catechol-like phenolic ligand-functionalized hydrothermal carbon: One-pot synthesis, characterization and sorption behavior toward uranium

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo; Ma, Lijian; Tian, Yin; Yang, Xiaodan; Li, Juan; Bai, Chiyao; Yang, Xiaoyu; Zhang, Shuang; Li, Shoujian, E-mail: sjli000616@scu.edu.cn; Jin, Yongdong, E-mail: jinyongdong@scu.edu.cn

    2014-04-01

    Highlights: • A new catechol-like ligand-functionalized hydrothermal carbon sorbent is synthesized. • A combination of bayberry tannin and glyoxal is firstly used as starting materials. • Simple, economically viable and environment-friendly synthesis method. • The sorbent exhibits high sorption capacity and distinct selectivity for uranium. - Abstract: We proposed a new approach for preparing an efficient uranium-selective solid phase extractant (HTC-btg) by choosing bayberry tannin as the main building block and especially glyoxal as crosslinking agent via a simple, economic, and green one-pot hydrothermal synthesis. The results of characterization and analysis show that after addition of glyoxal into only bayberry tannin-based hydrothermal reaction system, the as-synthesized HTC-btg displayed higher thermal stability, larger specific surface area and more than doubled surface phenolic hydroxyl groups. The sorption behavior of the sorbents toward uranium under various conditions was investigated in detail and the results indicated that the process is fast, endothermic, spontaneous, and pseudo-second-order chemisorption. The U(VI) sorption capacity reached up to 307.3 mg g{sup −1} under the current experimental conditions. The selective sorption in a specially designed multi-ion solution containing 12 co-existing cations over the range of pH 1.0–4.5 shown that the amount of uranium sorbed accounts for about 53% of the total sorption amount at pH 4.5 and distinctively about 85%, unreported so far to our knowledge, at pH 2.0. Finally, a possible mechanism involving interaction between uranyl ions and phenolic hydroxyl groups on HTC-btg was proposed.

  14. Synthesis, Spectroscopic, and Biological Studies on New Zirconium(IV Porphyrins with Axial Ligand

    Directory of Open Access Journals (Sweden)

    Gauri D. Bajju

    2013-01-01

    Full Text Available A series of parasubstituted tetraphenylporphyrin zirconium(IV salicylate complexes (SA/5-SSAZr(IVRTPP, R = p-H, p-CH3, p-NO2, p-Cl, SA = salicylate, and 5-SSA = 5-sulfosalicylate have been synthesized, and the spectral properties of free base porphyrins, their corresponding metallated, and axially ligated zirconium(IV porphyrin compounds were compared with each other. A detailed analysis of ultraviolet-visible (UV-vis, proton nulcear magnetic resonance (1H NMR spectroscopy, infrared (IR spectroscopy, and elemental analysis suggested the transformation from free base porphyrins to zirconium(IV porphyrins. The ability of the metal in this complex for extra coordination of solvent molecules was confirmed by ESI-MS spectra. Besides the fluorescence, cyclic voltammetry, and thermogravimetric studies, the complexes were also screened for antimicrobial and anticancer activities. Among all the complexes, 5-SSAZr(p-NO2TPP shows high antibacterial activity.

  15. Synthesis, biological evaluation, WAC and NMR studies of S-galactosides and non-carbohydrate ligands of cholera toxin based on polyhydroxyalkylfuroate moieties.

    Science.gov (United States)

    Ramos-Soriano, Javier; Niss, Ulf; Angulo, Jesús; Angulo, Manuel; Moreno-Vargas, Antonio J; Carmona, Ana T; Ohlson, Sten; Robina, Inmaculada

    2013-12-23

    The synthesis of several non-carbohydrate ligands of cholera toxin based on polyhydroxyalkylfuroate moieties is reported. Some of them have been linked to D-galactose through a stable and well-tolerated S-glycosidic bond. They represent a novel type of non-hydrolyzable bidentate ligand featuring galactose and polyhydroxyalkylfuroic esters as pharmacophoric residues, thus mimicking the GM1 ganglioside. The affinity of the new compounds towards cholera toxin was measured by weak affinity chromatography (WAC). The interaction of the best candidates with this toxin was also studied by saturation transfer difference NMR experiments, which allowed identification of the binding epitopes of the ligands interacting with the protein. Interestingly, the highest affinity was shown by non-carbohydrate mimics based on a polyhydroxyalkylfuroic ester structure.

  16. Co(III and Ni(II Complexes Containing Bioactive Ligands: Synthesis, DNA Binding, and Photocleavage Studies

    Directory of Open Access Journals (Sweden)

    M. C. Prabhakara

    2007-02-01

    Full Text Available DNA binding and photocleavage characteristics of a series of mixed ligand complexes of the type [M(bpy2qbdp](PF6n⋅xH2O (where M=Co(III or Ni(II, bpy=2.2′-bipryidine, qbdp = Quinolino[3,2-b]benzodiazepine, n=3 or 2 and x=5 or 2 have been investigated. The DNA binding property of the complexes with calf thymus DNA has been investigated by using absorption spectra, viscosity measurements, as well as thermal denaturation studies. Intrinsic binding constant (Kb has been estimated under similar set of experimental conditions. Absorption spectral studies indicate that the Co(III and Ni(II complexes intercalate between the base pairs of the CT-DNA tightly with intrinsic DNA binding constant of 1.3×106 and 3.1×105 M-1 in Tris-HCl buffer containing 50 mM NaCl, respectively. The proposed DNA binding mode supports the large enhancement in the relative viscosity of DNA on binding to quinolo[3,2-b]benzodiazepine. The oxidative as well as photo-induced cleavage reactions were monitered by gel electrophoresis for both complexes. The photocleavage experiments showed that the cobalt(III complex can cleave pUC19 DNA effectively in the absence of external additives as an effective inorganic nuclease.

  17. Exogenous bridging and nonbridging in Cu(II) complexes of Mannich base ligands: Synthesis and physical properties

    Indian Academy of Sciences (India)

    S Sujatha; T M Rajendiran; R Kannappan; R Venkatesan; P Sambasiva Rao

    2000-12-01

    Preparation of pentadentate ligands L1, L2, L3 and L4, where L1=4-chloro-3-methyl-2[(prolin-1-yl)methyl]-6-[N-phenyl piperazin-1-yl)methyl]phenol, L2= 4-ethyl-2-[(prolin-1-yl)methyl]-6-[(N-phenyl piperazin-1-yl)methyl]phenol, L3 =4-chloro-3-methyl-2-[(prolin-1-yl)methyl]-6-[N-methyl piperazin-1-yl]methyl phenol, L4 = 4-methoxy-2-[(prolin-1-yl)methyl]-6-[(N-phenyl piperazin-1-yl)methyl]phenol is described together with that of the corresponding Cu(II) complexes with various bridging motifs like OH, OAc and NO2. The complexes are characterized by elemental analysis, electrochemical and electron paramagnetic spectral studies. Redox properties of the complexes in acetonitrile are highly quasireversible due to the chemical or/and stereochemical changes subsequent to electron transfer. The complexes show resolved copper hyperfine EPR at room temperature, indicating the presence of weak antiferromagnetic coupling between the copper atoms. Strengths of the antiferromagnetic interactions are in the order NO2 > OAc > OH.

  18. Waterborne carboxyl-terminated hyperbranched oligomer polyester ligand: Synthesis, characterization and chelation with chromium(III)

    Science.gov (United States)

    Yao, Qi; Li, Chenying; Huang, Henghui; Chen, Hualin; Liu, Bailing

    2017-09-01

    A series of carboxyl-terminated hyperbranched oligomer polyester (HBP) with different degree of branching (DB) and number average molar mass (Mbarn) have been prepared. The molecular structure, degree of branching, molecular mass and its distribution of HBP were investigated by FTIR, 1H NMR, and GPC, respectively. And the coordination number, stability constant and degree of dissociation (α) between HBP and chromium(Ⅲ) were measured via continuous variation method (Job's plot). Experimental results show that the coordination capability between HBP and chromium(Ⅲ) affected by both DB and molecular mass, and the latter plays a decisive role. Moreover HBP outperforms low molecular weight of organic acids (citric acid, acetic acid) and linear polyacrylic acid with similar molecular mass. The coordination number and stability constants of HBP-3 (Mbarn = 1713 Da, Mbarw /Mbarn (PDI) = 1.11 and DB = 0.72) can reach 4 and 6.55e+008, which demonstrated it can be selected as a good ligand to coordination with chromium(Ⅲ). Therefore HBP can be used as chrome auxiliary in chrome tanning to improve the absorption of chromium.

  19. Synthesis and catalytic activity of iron complexes with bidentate NHC ligands.

    Science.gov (United States)

    Wu, Jianguo; Dai, Wei; Farnaby, Joy H; Hazari, Nilay; Le Roy, Jennifer J; Mereacre, Valeriu; Murugesu, Muralee; Powell, Annie K; Takase, Michael K

    2013-05-28

    A family of well-defined Fe(II) complexes of the type {BnN(N-CH2(CH2)n-N'-tert-butyl-imidazole-2-ylidene)2}FeCl2 (Bn = benzyl; n = 1 (1) or 2 (2)), {BnN(N-CH2(CH2)n-N'-methylbenzimidazole-2-ylidene)2}FeCl2 (n = 1 (3) or 2 (4)) and {BnN(N-CH2CH2CH2-N'-methylbenzimidazole-2-ylidene)2}FeBr2 (5) has been synthesized. These complexes are rare examples of Fe species supported by bidentate NHC ligands. Complexes 2, 3, 4 and 5 were characterized by X-ray crystallography and in all cases a distorted tetrahedral geometry is observed around the Fe center. The magnetic data is consistent with the complexes containing non interacting high spin Fe(II) centers (S = 2) and indicates that a large zero-field splitting (D) is present. The new complexes are highly active pre-catalysts for the homo-coupling of Grignard reagents.

  20. Amine ligand-based hydrothermal synthesis of Co3O4 nanoparticles, characterization and magnetic study

    Science.gov (United States)

    Mansournia, Mohammadreza; Rakhshan, Narges

    2016-12-01

    Cobalt(II,III) oxid (Co3O4) nanostructures have been successfully synthesized using [Co(NH3)6]Cl3 and [Co(en)3]Cl3 (en: ethylenediamine) as the single precursors via hydrothermal method, and CoCl2·6H2O through a facile ammonia-assisted approach. Indeed, ammine and en ligands, as well as ammonia vapor, act as the sources of hydroxide ion in the preparation of Co3O4 nanoparticles. The structure of products was confirmed by X-ray diffraction (XRD) technique and Fourier-transform infrared (FT-IR) spectroscopy and their morphologies were examined by scanning electron microscopy (SEM). The optical study of the as-prepared Co3O4 nanostructures using UV-Vis diffused reflectance spectroscopy (DRS) exhibited their semiconducting property by revealing one optical band gap in 3.3 eV. Moreover, the vibrating sample magnetometry (VSM) measurements showed a weak ferromagnetic behavior that could be attributed to uncompensated surface spins and/or finite-size effects. Further, the effects of the nature of the precursor, its concentration, temperature and reaction time on the size and morphology of the samples were studied in detail.

  1. Synthesis and characterization of a tetranuclear copper(Ⅱ) complex with a chiral Schiff base ligand

    Institute of Scientific and Technical Information of China (English)

    Hua Xiang; Long Jiang; Huan-Yong Li; Xiao-Dan Zheng; YU Li

    2013-01-01

    The title complex l-[CuⅡ4(Hvap)2(vap)2(MeOH)2](ClO4)2 1 has been synthesized and characterized by EA,IR,TGA,solid-state CD spectra and X-ray single-crystal analyses (I-H2vap:a Schiff base ligand derived from the condensation of o-vanillin and 1-2-amino-3-phenyl-1-propanol).Complex 1 crystallizes in monoclinic system,chiral space group P21 with a=10.4257(18),b=21.695(4),c=15.721(3) (A),β =94.443(3)°,V=3545.1 (11) (A)3,Z =2,Cu4C7oH78N4O22Cl2,Mr =1652.42,Dc =1.548 g/cm3,F(0 0 0) =1704 and μ(MoKα) =1.338 mm-1.The final R =0.0682 and wR =0.1420 for 6170 observed reflections with I > 2σ(Ⅰ) and R =0.1775 and wR =0.1830 for all data.The structure of complex 1 contains a boat-shaped {Cu4O4} motif.The solid-state CD spectra confirm the chiral nature of complex 1.

  2. Tetracarboxylatodirhenium complexes linked by axial cyano bridges to metalpentacarbonyl ligands - synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, F.E.; Wachter, W. [Technische Univ. Muenchen (Germany). Anorganisch-Chemisches Inst.; Goncalves, I.S. [Nova de Lisboa Univ. (Portugal). Inst. de Tecnologia Quimica e Biologica]|[Aveiro Univ. (Portugal). Dept. de Quimica; Lopes, A.D.; Lopes, J.P.; Romao, C.C. [Nova de Lisboa Univ. (Portugal). Inst. de Tecnologia Quimica e Biologica; Mink, J. [Hungarian Academy of Sciences (Hungary). Inst. of Isotope and Surface Chemistry]|[Veszprem Univ. (Hungary). Dept. of Analytical Chemistry; Hajba, L. [Veszprem Univ. (Hungary). Dept. of Analytical Chemistry; Parola, A.J.; Pina, F.; Sotomayor, J. [Nova de Lisboa Univ. (Portugal). Faculdade de Ciencias e Tecnologia

    1999-02-15

    Reaction of Re{sub 2}{l_brace}{mu}-O{sub 2}CC(CH{sub 3}){sub 3}{r_brace}{sub 4}Cl{sub 2} with [(CO){sub 5}M-CN]Na (M=Cr, Mo, W) leads to tetranuclear complexes of formula Re{sub 2}{l_brace}{mu}-O{sub 2}CC(CH{sub 3}){sub 3}{r_brace}{sub 4}[-NC-M(CO){sub 5}]{sub 2} (M=Cr, Mo, W). These complexes were characterized by {sup 1}H-, {sup 13}C-, and {sup 95}Mo-NMR, IR and Raman spectroscopy, elemental analysis and examined by cyclic voltammetry. The applied methods show the donor capabilities of the [(CO){sub 5}M-CN]{sup -} ligands which shift electron density towards the Re centers weakening the Re-Re quadruple bond. The Re-Re bond lengths and the {nu}(Re-Re) force constants are estimated based on the FT-IR and Raman examinations. Photchemical examinations and TG/MS experiments have also been conducted. The latter method shows that the product complexes decompose around 100 C, but first loosing their carbonyl substituents; as do the Cr, Mo, W precursor compounds. The dirhenium tetrapivalate unit decomposes only at higher temperatures in a distinct second step. (orig.)

  3. Synthesis and Crystal Structures of Two Dinuclear Iron(Ⅲ) Complexes with Tripodal Ligands

    Institute of Scientific and Technical Information of China (English)

    TIAN Jin-Lei; XIE Ming-Jin; YAN Shi-Ping; LIAO Dai-Zheng; JIANG Zong-Hui; CHENG Peng

    2005-01-01

    By using the tripodal tetradentate ligands of tris(2-pyridylmethyl)amine (TPA) or tris(2-benzimidazolylmethyl)-amine (NTB), two dinunclear iron(Ⅲ) complexes [Fe2L2(μ2-O)( μ2-p-NH2-C6H4COO)]3+ (L=TPA, 1 and L=NTB,2) were obtained. Both of the two complexes crystallize in monoclinic system with space group P2(1)/c. The cell parameters of 1: a= 1.4529(4) nm, b= 1.6622(5) nm, c=2.0625(6) nm,β=100.327(5)°, V=4.900(3) nm3, Z=4,F(000)=2344, Mr= 1142.91, Dc= 1.549 g/cm3, R1 =0.0544, R2=0.0962. The cell parameters of 2: a= 1.3378(4) nm,b=2.1174(7) nm, c=2.4351(7) nm, β=97.315(6)°, V=6.842(4) nm3, Z=4, F(000)=3116, Mr= 1505.08, Dc= 1.444g/cm3, R1=0.0793, R2=0.1623. In both cases, the central iron(Ⅲ) metal ions are coordinated to the four nitrogen atoms of TPA (or NTB) and two oxygen atoms from two different bridges to form a distorted octahedral geometry.

  4. Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions

    Indian Academy of Sciences (India)

    Singappagudem Govindaraju; Guddekoppa S Ananthnag; Susmita Naik; Shaikh M Mobin; Maravanji S Balakrishn

    2012-07-01

    Allyl functionalized phosphinite PPh2(OAr) [Ar=C6H4(-C3H5)] (1) and phosphonite PPh(OAr)2 (2) ligands were prepared by the reactions of 2-allylphenol with PPh2Cl and PPhCl2, respectively. The ruthenium(II) complexes, [Ru(6--cymene)(PPh2(OAr))Cl2] (3) and [Ru(6--cymene)(PPh(OAr)2Cl2)] (4) were obtained by reacting 1 or 2 with [Ru(6--cymene)Cl2]2 in 2:1 molar ratios, respectively. Reactions of 1 or 2 with AuCl(SMe2) gave [Au{PPh2(OAr)}Cl] (5) or [Au{PPh(OAr)2}Cl] (6) in good yield. The palladium complex, [Pd{PPh(OAr)2}2Cl2] (7) was prepared by reacting Pd(COD)Cl2 with 2 in 1:2 molar ratio. The reaction between Pd(COD)Cl2 and 1 yielded a mixture of orthopalladated cis- and trans-[Pd(Ph2P(OAr))Cl]2 (8a and 8b). The treatment of 8 with PPh3 and Ph2PCH2PPh2 resulted in the cleavage of chloro bridge to give respectively, [Ph2(OAr)PPd(PPh3)Cl] (9) and [Ph2(ArO)PPd(2-dppm)]OTf (10). Single crystal X-ray structure of the ruthenium complex 3 is described.

  5. Synthesis and NMR Spectral Analysis of Amine Heterocycles: The Effect of Asymmetry on the [superscript 1]H and [superscript 13]C NMR Spectra of N,O-Acetals

    Science.gov (United States)

    Saba, Shahrokh; Ciaccio, James A.; Espinal, Jennifer; Aman, Courtney E.

    2007-01-01

    The stereochemical investigation is conducted to give students the combined experience of chemical synthesis of amines and N-heterocycles and structural stereochemical analysis using NMR spectroscopy. Students are introduced to the concept of topicity-stereochemical relationships between ligands within a molecule by synthesizing N,O-acetals.

  6. A Novel 3D Zn-La Heterometallic Coordination Polymer Involving in situ Glycinate Ligand Synthesis

    Institute of Scientific and Technical Information of China (English)

    SONG Wen-Donga; LI Shi-Jie; GUO Jian; TONG Shao-Wei; JI Li-Li; MIAO Dong-Liang; AN Jing-Bo; NG Seik Weng

    2012-01-01

    One novel 3D 3d-4f coordination polymer, [LaZn(glc)(ox)2(H20)2]n (1, glc = glycinate, ox = oxalate), was obtained by the in situ synthesis of glycinate from the reaction of tetrazole-l-acetic acid, sodium oxalate, zinc nitrate and lanthanide oxide in the presence of a trace quantity of nitric acid under hydrothermal conditions. Compound 1 is of monoclinic, space group P21/n with a = 0.99601(9), b = 1.14592(10), c = 1.19107(10) nm and β = 108.7150(10)°. 1 exhibits an unusual 3D heterometallic coordination framework constructed by heterometallic dinuclear LaZn subunits and mixed ox and glc linkers with a uninodal 6-connected vine {33.43.58.6} net.

  7. Synthesis, characterization, antimicrobial activity and theoretical studies of new thiophene-based tripodal ligands

    Science.gov (United States)

    Harit, Tarik; Bellaouchi, Reda; Asehraou, Abdeslam; Rahal, Mahmoud; Bouabdallah, Ibrahim; Malek, Fouad

    2017-04-01

    The synthesis of new thiophene-tripods with different side arms was reported. These compounds were obtained in good yields and their structures were confirmed by NMR spectroscopy, elemental analysis, infrared spectroscopy and mass spectrometry. The in vitro antibacterial and antifungal activities of these products were screened against Gram positive bacteria (Micrococcus luteus and Bacillus subtilis), Gram negative bacteria (Escherichia coli) and fungi (Candida pelliculosa). The obtained results showed that tripods containing a hydroxyl group in the side arm inhibited both Gram-positive and Gram-negative bacteria, while the tripod with an isopropyl side arm inhibited only the Gram-negative bacteria. DFT calculations with B3LYP/6-31G* level have been used to analyze the electronic and geometric characteristics. The molecular electrostatic potential surface (MEPS) indicated that the presence of electrophile site in the side arm could be responsible for activities against Gram-positive bacteria.

  8. Assessment of dopamine (DA) synthesis rate in selected parts of the rat brain with central noradrenergic lesion after administration of 5-HT3 receptor ligands

    OpenAIRE

    Wojciech Roczniak

    2013-01-01

    Introduction: The study objective was to determine the effect of central noradrenergic system lesions performed in the early extrafetal life period on dopamine synthesis in the rat brain. The content of L-dihydroxyphenylalanine (L-DOPA) was assessed in the frontal lobe, thalamus, hypothalamus and brain stem of rats by high-pressure chromatography with electrochemical detection (HPLC/ED) after administration of 5-HT3 receptor ligands.Material and Methods: Adult male Wistar rats which underwent...

  9. Microwave-Assisted Synthesis of 3,5-Dibenzyl-4-amino-1,2,4-triazole and its Diazo Ligand, Metal Complexes Along with Anticancer Activity

    Directory of Open Access Journals (Sweden)

    Anjali Jha

    2010-01-01

    Full Text Available Synthesis of 3,5-dibenzyl-4-amino-1,2,4-triazole was accomplished via a conventional method as well as microwave irradiation method, followed by diazotization and coupling with 2,4-pentanedione. The dinucleating ligand was isolated and complexed with Ni(II, Cu(II and Ru(III chlorides. These complexes were screened on Jurkat, Raji & PBMC cell lines for anticancer activity. Ruthenium complexes showed potential anticancer activities.

  10. Microwave-Assisted Synthesis of 3,5-Dibenzyl-4-amino-1,2,4-triazole and its Diazo Ligand, Metal Complexes Along with Anticancer Activity

    OpenAIRE

    Anjali Jha; Murthy, Y. L. N.; Durga, G.; Sundari, T. T.

    2010-01-01

    Synthesis of 3,5-dibenzyl-4-amino-1,2,4-triazole was accomplished via a conventional method as well as microwave irradiation method, followed by diazotization and coupling with 2,4-pentanedione. The dinucleating ligand was isolated and complexed with Ni(II), Cu(II) and Ru(III) chlorides. These complexes were screened on Jurkat, Raji & PBMC cell lines for anticancer activity. Ruthenium complexes showed potential anticancer activities.

  11. Role of Carboxylate ligands in the Synthesis of AuNPs: Size Control, Molecular Interaction and Catalytic Activity

    KAUST Repository

    Aljohani, Hind Abdullah

    2016-05-22

    low temperature. The structure of the citrate layer on the AuNP surface may be a key factor in gaining a more detailed understanding of nanoparticle formation and stabilization. This can be affecting the catalytic activity. These thoughts invited us to systematically examine the role of sodium citrate as a stabilizer of gold nanoparticles, which is the main theme of this thesis. This research is focused on three main objectives, controlling the size of the gold nanoparticles based on citrate (and other carboxylate ligands Trisodium citrate dihydrate, Isocitric Acid, Citric acid, Trimesic acid, Succinic Acid, Phthalic acid, Disodium glutarate, Tartaric Acid, Sodium acetate, Acetic Acid and Formic Acid by varying the concentration of Gold/sodium citrate, investigating the interaction of the citrate layer on the AuNP surface, and testing the activity of the Au/TiO2 catalysts for the oxidation of carbon monoxide. This thesis will be divided into five chapters. In Chapter 1, a general literature study on the various applications and methods of synthesis of Au nanoparticles is described. Then we present the main synthetic pathways of Au nanoparticles we selected. A part of the bibliographic study was given to the use of Au nanoparticles in catalysis. In Chapter 2, we give a brief description of the different experimental procedures and characterization techniques utilized over the course of the present work. The study of the size control and the interaction between gold nanoparticles and the stabilizer (carboxylate groups) was achieved by using various characterization techniques such as UV-visible spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Nuclear Magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). In Chapter 3, we discuss the synthesis and size control of Au nanoparticles by following the growth of these nanoparticles by UV-Visible spectroscopy and TEM. We

  12. Ligand-optimized electroless synthesis of silver nanotubes and their activity in the reduction of 4-nitrophenol.

    Science.gov (United States)

    Muench, Falk; Rauber, Markus; Stegmann, Christian; Lauterbach, Stefan; Kunz, Ulrike; Kleebe, Hans-Joachim; Ensinger, Wolfgang

    2011-10-14

    A facile electroless plating procedure for the controlled synthesis of nanoscale silver thin films and derived structures such as silver nanotubes was developed and the products were characterized by SEM, TEM and EDS. The highly stable plating baths consist of AgNO(3) as the metal source, a suitable ligand and tartrate as an environmentally benign reducing agent. Next to the variation of the coordinative environment of the oxidizing component, the influence of the pH value was evaluated. These two governing factors strongly affect the plating rate and the morphology of the developing silver nanoparticle films and can be used to adapt the reaction to synthetic demands. The refined electroless deposition allows the fabrication of homogeneous high aspect-ratio nanotubes in ion track etched polycarbonate. Template-embedded metal nanotubes can be interpreted as parallelled microreactors. Following this concept, both the silver nanotubes and spongy gold nanotubes obtained by the use of the silver structures as sacrificial templates were applied in the reduction of 4-nitrophenol by sodium borohydride, proving to be extraordinarily effective catalysts.

  13. Enzymatic Synthesis of N-Acetyllactosamine (LacNAc Type 1 Oligomers and Characterization as Multivalent Galectin Ligands

    Directory of Open Access Journals (Sweden)

    Thomas Fischöder

    2017-08-01

    Full Text Available Repeats of the disaccharide unit N-acetyllactosamine (LacNAc occur as type 1 (Galβ1, 3GlcNAc and type 2 (Galβ1, 4GlcNAc glycosylation motifs on glycoproteins and glycolipids. The LacNAc motif acts as binding ligand for lectins and is involved in many biological recognition events. To the best of our knowledge, we present, for the first time, the synthesis of LacNAc type 1 oligomers using recombinant β1,3-galactosyltransferase from Escherichia coli and β1,3-N-acetylglucosaminyltranferase from Helicobacter pylori. Tetrasaccharide glycans presenting LacNAc type 1 repeats or LacNAc type 1 at the reducing or non-reducing end, respectively, were conjugated to bovine serum albumin as a protein scaffold by squarate linker chemistry. The resulting multivalent LacNAc type 1 presenting neo-glycoproteins were further studied for specific binding of the tumor-associated human galectin 3 (Gal-3 and its truncated counterpart Gal-3∆ in an enzyme-linked lectin assay (ELLA. We observed a significantly increased affinity of Gal-3∆ towards the multivalent neo-glycoprotein presenting LacNAc type 1 repeating units. This is the first evidence for differences in glycan selectivity of Gal-3∆ and Gal-3 and may be further utilized for tracing Gal-3∆ during tumor progression and therapy.

  14. Synthesis and structure of trinuclear W3S4 clusters bearing aminophosphine ligands and their reactivity toward halides and pseudohalides.

    Science.gov (United States)

    Beltrán, Tomás F; Pino-Chamorro, Jose Ángel; Fernández-Trujillo, M Jesús; Safont, Vicent S; Basallote, Manuel G; Llusar, Rosa

    2015-01-20

    The aminophosphine ligand (2-aminoethyl)diphenylphosphine (edpp) has been coordinated to the W3(μ-S)(μ-S)3 cluster unit to afford trimetallic complex [W3S4Br3(edpp)3](+) (1(+)) in a one-step synthesis process with high yields. Related [W3S4X3(edpp)3](+) clusters (X = F(-), Cl(-), NCS(-); 2(+)-4(+)) have been isolated by treating 1(+) with the corresponding halide or pseudohalide salt. The structure of complexes 1(+) to 4(+) contains an incomplete W3S4 cubane-type cluster unit, and only one of the possible isomers is formed: the one with the phosphorus atoms trans to the capping sulfur and the amino groups trans to the bridging sulphurs. The remaining coordination position on each metal is occupied by X. Detailed studies using stopped-flow, (31)P{(1)H} NMR, and ESI-MS have been carried out in order to understand the solution behavior and the kinetics of interconversion among species 1(+), 2(+), 3(+), and 4(+) in solution. Density functional theory (DFT) calculations have been also carried out on the reactions of cluster 1(+) with the different anions. The whole set of experimental and theoretical data indicate that the actual mechanism of substitutions in these clusters is strongly dependent on the nature of the leaving and entering anions. The interaction between an entering F(-) and the amino group coordinated to the adjacent metal have also been found to be especially relevant to the kinetics of these reactions.

  15. Lanthanide-directed synthesis of luminescent self-assembly supramolecular structures and mechanically bonded systems from acyclic coordinating organic ligands.

    Science.gov (United States)

    Barry, Dawn E; Caffrey, David F; Gunnlaugsson, Thorfinnur

    2016-06-01

    Herein some examples of the use of lanthanide ions (f-metal ions) to direct the synthesis of luminescent self-assembly systems (architectures) will be discussed. This area of lanthanide supramolecular chemistry is fast growing, thanks to the unique physical (magnetic and luminescent) and coordination properties of the lanthanides, which are often transferred to the resulting supermolecule. The emphasis herein will be on systems that are luminescent, and hence, generated by using either visibly emitting ions (such as Eu(III), Tb(III) and Sm(III)) or near infrared emitting ions (like Nd(III), Yb(III) and Er(III)), formed through the use of templating chemistry, by employing structurally simple ligands, possessing oxygen and nitrogen coordinating moieties. As the lanthanides have high coordination requirements, their use often allows for the formation of coordination compounds and supramolecular systems such as bundles, grids, helicates and interlocked molecules that are not synthetically accessible through the use of other commonly used templating ions such as transition metal ions. Hence, the use of the rare-earth metal ions can lead to the formation of unique and stable species in both solution and in the solid state, as well as functional and responsive structures.

  16. Synthesis, crystal structures and antitumor activities of copper(II) complexes with a 2-acetylpyrazine isonicotinoyl hydrazone ligand

    Science.gov (United States)

    Xu, Jun; Zhou, Tao; Xu, Zhou-Qing; Gu, Xin-Nan; Wu, Wei-Na; Chen, Hong; Wang, Yuan; Jia, Lei; Zhu, Tao-Feng; Chen, Ru-Hua

    2017-01-01

    Five complexes, [Cu(L)2]·4.5H2O (1), [Cu(HL)2](NO3)2·CH3OH (2) {[Cu2(L)2(NO3)(H2O)2]·(NO3)}n (3), [Cu2(HL)2(SO4)2]·2CH3OH (4) and [Cu4(L)4Cl4]·5H2O (5) based on HL (where HL = 2-acetylpyrazine isonicotinoyl hydrazone) have been synthesized and characterized by X-ray diffraction analyses. The counter anion and organic base during the synthesis procedure influence the structures of the complexes efficiently, which generate five complexes as mono-, bi-, tetra-nuclear and one-dimensional structures. The antitumor activities of the complexes 1-5 (except for complex 3 with the poor solubility) against the Patu8988 human pancreatic cancer, ECA109 human esophagus cancer and SGC7901 human gastric cancer cell lines are screened by MTT assay. The results indicate that the chelation of Cu(II) with the ligand is responsible for the observed high cytotoxicity of the copper(II) complexes and the 1:2 copper species 1 and 2 demonstrate lower antitumor activities than that of the 1:1 copper species 4 and 5. In addition, the in vitro apoptosis inducing activity of the copper(II) complex 5 against SGC7901 cell line is determined. And the results show that the complex can bring about apoptosis of the cancerous cells in vitro.

  17. External anion effect on the synthesis of new MOFs based on formate and a twisted divergent ligands

    Energy Technology Data Exchange (ETDEWEB)

    Lago, Ana Belén, E-mail: ablago@uvigo.es [Departamento de Química Inorgánica/Facultade de Química, Instituto de Investigación Biomédica (IBI), Universidade de Vigo, E-36310 Vigo, Galicia (Spain); Carballo, Rosa [Departamento de Química Inorgánica/Facultade de Química, Instituto de Investigación Biomédica (IBI), Universidade de Vigo, E-36310 Vigo, Galicia (Spain); Lezama, Luis [BCMaterials & Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apartado 644, 48080 Bilbao (Spain); Vázquez-López, Ezequiel M. [Departamento de Química Inorgánica/Facultade de Química, Instituto de Investigación Biomédica (IBI), Universidade de Vigo, E-36310 Vigo, Galicia (Spain)

    2015-11-15

    New copper(II) metal–organic compounds with the formulae [Cu{sub 3}Cl(HCO{sub 2}){sub 5}(SCS){sub 3}(H{sub 2}O){sub 2}]·8H{sub 2}O·EtOH (1) and [Cu{sub 3}(HCO{sub 2}){sub 4}(SCS){sub 4}(H{sub 2}O){sub 2}](NO{sub 3}){sub 2}·9H{sub 2}O (2) (SCS=bis(4-pyridylthio)methane) have been synthesized after a careful study of the reaction of the SCS ligand with copper(II) formate. The compounds were obtained in the presence of sodium chloride and nitrate salts under microwave irradiation. The influence of the anion at different metal/anion ratios on the final architecture has been studied. The new chloride-MOF 1 has been characterized by electron paramagnetic resonance (EPR), magnetic properties and single crystal X-ray diffraction studies. The thermal stability and topological analysis have also been investigated. - Highlights: • Microwave synthesis of coordination polymers. • Anion-derived structural changes. • Influence of anions at different metal/anion ratios on the final architectures. • EPR and magnetic characterization of a MOF compound.

  18. Synthesis, structure, theoretical studies and luminescent properties of a ternary erbium(III) complex with acetylacetone and bathophenanthroline ligands

    Energy Technology Data Exchange (ETDEWEB)

    Martín-Ramos, Pablo [CEMDRX, Department of Physics, Universidade de Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal); Advanced Materials Laboratory, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia (Spain); Silva, Pedro S. Pereira, E-mail: psidonio@pollux.fis.uc.pt [CEMDRX, Department of Physics, Universidade de Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal); Chamorro-Posada, Pedro [Higher Technical School of Telecommunications Engineering, Universidad de Valladolid, Campus Miguel Delibes, Paseo Belén 15, 47011 Valladolid (Spain); Silva, Manuela Ramos [CEMDRX, Department of Physics, Universidade de Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal); Milne, Bruce F. [Centre for Computational Physics, Department of Physics, Universidade de Coimbra, P-3004-516 Coimbra (Portugal); Donostia International Physics Centre, Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián (Spain); Nogueira, Fernando [Centre for Computational Physics, Department of Physics, Universidade de Coimbra, P-3004-516 Coimbra (Portugal); Martín-Gil, Jesús [Advanced Materials Laboratory, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia (Spain)

    2015-06-15

    A novel erbium(III) complex with acetylacetone (Hacac) and bathophenanthroline (4,7-diphenyl-1,10-phenanthroline, bath) ligands, formulated as [Er(acac){sub 3}(bath)], has been characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, absorption and emission spectroscopies. In the theoretical part of this study, semi-empirical quantum chemistry methods using AM1, PM3, PM6 and PM7 models have been employed to predict the structure of the complex, calculate the geometric and crystallographic parameters, and make comparisons with spectroscopic data using INDO/S-CI calculations. Real-time time-dependent density-functional theory (TDDFT) has also been used to calculate the optical absorption spectrum of the complex in the gas phase. - Highlights: • Synthesis and structure of a new erbium(III) β-diketonate complex. • TDDFT used for the first time to calculate the optical absorption spectrum. • Complex show strong near-infrared luminescence at 1.53 µm due to antenna effect.

  19. Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

    Directory of Open Access Journals (Sweden)

    Christoph Rehbock

    2014-09-01

    Full Text Available Due to the abundance of nanomaterials in medical devices and everyday products, toxicological effects related to nanoparticles released from these materials, e.g., by mechanical wear, are a growing matter of concern. Unfortunately, appropriate nanoparticles required for systematic toxicological evaluation of these materials are still lacking. Here, the ubiquitous presence of surface ligands, remaining from chemical synthesis are a major drawback as these organic residues may cause cross-contaminations in toxicological studies. Nanoparticles synthesized by pulsed laser ablation in liquid are a promising alternative as this synthesis route provides totally ligand-free nanoparticles. The first part of this article reviews recent methods that allow the size control of laser-fabricated nanoparticles, focusing on laser post irradiation, delayed bioconjugation and in situ size quenching by low salinity electrolytes. Subsequent or parallel applications of these methods enable precise tuning of the particle diameters in a regime from 4–400 nm without utilization of any artificial surface ligands. The second paragraph of this article highlights the recent progress concerning the synthesis of composition controlled alloy nanoparticles by laser ablation in liquids. Here, binary and ternary alloy nanoparticles with totally homogeneous elemental distribution could be fabricated and the composition of these particles closely resembled bulk implant material. Finally, the model AuAg was used to systematically evaluate composition related toxicological effects of alloy nanoparticles. Here Ag+ ion release is identified as the most probable mechanism of toxicity when recent toxicological studies with gametes, mammalian cells and bacteria are considered.

  20. Phenyl 1,2,3-triazole-thymidine ligands stabilize G-quadruplex DNA, inhibit DNA synthesis and potentially reduce tumor cell proliferation over 3'-azido deoxythymidine.

    Science.gov (United States)

    Mahesh Kumar, Jerald; Idris, Mohammed M; Srinivas, Gunda; Vinay Kumar, Pallerla; Meghah, Vuppalapaty; Kavitha, Mitta; Reddy, Chada Raji; Mainkar, Prathama S; Pal, Biswajit; Chandrasekar, Srivari; Nagesh, Narayana

    2013-01-01

    Triazoles are known for their non-toxicity, higher stability and therapeutic activity. Few nucleoside (L1, L2 and L3) and non-nucleoside 1,2,3-triazoles (L4-L14) were synthesised using click chemistry and they were screened for tumor cell cytotoxicity and proliferation. Among these triazole ligands studied, nucleoside ligands exhibited higher potential than non-nucleoside ligands. The nucleoside triazole analogues, 3'-Phenyl-1,2,3- triazole-thymidine (L2) and 3'-4-Chlorophenyl-1,2,3-triazole-thymidine (L3), demonstrated higher cytotoxicity in tumor cells than in normal cells. The IC₅₀ value for L3 was lowest (50 µM) among the ligands studied. L3 terminated cell cycle at S, G2/M phases and enhanced sub-G1 populations, manifesting induction of apoptosis in tumor cells. Confocal studies indicated that nucleoside triazole ligands (L2/L3) cause higher DNA fragmentation than other ligands. Preclinical experiments with tumor-induced mice showed greater reduction in tumor size with L3. In vitro DNA synthesis reaction with L3 exhibited higher DNA synthesis inhibition with quadruplex forming DNA (QF DNA) than non quadruplex forming DNA (NQF DNA). T(m) of quadruplex DNA increased in the presence of L3, indicating its ability to enhance stability of quadruplex DNA at elevated temperature and the results indicate that it had higher affinity towards quadruplex DNA than the other forms of DNA (like dsDNA and ssDNA). From western blot experiment, it was noticed that telomerase expression levels in the tissues of tumor-induced mice were found to be reduced on L3 treatment. Microcalorimetry results emphasise that two nucleoside triazole ligands (L2/L3) interact with quadruplex DNA with significantly higher affinity (K(d)≈10⁻⁷ M). Interestingly the addition of an electronegative moiety to the phenyl group of L2 enhanced its anti-proliferative activity. Though IC₅₀ values are not significantly low with L3, the studies on series of synthetic 1,2,3-triazole ligands are

  1. Phenyl 1,2,3-triazole-thymidine ligands stabilize G-quadruplex DNA, inhibit DNA synthesis and potentially reduce tumor cell proliferation over 3'-azido deoxythymidine.

    Directory of Open Access Journals (Sweden)

    Jerald Mahesh Kumar

    Full Text Available Triazoles are known for their non-toxicity, higher stability and therapeutic activity. Few nucleoside (L1, L2 and L3 and non-nucleoside 1,2,3-triazoles (L4-L14 were synthesised using click chemistry and they were screened for tumor cell cytotoxicity and proliferation. Among these triazole ligands studied, nucleoside ligands exhibited higher potential than non-nucleoside ligands. The nucleoside triazole analogues, 3'-Phenyl-1,2,3- triazole-thymidine (L2 and 3'-4-Chlorophenyl-1,2,3-triazole-thymidine (L3, demonstrated higher cytotoxicity in tumor cells than in normal cells. The IC₅₀ value for L3 was lowest (50 µM among the ligands studied. L3 terminated cell cycle at S, G2/M phases and enhanced sub-G1 populations, manifesting induction of apoptosis in tumor cells. Confocal studies indicated that nucleoside triazole ligands (L2/L3 cause higher DNA fragmentation than other ligands. Preclinical experiments with tumor-induced mice showed greater reduction in tumor size with L3. In vitro DNA synthesis reaction with L3 exhibited higher DNA synthesis inhibition with quadruplex forming DNA (QF DNA than non quadruplex forming DNA (NQF DNA. T(m of quadruplex DNA increased in the presence of L3, indicating its ability to enhance stability of quadruplex DNA at elevated temperature and the results indicate that it had higher affinity towards quadruplex DNA than the other forms of DNA (like dsDNA and ssDNA. From western blot experiment, it was noticed that telomerase expression levels in the tissues of tumor-induced mice were found to be reduced on L3 treatment. Microcalorimetry results emphasise that two nucleoside triazole ligands (L2/L3 interact with quadruplex DNA with significantly higher affinity (K(d≈10⁻⁷ M. Interestingly the addition of an electronegative moiety to the phenyl group of L2 enhanced its anti-proliferative activity. Though IC₅₀ values are not significantly low with L3, the studies on series of synthetic 1,2,3-triazole ligands

  2. Synthesis, characterization and reactivity of carbohydrate platinum(IV) complexes with thioglycoside ligands.

    Science.gov (United States)

    Vetter, Cornelia; Pornsuriyasak, Papapida; Schmidt, Jürgen; Rath, Nigam P; Rüffer, Tobias; Demchenko, Alexei V; Steinborn, Dirk

    2010-07-21

    Reactions of fac-[PtMe3(4,4'-R2bpy)(Me2CO)][BF4] (R = H, 1a; tBu, 1b) and fac-[PtMe3(OAc-kappa2O,O')(Me2CO)] (2), respectively, with thioglycosides containing thioethyl (ch-SEt) and thioimidate (ch-STaz, Taz = thiazoline-2-yl) anomeric groups led to the formation of the carbohydrate platinum(IV) complexes fac-[PtMe3(4,4-R2bpy)(ch*)][BF4] (ch* = ch-SEt, 8-14; ch-STaz, 15-23) and fac-[PtMe3(OAc-kappa2O,O')(ch*)] (ch* = ch-SEt, 24-28; ch-STaz = 29-35), respectively. NMR (1H, 13C, 195Pt) spectroscopic investigations and a single-crystal X-ray diffraction analysis of 19 (ch-STaz = 2-thiazolinyl 2,3,4,6-tetra-O-benzoyl-1-thio-beta-D-galactopyranose) revealed the S coordination of the ch-SEt glycosides and the N coordination of the ch-STaz glycosides. Furthermore, X-ray structure analyses of the two decomposition products fac-[PtMe3(bpy)(STazH-kappaS)][BF4] (21a) and 1,6-anhydro-2,3,4-tri-O-benzoyl-beta-D-glucopyranose (23a), where a cleavage of the anomeric C-S bond had occurred in both cases, gave rise to the assumption that this decomposition was mediated due to coordination of the thioglycosides to the high electrophilic platinum(IV) atom, in non-strictly dried solutions. Reactions of fac-[PtMe3(Me2CO)3][BF4] (3) with ch-SEt as well as with ch-SPT and ch-Sbpy thioglycosides (PT = 4-(pyridine-2-yl)-thiazole-2-yl; bpy = 2,2'-bipyridine-6-yl), having N,S and N,N heteroaryl anomeric groups, respectively, led to the formation of platinum(IV) complexes of the type fac-[PtMe3(ch*)][BF4] (ch* = ch-SEt, 36-40, ch-SPT 42-44, ch-Sbpy 45, 46). The thioglycosides were found to be coordinated in a tridentate kappaS,kappa2O,O, kappaS,kappaN,kappaO and kappaS,kappa2N,N coordination mode, respectively. Analogous reactions with ch-STaz ligands succeeded for 2-thiazolinyl 2,3,4-tri-O-benzyl-6-O-(2,2'-bipyridine-6-yl)-1-thio-beta-D-glucopyranoside (5h) resulting in fac-[PtMe3(ch-STaz)][BF4] (41, ch-STaz = 5h), having a kappa3N,N',N''coordinated thioglycoside ligand.

  3. Synthesis and structure of bivalent ytterbocenes and their coordination chemistry with pi-acceptor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Madeleine [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    The bivalent lanthanide metallocenes [1,3-(Me3C)2C5H3]2Yb and (Me4C5H)2Yb have been synthesized and their structures have been determined by X-ray crystallography. Comparison with the known structures of (Me5C5)2Yb and [1,3 -(Me3Si)2C5H3]2Yb leads to an understanding of the role of intermolecular contacts in stabilizing these coordinatively unsaturated molecules. The optical spectra of the base-free ytterbocenes and their Lewis-base adducts have been measured; the position of the HOMO - LUMO transition can be correlated with the degree of bending of the complexes in solution according to a molecular orbital model. Electron - electron repulsion, resulting from additional σ-donor ligands, also affects the HOMO - LUMO transition by increasing the energy of the filled f-orbitals. The base-free metallocene (Me5C5)2Yb coordinates carbon monoxide, resulting in a decrease in Vco relative to that of fi-ee carbon monoxide. This behavior is reminiscent of d-transition metallocene chemistry. Other base-free ytterbocenes also coordinate carbon monoxide and the degree of back-donation is related to the substituents on the cyclopentadienide rings. Isocyanides are coordinated in a 1:2 ratio by the ytterbocenes, giving complexes having vcN higher than those of the free isocyanides. An electrostatic bonding model has been used to explain the changes in CN stretching frequencies. The optical spectra of the carbonyl and isocyanide complexes are consistent with the molecular orbital model of the variation in the HOMO - LUMO gap upon bending, and the increase in electron - electron repulsion due to the additional ligands. The complex (Me5C5)2Yb(bipy) exhibits optical, infrared and NMIZ spectroscopy and an X-ray crystal

  4. Microwave Synthesis Under Solvent-Free Conditions and Spectral Studies of Some Mesoporphyrinic Complexes

    OpenAIRE

    Rica Boscencu

    2012-01-01

    A series of A3B and A4 type mesoporphyrinic complexes were synthesized with superior yields using microwave irradiation under solvent-free conditions. The structures of the complexes were confirmed using elemental analysis, FT-IR, UV-Vis, EPR and NMR spectral data. The influence of environmental polarity on spectral properties of the mesoporphyrinic complexes was investigated. The obtained results indicate that the shape of absorption and fluoresc...

  5. Synthesis, spectral correlation and insect antifeedant activities of some 2-benzimidazole chalcones

    OpenAIRE

    2016-01-01

    Some substituted styryl 2-benzimidazole ketones have been synthesised by fly-ash:H2SO4 catalysed aldol condensation of 2-benzimidazole methyl ketone and various substituted benzaldehydes in microwave oven. The yields of these chalcones are more than 70%. The purities of synthesised benzimidazole chalcones were checked by their physical constants and spectral data earlier published in the literature. The spectral frequencies of these chalcones have been correlated with Hammett substituent cons...

  6. DPA-714, a new translocator protein-specific ligand: Synthesis, radio-fluorination, and pharmacologic characterization

    Energy Technology Data Exchange (ETDEWEB)

    James, M. [Univ Sydney, Dept Pharmacol, Sydney, NSW 2006 (Australia); Fulton, R.R.; Henderson, D.J. [Royal Prince Alfred Hosp, Dept PET and Nucl Med, Camperdown, NSW 2050 (Australia); Vercoullie, J.; Garreau, L.; Chalon, S. [INSERM, U619, Tours (France); Dolle, F. [Inst Imagerie Biomed, Serv Hosp Frederic Joliot, CEA, Orsay (France); Selleri, S. [Univ Florence, Dipartimento Sci Farmaceut, I-50121 Florence (Italy); Kassiou, M. [Univ Sydney, Brain and Mind Res Inst, Camperdown, NSW 2050 (Australia); Kassiou, M. [Univ Sydney, Discipline Med Radiat Sci, Sydney, NSW 2006 (Australia); Kassiou, M. [Univ Sydney, Sch Chem, Camperdown, NSW 2050 (Australia)

    2008-07-01

    The translocator protein (18 kDa) (TSPO), formerly known as the peripheral benzodiazepine receptor, is dramatically up-regulated under pathologic conditions. Activated micro-glia are the main cell type expressing the TSPO at sites of central nervous system pathology. Radioligands for the TSPO can therefore measure active disease in the brain. This article details the synthesis, radio-fluorination, and pharmacologic evaluation of a new TSPO-specific pyrazolopyrimidine, DPA-714. Methods: The affinity of DPA-714 for the TSPO was measured in rat kidney membranes with {sup 3}H-PK11195. The in vitro functional activity of DPA-714 was measured in a steroidogenic assay in which the ability of DPA-714 to increase pregnenolone synthesis was measured with rat C6 glioma cells. The radio-fluorination of DPA-714 was achieved by nucleophilic {sup 18}F-fluoride displacement of the tosylate precursor. {sup 18}F-DPA-714 was assessed in rats harboring unilateral quinolinic acid (QA) lesions. In addition, pretreatment experiments were performed with PK11195 (5 mg/kg), DPA-714 (1 mg/kg), and DPA-713 (1 mg/kg). The in vivo binding and biodistribution of {sup 18}F-DPA-714 were determined in a baboon with PET. Experiments involving presaturation with PK11195 (1.5 mg/kg) and displacement with DPA-714 (1 mg/kg) were conducted to evaluate the specificity of radioligand binding. Results: In vitro binding studies revealed that DPA-714 displayed a high affinity for the TSPO (dissociation constant, 7.0 nM). DPA-714 stimulated pregnenolone synthesis at levels 80% above the baseline. {sup 18}F-DPA-714 was prepared at a 16% radiochemical yield and a specific activity of 270 GBq/{mu}mol. In rats harboring unilateral QA lesions, an 8-fold-higher level of uptake of {sup 18}F-DPA-714 was observed in the ipsilateral striatum than in the contralateral striatum. Uptake in the ipsilateral striatum was shown to be selective because it was inhibited to the level in the contralateral striatum in the presence

  7. Metal complexes of a novel Schiff base derived from sulphametrole and varelaldehyde. Synthesis, spectral, thermal characterization and biological activity

    Science.gov (United States)

    Mohamed, Gehad G.; Zayed, M. A.; Abdallah, S. M.

    2010-08-01

    Metal complexes of a novel Schiff base (HL = 3-(4'-ethylazomethinobenzene sulphonamide)-4-methoxy-1,2,5-thiadiazole) derived from condensation of sulphametrole and varelaldehyde are reported and characterized based on elemental analyses, IR, solid reflectance, magnetic moment, molar conductance, and thermal analysis (TG). From the elemental analyses data, 1:1 metal complexes are formed having the general formulae [MCl 3(HL)(H 2O)]·3H 2O (M = Cr(III), Fe(III)) and [MCl 2(HL)(H 2O) 2]· yH 2O (where M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II), y = 0-3). The important infrared (IR) spectral bands corresponding to the active groups in the ligand and the solid complexes under investigation were studied. IR spectra show that HL is coordinated to the metal ions in a neutral bidentate manner with ON donor sites of the enolic sulphonamide- OH and thiodiaza- N. The solid complexes have been synthesized and studied by thermogravimetric analysis. The thermal dehydration and decomposition of these complexes were studied kinetically using the integral method applying the Coats-Redfern equation. All the metal chelates are found to be non-electrolytes. From the magnetic and solid reflectance spectra, the complexes have octahedral structures. The antibacterial and antifungal activities of the synthesized ligand and its metal complexes were screened against bacterial species ( Escherichia coli and Staphylococcus aureus) and fungi ( Candida and Aspergillus flavus). The activity data show that the metal complexes have a promising biological activity comparable with the parent Schiff base ligand against bacterial and fungal species.

  8. Synthesis, characterization, electrochemical behavior and antibacterial/antifungal activities of [Cd(lX2] complexes with a Schiff base ligand

    Directory of Open Access Journals (Sweden)

    Montazerozohori Morteza

    2014-01-01

    Full Text Available A new symmetrical bidentate Schiff base ligand (L was applied for the synthesis of some new cadmium coordination compounds with general formula of [Cd(LX2] in which X is halide and pseudo-halide. The ligand and all cadmium complexes were characterized by some techniques such as elemental analysis, FT-IR, 1H, 13C NMR, UV-Visible and molar conductance. Electrochemical behavior of ligand and Cd(II complexes were investigated by cyclic voltammetry method. Morphology and shape of [Cd(LCl2] particles were depicted by SEM. Antimicrobial properties such as antibacterial and antifungal activities of the complexes as compared with ligand were checked against three Gram-negative bacteria; Escherichia coli (ATCC 25922, Pseudomunase aeroginosa (ATCC 9027 and Salmonella Spp. and two Gram-positive bacteria; Staphylococcus aureus (ATCC 6538 and Corynebacterium renale and three fungal strains including Aspergillus Niger, Penicillium chrysogenum and Candida albicans. The results revealed appropriate antibacterial and antifungal activities for all compounds, and it was also found that the coordination of ligand to Cd (II lead to an increase in the antimicrobial activities in most of cases.

  9. Discrete polynuclear manganese(ii) complexes with thiacalixarene ligands: synthesis, structures and photophysical properties.

    Science.gov (United States)

    Suffren, Yan; O'Toole, Niall; Hauser, Andreas; Jeanneau, Erwann; Brioude, Arnaud; Desroches, Cédric

    2015-05-07

    The synthesis, crystal structure and photophysical properties of the new compound [Mn4(ThiaSO2)2F][K(18-crown-6)], ThiaSO2 = p-tert-butylsulphonylcalix[4]arene, are presented and compared to the ones of [Mn4(ThiaSO2)2F]K. The strong orange luminescence is attributed to the Mn(2+) centred (4)T1→(6)A1 transition. Its temperature and pressure dependence and quenching by molecular dioxygen are reported. The latter is attributed to energy transfer from the (4)T1 state exciting dioxygen to its (1)∑(+)g state. In the solid state, the quenching is much more efficient in [Mn4(ThiaSO2)2F][K(18-crown-6)] than in [Mn4(ThiaSO2)2F]K. This is attributed to the open pore structure of the former allowing fast diffusion of dioxygen into the crystal lattice.

  10. Synthesis and pharmacology of glutamate receptor ligands: new isothiazole analogues of ibotenic acid.

    Science.gov (United States)

    Jørgensen, Charlotte G; Clausen, Rasmus P; Hansen, Kasper B; Bräuner-Osborne, Hans; Nielsen, Birgitte; Metzler, Bjørn; Metzler, Birgitte Bjørn; Kehler, Jan; Krogsgaard-Larsen, Povl; Madsen, Ulf

    2007-02-07

    The naturally occurring heterocyclic amino acid ibotenic acid (Ibo) and the synthetic analogue thioibotenic acid (Thio-Ibo) possess interesting but dissimilar pharmacological activity at ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs). Therefore, a series of Thio-Ibo analogues was synthesized. The synthesis included introduction of substituents by Suzuki and Grignard reactions on 4-halogenated 3-benzyloxyisothiazolols, reduction of the obtained alcohols, followed by introduction of the amino acid moiety by use of 2-(N-tert-butoxycarbonylimino)malonic acid diethyl ester. The obtained Thio-Ibo analogues (1, 2a-g) were characterized in functional assays on recombinant mGluRs and in receptor binding assays on native iGluRs. At mGluRs, the activity at Group II was retained for compounds with small substituents (2a-2d), whereas the Group I and Group III receptor activities for all new compounds were lost. Detection of NMDA receptor affinity prompted further characterization, and two-electrode voltage-clamp recordings at recombinant NMDA receptor subtypes NR1/NR2A-D expressed in Xenopus oocytes were carried out for compounds with small substituents (chloro, bromo, methyl or ethyl, compounds 2a-d). This series of Thio-Ibo analogues defines a structural threshold for NMDA receptor activation and reveals that the individual subtypes have different steric requirements for receptor activation. The compounds 2a and 2c are the first examples of agonists discriminating individual NMDA subtypes.

  11. Synthesis and Structure of Vanadium Halide Complexes Containing Diphosphine Ligands with Pendant Amines

    Energy Technology Data Exchange (ETDEWEB)

    Egbert, Jonathan D.; Labios, Liezel A.; Darmon, Jonathan M.; Piro, Nicholas A.; Scott Kassel, W.; Mock, Michael T.

    2016-02-18

    A series of vanadium(III) diiodide complexes of the formula CpV(PRNR'PR)I2 (Cp = 5-C5H5; PRNR'PR = (R2PCH2)2N(R)), where R = Et, R = Me (1a), R = Ph (1b); R = Ph, R = Me (1c)) is reported. The corresponding vanadium(II) monoiodide complexes of the formula CpV(PRNR'PR)I, where R = Et, R = Me (2a), R = Ph (2b); R = Ph, R = Me (2c)) were prepared in THF by reduction of 1a-c with Zn powder. The paramagnetic complexes 1a-c and 2a-c are characterized by elemental analysis, 1H NMR spectroscopy, and by cyclic voltammetry for complexes 2b and 4b. Complexes 1c and 2a-c were also characterized in the single crystal by X-ray crystallography. We report the preparation of the vanadium(II) complexes CpV(PPh2NPh2)I (3) (PPh2NPh2 = 1,5-diphenyl-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane) and trans-[VCl2(PEtNMePEt)2] (4a) and trans-[VCl2(PEtNPhPEt)2] (4b). These complexes represent initial coordination chemistry of vanadium complexes with PRNR'PR and PPh2NPh2 diphosphine ligands, which contain a pendant amine in the second coordination sphere. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  12. Semi-empirical AGN detection threshold in spectral synthesis studies of Lyman-continuum-leaking early-type galaxies

    Science.gov (United States)

    Cardoso, Leandro S. M.; Gomes, Jean-Michel; Papaderos, Polychronis

    2016-10-01

    Various lines of evidence suggest that the cores of a large portion of early-type galaxies (ETGs) are virtually evacuated of warm ionised gas. This implies that the Lyman-continuum (LyC) radiation produced by an assumed active galactic nucleus (AGN) can escape from the nuclei of these systems without being locally reprocessed into nebular emission, which would prevent their reliable spectroscopic classification as Seyfert galaxies with standard diagnostic emission-line ratios. The spectral energy distribution (SED) of these ETGs would then lack nebular emission and be essentially composed of an old stellar component and the featureless power-law (PL) continuum from the AGN. A question that arises in this context is whether the AGN component can be detected with current spectral population synthesis in the optical, specifically, whether these techniques effectively place an AGN detection threshold in LyC-leaking galaxies. To quantitatively address this question, we took a combined approach that involves spectral fitting with Starlight of synthetic SEDs composed of stellar emission that characterises a 10 Gyr old ETG and an AGN power-law component that contributes a fraction 0 ≤ xAGN nuclear activity may be missing in the AGN demographics.

  13. Synthesis, Crystal Structure and Luminescent Property of A Novel Cd(II) Coordination Polymer with Bis-imidazole Ligand

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yong Hong [Huaibei Normal Univ., Huaibei (China)

    2013-04-15

    The key to the successful design of metal-organic coordination polymers is the judicious selection of organic ligand. Recently, polydentate aromatic nitrogen heterocyclic ligands with five-membered rings have been well-studied in the construction of supramolecular structure for their N-coordinated sites apt to coordinating to transition metals. Similar to six-membered N-heterocyclic ligands, the azole-based five-membered N-heterocyclic ligands, such as imidazoles, triazoles and tetrazoles have been extensively employed in the construction of various coordination polymers with diverse topologies and interesting properties. The bis(azole) ligands in which N-donor azole rings (imidazole, triazole, or tetrazole) are separated by alkyl, (CH{sub 2}){sub n}, spacers are good choices for flexible bridging ligands. The conformational flexibility of the spacers makes the ligands adaptable to various coordination networks with one-, two-, and three dimensional structures.

  14. Synthesis, structural, DFT studies, docking and antibacterial activity of a xanthene based hydrazone ligand

    Science.gov (United States)

    Naseem, Saira; Khalid, Muhammad; Tahir, Muhammad Nawaz; Halim, Mohammad A.; Braga, Ataualpa A. C.; Naseer, Muhammad Moazzam; Shafiq, Zahid

    2017-09-01

    Herein, we present the synthesis of novel xanthene-based hydrazone (1). The chemical structure of 1 was resolved using spectroscopic techniques such as NMR, FT-IR, UV-VIS and X-ray crystallographic approaches. X-ray diffraction analysis shows that the compound (1) crystallizes in triclinic crystal lattice with the Pbar1 space group and diffused to form multi-layered structure due to non-covalent interactions such as intramolecular hydrogen bonding (H.B). In addition to experimental investigation, density functional theory (DFT) calculation with M06-2X/6-31G(d,p) and B3LYP/6-31G(d,p) level of theories was performed on compound (1) to obtain optimized geometry, spectroscopic and electronic properties. DFT optimized geometry shows good agreement with the experimental XRD structure. The hyper conjugative interactions and hydrogen bonding network are responsible for the stability of compound (1) as revealed by natural bond orbital (NBO) calculation. Moreover, hydrogen bonding network in the dimer is confirmed by FT-IR and thermodynamic studies showing excellent agreement with XRD and NBO findings. TD-DFT/UV-VIS analysis provides insight that maximum excitation is found in 1 which shows good agreement with experimental UV-VIS result. The global reactivity parameters are calculated using the energies of frontier molecular orbitals also disclosed that the compound is more stable might be due to hydrogen bonding network. Experimental and molecular docking studies indicated that this compound has anti-bacterial and anti-diabetic properties. The binding affinity of this compound against the multidrug efflux pump subunit AcrB OS=Escherichia coli (strain K12) and Human Pancreatic Alpha-Amylase is -9.2 and -10.00 kcal/mol which are higher than the control drugs. Pi-Pi, Pi-anaion, amide-pi and pi-alkyl bonds play key role in drug-protein complexes.

  15. Studies on Synthesis and Spectral Characterization of Some Transition Metal Complexes of Azo-Azomethine Derivative of Diaminomaleonitrile

    Directory of Open Access Journals (Sweden)

    C. Anitha

    2013-01-01

    Full Text Available New complexes of 2,3-bis(5-(4-chlorophenyldiazenyl-2-hydroxybenzylideneaminomaleonitrile (CDHBDMN with VO(II, Mn(II, Co(II, Ni(II, Cu(II, and Zn(II were synthesized and characterized by analytical and physicochemical techniques, that is, elemental analyses, molar conductivity, UV, IR, EPR, 1H-NMR spectra, magnetic susceptibility and also by aid of scanning electron microscopy (SEM, nonlinear optical study (NLO, fluorescence spectral studies, and solvatochromic behaviors. Electronic and magnetic susceptibility measurements of the complexes indicate square pyramidal geometry for VO(II, octahedral for Ni(II, and square planar geometry for all the other complexes. The EPR spectral data provide information about their structures on the basis of Hamiltonian parameters and the degree of covalency. These metal complexes were also tested for their antibacterial and antifungal activities to assess their inhibiting potential. Metal-mediated fluorescence enhancement is observed on complexation of the azo Schiff base ligand. The synthesized compounds were investigated for nonlinear optical properties, and the surface morphology of the Cu(II complex was studied by scanning electron microscopy.

  16. Synthesis, structural characterization, thermal and electrochemical studies of mixed ligand Cu(II) complexes containing 2-phenyl-3-(benzylamino)-1,2-dihydroquinazoline-4-(3H)-one and bidentate N-donor ligands.

    Science.gov (United States)

    Sawant, V A; Yamgar, B A; Sawant, S K; Chavan, S S

    2009-12-01

    Some mixed ligand Cu(II) complexes of the type [Cu(L)(en)X(2)] (1a-3a), [Cu(L)(en)](ClO(4))(2) (4a), [Cu(L)(phen)X(2)] (1b-3b) and [Cu(L)(phen)](ClO(4))(2) (4b) [where L = 2-phenyl-3-(benzylamino)-1,2-dihydroquinazoline-4-(3H)-one; en = ethylenediamine; phen = 1,10-phenanthroline; X = Cl(-), N(3)(-) and NCS(-)] have been prepared. The complexes were characterized on the basis of elemental analysis, molar conductance, magnetic moment, IR, UV-vis, mass, ESR and thermal studies. On the basis of electronic spectral data and magnetic susceptibility measurement octahedral geometry has been proposed for 1a-3a and 1b-3b and square-planer geometry for 4a and 4b. The ESR spectral data of complexes provided information about their structure on the basis of Hamiltonian parameters and degree of covalency. The electrochemical behaviour of mixed ligand Cu(II) complexes was studied which showed that complexes of phen appear at more positive potential as compared to those for corresponding en complexes.

  17. Synthesis and Characterization of a New Bidentate Ligand 5-Substituted-(2-methyl-5-nitro-1-imidazomethyl-1,3,4-oxadiazole-2-thione and its Metal Complexes of Ag(I, Cu(II and Zn(II

    Directory of Open Access Journals (Sweden)

    Shabbir A. A. Kazi

    2011-01-01

    Full Text Available A new ligand (2-methyl-5-nitro-1-imidazomethyl-1,3,4-oxadiazole-2-thione (L and its Ag(I,Cu(II and Zn(II complexes were synthesized. The authenticity of the ligand and its transition metal complexes were established by elemental analyses, conductance and magnetic susceptibility measurements, as well as spectroscopic (IR, 1H NMR, electronic, mass and ESR and thermal studies. The IR spectral studies revealed the existence thiol-thione tautamerism in the ligand molecule. The magnetic and electronic spectral studies suggest an octahedral geometry for Cu(II and Zn(II complexes. The ligand acts as a bidentate coordinating through the N-3 nitrogen and the exocyclic sulfur atoms of oxadiazole rings. Antimicrobial screening of the ligand and its metal complexes were determined against the bacteria Escherichia coli and Salmonella paratyphiA.

  18. Organotin(IV) complexes of thiohydrazides and thiodiamines: synthesis, spectral and thermal studies.

    Science.gov (United States)

    Singh, Rajeev; Kaushik, N K

    2006-11-01

    Organotin(IV) complexes of tribenzyltin(IV) chloride and di(para-chlorobenzyl)tin(IV) dichloride with thiohydrazides have been reported. The ligands synthesized were bidentate coordinating through sulphur and terminal nitrogen atoms. These form 1:1 metal-ligand complexes. The following organotin(IV) complexes have been synthesized: (C(6)H(5)CH(2))(3)Sn(L(1))Cl, (p-ClC(6)H(4)CH(2))(2)Sn(L(1))Cl(2), (C(6)H(5)CH(2))(3)Sn(L(1))Cl, (p-ClC(6)H(4)CH(2))(2)Sn(L(2))Cl(2), (C(6)H(5)CH(2))(3)Sn(L(3))Cl, (p-ClC(6)H(4)CH(2))(2)Sn(L(3))Cl(2), where (L(1)): 2-phenylethyl N-thiohydrazide, (L(2)): N-(2-phenylethyl-N-thio)-1,3-propane diamine, (L(3)): N-(2-phenylethyl-N-thio)-1,2-ethane diamine. The complexes were synthesized by directly mixing, refluxing and stirring the ligands with organotin(IV) chlorides in a suitable solvent. The complexes were found to be pure and were characterized by elemental analysis, electronic, infrared, (1)H and (13)C NMR spectroscopy. These complexes were also studied for their thermal decomposition by thermogravimetry (TG) and differential thermal analysis (DTA). Various kinetic and thermodynamic parameters, viz. activation energy (E(a)), order of reaction (n), apparent activation entropy (S(#)) and heat of reaction (DeltaH) have been determined by using Horowitz-Metzger method. It was observed that these complexes are highly stable and the thermal degradation of these complexes is a spontaneous process. The ligands and their tin complexes have also been screened for their fungitoxicity activity and found to be quite active in this respect.

  19. Synthesis and spectral and redox properties of three triply bridged complexes of ruthenium

    Science.gov (United States)

    Llobet, A.; Curry, M.E.; Evans, H.T.; Meyer, T.J.

    1989-01-01

    Syntheses are described for the ligand-bridged complexes [(tpm)RuIII(??-O)(??-L)2RuIII(tpm) n+ (L = O2P(O)(OH), n = 0 (1); L = O2CO, n = 0 (2); L = O2CCH3, n = 2 (3); tpm is the tridentate, facial ligand tris(1-pyrazolyl)methane. The X-ray crystal structure of [(tpm)Ru(??-O)(??-O2P(O)(OH))2Ru(tpm)]??8H 2O was determined from three-dimensional X-ray counter data. The complex crystallizes in the trigonal space group P3221 with three molecules in a cell of dimensions a = 18.759 (4) A?? and c = 9.970 (6) A??. The structure was refined to a weighted R factor of 0.042 based on 1480 independent reflections with I ??? 3??(I). The structure reveals that the complex consists of two six-coordinate ruthenium atoms that are joined by a ??-oxo bridge (rRU-O = 1.87 A??; ???RuORu = 124.6??) and two ??-hydrogen phosphato bridges (average rRu-O = 2.07 A??) which are capped by two tpm ligands. The results of cyclic voltammetric and coulometric experiments show that the complexes undergo both oxidative and reductive processes in solution. Upon reduction, the ligand-bridged structure is lost and the monomer [(tpm)Ru(H2O)3]2+ appears quantitatively. All three complexes are diamagnetic in solution. The diamagnetism is a consequence of strong electronic coupling between the low-spin d5 Ru(III) metal ions through the oxo bridge and the relatively small Ru-O-Ru angle. ?? 1989 American Chemical Society.

  20. Fitting Analysis using Differential evolution Optimization (FADO):. Spectral population synthesis through genetic optimization under self-consistency boundary conditions

    Science.gov (United States)

    Gomes, J. M.; Papaderos, P.

    2017-07-01

    The goal of population spectral synthesis (pss; also referred to as inverse, semi-empirical evolutionary- or fossil record approach) is to decipher from the spectrum of a galaxy the mass, age and metallicity of its constituent stellar populations. This technique, which is the reverse of but complementary to evolutionary synthesis, has been established as fundamental tool in extragalactic research. It has been extensively applied to large spectroscopic data sets, notably the SDSS, leading to important insights into the galaxy assembly history. However, despite significant improvements over the past decade, all current pss codes suffer from two major deficiencies that inhibit us from gaining sharp insights into the star-formation history (SFH) of galaxies and potentially introduce substantial biases in studies of their physical properties (e.g., stellar mass, mass-weighted stellar age and specific star formation rate). These are i) the neglect of nebular emission in spectral fits, consequently; ii) the lack of a mechanism that ensures consistency between the best-fitting SFH and the observed nebular emission characteristics of a star-forming (SF) galaxy (e.g., hydrogen Balmer-line luminosities and equivalent widths-EWs, shape of the continuum in the region around the Balmer and Paschen jump). In this article, we present fado (Fitting Analysis using Differential evolution Optimization) - a conceptually novel, publicly available pss tool with the distinctive capability of permitting identification of the SFH that reproduces the observed nebular characteristics of a SF galaxy. This so-far unique self-consistency concept allows us to significantly alleviate degeneracies in current spectral synthesis, thereby opening a new avenue to the exploration of the assembly history of galaxies. The innovative character of fado is further augmented by its mathematical foundation: fado is the first pss code employing genetic differential evolution optimization. This, in conjunction

  1. Spectral Analysis, Synthesis, & Energy Distributions of Nearby E+A Galaxies Using SDSS-IV MaNGA

    Science.gov (United States)

    Weaver, Olivia A.; Anderson, Miguel Ricardo; Wally, Muhammad; James, Olivia; Falcone, Julia; Liu, Allen; Wallack, Nicole; Liu, Charles; SDSS Collaboration

    2017-01-01

    Utilizing data from the Mapping Nearby Galaxies at APO (MaNGA) Survey (MaNGA Product Launch-4, or MPL-4), of the latest generation of the Sloan Digital Sky Survey (SDSS-IV), we identified nine post-starburst (E+A) systems that lie within the Green Valley transition zone. We identify the E+A galaxies by their SDSS single fiber spectrum and u-r color, then confirmed their classification as post-starburst by coding/plotting methods and spectral synthesis codes (FIREFLY and PIPE3D), as well as with their Spectral Energy Distributions (SEDs) from 0.15 µm to 22 µm, using GALEX, SDSS, 2MASS, and WISE data. We produced maps of gaussian-fitted fluxes, equivalent widths, stellar velocities, metallicities and age. We also produced spectral line ratio diagrams to classify regions of stellar populations of the galaxies. We found that our sample of E+As retain their post-starburst properties across the entire galaxy, not just at their center. We detected matching a trend line in the ultraviolet and optical bands, consistent with the expected SEDs for an E+A galaxy, and also through the J, H and Ks bands, except for one object. We classified one of the nine galaxies as a luminous infrared galaxy, unusual for a post-starburst object. Our group seeks to further study stellar population properties, spectral energy distributions and quenching properties in E+A galaxies, and investigate their role in galaxy evolution as a whole. This work was supported by the Alfred P. Sloan Foundation via the SDSS-IV Faculty and Student Team (FAST) initiative, ARC Agreement #SSP483 to the CUNY College of Staten Island. This work was also supported by grants to The American Museum of Natural History, and the CUNY College of Staten Island through from National Science Foundation.

  2. Hyper-Spectral Synthesis of Active OB Stars Using GLaDoS

    Science.gov (United States)

    Hill, N. R.; Townsend, R. H. D.

    2016-11-01

    In recent years there has been considerable interest in using graphics processing units (GPUs) to perform scientific computations that have traditionally been handled by central processing units (CPUs). However, there is one area where the scientific potential of GPUs has been overlooked - computer graphics, the task they were originally designed for. Here we introduce GLaDoS, a hyper-spectral code which leverages the graphics capabilities of GPUs to synthesize spatially and spectrally resolved images of complex stellar systems. We demonstrate how GLaDoS can be applied to calculate observables for various classes of stars including systems with inhomogenous surface temperatures and contact binaries.

  3. Solvent free synthesis, spectral correlation and antimicrobial activities of some 2E 4′-nitrochalcones

    Directory of Open Access Journals (Sweden)

    Renganathan Arulkumaran

    2016-09-01

    Full Text Available A series containing twelve substituted styryl 4′-nitrophenyl ketones have been synthesized using solvent free SiO2–H2SO4 catalysed aldol reaction under microwave condition. The yield of chalcones is found to be more than 80%. These synthesized ketones have been characterized by their physical constants and spectral data. The spectral frequencies of these chalcones have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses the effect of substituents on the frequencies has been predicted. The antimicrobial activities of all ketones have also been studied with the help of Bauer–Kirby method.

  4. Microwave synthesis under solvent-free conditions and spectral studies of some mesoporphyrinic complexes.

    Science.gov (United States)

    Boscencu, Rica

    2012-05-10

    A series of A₃B and A₄ type mesoporphyrinic complexes were synthesized with superior yields using microwave irradiation under solvent-free conditions. The structures of the complexes were confirmed using elemental analysis, FT-IR, UV-Vis, EPR and NMR spectral data. The influence of environmental polarity on spectral properties of the mesoporphyrinic complexes was investigated. The obtained results indicate that the shape of absorption and fluorescence spectra does not depend on the solvent polarity under the experimental conditions used. The small shifts of the absorption and emission maximums that occur by increasing of solvent polarity reflects the physical interaction between the porphyrinic substituents and the solvent molecules.

  5. Mixed Ligand Complexes of N-Methyl-N-phenyl Dithiocarbamate: Synthesis, Characterisation, Antifungal Activity, and Solvent Extraction Studies of the Ligand.

    Science.gov (United States)

    Ekennia, Anthony C; Onwudiwe, Damian C; Ume, Cyril; Ebenso, Eno E

    2015-01-01

    A series of mixed ligand dithiocarbamate complexes with a general formula [ML2(py)2], where M = Mn(II), Co(II), Ni(II), and Cu(II), py = pyridine, and L = N-methyl-N-phenyl dithiocarbamate have been prepared and characterised by elemental analysis, FTIR and Uv spectroscopy, magnetic moment, and thermogravimetric and conductance analysis. The infrared spectra showed that symmetrical bidentate coordination occurred with the dithiocarbamate moiety through the sulfur atoms, while neutral monodentate coordination occurred through the nitrogen atom for the pyridine molecule in the complexes. The electronic spectra, elemental analysis, and magnetic moment results proved that the complexes adopted octahedral geometry. The conductance measurement showed that the complexes are nonelectrolytes proving their nonionic nature. The compounds were screened for three human pathogenic fungi: Aspergillus flavus, Aspergillus niger, and Candida albicans. The cobalt complex showed the best antifungal activity among the test compounds. Liquid-liquid extractive abilities of the ligand towards copper and nickel ions in different solvent media were investigated. The ligand showed a strong binding affinity towards the metals ions with an extractive efficiency of about 99%.

  6. Nanocrystalline Mixed Ligand Complexes of Cu (II, Ni (II, Co (II with N, O Donor Ligands: Synthesis, Characterization, and Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Kolhe Nitin H

    2016-12-01

    Full Text Available In present investigation nanocrystalline mixed ligand complexes were synthesized using 8-hydroxyquinoline, salicylaldoxime with metals like Cu (II, Ni (II and Co (II. The metal: ligand ratio was found to be 1:1:1. These complexes were characterized using electronic spectra, FTIR spectra, elemental analysis, magnetic susceptibility, thermogravimetric analysis, conductivity measurement, powder X-ray diffraction and Scanning Electron Microscopy with electron dispersive spectroscopic methods. The electronic spectra of complexes suggest that they have square planer geometries. In FTIR analysis characteristic bands of ν (M-N and ν (M-O.The Co (II and Cu (II complexes are paramagnetic in nature and these had square planer geometry. While Ni (II complexes are diamagnetic nature and having square planer geometry. The thermal analysis of complexes was studied in an attempt to assign intermediate compounds. Low molar conductance values indicate non – electrolytic nature of the complexes. The Powder X-ray diffraction study shows formation of nanocrystalline phase as well as the grain size of complexes is less than 10 nm. The EDS study is shows good agreement for formation of mixed ligand metal complexes . Complex: [C16H12CuN2O2], [C14H12N2NiO4 ], [C16H12NiN2O2] and [C16H12CoN2O2] had antimicrobial activity against four bacteria tested. Bacteria were resistant to other five complexes.

  7. Synthesis and characterization of bioactive binuclear transition metal complexes of Schiff base ligand derived from 4-amino-pyrimidine-2-one, diacetyl and glycine

    Directory of Open Access Journals (Sweden)

    Srivastava Abhay Nanda

    2014-01-01

    Full Text Available A series of novel binuclear transition metal complexes was synthesized by reaction of a Schiff base ligand (1-Methyl-2-(2-oxo-1,2-dihydro-pyrimidin-4-ylimino-propylideneamino-acetic acid (LaH derived from 4-amino-pyrimidine-2-one, diacetyl, glycine and corresponding chloride salt of Cu(II, Ni(II, Co(II and Zn(II metals in 1:1 (metal : ligand molar ratio. The compounds were characterized by elemental analyses, molar conductance measurement, magnetic moment measurement and various spectral studies viz. IR, UV-visible, 1H-NMR, 13C-NMR, EPR and ESI-MS. Molar conductance measurement data revealed non-electrolytic nature of metal complexes. Electronic absorption spectral data, electronic paramagnetic resonance parameters and magnetic moment values revealed an octahedral geometry for binuclear metal complexes. Cyclic voltammetric study of Ni(II complex shows a couple of one electron anodic responses near 0.70 V and 1.10 V. In vitro biological activity of Schiff base ligand and binuclear complexes has been checked against bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Salmonella typhi and fungi (Candida albicans and Candida parapsilosis to assess their antibacterial and antifungal properties.

  8. Synthesis and characterization of lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand

    Institute of Scientific and Technical Information of China (English)

    LI Bangyu; YAO Yingming; WANG Yaorong; ZHANG Yong; SHEN Qi

    2008-01-01

    The lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand 3,5-But2-2-(OH)C6H2CH=N-8-C9H6N (HL) were synthesized and characterized. The reaction of anhydrous LnCl3 with NaL formed in situ in a 1:1 molar ratio in THF at room temperature afforded the lanthanide Schiff base dichloride complexes LnLCl2(DME) (Ln=Eu (1);Sm (2)). Complexes 1 and 2 can be used as precursors for the synthesis of the lanthanide cyclopentadienyl Schiff base derivatives. The reactions of complexes 1 and 2 with one equiv of NaCH3C5H4 in THF provided the desired products LnL(CH3C5H4)Cl(THF)·THF (Ln=Eu (3);Sm (4)) in good isolated yields. These complexes were characterized by elemental analysis, IR spectra, and X-ray structural determination, in the case of complexes 3 and 4. The crystal data of complex 3 are monoclinic, P21/c space group, a=1.3370(2) nm, b=1.5190(2) nm, c=1.8910(3) nm, β=109.846(4)°, V=3.6125(8) nm3, Z=4, Dc=1.416 mg/m3, μ=1.847 mm-1, F(000)=1584, R=0.0707, wR=0.1350. The crystal data of complex 4 are monoclinic, P21/c space group, a=1.3383(1) nm, b=1.5210(2) nm, c=1.8960(2) nm, β =109.878(3)°, V=3.6293(7) nm3, Z=4, Dc=1.407 mg/m3, μ=1.728 mm-1, F(000)=1580, R=0.0670, wR=0.1385.

  9. Synthesis, Characterization, and Interaction with Biomolecules of Platinum(II Complexes with Shikimic Acid-Based Ligands

    Directory of Open Access Journals (Sweden)

    Yan Peng

    2013-01-01

    Full Text Available Starting from the active ingredient shikimic acid (SA of traditional Chinese medicine and NH2(CH2nOH, (n=2–6, we have synthesized a series of new water-soluble Pt(II complexes PtLa–eCl2, where La–e are chelating diamine ligands with carbon chain covalently attached to SA (La–e = SA-NH(CH2nNHCH2CH2NH2; La, n=2; Lb, n=3; Lc, n=4; Ld, n=5; Le, n=6. The results of the elemental analysis, LC-MS, capillary electrophoresis, and 1H, 13C NMR indicated that there was only one product (isomer formed under the present experimental conditions, in which the coordinate mode of PtLa–eCl2 was two-amine bidentate. Their in vitro cytotoxic activities were evaluated by MTT method, where these compounds only exhibited low cytotoxicity towards BEL7404, which should correlate their low lipophilicity. The interactions of the five Pt(II complexes with DNA were investigated by agarose gel electrophoresis, which suggests that the Pt(II complexes could induce DNA alteration. We also studied the interactions of the Pt(II complexes with 5′-GMP with ESI-MS and 1H NMR and found that PtLbCl2, PtLcCl2, and PtLdCl2 could react with 5′-GMP to form mono-GMP and bis-GMP adducts. Furthermore, the cell-cycle analysis revealed that PtLbCl2, PtLcCl2 cause cell G2-phase arrest after incubation for 72 h. Overall, these water-soluble Pt(II complexes interact with DNA mainly through covalent binding, which blocks the DNA synthesis and replication and thus induces cytotoxicity that weakens as the length of carbon chain increases.

  10. Synthesis, spectral characterization and biological evaluation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with thiosemicarbazone ending by pyrazole and pyridyl rings

    Science.gov (United States)

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

    2014-08-01

    Here we present the synthesis of the new Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with chelating ligand (Z)-(2-((1,3-diphenyl-1H-pyrazol-4-yl)methylene) hydrazinyl)(pyridin-2-ylamino)methanethiol. All the complexes were characterized by elemental analysis, IR, 1H NMR, UV-vis, magnetic susceptibility measurements and EPR spectral studies. IR spectra of complexes showed that the ligand behaves as NN neutral bidentate, NSN mononegative tridentate and NSNN mononegative tetradentate. The electronic spectra and the magnetic measurements suggested the octahedral geometry for all complexes as well as the EPR confirmed the tetragonal distorted octahedral for Cu(II) complex. Cd(II) complex showed the highest inhibitory antioxidant activity either using ABTS method. The SOD-like activity exhibited those Cd(II) and Zn(II) complexes have strong antioxidative properties. We tested the synthesized compounds for antitumor activity and showed that the ability to kill liver (HePG2) and breast (MCF-7) cancer cells definitely.

  11. Convenient Synthesis of Multi-dentate P,N-Ligand by HCl Elimination of N-Hetrocycle with Organophosphine Reagent

    Institute of Scientific and Technical Information of China (English)

    LI,Qing-Shan; WAN,Chong-Qing; XU,Feng-Bo; ZHANG,Zheng-Zhi

    2004-01-01

    @@ The multi-dentate ligands and their complexes have attracted more and more interests in supramolecular chemistry and catalysis.[1,2] Recently, we found a convenient and efficient method to synthesize this kind of P,N-ligands. The C-Hor C-Cl bond in N-heterocycle was activated in presence of corresponding organophospine reagent and the HCl elimination was fluent, giving the multi-dentate P,N-ligands.

  12. Palladium(II) and zinc(II) complexes of neutral [N2O2] donor Schiff bases derived from furfuraldehyde: Synthesis, characterization, fluorescence and corrosion inhibitors of ligands

    Science.gov (United States)

    Ali, Omyma A. M.

    2014-11-01

    Metal complexes of Schiff bases derived from furfuraldehyde and 4,5-dimethyl-1,2-phenylendiamine (L1) or 4,5-dichloro-1,2-phenylendiamine (L2) have been reported and characterized based on elemental analyses, IR, 1H NMR, UV-Vis, magnetic moment, molar conductance and thermal analysis. The complexes are found to have the formulae [PdL1-2]Cl2 and [ZnL1-2](AcO)2·H2O. The molar conductance data reveal that Pd(II) and Zn(II) chelates are ionic in nature and are of the type 2:1 electrolytes. The spectral data are consistent with a square planar and tetrahedral geometry around Pd(II) and Zn(II), respectively, in which the ligands act as tetradentate ligands. The thermal behavior of some chelates is studied and the activation thermodynamic parameters are calculated using Coats-Redfern method. The corrosion inhibition of stainless steel types 410 and 304 in 1 M HCl using the synthesized Schiff bases as inhibitors have been studied by weight loss method. The obtained data considered these ligands as efficient corrosion inhibitors. The ligands and their metal complexes exhibited considerable antibacterial activity against Staphylococcusaureus, and Escherichiacoli and antifungal activity against Candida albicans.

  13. Palladium(II) and zinc(II) complexes of neutral [N2O2] donor Schiff bases derived from furfuraldehyde: synthesis, characterization, fluorescence and corrosion inhibitors of ligands.

    Science.gov (United States)

    Ali, Omyma A M

    2014-11-11

    Metal complexes of Schiff bases derived from furfuraldehyde and 4,5-dimethyl-1,2-phenylendiamine (L1) or 4,5-dichloro-1,2-phenylendiamine (L2) have been reported and characterized based on elemental analyses, IR, 1H NMR, UV-Vis, magnetic moment, molar conductance and thermal analysis. The complexes are found to have the formulae [PdL1-2]Cl2 and [ZnL1-2](AcO)2·H2O. The molar conductance data reveal that Pd(II) and Zn(II) chelates are ionic in nature and are of the type 2:1 electrolytes. The spectral data are consistent with a square planar and tetrahedral geometry around Pd(II) and Zn(II), respectively, in which the ligands act as tetradentate ligands. The thermal behavior of some chelates is studied and the activation thermodynamic parameters are calculated using Coats-Redfern method. The corrosion inhibition of stainless steel types 410 and 304 in 1 M HCl using the synthesized Schiff bases as inhibitors have been studied by weight loss method. The obtained data considered these ligands as efficient corrosion inhibitors. The ligands and their metal complexes exhibited considerable antibacterial activity against Staphylococcusaureus, and Escherichiacoli and antifungal activity against Candida albicans.

  14. Spectral harmonic analysis and synthesis of Earth’s crust gravity field

    NARCIS (Netherlands)

    Tenzer, R.; Novák, P.; Vajda, P.; Gladkikh, V.; Hamayun, K.

    2011-01-01

    We developed and applied a novel numerical scheme for a gravimetric forward modelling of the Earth’s crustal density structures based entirely on methods for a spherical analysis and synthesis of the gravitational field. This numerical scheme utilises expressions for the gravitational potentials and

  15. Synthesis and characterization of an iron complex bearing a cyclic tetra-N-heterocyclic carbene ligand: An artifical heme analogue?

    KAUST Repository

    Anneser, Markus R.

    2015-04-20

    An iron(II) complex with a cyclic tetradentate ligand containing four N-heterocyclic carbenes was synthesized and characterized by means of NMR and IR spectroscopies, as well as by single-crystal X-ray structure analysis. The iron center exhibits an octahedral coordination geometry with two acetonitrile ligands in axial positions, showing structural analogies with porphyrine-ligated iron complexes. The acetonitrile ligands can readily be substituted by other ligands, for instance, dimethyl sulfoxide, carbon monoxide, and nitric oxide. Cyclic voltammetry was used to examine the electronic properties of the synthesized compounds. © 2015 American Chemical Society.

  16. Metal-pyrazolyl diazine interaction: synthesis, structure and electrochemistry of binuclear transition metal(II) complexes derived from an 'end-off' compartmental Schiff base ligand.

    Science.gov (United States)

    Budagumpi, Srinivasa; Revankar, Vidyanand K

    2010-09-15

    Pyrazolyl diazine (mu-NN) bridged late first row transition metal(II) complexes have been prepared by the interaction of metal(II) chlorides with an 'end-off' compartmental Schiff base ligand. The ligand system has a strong diazine bridging component and obtained as a condensation product between 1H-pyrazole-3,5-dicarbohydrazide and 3-acetylcoumarin in absolute ethanol. All synthesized compounds are characterized on the basis of various spectral and analytical techniques. Complexes are found to be non-electrolytes and monomeric in nature. The magnetic exchange interactions are very weak because of the more electronegative exogenous chloride, though diazine bridging group bring metal centers in a close proximity.

  17. Synthesis, structural characterization and DFT calculation on a square-planar Ni(II) complex of a compartmental Schiff base ligand

    Science.gov (United States)

    Biswas, Surajit; Dolai, Malay; Dutta, Arpan; Ali, Mahammad

    2016-12-01

    Reaction of a symmetric compartmental Schiff-base ligand, (H2L) with nickel(II) perchlorate hexahydrate in 1:1 M ratio in methanol gives rise to a mononuclear nickel(II) compound, NiL (1). The compound has been characterized by C, H, N microanalyses and UV-Vis spectra. The single crystal X-ray diffraction studies reveal a square planar geometry around the Ni(II) center. The compound crystallizes in monoclinic system with space group C2/c with a = 21.6425(6), b = 9.9481(3), c = 13.1958(4) Å, β = 107.728(2)°, V = 2706.16(14) Å3 and Z = 4. Ground state DFT optimization and TDDFT calculations on the ligand and complex were performed to get their UV-Vis spectral pattern.

  18. Design, synthesis and physico-chemical investigation of a dinuclear zinc(II) complex with a novel ‘end-off’ compartmental ligand

    Indian Academy of Sciences (India)

    Anil D Naik; Vidyanand K Revankar

    2001-08-01

    A novel dinucleating pentadentate Schiff base, resulting from the condensation of 2,6-diformyl--cresol and N-methyl-indolyl-3-thiohydrazide, and its Zn complex have been prepared and characterized on the basis of elemental analysis, IR, UV-Visible, 1H NMR and 13C NMR studies. The ligand is acyclic and consists of a phenolate head unit, with two inbuilt azomethine shoulders and two indole thiohydrazide arms forming SNONS coordinating sites. NMR and IR spectral studies show that the ligand exists in thioketo form. Each Zn ion in the dinuclear core is in tetrahedral environment with endogenous phenolate bridging and exogenous acetate bridging. The zinc complex in DMF exhibits fluorescence.

  19. Design, synthesis and characterization of macrocyclic ligand based transition metal complexes of Ni(II), Cu(II) and Co(II) with their antimicrobial and antioxidant evaluation

    Science.gov (United States)

    Gull, Parveez; Malik, Manzoor Ahmad; Dar, Ovas Ahmad; Hashmi, Athar Adil

    2017-04-01

    Three new complexes Ni(II), Cu(II) and Co(II) were synthesized of macrocyclic ligand derived from 1, 4-dicarbonyl-phenyl-dihydrazide and O-phthalaldehyde in the ratio of 2:2. The synthesized compounds were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, FTIR, UV-Vis., Mass and 1H NMR spectral studies. The electronic spectra of the metal complexes indicate a six coordinate octahedral geometry of the central metal ion. These metal complexes and the ligand were evaluated for antimicrobial activity against bacteria (E. coli, B. subtilis, S. aureus) and fungi (A. niger, A. flavus, C. albicans) and compared against standard drugs chloramphenicol and nystatin respectively. In addition, the antioxidant activity of the compounds was also investigated through scavenging effect on DPPH radicals.

  20. Palladium and platinum complexes of 2-(2'-carboxyphenylazo)-4 methylphenol: Synthesis, structure and spectral properties

    Indian Academy of Sciences (India)

    Sarmistha Halder; Michael G B Drew; Samaresh Bhattacharya

    2008-09-01

    Reaction of 2-(2'-carboxyphenylazo)-4-methylphenol (H2L) with [M(PPh3)2Cl2] (M = Pd, Pt) affords mixed-ligand complexes of type [M(PPh3)(L)]. Structures of both the complexes have been determined by X-ray crystallography. Both the complexes are square planar, where the 2-(2'-carboxyphenylazo)-4-methylphenol is coordinated to the metal center, via dissociation of the two acidic protons, as a dianionic tridentate O,N,O-donor, and the fourth position is occupied by the triphenylphosphine. These complexes show intense MLCT transitions in the visible region.

  1. Synthesis, Spectral and Thermal Behavior of Some New Four Coordinated Complexes

    OpenAIRE

    Montazerozohori,M.; Khani, S.; S. Joohari; Musavi, S. A.

    2012-01-01

    A new symmetric bidentate Schiff base N, N′ bis(4-fluorobenzal-dehydene)-1,2-diaminoethane(L) and its complexes with general formula MLX2 (M= Zn(II), Cd(II) and Hg(II) and X=chloride, bromide, iodide, thiocyanate and azide) have been prepared. The ligand and complexes have been established by microanalysis, electronic, FT-IR, 1H and 13C NMR spectra, and by molar conductivity measurements. All compounds are non-electrolytes in chloroform or DMSO-d6. The thermal behavior of the complexes shows ...

  2. Influence of synthesis conditions on complexation of Cu (II) with O,N,O tridentate hydrazone ligand. X-ray diffraction and spectroscopic investigations

    Science.gov (United States)

    Repich, H. H.; Orysyk, S. I.; Orysyk, V. V.; Zborovskii, Yu. L.; Melnyk, A. K.; Trachevskyi, V. V.; Pekhnyo, V. I.; Vovk, M. V.

    2017-10-01

    Four novel Cu2+ coordination compounds with a (E)-N‧-(2-hydroxybenzylidene)-2-phenylacetohydrazide (HBPAH, H2L) have been synthesized and characterized by single crystal X-ray diffraction method, IR, UV-Vis and EPR spectroscopy. In all obtained compounds the ligand is coordinated in typical O,N,O-tridentate chelate manner. It has been shown that synthesis conditions have a great influence on a structure of resulting complex compounds. Depending on starting Cu2+ compounds, concentration of reagents, pH and the presence of secondary ligands the HBPAH coordinates as a neutral molecule, mono- or dianion with formation of four different complexes: [Cu(HL)(H2L)]NO3 (I), [Cu(HL)Cl] (II), [Cu2(HL)2Cl2] (III) and [Cu2(L)2Py2] (IV). Complex I is interesting by the presence of two differently coordinated ligand molecules. Mononuclear complex compound II and its dimeric analogue III were obtained from the same reagents: CuCl2 and HBPAH but in different reaction conditions. In dimeric complex IV the HBPAH molecules are coordinated as dianions in imidol tautomeric form, the pyridine molecules act as secondary ligands complementing the coordination polyhedra of Cu2+ ions. Study of UV-Vis and EPR spectra of complex compounds I-IV in solutions showed that all the complexes undergo partial solvolysis upon dissolution.

  3. Synthesis, Characterization and in Vitro Antibacterial Activities of CdO Nanoparticle and Nano-sheet Mixed-ligand of Cadmium(ІІ Complex

    Directory of Open Access Journals (Sweden)

    Zohreh Rashidi Ranjbar

    2016-07-01

    Full Text Available Here, we report the synthesis of a Schiff-base mixed-ligand complex of cadmium(ІІ in bulk and nano-scales via the precipitation and sonochemical methods, respectively. The complex formula is [Cd(3-bpdh(3-bpdbCl2]n (1, where the ligands are 3-bpdh = 2,5-bis(3-pyridyl-3,4-diaza-2,4-hexadiene and 3-bpdb = 1,4-bis(3-pyridyl-2,3-diaza-1,3-butadiene. The structure of mixed-ligand complex (1 was characterized by IR, 1H NMR and elemental analyses. Cadmium(ІІ oxide nanoparticles were prepared by direct thermolysis from nanosheet of complex (1. The cadmium(ІІ oxide structure was characterized by X-ray Diffraction (XRD and Energy Dispersive X-ray  analyses (EDAX. Size, morphology and structural dispersion of all obtained nanostructures were characterized by Scanning Electron Microscopy (SEM. The Schiff-base ligands, bulk and nano-scales of complex (1 and cadmium(ІІ oxide nanoparticles were analyzed for antibacterial activities against Bacillus alvei (bacteria causing the honey bee European foulbrood disease. The Minimum Inhibitory Concentrations (MIC has been shown moderate antibacterial activities compared with some other standard drugs. Known antibiotics like penicillin and SXT (Trimethoprim/sulfamethoxazole were used as positive control.

  4. Enantioselective synthesis of α-phenyl- and α-(dimethylphenylsilyl)alkylboronic esters by ligand mediated stereoinductive reagent-controlled homologation using configurationally labile carbenoids.

    Science.gov (United States)

    Barsamian, Adam L; Wu, Zhenhua; Blakemore, Paul R

    2015-03-28

    Chain extension of boronic esters by the action of configurationally labile racemic lithium carbenoids in the presence of scalemic bisoxazoline ligands was explored for the enantioselective synthesis of the two title product classes. Enantioenriched 2° carbinols generated by oxidative work-up (NaOOH) of initial α-phenylalkylboronate products were obtained in 35-83% yield and 70-96% ee by reaction of B-alkyl and B-aryl neopentyl glycol boronates with a combination of O-(α-lithiobenzyl)-N,N-diisopropylcarbamate and ligand 3,3-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl] pentane in toluene solvent (-78 °C to rt) with MgBr2·OEt2 additive. Enantioenriched α-(dimethylsilylphenylsilyl)alkylboronates were obtained in 35-69% yield and 9-57% ee by reaction of B-alkyl pinacol boronates with a combination of lithio(dimethylphenylsilyl)methyl 2,4,6-triisopropylbenzoate and ligand 2,2-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl]propane in cumene solvent (-45 °C to -95 °C to rt). The stereochemical outcome of the second type of reaction depended on the temperature history of the organolithium·ligand complex indicating that the stereoinduction mechanism in this case involves some aspect of dynamic thermodynamic resolution.

  5. Microwave Synthesis Under Solvent-Free Conditions and Spectral Studies of Some Mesoporphyrinic Complexes

    Directory of Open Access Journals (Sweden)

    Rica Boscencu

    2012-05-01

    Full Text Available A series of A3B and A4 type mesoporphyrinic complexes were synthesized with superior yields using microwave irradiation under solvent-free conditions. The structures of the complexes were confirmed using elemental analysis, FT-IR, UV-Vis, EPR and NMR spectral data. The influence of environmental polarity on spectral properties of the mesoporphyrinic complexes was investigated. The obtained results indicate that the shape of absorption and fluorescence spectra does not depend on the solvent polarity under the experimental conditions used. The small shifts of the absorption and emission maximums that occur by increasing of solvent polarity reflects the physical interaction between the porphyrinic substituents and the solvent molecules.

  6. Synthesis, spectral characterization and catalytic activity of Co(II) complexes of drugs: Crystal structure of Co(II)-trimethoprim complex

    Science.gov (United States)

    Madhupriya, Selvaraj; Elango, Kuppanagounder P.

    2014-01-01

    New Co(II) complexes with drugs such as trimethoprim (TMP), cimetidine (CTD), niacinamide (NAM) and ofloxacin (OFL) as ligands were synthesized. The complexes were characterized by analytical analysis, various spectral techniques such as FT-IR, UV-Vis, magnetic measurements and molar conductivity. The magnetic susceptibility results coupled with the electronic spectra suggested a tetrahedral geometry for the complexes. The coordination mode of trimethoprim ligand and geometry of the complex were confirmed by single crystal X-ray studies. In this complex the metal ion possesses a tetrahedral geometry with two nitrogen atom from two TMP ligands and two chloride ions coordinated to it. The catalytic activity of the complexes in aryl-aryl coupling reaction was screened and the results indicated that among the four complexes [Co(OFL)Cl(H2O)] exhibited excellent catalytic activity.

  7. Microwave synthesis, spectral, thermal, and antimicrobial activities of some transition metal complexes involving 5-bromosalicylaldehyde moiety

    Directory of Open Access Journals (Sweden)

    Rajendra K. Jain

    2012-07-01

    Full Text Available The coordination complexes of Co(II, Ni(II and Cu(II derived from 5-bromosalicylidene-3,4-dimethylaniline (BSMA and 5-bromosalicylidene-3,4-dichloroaniline (BSCA have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, molar conductance, electronic spectra, 1H-NMR, FAB-mass, ESR, magnetic susceptibility, electrical conductivity and thermal analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand ratio with coordination number 4 or 6. IR data shows that the ligand coordinates with the metal ions in a bidentate manner through the phenolic oxygen and azomethine nitrogen. FAB-mass and thermal data show degradation pattern of the complexes. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes show a good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans.

  8. Two 8-Hydroxyquinolinate Based Supramolecular Coordination Compounds: Synthesis, Structures and Spectral Properties

    Directory of Open Access Journals (Sweden)

    Chengfeng Zhu

    2017-03-01

    Full Text Available Two new Cr(III complexes based on 2-substituted 8-hydroxyquinoline ligands, namely [Cr(L13] (1, (HL1=(E-2-[2-(4-nitro-phenyl-vinyl]-8-hydroxy-quinoline and [Cr(L23] (2, (HL2=(E-2-[2-(4-chloro-phenylvinyl]-8-hydroxy-quinoline, were prepared by a facile hydrothermal method and characterized thoroughly by single crystal X-ray diffraction, powder X-ray diffraction, FTIR, TGA, ESI-MS, UV-Visible absorption spectra and fluorescence emission spectra. Single crystal X-ray diffraction analyses showed that the two compounds featured 3D supramolecular architectures constructed from noncovalent interactions, such as π···π stacking, C-H···π, C-H···O, C-Cl···π, C-H···Cl interactions. The thermogravimetric analysis and ESI-MS study of compounds 1 and 2 suggested that the Cr(III complexes possessed good stability both in solid and solution. In addition, the ultraviolet and fluorescence response of the HL1 and HL2 shown marked changes upon their complexation with Cr(III ion, which indicated that the two 8-hydroxyquinolinate based ligand are promising heavy metal chelating agent for Cr3+.

  9. Copper(II Complexes with Ligands Derived from 4-Amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one: Synthesis and Biological Activity

    Directory of Open Access Journals (Sweden)

    Raluca Cernat

    2006-11-01

    Full Text Available The synthesis of Cu(II complexes derived from Schiff base ligands obtainedby the condensation of 2-hydroxybenzaldehyde or terephtalic aldehyde with 4-amino-antipyrine (4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one is presented. The newlyprepared compounds were characterized by 1H-NMR, UV-VIS, IR and ESRspectroscopy. The determination of the antimicrobial activity of the ligands and of thecomplexes was carried out on samples of Escherichia coli, Klebsiella pneumoniae,Acinetobacter boumanii, Pseudomonas aeruginosa, Staphylococcus aureus and Candidasp. The qualitative and quantitative antimicrobial activity test results proved that all theprepared complexes are very active, especially against samples of Ps. aeruginosa, A.Boumanii, E. coli and S. aureus.

  10. Synthesis of novel chiral phosphine-triazine ligand derived from α-phenylethylamine for Pd-catalyzed asymmetric allylic alkylation

    Institute of Scientific and Technical Information of China (English)

    Jia Di Huang; Xiang Ping Hu; Zhuo Zheng

    2008-01-01

    A novel chiral phosphine-triazine ligand was synthesized from chiral model reaction of Pd-catalyzed allylic alkylation of rac-l,3-diphenylprop-2-en-l-yl pivalate with dimethyl malonate, good enantioselectivity (90% e.e.) was obtained by using this ligand.

  11. Synthesis, spectroscopic, coordination and biological activities of some organometallic complexes derived from thio-Schiff base ligands

    Science.gov (United States)

    Abou-Hussein, Azza A.; Linert, Wolfgang

    2014-01-01

    Two series of mono- and binuclear complexes cyclic or acyclic thio-ferocine Schiff base ligands, derived from the condensation of 2-aminobenzenthiol (L) with monoacetyl ferrocene in the molar ratio 1:1 or in the molar ratio 1:2 for diacetyl ferocine have been prepared. The condensation reactions yield the corresponding Schiff Base ligands, HLa-Maf and H2Lb-Daf. The chelation of the ligands to metal ions occurs through the sulfur of the thiol group as well as the nitrogen atoms of the azomethine group of the ligands. HLa-Maf acts as monobasic bidentate or dibasic tetradentate, while H2Lb-Daf behaves as twice negatively cargend tetradentate ligand. The structures of these ligands were elucidated by elemental analysis, infrared, ultraviolet-visible spectra, as well as 1H NMR spectra. Reactions of the Schiff bases ligands with ruthenium(III), oxovanadium(IV) and dioxouranium(VI) afforded the corresponding transition metal complexes. The properties of the newly prepared complexes were analyse by elemental analyses, infrared, electronic spectra, 1H NMR as well as the magnetic susceptibility and conductivity measurement. The metal complexes exhibits different geometrical arrangements such as octahedral and square pyramidal coordination. Schiff base ligands and their metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi to study their biological activity. All the complexes exhibit antibacterial and antifungal activities against these organisms.

  12. Beyond the Lick Indices: The High-Resolution Spectral Synthesis of Stellar Populations

    Science.gov (United States)

    Buzzoni, Alberto; Bertone, Emanuele; Rodríguez-Merino, Lino H.; Chávez, Miguel

    Up-to-date theoretical SED of stellar populations at 2 Å FWHM resolution is obtained by coupling a new library of synthetic spectra from the ATLAS and NextGen atmosphere database with the Buzzoni population synthesis code. We briefly outline the current status of the project, aimed at settling a new theoretical framework of narrow-band spectrophotometric indices to study stellar populations of galaxies.

  13. Biogenic silver nanoparticles using Rhinacanthus nasutus leaf extract: synthesis, spectral analysis, and antimicrobial studies.

    Science.gov (United States)

    Pasupuleti, Visweswara Rao; Prasad, T N V; Shiekh, Rayees Ahmad; Balam, Satheesh Krishna; Narasimhulu, Ganapathi; Reddy, Cirandur Suresh; Ab Rahman, Ismail; Gan, Siew Hua

    2013-01-01

    Nanotechnology is gaining momentum due to its ability to transform metals into nanoparticles. The synthesis, characterization, and applications of biologically synthesized nanomaterials have become an important branch of nanotechnology. Plant extracts are a cost-effective, ecologically friendly, and efficient alternative for the large-scale synthesis of nanoparticles. In this study, silver nanoparticles (AgNps) were synthesized using Rhinacanthus nasutus leaf extract. After exposing the silver ions to the leaf extract, the rapid reduction of silver ions led to the formation of AgNps in solution. The synthesis was confirmed by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The in vitro antimicrobial activity of the AgNps synthesized using R. nasutus leaf extract was investigated against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli, Aspergillus niger, and Aspergillus flavus using a disc diffusion method. The AgNps showed potential activity against all of the bacterial strains and fungal colonies, indicating that R. nasutus has the potential to be used in the development of value-added products in the biomedical and nanotechnology-based industries.

  14. Synthesis, structural diversity and fluorescent characterisation of a series of d10 metal-organic frameworks (MOFs): reaction conditions, secondary ligand and metal effects.

    Science.gov (United States)

    Zhang, Wei Hong; Dong, Zhe; Wang, Yao Yu; Hou, Lei; Jin, Jun Cheng; Huang, Wen Huan; Shi, Qi Zhen

    2011-03-21

    Along with our recent investigation on the flexible ligand of H(2)ADA (1,3-adamantanediacetic acid), a series of Zn(II) and Cd(II) metal-organic frameworks, namely, [Zn(3)(ADA)(3)(H(2)O)(2)](n)·5nH(2)O (1), [Zn(ADA)(4,4'-bipy)(0.5)](n) (2), [Zn(2)(ADA)(2)(bpa)](n) (3), [Zn(2)(ADA)(2)(bpa)](n) (4), [Zn(2)(ADA)(2)(bpp)](n) (5), [Cd(HADA)(2)((4,4'-bipy)](n) (6), [Cd(3)(ADA)(3)(bpa)(2)(CH(3)OH)(H(2)O)](n) (7), and [Cd(2)(ADA)(2)(bpp)(2)](n)·7nH(2)O (8) have been synthesized and structurally characterized (where 4,4'-bipy = 4,4'-dipyridine, bpa = 1,2-bis(4-pyridyl)ethane and bpp = 1,3-bis(4-pyridyl)propane). Due to various coordination modes and conformations of the flexible dicarboxylate ligand and the different pyridyl-containing coligands, these complexes exhibit structural and dimensional diversity. Complex 1 exhibits a three-dimensional (3D) framework containing one-dimensional (1D) Zn(II)-O-C-O-Zn(II) clusters. Complex 2 exhibits a 2D structure constructed by 1D double chains based on [Zn(2)ADA(2)] units and a 4,4'-bipy pillar. Complexes 3 and 4 possess isomorphic 2D layer structures, resulting from the different coordination modes of carboxylate group of ADA ligands. Complex 5 features a 2D 4(4) layer in which ADA ligands and Zn(II) atoms construct a 1D looped chain and the chains are further connected by bpp ligands. Complex 6 is composed of 1D zig-zag chains that are entangled through hydrogen-bonding interactions to generate a 2D network. Complex 7 is a rare (3,5)-connected network. Complex 8 possesses a 3D microporous framework with lots of water molecules encapsulated in the channels. The structural diversity of the complexes perhaps mainly results from using diverse secondary ligands and different metal centre ions, and means the assistant ligand and metal centre play important roles in the design and synthesis of target metal-organic frameworks. This finding revealed that ADA could be used as an effective bridging ligand to construct MOFs and change

  15. Synthesis, characterization and biological relevance of some metal (II) complexes with oxygen, nitrogen and oxygen (ONO) donor Schiff base ligand derived from thiazole and 2-hydroxy-1-naphthaldehyde

    Science.gov (United States)

    Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2015-04-01

    The novel Schiff base ligand 2-((2-hydroxynaphthalen-1-yl)methylene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-hydroxy-1-naphthaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), Zn(II) and Cd(II) complexes have been characterized by microanalysis, molar conductance, IR, 1H NMR, ESI-mass, UV-Visible, TGA/DTA, ESR and powder X-ray diffraction data to explicate their structures. The IR results confirmed the tridentate binding of the ligand involving oxygen atom of amide carbonyl, azomethine nitrogen and naphthol oxygen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. Thermogravimetric studies for Cu(II) and Ni(II) complexes indicated the presence of coordinated water molecules and the final product is the metal oxide. In order to appraise the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antimicrobial activity by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 (Bangal re Genei, Bengaluru, Cat. No 105850) as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties against Artemia salina. Furthermore, the antioxidant activity were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH). The ligand exhibited better in vitro-antioxidant activity than its metal complexes.

  16. Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes

    Science.gov (United States)

    Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M. Arif

    2016-05-01

    We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica.

  17. Probing Atlas model atmospheres at high spectral resolution. Stellar synthesis and reference template validation

    Science.gov (United States)

    Bertone, E.; Buzzoni, A.; Chávez, M.; Rodríguez-Merino, L. H.

    2008-07-01

    Aims: The fast improvement of spectroscopic observations makes mandatory a strong effort on the theoretical side to better reproduce the spectral energy distribution (SED) of stars at high spectral resolution. In this regard, relying on the Kurucz Atlas/Synthe original codes we computed the Bluered library, consisting of 832 synthetic SED of stars, that cover a large parameter space at very high spectral resolution (R = 500 000) along the 3500-7000 Å wavelength range. Methods: Bluered synthetic spectra have been used to assess in finer detail the intrinsic reliability and the performance limits of the Atlas theoretical framework. The continuum-normalized spectra of the Sun, Arcturus, and Vega, plus a selected list of 45 bright stars with high-quality SEDs from the Prugniel & Soubiran Elodie catalog, form our sample designed to probe the global properties of synthetic spectra across the entire range of H-R parameters. Results: Atlas models display a better fitting performance with increasing stellar temperature. High-resolution spectra of Vega, the Sun, and Arcturus have been reproduced at R=100 000, respectively, within a 0.7%, 4.5%, and 8.8% relative scatter in residual flux. In all the three cases, the residual flux distribution shows a significant asymmetry (skewness parameter γ = -2.21, -0.98, -0.67, respectively), which neatly confirms an overall “excess” of theoretical line blanketing. For the Sun, this apparent discrepancy is alleviated, but not recovered, by a systematic decrease (-40%) of the line oscillator strengths, log (gf), especially referring to iron transitions. Definitely, a straight “astrophysical” determination of log (gf) for each individual atomic transition has to be devised to overcome the problem. By neglecting overblanketing effects in theoretical models when fitting high-resolution continuum-normalized spectra of real stars, we lead to a systematically warmer effective temperature (between +80 and +300 K for the solar fit) and a

  18. Synthesis, structural characterization and antitumor activity of a Ca(II) coordination polymer based on 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide ligands

    Science.gov (United States)

    Tai, Xi-Shi; Wang, Xin

    2017-03-01

    A new Ca(II) coordination polymer, {[CaL(H2O)4] · (H2O)4} n (L = 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide) has been prepared by one-pot synthesis method. And it was characterized by elemental analysis, IR and thermal analysis. The result of X-ray single-crystal diffraction analysis shows that the Ca(II) complex molecules form one-dimensional chain structure by the bridging oxygen atoms. The anti-tumor activity of L ligand and the Ca(II) coordination polymer has also been studied.

  19. Rh2 (S-1,2-NTTL)4 : A novel Rh2 (S-PTTL)4 analog with lower ligand symmetry for asymmetric synthesis of chiral cyclopropylphosphonates.

    Science.gov (United States)

    Adly, Frady G; Maddalena, Johncarlo; Ghanem, Ashraf

    2014-11-01

    A new series of dirhodium(II) tetracarboxylate was derived from N-1,2-naphthaloyl-(S)-amino acid ligands. In terms of enantioselectivity, Rh2 (S-1,2-NTTL)4 () derived from N-1,2-naphthaloyl-(S)-tert-leucine, was the best-performing catalyst among the new series in the enantioselective synthesis of cyclopropylphosphonate derivatives (up to >99% enantiomeric excess). A predictive model was proposed to justify the observed high enantiomeric induction exhibited by Rh2 (S-1,2-NTTL)4 with donor-acceptor phosphonate carbenoids.

  20. The synthesis of N-Zn, N-Cu complexes involving 2-amino pyridine and ethylenediamine ligands and application to the Henry reaction

    Indian Academy of Sciences (India)

    Luo Mei; Tang Hai Ming; Li Qian Rong; Sun Jie; Yang Shan Zhong; Li Xue Liang

    2009-07-01

    The synthesis and characterization of a series of N-Zn, N-Cu complexes with 2-amino pyridine and ethylenediamine ligands (1a-b and 2a-b) have been described. They were synthesized with a simple, one-pot method, and the crystal structures of 1a, 1b, 2a and 2b were determined by X-ray crystallography. The complexes were also characterized by NMR, IR, and elemental analysis. They were used as the catalysts in an application to the Henry reaction, and high yields were obtained under the optimum conditions.

  1. A Novel Tris(2-aminoethylamine Based Tripodal Ligand: Synthesis and Solution Coordination Studies with Trivalent Iron and Chromium

    Directory of Open Access Journals (Sweden)

    Minati Baral

    2016-01-01

    Full Text Available A novel tris(2-aminoethylamine (TREN based tripodal ligand TRENOL (L has been synthesized and characterized by elemental analysis and UV-VIS, IR, 1H, and 13C NMR spectroscopic methods. The coordination behaviour of the ligand with H+ and trivalent metal ions, Fe(III and Cr(III, was investigated in aqueous medium at 0.1 M KCl at 25±1°C by potentiometric and spectrophotometric studies. Tripodal ligand showed seven protonation constants in the adopted pH range 2–11 and its electronic spectra exhibited three bands at 216, 323, and 423 nm. Ligand formed various metal complex species of the type MLH5, MLH4, MLH3, MLH, and ML with trivalent metal ions. The determined values of the formation constants (for ML species of the ligand with Fe(III and Cr(III were 24.19 and 18.64, respectively. Molecular modeling studies revealed that the metal complexes formed distorted octahedral geometry. Besides, ligand showed fluorescence at 496 nm when excited at 289 nm. The fluorescence behaviour of the ligand in the presence of Fe(III ions showed noticeable quenching in comparison to the other metal ions at physiological pH (7.4. So, as per the outcomes of the present study, TRENOL has the potential to be used as the iron detector in environmental, agricultural, and medical fields.

  2. Synthesis, structural, thermal studies and biological activity of a tridentate Schiff base ligand and their transition metal complexes.

    Science.gov (United States)

    Abd El-halim, Hanan F; Omar, M M; Mohamed, Gehad G

    2011-01-01

    Schiff base (L) ligand is prepared via condensation of pyridine-2,6-dicarboxaldehyde with -2-aminopyridine. The ligand and its metal complexes are characterized based on elemental analysis, mass, IR, solid reflectance, magnetic moment, molar conductance, and thermal analyses (TG, DTG and DTA). The molar conductance reveals that all the metal chelates are non-electrolytes. IR spectra shows that L ligand behaves as neutral tridentate ligand and bind to the metal ions via the two azomethine N and pyridine N. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral (Cr(III), Fe(III), Co(II), Ni(II), Cu(II), and Th(IV)) and tetrahedral (Mn(II), Cd(II), Zn(II), and UO2(II)). The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, ΔH*, ΔS* and ΔG* are calculated from the DTG curves using Coats-Redfern method. The synthesized ligand, in comparison to their metal complexes also was screened for its antibacterial activity against bacterial species, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus pyogones and Fungi (Candida). The activity data shows that the metal complexes to be more potent/antibacterial than the parent Schiff base ligand against one or more bacterial species.

  3. Zeolitic polyoxometalates metal organic frameworks (Z-POMOF) with imidazole ligands and epsilon-Keggin ions as building blocks; computational evaluation of hypothetical polymorphs and a synthesis approach.

    Science.gov (United States)

    Rodriguez Albelo, L Marleny; Ruiz-Salvador, A Rabdel; Lewis, Dewi W; Gómez, Ariel; Mialane, Pierre; Marrot, Jérome; Dolbecq, Anne; Sampieri, Alvaro; Mellot-Draznieks, Caroline

    2010-08-14

    We investigate here a new family of zeolitic Metal Organic Frameworks (MOFs) based on imidazole (im) as the ligand and epsilon-type Keggin PolyOxoMetalates (POMs) as building units. The POM used in this study is the epsilon-{PMo(12)O(40)} Keggin isomer capped by four Zn(ii) ions (noted epsilon-Zn) in tetrahedral coordination. We describe here our methods to first construct and then evaluate the stability of hypothetical 3-D POMOFs possessing a tetrahedral network, typified by dense silica polymorphs and zeotypes and referred here to as Z-POMOFs. We use the analogy between the connectivity of silicon ion in dense minerals or zeolites and the epsilon-Zn, using imidazolate ligands to mimic the role of oxygen atoms in zeolites. Handling the epsilon-Keggin and imidazole as the constitutive building-blocks, a selection of 40 polymorphs were constructed and their relative stabilities computed. Among these Z-POMOFs, the cristobalite-like and zni-structure were identified as the most stable candidates. In parallel, we have attempted to synthesize Z-POMOF structures with epsilon-Zn POMs, synthesized in situ under hydrothermal conditions, and imidazole ligands. We present our first experimental result, the extended material [NBu(4)][PMo(V)(8)Mo(VI)(4)O(37)(OH)(3)Zn(4)(im)(Him)], named epsilon(im)(2). The structure of the hybrid framework is built by the connection of dimerized epsilon-Zn POMs to imidazole ligands in two directions. The obtaining of the first POMOF based on imidazole ligand is an encouraging step towards the synthesis of a new family of POMOFs.

  4. Synthesis and luminescent properties of novel lanthanide(III) beta-diketone complexes with nitrogen p,p'-disubstituted aromatic ligands.

    Science.gov (United States)

    Bellusci, Anna; Barberio, Giovanna; Crispini, Alessandra; Ghedini, Mauro; La Deda, Massimo; Pucci, Daniela

    2005-03-21

    Tris-beta-diketonate lanthanide(III) complexes (Ln = Eu, Er, Yb, Tb), of general formula [Ln(acac)3 L(m)], with chelating ligands such as 4,7-disubstituted-1,10-phenanthrolines and 4,4'-disubstituted-2,2'-bipyridines, have been synthesized and fully characterized. The inductive effects of the para-substituents on the aromatic N-donor ligands have been investigated both in the solid and in the solution states. Single-crystal X-ray structures have been determined for the diethyl 1,10-phenanthroline-4,7-dicarboxylate europium and 4,4'-dimethoxy-2,2'-bipyridine erbium derivatives, revealing a distorted square antiprismatic geometry around the lanthanide atom in both cases. The influence exerted by the p,p'-substituents with respect to the nitrogen coordinating atoms on the Ln-N bond distances is discussed comparing the geometrical parameters with those found for the crystal structures containing the fragments [Ln(III)(phen)] and [Ln(III)(bipy)] obtained from the Cambridge Structural Database. The influence exerted by the electron-attracting groups on the coordination ability of the ligands, that in some cases becomes lack of coordination of the lanthanide ions, has been also detected in solution where the loss of the ligand has been followed by UV-vis spectroscopy. Moreover, the use of relatively long alkoxy chains as substituents on the 1,10-phenanthroline ligand led to the formation of a promesogenic lanthanide complex, whose thermal behavior is encouraging for the synthesis of new lanthanide liquid-crystalline species.

  5. Synthesis, spectral characterization, crystal structure and molecular docking study of 2,7-diaryl-1,4-diazepan-5-ones

    Science.gov (United States)

    Sethuvasan, S.; Sugumar, P.; Maheshwaran, V.; Ponnuswamy, M. N.; Ponnuswamy, S.

    2016-07-01

    In this study, a series of variously substituted r-2,c-7-diaryl-1,4-diazepan-5-ones 9-16 have been synthesized using Schmidt rearrangement and are characterized by IR, mass and 1D & 2D NMR spectral data. The proton NMR coupling constant and estimated dihedral angles reveal that the compounds 9-16 prefer a chair conformation with equatorial orientation of alkyl and aryl groups. Single crystal X-ray structure has been solved for compounds 9 and 11 which also indicates the preference for distorted chair conformation with equatorial orientation of substituents. The compounds 9-16 have been docked with the structure of Methicillin-resistant Staphylococcus aureus (MRSA) and the results demonstrate that compound 10 is having better docking score and glide energy than others and it is comparable to co-crystal ligand. Furthermore, all the compounds have been evaluated for their antibacterial and antioxidant activities. All the compounds show moderate antibacterial activity and only 11 exhibits better activity against S. aures and Escherichia coli. The compounds 11, 13 and 14 exhibit half of the antioxidant power when compared to the BHT and the remaining compounds show moderate activity.

  6. Synthesis, spectral, antitumor and antimicrobial studies on Cu(II) complexes of purine and triazole Schiff base derivatives

    Science.gov (United States)

    Amer, Said; El-Wakiel, Nadia; El-Ghamry, Hoda

    2013-10-01

    A series of copper (II) complexes of Schiff bases derived from 7H-2,6-diaminopurine and 4H-3,5-diamino-1,2,4-triazole with 2-pyridinecarbaldehyde, salicylaldehyde, 2,4-dihydroxybenzaldehyde and 2-hydroxy-1-naphthaldehyde have been prepared. The donor atoms and the possible geometry of the complexes were investigated by means of elemental and thermal analyses, molar conductance, magnetic moment, UV-Vis, IR, ESR and mass spectra. The ligands behaved as tetradentate, coordinating through the nitrogen atom of the azomethine group and the nearest nitrogen atom to it or oxygen atom of α-hydroxyl group. The results of simultaneous DTA & TGA analyses of the complexes showed the final degradation product for these complexes is CuO. The spectral studies confirmed a four coordinate environment around the metal ion. The obtained results were supported by 3D molecular modeling of complexes using molecular mechanics (MM+) and semiempirical molecular orbital calculations (PM3). These complexes were also tested for their in vitro antimicrobial activities against some bacterial and fungal strains. Complex 2 was investigated for its cyctotoxic effect against human breast cancer (MCF7), liver carcinoma (HEPG2) and colon carcinoma cell lines (HCT116). This compound exhibited a moderate activity against the tested cell lines with IC50 of 10.3, 9.8 and 8.7 μg/ml against MCF7, HCT116 and HEPG2, respectively.

  7. Synthesis, Spectral Analysis and Preliminary in Vitro Evaluation of Some Tetrapyrrolic Complexes with 3d Metal Ions

    Directory of Open Access Journals (Sweden)

    Radu Socoteanu

    2015-08-01

    Full Text Available In this paper, two tetrapyrrolic complexes, Zn(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin and Cu(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin were synthesized, and characterized from a spectral and biological point of view. The study provided data concerning the behavior of identical external substituents vs. two different core insertions. Some of the properties of the proposed tetrapyrrolic structures were highlighted, having photodynamic therapy of cancer as a targeted biomedical application. Elemental analysis, NMR, FTIR and UV-Vis data in various solvents were provided. A preliminary in vitro study on normal and cancer cultured cells was carried out for biocompatibility assessment in dark conditions. The preliminary in vitro study performed on human peripheral mononuclear cells exposed to tetrapyrrolic compounds (2 µM showed that the proposed compounds had a convenient cytotoxic profile on human normal peripheral blood mononuclear cells under dark conditions. Meanwhile, the investigated compounds reduced the number of metabolically active breast tumor MCF-7 cells, with the exception of Zn(II complex-containing a symmetrical ligand. Accordingly, preliminary in vitro data suggest that the proposed tetrapyrrolic compounds are good candidates for PDT, as they limit tumor expansion even under dark conditions, whilst sparing normal cells.

  8. [Synthesis and luminescent spectral characteristics of porphyrin complexes with platinum group metals].

    Science.gov (United States)

    Rumiantseva, V D; Ivanovskaia, N P; Konovalenko, L I; Tsukanov, S V; Mironov, A F; Osin, N S

    2008-01-01

    The synthesis of natural and synthetic porphyrin complexes with Pt, Pd, Rh, and Ru is reported. Their electronic absorption spectra, phosphorescence spectra, and lifetimes at room temperature both in the presence and in the absence of oxygen were studied. It has been shown that the variation of the nature of the central metal atom and of the substituents in pyrrole and phenyl rings allows the obtaining of metalloporphyrins with various phosphorescence excitation and phosphorescing emission spectra at room temperature. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2008, vol. 34, no. 2; see also http://www.maik.ru.

  9. Microwave Synthesis, Spectral, Thermal and Electrical Properties of Some Metal Complexes Involving 5-Bromosalicylaldehyde

    OpenAIRE

    Rajendra K. Jain; A. P. Mishra; Mishra, D. K.; S.K Gupta

    2012-01-01

    Microwave-assisted synthesis is a branch of green chemistry. The salient features of microwave approach are shorter reaction times, simple reaction conditions and enhancements in yields. Some new Schiff base complexes of Cr(III), Co(II), Ni(II) and Cu(II) derived from 5-bromosalicylaldehyde with 4-nitro-1,2-phenylenediamine (H2L1) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductanc...

  10. Aziridine- and Azetidine-Pd Catalytic Combinations. Synthesis and Evaluation of the Ligand Ring Size Impact on Suzuki-Miyaura Reaction Issues

    Directory of Open Access Journals (Sweden)

    Hamza Boufroura

    2017-01-01

    Full Text Available The synthesis of new vicinal diamines based on aziridine and azetidine cores as well as the comparison of their catalytic activities as ligand in the Suzuki-Miyaura coupling reaction are described in this communication. The synthesis of three- and four-membered ring heterocycles substituted by a methylamine pendant arm is detailed from the parent nitrile derivatives. Complexation to palladium under various conditions has been examined affording vicinal diamines or amine-imidate complexes. The efficiency of four new catalytic systems is compared in the preparation of variously substituted biaryls. Aziridine- and azetidine-based catalytic systems allowed Suzuki-Miyaura reactions from aryl halides including chlorides with catalytic loadings until 0.001% at temperatures ranging from 100 °C to r.t. The evolution of the Pd-metallacycle ring strain moving from azetidine to aziridine in combination with a methylamine or an imidate pendant arm impacted the Suzuki-Miyaura reaction issue.

  11. Synthesis and Characterization of Porphyrin.Trisbenzimidazole Dinucleating Ligand and Its Heterodinuclear Complex as CcO Active Site Model

    Institute of Scientific and Technical Information of China (English)

    LuWei-bing; WangCun-xin; DengLi-zhi; ZhouXiao-hai; RenJian-guo

    2003-01-01

    A new dinucleating ligand having two metalbinding sites has been designed and synthesized as model ligand for Cytochrome c Oxidase. The corresponding heterodinuclear complex, as an active site model of Cytochrome c Oxidase, consisting of a porphyrinatocobalt compound covalently linked with a copper derivative of tris(2-benzimidazylmethyl)amine bearing three benzimidazole ligands for copper was synthesized and spectroscopically characterized. The spectra data suggest that there are interactions between the cobalt and copper coordination units. The cobalt is coordinated to four central nitrogens of the porphyrin and the copper has pentacoordinate geometry with the four tertiary amine nitrogens and a chloride.

  12. Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

    Directory of Open Access Journals (Sweden)

    Louis P. Sandjo

    2015-09-01

    Full Text Available This review focuses on pyridoacridine-related metabolites as one biologically interesting group of alkaloids identified from marine sources. They are produced by marine sponges, ascidians and tunicates, and they are structurally comprised of four to eight fused rings including heterocycles. Acridine, acridone, dihydroacridine, and quinolone cores are features regularly found in these alkaloid skeletons. The lack of hydrogen atoms next to quaternary carbon atoms for two or three rings makes the chemical shift assignment a difficult task. In this regard, one of the aims of this review is the compilation of previously reported, pyridoacridine 13C NMR data. Observations have been made on the delocalization of electrons and the presence of some functional groups that lead to changes in the chemical shift of some carbon resonances. The lack of mass spectra information for these alkaloids due to the compactness of their structures is further discussed. Moreover, the biosynthetic pathways of some of these metabolites have been shown since they could inspire biomimetic synthesis. The synthesis routes used to prepare members of these marine alkaloids (as well as their analogues, which are synthesized for biological purposes are also discussed. Pyridoacridines were found to have a large spectrum of bioactivity and this review highlights and compares the pharmacophores that are responsible for the observed bioactivity.

  13. Spectral and thermal studies with anti-fungal aspects of some organotin(IV) complexes with nitrogen and sulphur donor ligands derived from 2-phenylethylamine

    Science.gov (United States)

    Singh, Rajeev; Kaushik, N. K.

    2008-11-01

    Some complexes of 2-phenylethyl dithiocarbamate, thiohydrazides and thiodiamines with dibenzyltin(IV) chloride, tribenzyltin(IV) chloride and di( para-chlorobenzyl)tin(IV) dichloride have been synthesized and investigated in 1:2 and 1:1 molar ratio. The dithiocarbamate ligand act as monoanionic bidentate and thiohydrazide, thiodiamines act as neutral bidentate ligand. The synthesized complexes have been characterized by elemental analysis and molecular weight determination studies and their bonding pattern suggested on the basis of electronic, infrared, 1H and 13C NMR spectroscopy. Using thermogravimetric (TG) and differential thermal analysis (DTA) various thermodynamic and kinetic parameters viz. reaction order ( n), apparent activation energy ( Ea), apparent activation entropy ( S#) and heat of reaction (Δ H) have been calculated and correlated with the structural aspects for solid-state decomposition of complexes. The ligands and their tin complexes have also been screened for their fungitoxicity activity against Rhizoctonia solanii and Sclerotium rolfsii and their ED 50 values calculated.

  14. Synthesis and biological activity of small peptides as NOP and opioid receptors' ligands: view on current developments.

    Science.gov (United States)

    Naydenova, Emilia; Todorov, Petar; Zamfirova, Rositza

    2015-01-01

    The heptadecapeptide nociceptin, also called orphanin FQ (N/OFQ), is the endogenous agonist of the N/OFQ peptide receptor (NOP receptor) and is involved in several central nervous system pathways, such as nociception, reward, tolerance, and feeding. The discovery of small molecule ligands for NOP is being actively pursued for several therapeutic applications. This review presents overview of the several recently reported NOP ligands (agonists and antagonists), with an emphasis of the structural features that may be important for modulating the intrinsic activity of these ligands. In addition, a brief account on the characterization of newly synthesized ligands of NOP receptor with aminophosphonate moiety and β-tryptophan analogues will be presented.

  15. Synthesis and luminescence properties of lanthanide complexes with a new tripodal ligand featuring N-thenylsalicylamide arms.

    Science.gov (United States)

    Song, Xue-Qin; Zheng, Qing-Fang; Wang, Li; Liu, Wei-Sheng

    2012-01-01

    To explore the relationship between the structure of the ligands and the luminescent properties of the lanthanide complexes, luminescent lanthanide complexes of a new tripodal ligand, featuring N-thenylsalicylamide arms, were synthesized and characterized by elemental analysis, IR and TGA measurements. Photophysical properties of the complexes were studied by means of UV - visible absorption and steady-state luminescence spectroscopy. The results of UV - vis spectra indicate that metal binding does not disturb the electronic structure of the ligand. Excited-state luminescence lifetimes and quantum yields of the complexes were determined. The photoluminescence analysis suggested that there is an efficient ligand - Ln(III) energy transfer for the Tb(III) complex, and the ligand is an efficient 'antenna' for Tb(III). From a more general perspective, the results demonstrated the potential application of the lanthanide complex as luminescent materials in material chemistry. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Synthesis of Novel C2-Symmetrical Bidentate Phosphoramidite Ligands for Rh-catalyzed Asymmetric Hydrogenation of β-(Acylamino)acrylates

    Institute of Scientific and Technical Information of China (English)

    Qing Heng ZENG; Xiang Ping HU; Xin Miao LIANG; Zhuo ZHENG

    2006-01-01

    Two new C2-symmetrical bidentate phosphoramidite ligands were synthesized and employed in the Rh-catalyzed asymmetric hydrogenation of β-(acylamino)acrylates, up to 89% ee with full conversions was obtained.

  17. Synthesis and preliminary evaluation of (S)-[C-11]-exaprolol, a novel beta-adrenoceptor ligand for PET

    NARCIS (Netherlands)

    van Waarde, Aren; Doorduin, Janine; de Jong, Johan R.; Dierckx, Rudi A.; Elsinga, Philip H.

    2008-01-01

    Positron-emitting beta-adrenoceptor ligands for the CNS could allow determination of changes in P-adrenoceptor availability after treatment of patients with norepinephrine reuptake inhibitors or tricyclic antidepressants, and differential diagnosis between multiple sclerosis and other brain

  18. Synthesis, Spectral and Antimicrobial Studies of Some N(2)-Substituted Tetrahydroindazoles

    Energy Technology Data Exchange (ETDEWEB)

    Amirthaganesan, Shanmugasundaram; Aridoss, Gopalakrishnan; Park, Keun Soo; Lim, Kwon Taek; Jeong, Yeon Tae [Pukyong National University, Busan (Korea, Republic of)

    2010-05-15

    A series of N(2)-benzothiazolyl substituted tetrahydroindazoles has been synthesized via cyclic β keto esters. Optimum reaction condition was found as acidic toluene and effect of higher acidity towards substituted hydrazines in situ was described. Synthesized compounds have been achieved as single isomer and characterized by using 1D and 2D NMR spectral reports. Antimicrobial screening was carried out for the synthesized compounds along with a series of N(2)-pyridyl tetrahydroindazoles.{sup 1} The results of the in vitro antimicrobial screening studies revealed that compounds 13, 16 against Staphylococcus aureus, 11 against Escherichia coli, 10-12, 16 against Pseudomonas aeruginosa and 12 against Klebsiella pneumoniae recorded almost two-fold better activity compared to the standard drug used.

  19. A spectral synthesis method to suppress aliasing and calibrate for delay errors in Fourier transform correlators

    CERN Document Server

    Kaneko, Tak

    2008-01-01

    Context: Fourier transform (or lag) correlators in radio interferometers can serve as an efficient means of synthesising spectral channels. However aliasing corrupts the edge channels so they usually have to be excluded from the data set. In systems with around 10 channels, the loss in sensitivity can be significant. In addition, the low level of residual aliasing in the remaining channels may cause systematic errors. Moreover, delay errors have been widely reported in implementations of broadband analogue correlators and simulations have shown that delay errors exasperate the effects of aliasing. Aims: We describe a software-based approach that suppresses aliasing by oversampling the cross-correlation function. This method can be applied to interferometers with individually-tracking antennas equipped with a discrete path compensator system. It is based on the well-known property of interferometers where the drift scan response is the Fourier transform of the source's band-limited spectrum. Methods: In this p...

  20. SYNTHESIS AND SPECTRAL STUDY OF 2-(4-{[(SUBSTITUTEDPHENYLIMINO]METHYL}PHENOXYACETO HYDRAZIDE

    Directory of Open Access Journals (Sweden)

    Pinka Patel , Deepa Gor and P.S. Patel*

    2012-07-01

    Full Text Available Heterocyclic Compounds having a valuable place in a Heterocyclic Chemistry and Heterocyclic Compounds having an excellent properties such as drugs, dyes etc, These compounds shows anti-microbial, anti-fungal, anti-bacterial, anti-inflammatory, anti-diabetic, anti-hypertensive etc. properties. In present investigation, we have prepared 2-4-{[(substitutedphenylimino]methyl} phenoxyacetohydrazide from amine of (4-{[substitutedphenylimino] methyl}phenoxyacetic acid and Hydrazine hydrate in presence of ethanol. The intermediate (4-{[(substitutedphenylimino]methyl} phenoxy acetic acid from (4-formylphenoxyacetic acid and substitutedaniline by using ethanol as a solvent. Compound having an excellent properties regarding as per as anti cancer and HIV as compare to this compound. Physical properties of pure crystallized substance 2-4-{[(substitutedphenyl imino]methyl}phenoxy acetohydrazide like M.P., elementary analysis and spectral data of compound and such as IR and NMR will be evaluated and confirm the structure of compound.

  1. Synthesis, characterization, biological activities and luminescent properties of lanthanide complexes with [2-thiophenecarboxylic acid, 2-(2- pyridinylmethylene)hydrazide] Schiff bases ligand

    Institute of Scientific and Technical Information of China (English)

    Abdulaziz M Ajlouni; Qutaiba Abu-Salem; Ziyad A Taha; Ahmed K Hijazi; Waleed Al Momani

    2016-01-01

    A Schiff baseL[2-thiophenecarboxylic acid, 2-(2-pyridinylmethylene)hydrazide] with its lanthanide metal complexeswas synthesized. These complexes were characterized by elemental analysis, molar conductivity measurements, spectral analysis (NMR, FT-IR, and UV-Vis), luminescence and thermal gravimetric analysis. The Schiff base ligandwas a tridentate chelate and coordinates to the central lanthanide ion with 1:2 metal:ligand ratio. The conductivity data showeda1:1 electrolytic nature with a general formula [LnL2(NO3)2]NO3. The luminescence emission properties for Sm,Tb, and Eu complexeswere observed and showedthat the ligandL couldabsorb and transfer energy to Sm(III), Tb(III) and Eu(III)ions. The complexes possesseda good antibacterial activity against different bacterial strains. In addition,the scavenging activity of the Ln(III) complexes on DPPHwas concentration dependant and the complexeswere significantly more efficient in quenching DPPH than the free Schiff base ligand.

  2. Synthesis, characterization and catechol oxidase biomimetic catalytic activity of cobalt(II and copper(II complexes containing N2O2 donor sets of imine ligands

    Directory of Open Access Journals (Sweden)

    Mohamed I. Ayad

    2016-11-01

    Full Text Available New tetradentate imine ligands are derived from Schiff base condensation in a 1:2 molar ratio of the 1,2,4,5-tetra-amino benzene with 2-hydroxy benzaldehyde, (L1, 2,4-dihydroxy benzaldehyde (L2 and 2-hydroxy naphthaldehyde (L3. These ligands react with CoCl2 and CuCl2 in refluxing ethanol to yield a series of cobalt(II and copper(II complexes of the type [M2IILn] nH2O. The structure of the obtained ligands and their metal(II complexes were characterized by various physicochemical techniques, viz. elemental analysis, molar conductance, magnetic susceptibility measurements, thermal analysis (TGA & DTG, IR, electronic absorption and ESR spectral studies. Four-coordinate tetrahedral and square–planar structures were proposed for cobalt(II and copper(II complex species respectively. The ability of the synthesized complexes to catalyze the aerobic oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC to the light absorbing 3,5-di-tert-butylquinone (3,5-DTBQ has been investigated. The results obtained show that all complexes catalyze this oxidation reaction and slight variations in the rate were observed. The probable mechanistic implications of the catalytic oxidation reactions are discussed.

  3. Synthesis of novel chiral N, P-containing multidentate ligands and their applications in asymmetric transfer hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Shen Luan Yu; Yan Yun Li; Zhen Rong Dong; Juan Ni Zhang; Qi Li; Jing Xing Gao

    2011-01-01

    Novel chiral PN4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis(o-formylphenyl)phenylphosphane and various chiral amino-sulfonamides. Their structures were fully characterized by IR, EI-MS and NMR. The catalytic systems, prepared in situ from the multidentate ligands and iridium(I) complexes, showed high activity in asymmetric transfer hydrogenation of propiophenone in 2-propanol solution, leading to corresponding optical alcohol with up to 75% ee.

  4. Cell-free synthesis of functional human epidermal growth factor receptor: Investigation of ligand-independent dimerization in Sf21 microsomal membranes using non-canonical amino acids

    Science.gov (United States)

    Quast, Robert B.; Ballion, Biljana; Stech, Marlitt; Sonnabend, Andrei; Varga, Balázs R.; Wüstenhagen, Doreen A.; Kele, Péter; Schiller, Stefan M.; Kubick, Stefan

    2016-01-01

    Cell-free protein synthesis systems represent versatile tools for the synthesis and modification of human membrane proteins. In particular, eukaryotic cell-free systems provide a promising platform for their structural and functional characterization. Here, we present the cell-free synthesis of functional human epidermal growth factor receptor and its vIII deletion mutant in a microsome-containing system derived from cultured Sf21 cells. We provide evidence for embedment of cell-free synthesized receptors into microsomal membranes and asparagine-linked glycosylation. Using the cricket paralysis virus internal ribosome entry site and a repetitive synthesis approach enrichment of receptors inside the microsomal fractions was facilitated thereby providing analytical amounts of functional protein. Receptor tyrosine kinase activation was demonstrated by monitoring receptor phosphorylation. Furthermore, an orthogonal cell-free translation system that provides the site-directed incorporation of p-azido-L-phenylalanine is characterized and applied to investigate receptor dimerization in the absence of a ligand by photo-affinity cross-linking. Finally, incorporated azides are used to generate stable covalently linked receptor dimers by strain-promoted cycloaddition using a novel linker system. PMID:27670253

  5. Palladium complexes of pyrrole-2-aldehyde thiosemicarbazone: Synthesis, structure and spectral properties

    Indian Academy of Sciences (India)

    Piyali Paul; Samaresh Bhattacharya

    2014-09-01

    Reaction of pyrrole-2-aldehyde thiosemicarbazone (abbreviated as H2L, where H2 stands for the two potentially dissociable protons) with [Pd(PPh3)2Cl2] in ethanol in the presence of NEt3 afforded two complexes, [Pd(PPh3)(HLNS)Cl] and [Pd(PPh3)(LNNS)], where the thiosemicarbazone ligand is coordinated to the metal centre respectively as monoanionic N,S-donor (depicted by HLNS) and dianionic N,N,S-donor (depicted by LNNS). Similar reaction with Na2[PdCl4] afforded a bis-complex, [Pd(HLNS)2]. Crystal structures of all the three complexes have been determined.With reference to the structure of the uncoordinated thiosemicarbazone (H2L), the N,S-coordinationmode observed in [Pd(PPh3)(HLNS)Cl] and [Pd(HLNS)2] is associated with a geometrical change around the imine bond.While the N,N,S-mode of binding observed in [Pd(PPh3)(LNNS)] takes place without any such geometrical change. All three complexes display intense absorptions in the visible and ultraviolet regions, which have been analyzed by TDDFT method.

  6. Room temperature synthesis and spectral characterization of Cu2+-doped CdO powder

    Science.gov (United States)

    Venkata Reddy, Ch.; Shim, J.; Byon, C.; Krishna Rao, L. V.; Satish, D. V.; Ravikumar, R. V. S. S. N.

    2016-03-01

    In the present study, we have synthesized undoped and Cu2+-doped CdO nanopowders by a mild solution method at room temperature. Powder X-ray diffraction, optical absorption, electron paramagnetic resonance and Fourier transform infrared measurements are used to characterize prepared powders. The powder X-ray diffraction patterns reflect the cubic crystal structure for undoped and Cu2+-doped CdO powders. Surface morphology images and compositional features are studied by scanning electron microscopy and energy-dispersive X-ray techniques, respectively. The optical absorption spectra exhibit a single absorption band for Cu2+-doped sample, which is the characteristic absorption band of distorted octahedral site symmetry. By correlating the electron paramagnetic resonance and optical results for Cu2+-doped CdO nanopowder, bonding parameters are evaluated. These values indicate the partial covalency of in-plane σ ( α 2) and in-plane π bonding ( β12 ) between copper ions and their ligands. The FT-IR spectra indicate the fundamental vibrations of Cd-O.

  7. Tris-(1,3-diaryltriazenide) complexes of rhodium - Synthesis, structure and, spectral and electrochemical properties

    Indian Academy of Sciences (India)

    Chhandasi Guharoy; Michael G B Drew; Samaresh Bhattacharya

    2009-05-01

    Reaction of 1,3-diaryltriazenes (abbreviated in general as HL-R, where R stands for the para-substituent in the aryl fragment and H stands for the dissociable hydrogen atom, R = OCH3, CH3, H, Cl, NO2) with [Rh(PPh3)2(CO)Cl] in ethanol in the presence of NEt3 produces a series of trisdiaryltriazenide complexes of rhodium of type [Rh(L-R)3], where the triazenes are coordinated to rhodium as monoanionic, bidentate N,N-donors. Structure of the [Rh(L-OCH3)3] complex has been determined by X-ray crystallography. The complexes are diamagnetic, and show characteristic 1H NMR signals and intense MLCT transitions in the visible region. They also fluoresce in the visible region under ambient condition while excited at around 400 nm. Cyclic voltammetry on these complexes shows a Rh(III)-Rh(IV) oxidation (within 0.84-1.67 V vs SCE), followed by an oxidation of the coordinated triazene ligand (except the R = NO2 complex). An irreversible reduction of the coordinated triazene is also observed for all the complexes below -1.03 V vs SCE.

  8. Synthesis, crystal structure and luminescence properties of acenaphthene benzohydrazide based ligand and its zinc(II) complex

    Science.gov (United States)

    Kumar, Mukesh; Roy, Soumyabrata; Faizi, Md. Serajul Haque; Kumar, Santosh; Singh, Mantu Kumar; Kishor, Shyam; Peter, Sebastian C.; John, Rohith P.

    2017-01-01

    The complex compound of zinc(II) supported by (Z)-2-hydroxy-N‧-(1-oxoacenaphthylen-2(1H) ylidene)benzohydrazide ligand (H2L1) has been reported and discussed. The reaction of zinc acetate with H2L1 ligand leads to the formation of a mononuclear zinc(ii) complex, [Zn(HL1)2H2O]. The ligand, H2L1 has been characterized by elemental analysis, 1H, 13C and 1Hsbnd COSY -NMR, IR and ESI-MS, while the complex was characterized by elemental analysis, IR, and ESI-MS. The crystal structures of the free ligand H2L1 and the complex have also been determined by single crystal X-ray diffraction. The ligand chelates with metal centre with a nitrogen atom of imino moiety and an oxygen atom of enolic group. The complex shows distorted trigonal bipyramidal geometry around the metal centre with oxygen atoms lying in the equatorial plane and imino nitrogen atoms along the axial direction. The DFT/TD-DFT calculations were performed on both the ligand and its zinc complex to get insight into the structural, electronic and optical properties. The photoluminescence, fluorescence properties of the complex have been investigated.

  9. Troponate/Aminotroponate Ruthenium-Arene Complexes: Synthesis, Structure, and Ligand-Tuned Mechanistic Pathway for Direct C-H Bond Arylation with Aryl Chlorides in Water.

    Science.gov (United States)

    Dwivedi, Ambikesh D; Binnani, Chinky; Tyagi, Deepika; Rawat, Kuber S; Li, Pei-Zhou; Zhao, Yanli; Mobin, Shaikh M; Pathak, Biswarup; Singh, Sanjay K

    2016-07-05

    A series of water-soluble troponate/aminotroponate ruthenium(II)-arene complexes were synthesized, where O,O and N,O chelating troponate/aminotroponate ligands stabilized the piano-stool mononuclear ruthenium-arene complexes. Structural identities for two of the representating complexes were also established by single-crystal X-ray diffraction studies. These newly synthesized troponate/aminotroponate ruthenium-arene complexes enable efficient C-H bond arylation of arylpyridine in water. The unique structure-activity relationship in these complexes is the key to achieve efficient direct C-H bond arylation of arylpyridine. Moreover, the steric bulkiness of the carboxylate additives systematically directs the selectivity toward mono- versus diarylation of arylpyridines. Detailed mechanistic studies were performed using mass-spectral studies including identification of several key cyclometalated intermediates. These studies provided strong support for an initial cycloruthenation driven by carbonate-assisted deprotonation of 2-phenylpyridine, where the relative strength of η(6)-arene and the troponate/aminotroponate ligand drives the formation of cyclometalated 2-phenylpyridine Ru-arene species, [(η(6)-arene)Ru(κ(2)-C,N-phenylpyridine) (OH2)](+) by elimination of troponate/aminotroponate ligands and retaining η(6)-arene, while cyclometalated 2-phenylpyridine Ru-troponate/aminotroponate species [(κ (2)-troponate/aminotroponate)Ru(κ(2)-C,N-phenylpyridine)(OH2)2] was generated by decoordination of η(6)-arene ring during initial C-H bond activation of 2-phenylpyridine. Along with the experimental mass-spectral evidence, density functional theory calculation also supports the formation of such species for these complexes. Subsequently, these cycloruthenated products activate aryl chloride by facile oxidative addition to generate C-H arylated products.

  10. Synthesis, Spectral Characterization, and Antibacterial and Antifungal Studies of PANI/V2O5 Nanocomposites

    Directory of Open Access Journals (Sweden)

    Chakradhar Sridhar

    2016-01-01

    Full Text Available The present study deals with the synthesis and characterization of nanocrystalline vanadium pentoxide (V2O5 nanoparticles and their antibacterial and antifungal activity on Staphylococcus aureus and Aspergillus niger, respectively, by agar diffusion method. The metal oxide has been synthesized by employing the sol-gel method, polyaniline (PANI has been synthesized by chemical oxidation, and PANI/V2O5 composites have been synthesized by in situ polymerization method with different ratios (10, 20, 30, 40, and 50 weight% of V2O5 in PANI. The newly prepared composites were characterized by FTIR and powder X-ray diffraction (P-XRD techniques and are found to be formed of PANI/V2O5 nanocomposites, and also the compounds showed moderate antibacterial and antifungal activity.

  11. Opuntia ficus indica peel derived pectin mediated hydroxyapatite nanoparticles: Synthesis, spectral characterization, biological and antimicrobial activities

    Science.gov (United States)

    Gopi, D.; Kanimozhi, K.; Kavitha, L.

    2015-04-01

    In the present study, we have adapted a facile and efficient green route for the synthesis of HAP nanoparticles using pectin as a template which was extracted from the peel of prickly pear (Opuntia ficus indica) fruits. The concentration of pectin plays a major role in the behavior of crystallinity, purity, morphology as well as biological property of the as-synthesized HAP nanoparticles. The extracted pectin and the as-synthesized nanoparticles were characterized by various analytical techniques. The in vitro apatite formation on the surface of the as-synthesized nanoparticles in simulated body fluid (SBF) for various days showed an enhanced bioactivity. Also, the antimicrobial activity was investigated using various microorganisms. All the results revealed the formation of pure, low crystalline and discrete granular like HAP nanoparticles of size around 25 nm with enhanced biological and antimicrobial activities. Hence the as-synthesized nanoparticles can act as a better bone regenerating material in the field of biomedicine.

  12. New chiral phosphinephosphinite ligands: Application to stereoselective synthesis of a key intermediate of 1{beta}-methyl carbapenems by Rh(I)-catalyzed asymmetric hydroformylation

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Takao; Yoshida, Akifumi; Matsumura, Kazuhiko [Takasago International Corp., Kanagawa (Japan)] [and others

    1995-12-31

    Transition metal catalyzed asymmetric hydroformylation is an attractive and highly useful homologation process for organic synthesis. Recently, the authors reported that the Rh(I) complexes of phosphinephosphite BINAPHOS are highly efficient catalysts for enantioselective hydroformylation of a variety of olefins. This time, the authors have designed and synthesized new chiral phosphinephosphinite ligands having binaphthyl backbone, (R)-2-diarylphosphino-2{prime}-diarylphosphinoxy-1,1{prime}-binaphthy1 (hereafter abbreviated (R)-BIPNITE). The Rh(I) complexes of these ligands are effective catalysts for the asymmetric hydroformylation of 4-vinylazetidin-2-one to give the corresponding oxo-aldehyde 3{beta} as the major product in very high diastereoselectivities and in good regioselectivities. Interestingly, modifications of the aryl substituents in phosphine and phosphinite moieties afforded higher selectivities. Aldehyde 3{beta} was easily oxidized with NaClO{sub 2} to 4, a key intermediate of 1{beta}-methyl carbapenems. Thus, the present method provides a new practical route to a versatile key intermediate for the synthesis of carbapenem antibiotics.

  13. Synthesis and structural studies of 1,4-di(2-pyridyl)-1,2,3-triazole and its transition metal complexes; a versatile and subtly unsymmetric ligand.

    Science.gov (United States)

    McCarney, Eoin P; Hawes, Chris S; Blasco, Salvador; Gunnlaugsson, Thorfinnur

    2016-06-21

    The synthesis of the 'click' derived 1,4-di(2-pyridyl)-1,2,3-triazole () chelator/ligand from 2-azidopyridine and 2-ethynylpyridine using Cu(i) and TBTA by microwave assisted synthesis is presented. The complexes of the subtly unsymmetric ligand with Cu(i), Pt(ii), Co(ii), and Ag(i) were structurally characterised by using conventional methods, as well as using single crystal and powder diffraction analysis. The results of the studies showed formation of discrete molecules displaying preferential binding of the d-metal cations through the pyridyl nitrogen N1 and the proximal triazolyl nitrogen N2 i.e. the 2-(1H-1,2,3-triazol-4-yl)pyridine or 'regular' chelate moiety despite the presence of a second potential binding pocket i.e. the 2-(1H-1,2,3-triazol-1-yl)pyridine chelate or 'inverse' moiety. This binding selectivity was corroborated through the study of the self-assembly of with Cu(i) and Ag(i) using (1)H NMR titration in CD3CN solution, as well as using UV-Vis absorption titrations; the former showing a broadening of the proton peaks associated with that chelate pocket.

  14. One-pot synthesis of four-coordinate boron(III) complexes by the ligand-promoted organic group migration between boronic acids.

    Science.gov (United States)

    Sadu, Venkata S; Bin, Hye-Rin; Lee, Do-Min; Lee, Kee-In

    2017-03-21

    Multidisciplinary applications of four-coordinate boron(III) complexes make them very attractive and challenging research field in chemistry, biology and material sciences. The dual role played by boron atom in stabilising the chelate ligand and enhancing the π-conjugation makes them very useful as luminescent materials for organic electronics and photonics, and sensing and imaging probes for biomedical purposes. The conventional methods involve the use of diarylborinic acids or anhydrides and triaryl boranes, which are made from organometallic reagents. The strong nucleophilicity of these reagents limits the peripheral modifications onto the boron cores. Here, we report a metal-free one-pot synthesis of four-coordinate organoborons using boronic acids, which represents the first instance of ligand assisted organic group migration between boronic acids. A tetrahedral boron 'ate' complex capable of transferring an organic group to the adjacent sp(2) boron within a boronic anhydride intermediate is proposed and preliminary mechanistic studies by MALDI-TOF and (11)B NMR support this proposal. The products are available from a series of N,O-, N,N- and O,O-bidentate ligands upon a wide array of boronic acids. We anticipate that this reaction will impact the way of producing the four-coordinate organoborons, and propel a new discovery of such materials for optoelectronic and biomedical applications.

  15. Coordination mode of pentadentate ligand derivative of 5-amino-1,3,4-thiadiazole-2-thiol with nickel(II) and copper(II) metal ions: synthesis, spectroscopic characterization, molecular modeling and fungicidal study.

    Science.gov (United States)

    Chandra, Sulekh; Gautam, Seema; Kumar, Amit; Madan, Molly

    2015-02-01

    Complexes of nickel(II), and copper(II) were synthesized with pantadentate ligand i.e. 3,3'-thiodipropionicacid-bis(5-amino-1,3,4-thiadiazole-2-thiol) (L). The ligand was synthesized by the condensation of thiodipropionic acid and 5-amino-1,3,4-thiadiazole-2-thiol in 1:2 ratio, respectively. Synthesized ligand was characterized by elemental analysis, mass, (1)H NMR, IR, and molecular modeling. All the complexes were characterized by elemental analysis, molar conductance, magnetic moment, IR, electronic spectra, ESR, and molecular modeling. The newly synthesized complexes possessed general composition [M(L)X2] where M = Ni(II), Cu(II), L = pantadentate ligand and X = Cl(-), CH3COO(-). The IR spectral data indicated that the ligand behaved as a pantadentate ligand and coordinated to the metal ion through N2S3 donor atoms. The molar conductance value of Ni(II), and Cu(II) complexes in DMSO corresponded to their electrolytic behavior. On the basis of spectral study, octahedral and tetragonal geometry was assigned for Ni(II) and Cu(II) complexes, respectively. In vitro fungicidal study of ligand and its complexes was investigated against fungi Candida albicans, Candida parapsilosis, Candidia krusei, and Candida tropicalis by means of well diffusion method.

  16. Five Years of Synthesis of Solar Spectral Irradiance from SDID/SISA and SDO/AIA Images

    Science.gov (United States)

    Fontenla, J. M.; Codrescu, M.; Fedrizzi, M.; Fuller-Rowell, T.; Hill, F.; Landi, E.; Woods, T.

    2017-01-01

    In this paper we describe the synthetic solar spectral irradiance (SSI) calculated from 2010 to 2015 using data from the Atmospheric Imaging Assembly (AIA) instrument, on board the Solar Dynamics Observatory spacecraft. We used the algorithms for solar disk image decomposition (SDID) and the spectral irradiance synthesis algorithm (SISA) that we had developed over several years. The SDID algorithm decomposes the images of the solar disk into areas occupied by nine types of chromospheric and 5 types of coronal physical structures. With this decomposition and a set of pre-computed angle-dependent spectra for each of the features, the SISA algorithm is used to calculate the SSI. We discuss the application of the basic SDID/SISA algorithm to a subset of the AIA images and the observed variation occurring in the 2010–2015 period of the relative areas of the solar disk covered by the various solar surface features. Our results consist of the SSI and total solar irradiance variations over the 2010–2015 period. The SSI results include soft X-ray, ultraviolet, visible, infrared, and far-infrared observations and can be used for studies of the solar radiative forcing of the Earth’s atmosphere. These SSI estimates were used to drive a thermosphere–ionosphere physical simulation model. Predictions of neutral mass density at low Earth orbit altitudes in the thermosphere and peak plasma densities at mid-latitudes are in reasonable agreement with the observations. The correlation between the simulation results and the observations was consistently better when fluxes computed by SDID/SISA procedures were used.

  17. Structural, spectral and biological studies of binuclear tetradentate metal complexes of N 3O Schiff base ligand synthesized from 4,6-diacetylresorcinol and diethylenetriamine

    Science.gov (United States)

    Emara, Adel A. A.

    2010-09-01

    The binuclear Schiff base, H 2L, ligand was synthesized by reaction of 4,6-diacetylresorcinol with diethylenetriamine in the molar ratio 1:2. The coordination behavior of the H 2L towards Cu(II), Ni(II), Co(II), Zn(II), Fe(III), Cr(III), VO(IV) and UO 2(VI) ions has been investigated. The elemental analyses, magnetic moments, thermal studies and IR, electronic, 1H NMR, ESR and mass spectra were used to characterize the isolated ligand and its metal complexes. The ligand acts as dibasic with two N 3O-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The bonding sites are the nitrogen atoms of the azomethine and amine groups and the oxygen atoms of the phenolic groups. The metal complexes exhibit either square planar, tetrahedral, square pyramid or octahedral structures. The Schiff base ligand and its metal complexes were tested against four pathogenic bacteria ( Staphylococcus aureus and Streptococcus pyogenes) as Gram-positive bacteria, and ( Pseudomonas fluorescens and Pseudomonas phaseolicola) as Gram-negative bacteria and two pathogenic fungi ( Fusarium oxysporum and Aspergillus fumigatus) to assess their antimicrobial properties. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

  18. Synthesis, evaluation, and comparative molecular field analysis of 1-phenyl-3-amino-1,2,3,4-tetrahydronaphthalenes as ligands for histamine H(1) receptors.

    Science.gov (United States)

    Bucholtz, E C; Brown, R L; Tropsha, A; Booth, R G; Wyrick, S D

    1999-08-12

    A series of 1-phenyl-3-amino-1,2,3,4-tetrahydronaphthalenes (1-phenyl-3-aminotetralins, PATs) previously was found to modulate tyrosine hydroxylase activity and dopamine synthesis in rodent forebrain through interaction with a binding site labeled by [(3)H]-(-)-(1R,3S)-trans-H(2)-PAT. Recently, we have discovered that PATs also bind with high affinity to the [(3)H]mepyramine-labeled H(1) receptor in rat and guinea pig brain. Here, we report the synthesis and biological evaluation of additional PAT analogues in order to identify differences in binding at these two sites. Further molecular modifications involve the pendant phenyl ring as well as quaternary amine compounds. Comparison of about 38 PAT analogues, 10 structurally diverse H(1) ligands, and several other CNS-active compounds revealed no significant differences in affinity at [(3)H]-(-)-trans-H(2)-PAT sites versus [(3)H]mepyramine-labeled H(1) receptors. These results, together with previous autoradiographic brain receptor-mapping studies that indicate similar distribution of [(3)H]-(-)-trans-H(2)-PAT sites and [(3)H]mepyramine-labeled H(1) receptors, suggest that both radioligands label the same histamine H(1) receptors in rodent brain. We also report a revision of our previous comparative molecular field analysis (CoMFA) study of the PAT ligands that yields a highly predictive model for 66 compounds with a cross-validated R(2) (q(2)) value of 0.67. This model will be useful for the prediction of high-affinity ligands at radiolabeled H(1) receptors in mammalian brain.

  19. Synthesis and characterization of divalent manganese, iron, and cobalt complexes in tripodal phenolate/N-heterocyclic carbene ligand environments.

    Science.gov (United States)

    Käß, Martina; Hohenberger, Johannes; Adelhardt, Mario; Zolnhofer, Eva M; Mossin, Susanne; Heinemann, Frank W; Sutter, Jörg; Meyer, Karsten

    2014-03-03

    Two novel tripodal ligands, (BIMPN(Mes,Ad,Me))(-) and (MIMPN(Mes,Ad,Me))(2-), combining two types of donor atoms, namely, NHC and phenolate donors, were synthesized to complete the series of N-anchored ligands, ranging from chelating species with tris(carbene) to tris(phenolate) chelating arms. The complete ligand series offers a convenient way of tuning the electronic and steric environment around the metal center, thus, allowing for control of the complex's reactivity. This series of divalent complexes of Mn, Fe, and Co was synthesized and characterized by (1)H NMR, IR, and UV/vis spectroscopy as well as by single-crystal X-ray diffraction studies. Variable-temperature SQUID magnetization measurements in the range from 2 to 300 K confirmed high-spin ground states for all divalent complexes and revealed a trend of increasing zero-field splitting |D| from Mn(II), to Fe(II), to Co(II) complexes. Zero-field (57)Fe Mössbauer spectroscopy of the Fe(II) complexes 3, 4, 8, and 11 shows isomer shifts δ that increase gradually as carbenes are substituted for phenolates in the series of ligands. From the single-crystal structure determinations of the complexes, the different steric demand of the ligands is evident. Particularly, the molecular structure of 1-in which a pyridine molecule is situated next to the Mn-Cl bond-and those of azide complexes 2, 4, and 6 demonstrate the flexibility of these mixed-ligand derivatives, which, in contrast to the corresponding symmetrical TIMEN(R) ligands, allow for side access of, e.g., organic substrates, to the reactive metal center.

  20. Mononuclear Ru(III) Schiff base complexes: Synthesis, spectral, redox, catalytic and biological activity studies

    Science.gov (United States)

    Priya, N. Padma; Arunachalam, S.; Manimaran, A.; Muthupriya, D.; Jayabalakrishnan, C.

    2009-04-01

    An octahedral ruthenium(III) Schiff base complexes of the type [RuX(EPh 3)(L)] (where, X = Cl/Br; E = As/P; L = dianion of the Schiff bases derived from acetoacetanilide with o-phenylenediamine and salicylaldehyde/ o-hydroxyacetophenone/ o-vanillin/2-hydroxy-1-naphthaldehyde) have been synthesized from the reactions of equimolar reactions of [RuX 3(EPh 3) 3] and Schiff bases in benzene. The new Ru(III) Schiff base complexes have been characterized by elemental analyses, FT-IR, electronic, 1H NMR and 13C NMR spectra, EPR spectral studies, powder X-ray diffraction (XRD) and electrochemical studies. The new complexes were found to be effective catalysts for aryl-aryl coupling and the oxidation of alcohols into their corresponding carbonyl compounds, respectively, using molecular oxygen atmosphere at ambient temperature. Further, the new Ru(III) Schiff base complexes were screened for their antibacterial activity against Pseudomonas aeruginosa, Vibrio cholera, Salomonella typhi and Staphylococcus aureaus.