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Sample records for bidentate schiff base

  1. Nonlinear Optical Properties of Novel Mono-O-Hydroxy Bidentate Schiff Base: Quantum Chemical Calculations

    OpenAIRE

    N. S. Labidi

    2013-01-01

    The semiempirical AM1 SCF method is used to study the first static hyperpolarizabilities β of some novel mono-O-Hydroxy bidentate Schiff base in which electron donating (D) and electron accepting (A) groups were introduced on either side of the Schiff base ring system. Geometries of all molecules were optimized at the semiempirical AM1. The first static hyperpolarizabilities of these molecules were calculated using Hyperchem package. To understand this phenomenon in the context of molecular o...

  2. Nonlinear Optical Properties of Novel Mono-O-Hydroxy Bidentate Schiff Base: Quantum Chemical Calculations

    Directory of Open Access Journals (Sweden)

    N. S. Labidi

    2013-01-01

    Full Text Available The semiempirical AM1 SCF method is used to study the first static hyperpolarizabilities β of some novel mono-O-Hydroxy bidentate Schiff base in which electron donating (D and electron accepting (A groups were introduced on either side of the Schiff base ring system. Geometries of all molecules were optimized at the semiempirical AM1. The first static hyperpolarizabilities of these molecules were calculated using Hyperchem package. To understand this phenomenon in the context of molecular orbital picture, we examined the molecular HOMO and molecular LUMO generated via Hyperchem. The study reveals that the mono-O-Hydroxy bidentate Schiff bases have large β values and hence in general may have potential applications in the development of nonlinear optical materials.

  3. Syntheses, magnetic and spectral studies on polystyrene supported coordination compounds of bidentate and tetradentate Schiff bases

    Indian Academy of Sciences (India)

    D Kumar; P K Gupta; A Syamal

    2005-05-01

    The reaction of aminomethylated polystyrene (PSCH2-NH2) and 2-hydroxyacetanilide in DMF results in the formation of polystyrene-anchored monobasic bidentate Schiff base, PSCH2-LH (I). On the other hand, the reaction of chloromethylated polystyrene (PSCH2-Cl), 3-formylsalicylic acid, ethylenediamine and acetylacetone in DMF in presence of ethyl acetate (EA) and triethylamine (TEA) produces another polystyrene-anchored dibasic tetradentate Schiff base, PSCH2-L'H2 (II). Both I and II react with a number of di-, tri- and hexavalent metal ions like Co, Ni, Cu, Zn and Cd to form polystyreneanchored coordination compounds, and these have been characterized and discussed.

  4. Ruthenium(II) complexes containing bidentate Schiff bases and triphenylphosphine or triphenylarsine

    Indian Academy of Sciences (India)

    P Viswanathamurthi; R Karvembu; V Tharaneeswaran; K Natarajan

    2005-05-01

    Reactions of ruthenium(II) complexes [RuHX(CO)(EPh3)2(B)] (X = H or Cl; B = EPh3, pyridine (py) or piperidine (pip); E = P or As) with bidentate Schiff base ligands derived by condensing - hydroxyacetophenone with aniline, - or -methylaniline have been carried out. The products were characterized by analytical, IR, electronic and 1H-NMR spectral studies and are formulated as [Ru(X)(CO) (L)(EPh3)(B)] (L = Schiff base anion; X = H or Cl; B = EPh3, py or pip; E = P or As). An octahedral structure has been tentatively proposed for the new complexes. The new complexes were tested for their catalytic activities in the oxidation of benzyl alcohol to benzaldehyde.

  5. Mesogenic copper(II) complexes with [1,2,3]-triazole-based bidentate Schiff bases

    Indian Academy of Sciences (India)

    Guan-Yeow Yeap; Boon-Teck Heng

    2014-01-01

    The first mesogenic Cu(II) complex with [1,2,3]-triazole-based bidentate Schiff bases with flexible terminal alkyl chain, CnH2n+1 (even parity of n = 10-18) has been successfully synthesized. The heterocyclic triazole core was introduced into the target compound through the click reaction between azidoalkane and propargyl aldehyde. All the uncoordinated ligands and target complexes were characterized by elemental analysis, FT-IR, 1H-NMR and UV-visible spectroscopic techniques. The observation under the polarized light and differential scanning calometry (DSC) shows that the triazole-based ligands exhibit unstable SmA phase which are not reproducible upon subsequent heating and cooling. Interestingly, the whole homologues of Cu(II) complexes show exclusively stable focal conic fan-shaped texture characteristic of SmA phase. This can be ascribed to the presence of Cu-N and Cu-O coordination modes which enhance the collinearity and molecular anisotropy. On the other hand, the Cu(II) complexes are thermally more stable as compared to their corresponding ligands.

  6. Synthesis, characterization, biological and electrochemical evaluation of novel ether based ON donor bidentate Schiff bases

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Ismail, Hammad; Mirza, Bushra; McKee, Vickie; Bolte, Michael

    2016-07-01

    Four novel ON donor Schiff bases (E)-2-((4-phenoxyphenylimino)methyl)phenol (HL1), (E)-2-((4-(4-biphenyloxy)phenylimino)methyl)phenol(HL2), (E)-2-((4-(naphthalen-1-yloxy) phenylimino)methyl)phenol(HL3)and(E)-2-((4-(2-naphthoxy)phenylimino)methyl)phenol (HL4)have been synthesized and characterized by various spectroscopic, analytical and electro-analytical techniques. Single crystal X-ray diffraction analysis of Schiff base (HL3) revealed that phenol and anthracene rings are inclined at 30.25(9)° and 89.64(4)° to the central phenyl ring, respectively. Intra and inter molecular interactions are observed in single crystal analysis of HL3 Intramolecular interactions are hydrogen bonding but most of the intermolecular interactions are of the C-H … π type. There is a bit of π … π stacking between the anthracene groups. Only compounds (HL1) and (HL3) have been investigated for the biological activities due to slight solubility of (HL2) and (HL4) in DMSO. The results of brine shrimp cytotoxicity assay indicated LD50 values IC50 values 14.20 and 4.54 μg/ml respectively. The compounds were highly active in protecting DNA against hydroxyl free radicals in concentration dependent manner. Voltammetric results indicated that one electron irreversible oxidation product is formed due to hydroxyl moiety and the process is diffusion controlled. On exposing to DNA environment the electrooxidised product developed electrostatic linkage and groove binding intercalation while consuming the DNA concentration substantially. The binding strength was quantitative in terms of drug-DNA binding of the order of 104 M-1.

  7. Synthesis, structural characterization, catalytic, thermal and electrochemical investigations of bidentate Schiff base ligand and its metal complexes.

    Science.gov (United States)

    Dolaz, Mustafa; McKee, Vickie; Uruş, Serhan; Demir, Necmettin; Sabik, Ali E; Gölcü, Ayşegül; Tümer, Mehmet

    2010-07-01

    In this study, we prepared the Schiff base ligand (L) and its Cu(II), Co(II) and Ni(II) complexes. The compounds were characterized by the analytical and spectroscopic methods. The ligand (L) behaves as a bidentate ligand and coordinates to the metal ions via the nitrogen atoms. The complexes have the mononuclear structures. The analytical and spectroscopic results indicated that the chloride ions coordinate to the metal ions. The complexes have the general formulae [M(L)(Cl)(2)] (M: Cu(II), Co(II) and Ni(II) metal ions). Electrochemical properties were investigated as ligand and metal centres in the different solvents and at the scan rates, respectively. The thermal properties of the metal complexes were studied in the N(2) atmosphere. We investigated the improved catalytic activity of the Cu(II), Co(II) and Ni(II) complexes on the cyclohexane as a substrate. Obtained data showed that the best catalyst is the Cu(II) complex. The single crystal of the ligand (L) was obtained from CH(3)CN solution. There is a C-H...N H-bond linking the molecules into chains (C6)...N(2) 3.4415(18)A under symmetry operation (x+1,y,z) as well as pi-pi stacking on the outside of the "V" shape--nothing on the inside.

  8. Eco-friendly and Efficient Synthesis, Characterisation and Antibacterial Studies of Unsymmetrical Bidentate Schiff Bases and their Zn(II Complexes

    Directory of Open Access Journals (Sweden)

    K. P.Srivastava

    2014-09-01

    Full Text Available A rapid, efficient, clean and environmentally benign exclusive synthesis of Schiff bases as new ligands and their complexes with Zn(II have been developed using condensation of pyridoxalwith amoxicillin (L1, cephalexin (L2, sulphamethoxazole (L3 and trimethoprim (L4 efficiently in analcoholic suspension medium using alkali catalyst with excellent yields under microwaves irradiation. This method provides several advantages such as environmental friendliness, simple work-up procedure, short reaction times, non-hazardous and excellent yield of products.The results are compared with conventional methods for their yield and reaction time. The Schiff base ligands and the complexes were characterized by micro-analytical, thermo-gravimetric, magnetic and spectroscopic studies.All the Schiff bases were bidentate (NO donor ligands. All complexes were found to be six co-ordinate dihydrates and ML2[1:2 (metal: ligand ratio] type. The complexes are coloured and stable in air. All the complexes under investigation possess antibacterial activity. The antibacterial activity showed the following trend:

  9. Synthesis, spectroscopic characterisation, DNA cleavage, superoxidase dismutase activity and antibacterial properties of some transition metal complexes of a novel bidentate Schiff base derived from isatin and 2-aminopyrimidine

    Science.gov (United States)

    Nitha, L. P.; Aswathy, R.; Mathews, Niecy Elsa; Sindhu kumari, B.; Mohanan, K.

    2014-01-01

    Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a Schiff base, formed by the condensation of isatin with 2-aminopyrimidine have been synthesised and characterised through elemental analysis, molar conductance measurements, magnetic susceptibility, IR, UV-Vis, 1HNMR, FAB mass and EPR spectral studies. The spectral data revealed that the ligand acts as neutral bidentate, coordinating to the metal ion through the carbonyl oxygen and azomethine nitrogen. Molar conductance values adequately support the electrolytic nature of the complexes. On the basis of the above observations the complexes have been formulated as [M(ISAP)2]X2, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X = Cl, OAc; ISAP = 2-[N-indole-2-one]aminopyrimidine. The ligand and copper(II) complex were subjected to X-ray diffraction studies. The DNA cleavage study was monitored by gel electrophoresis method. The superoxide dismutase (SOD) mimetic activities of the ligand and the metal complexes were checked using NBT assay. The in vitro antibacterial activity of the synthesized compounds has been tested against gram negative and gram positive bacteria.

  10. Synthesis, spectroscopic characterisation, DNA cleavage, superoxidase dismutase activity and antibacterial properties of some transition metal complexes of a novel bidentate Schiff base derived from isatin and 2-aminopyrimidine.

    Science.gov (United States)

    Nitha, L P; Aswathy, R; Mathews, Niecy Elsa; Kumari, B Sindhu; Mohanan, K

    2014-01-24

    Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a Schiff base, formed by the condensation of isatin with 2-aminopyrimidine have been synthesised and characterised through elemental analysis, molar conductance measurements, magnetic susceptibility, IR, UV-Vis, (1)HNMR, FAB mass and EPR spectral studies. The spectral data revealed that the ligand acts as neutral bidentate, coordinating to the metal ion through the carbonyl oxygen and azomethine nitrogen. Molar conductance values adequately support the electrolytic nature of the complexes. On the basis of the above observations the complexes have been formulated as [M(ISAP)2]X2, where M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X=Cl, OAc; ISAP=2-[N-indole-2-one]aminopyrimidine. The ligand and copper(II) complex were subjected to X-ray diffraction studies. The DNA cleavage study was monitored by gel electrophoresis method. The superoxide dismutase (SOD) mimetic activities of the ligand and the metal complexes were checked using NBT assay. The in vitro antibacterial activity of the synthesized compounds has been tested against gram negative and gram positive bacteria.

  11. Synthesis, Thermal, Electrical and Catalytic Studies of Some Transition Metal Polychelates of Bis-bidentate Schiff Base

    Institute of Scientific and Technical Information of China (English)

    BANSOD Ashish; ASWAR Anand

    2007-01-01

    Polychelates of Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ), Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ) and Cd(Ⅱ) with the bis salen-type ligand derivedfrom 4,4'-bis[(salicylaldehyde-5)azo]biphenyl and 1,4-diaminobutane have been synthesized.All the polychelates have been characterized by elemental analysis,magnetic susceptibility measurements,IR,electronic spectra and thermogravimetric studies.All the complexes isolated in solid state are dark coloured and insoluble in water and common organic solvents.The ligand behaves as a bis-bidentate molecule coordinating through the phenolic oxygen and azomethine nitrogen atoms.The thermal decomposition of these metal complexes was investigated by thermogravimetric analysis and data have been analyzed for kinetic parameters using Broido equation.The solid-state electrical conductivity of the ligand and its polychelates in the form of compressed pellet was studied in the temperature range from 313 to 413 K.All the polychelates were found to show semiconducting nature.The Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ) and Ni(Ⅱ) polychelates have been assessed for the catalytic epoxidation of styrene.

  12. 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.

  13. Synthesis, spectral, thermal, fluorescence, antimicrobial, anthelmintic and DNA cleavage studies of mononuclear metal chelates of bi-dentate 2H-chromene-2-one Schiff base.

    Science.gov (United States)

    Prabhakara, Chetan T; Patil, Sangamesh A; Kulkarni, Ajaykumar D; Naik, Vinod H; Manjunatha, M; Kinnal, Shivshankar M; Badami, Prema S

    2015-07-01

    The Co(II), Ni(II) and Cu(II) complexes have been synthesized with Schiff base (HL), derived from 8-formyl-7-hydroxy-4-methylcoumarin with benzylamine. The Schiff base and its metal complexes were structurally characterized based on IR, (1)H NMR, (13)C NMR, UV-visible, ESR, magnetic, thermal, fluorescence, mass and ESI-MS studies. The complexes are completely soluble in DMF and DMSO. The molar conductance values indicate that, all synthesized metal complexes are non-electrolytic in nature. Elemental analysis reveals [ML2(H2O)2] stoichiometry, here MCo(II), Ni(II) and Cu(II), L=deprotonated ligand. The coordination between metal ion and Schiff base was supported by IR data, through deprotonation of phenolic oxygen of coumarin and azomethine nitrogen atoms. Solution electronic spectral results unveiled that all the synthesized complexes posses six coordinated geometry around metal ion. Thermal studies suggest the presence of coordinated water molecules. The Schiff base and its metal complexes have been screened for their antibacterial (Escherichia coli, Pseudomonas aureginosa, Klebsiella pneumoniae and Staphylococcus aureus) and antifungal (Penicillium chrysogenum and Aspergillus niger), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activities.

  14. Synthesis, characterization and biological approach of metal chelates of some first row transition metal ions with halogenated bidentate coumarin Schiff bases containing N and O donor atoms.

    Science.gov (United States)

    Prabhakara, Chetan T; Patil, Sangamesh A; Toragalmath, Shivakumar S; Kinnal, Shivashankar M; Badami, Prema S

    2016-04-01

    The impregnation of halogen atoms in a molecule is an emerging trend in pharmaceutical chemistry. The presence of halogens (Cl, Br, I and F) increases the lipophilic nature of molecule and improves the penetration of lipid membrane. The presence of electronegative halogen atoms increases the bio- activity of core moiety. In the present study, Co(II), Ni(II) and Cu(II) complexes are synthesised using Schiff bases (HL(I) and HL(II)), derived from 8-formyl-7-hydroxy-4-methylcoumarin/3-chloro-8-formyl-7-hydroxy-4-methylcoumarin with 2,4-difluoroaniline/o-toluidine respectively. The synthesized compounds were characterized by spectral (IR, NMR, UV-visible, Mass, ESI-MS, ESR), thermal, fluorescence and molar conductivity studies. All the synthesized metal complexes are completely soluble in DMF and DMSO. The non-electrolytic nature of the metal complexes was confirmed by molar conductance studies. Elemental analysis study suggest [ML2(H2O)2] stoichiometry, here M=Co(II), Ni(II) and Cu(II), L=deprotonated ligand. The obtained IR data supports the binding of metal ion to Schiff base. Thermal study suggests the presence of coordinated water molecules. Electronic spectral results reveal six coordinated geometry for the synthesized metal complexes. The Schiff bases and their metal complexes were evaluated for antibacterial (Pseudomonas aureginosa and Proteus mirabilis), antifungal (Aspergillus niger and Rhizopus oryzae), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activities.

  15. Imidazolidine ring as a reduced heterocyclic spacer in a new all-N-donor -bis(bidentate) Schiff base ligand: Synthesis, characterization and electron transfer properties of imidazolidine-bridged dicopper complexes

    Indian Academy of Sciences (India)

    Manindranath Bera; Prasant Kumar Nanda; Uday Mukhopadhyay; Debashis Ray

    2004-03-01

    Low-temperature stoichiometric Schiff base reaction in air in 3 : 1 mole ratio between benzaldehyde and triethylenetetramine (trien) in methanol yields a novel tetraaza m-bis(bidentate) acyclic ligand L. It was characterized by elemental analysis, IR, EI mass and NMR (1H and 13C) spectra. The formation of a five-membered imidazolidine ring from the ethylenediamine backbone as a spacer-cumbridging unit gives rise to a new type of imidazolidine-bridged ligand. A geometric optimisation was made of the synthesized ligand and its complexes by the method of molecular mechanics (MM2) method in order to establish the stable conformations. This hitherto unknown tetraaza acyclic ligand affords new cationic dicopper(I/I) and dicopper(II/II) complexes in good yield. Dicopper(II/II) complex displays weak - transition bands in the visible region, while dicopper(I/I) complex displays strong MLCT band in the same region. Both the dinuclear complexes are of non-intimate nature and show interesting solution electrochemical behaviour. EPR spectral study of -bis(imidazolidino) bridged dicopper(II/II) complex also supports the non-communicative nature of the two copper centres within the same molecule.

  16. Theoretical and experimental studies of Cu(II) and Zn(II) coordination compounds with N,O donor bidentate Schiff base ligand containing amino phenol moiety

    Science.gov (United States)

    Kusmariya, Brajendra S.; Tiwari, Anjali; Mishra, A. P.; Naikoo, Gowhar Ahmad

    2016-09-01

    We report here two mononuclear Cu(II) and Zn(II) coordination compounds of general formula [CuII(L)2].2H2O (1) and [ZnII(L)2].3H2O (2) derived from bidentate 2-chloro-6-{[(4-hydroxy-3-methoxyphenyl)methylidene]amino}-4 nitrophenol ligand (HL). These compounds were synthesized and characterized by elemental analysis, FT-IR, uv-vis, 1H NMR, molar conductance, thermal, PXRD, SEM-EDX and electrochemical studies. The PXRD and SEM analysis shows the amorphous/nanocrystalline nature of 1 and crystalline nature of 2. The diffraction peak broadening was explained in terms of domain size and the crystallite lattice strain. Thermogravimetric analysis in the range of 300-1172 K has been performed to determine the thermal stability of synthesized compounds. The non-isothermal kinetic parameters of degradation process were calculated using Coats-Redfern (C-R), Piloyan-Novikova (P-N) and Horowitz-Metzger (H-M) methods assuming first order degradation and proposed a random nucleation mechanism of thermal decomposition for both compounds. The cyclic voltammetric studies reveal the irreversibility of the oxidation/reduction process of synthesized compounds. To support the experimental findings theoretical calculations by means of DFT and TD-DFT at B3LYP level were incorporated. In addition; frequency calculations, HOMO-LUMO, energy gap (ΔE), molecular electrostatic potential (MEP), spin density and crystal packing were also computed at the same level of theory.

  17. Tuning the cytotoxic properties of new ruthenium(III) and ruthenium(II) complexes with a modified bis(arylimino)pyridine Schiff base ligand using bidentate pyridine-based ligands.

    Science.gov (United States)

    Garza-Ortiz, Ariadna; Maheswari, Palanisamy Uma; Lutz, Martin; Siegler, Maxime A; Reedijk, Jan

    2014-06-01

    Synthesis, spectroscopy, characterization, structures, and cytotoxicity studies of 2,6-bis(2,6-diisopropylphenyliminomethyl)pyridine (LLL) ruthenium compounds are described. The starting compound [RuCl3(LLL)] has been fully characterized using IR spectroscopy, UV-vis spectroscopy, electrospray ionization mass spectrometry, and NMR spectroscopy. In addition, the crystal structure of the ligand LLL has been determined using single-crystal X-ray diffraction. With the ruthenium(III) trichloride compound as starting material, a new family of Ru(II) complexes with a number of neutral and charged bidentate co-ligands have been synthesized and used for characterization and cytotoxicity studies. The synthesis of the corresponding [Ru(II)LLL(LL)Cl](+/0) complexes with co-ligands- LL is 1,10-phenanthroline, 2,2'-bipyridyl, 2-(phenylazo)pyridine, 2-(phenylazo)-3-methylpyridine, 2-(tolylazo)pyridine, or the anionic 2-picolinate-is reported. Analytical, spectroscopic (IR spectroscopy, UV-vis spectroscopy, (1)H NMR spectroscopy, and electrospray ionization mass spectrometry), and structural characterization of the new compounds is described. Crystal structure analyses of two Ru(II) compounds show a slightly distorted octahedral Ru(II) geometry with tridentate LLL coordinated in a planar meridional fashion, and the chelating co-ligand (LL) and a chloride ion complete the octahedron. The co-ligand plays a significant role in modulating the physicochemical and cytotoxic properties of these new ruthenium complexes. The in vitro cytotoxicity of these new Ru(II) complexes (half-maximal inhibitory concentration, IC50, of 0.5-1.5 μM), in comparison with the parent Ru(III) compound (half-maximal inhibitory concentration of 3.9-4.3 μM) is higher for several of the human cancer cell lines tested. The cytotoxic activity of some of the new ruthenium compounds is even higher than that of cisplatin in the same cancer cell lines. The cytotoxicity of these new anticancer compounds is

  18. Synthesis and Structural Studies of Transition Metal Complexes with Bidentate Schiff Base Derived from 3-Acetyl-6-methyl-(2H-pyran-2,4(3H-dione

    Directory of Open Access Journals (Sweden)

    Praveen S. Mane

    2011-01-01

    Full Text Available The solid complexes of Cu(II, Ni(II, Co(II, Mn(II and Fe(III with Schiff base ligands derived from heterocyclic compounds 3-acetyl-6-methyl-(2H-pyran-2,4(3H-dione (Dehydroacetic acid and o-chloroaniline were synthesized and characterized by elemental analysis, conductance, magnetic, thermal, UV-Vis and 1H-NMR spectroscopy. The ligand field parameters have been evaluated for Cu(II, Ni(II, Co(II, Mn(II and Fe(III complexes which suggest an octahedral geometry for each of them. The magnetic moment and spectral data suggest the dimeric nature of Mn(II complexes with octahedral geometry. The fungicidal activities of the ligands and their metal complexes have been screened in vitro against Aspergillus niger and the percentage inhibition of the metal complexes is found to be increased considerably then that of their corresponding ligands and the order is Cu>Ni>Fe>Mn>Co.

  19. Schiff Bases: A Versatile Pharmacophore

    Directory of Open Access Journals (Sweden)

    Anu Kajal

    2013-01-01

    Full Text Available Schiff bases are condensation products of primary amines with carbonyl compounds gaining importance day by day in present scenario. Schiff bases are the compounds carrying imine or azomethine (–C=N– functional group and are found to be a versatile pharmacophore for design and development of various bioactive lead compounds. Schiff bases exhibit useful biological activities such anti-inflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic, antiglycation, and antidepressant activities. Schiff bases are also used as catalysts, pigments and dyes, intermediates in organic synthesis, polymer stabilizers, and corrosion inhibitors. The present review summarizes information on the diverse biological activities and also highlights the recently synthesized numerous Schiff bases as potential bioactive core.

  20. Olefin Metathesis Mediated By: - Schiff Base Ru-Alkylidenes -Ru-Alkylidenes Bearing Unsymmetrical NH Ligands

    Science.gov (United States)

    Monsaert, Stijn; Voort, Pascal Van Der; Ledoux, Nele; Allaert, Bart; Drozdzak, Renata; Verpoort, Francis

    The classic Grubbs second-generation complex 2 was modified through 1. The introduction of a bidentate Schiff base ligand 2. Changes in the amino side groups of the NHC ligand Representative olefin metathesis test reactions show the effects induced by the ligand modifications and demonstrate some interesting new properties of the described catalysts. catalysts.

  1. Progress of Chiral Schiff Bases with C1 Symmetry in Metal-Catalyzed Asymmetric Reactions.

    Science.gov (United States)

    Hayashi, Masahiko

    2016-12-01

    In this Personal Account, various chiral Schiff base-metal-catalyzed enantioselective organic reactions are reported; the Schiff bases used were O,N,O- as well as N,N,P-tridentate ligands and N,N-bidentate ligands having C1 symmetry. In particular, the enantioselective addition of trimethylsilyl cyanide, dialkylzinc, and organozinc halides to aldehydes, enantioselective 1,4-addition of dialkylzinc to cyclic and acyclic enones, and asymmetric allylic oxidation are reported. Typically, ketimine-type Schiff base-metal complexes exhibited higher reactivity and enantioselectivity compared with the corresponding aldimine-type Schiff base-metal complexes. Notably, remarkable ligand acceleration was observed for all reactions. The obtained products can be used as key intermediates for optically active natural products and pharmaceuticals.

  2. Asymmetric Schiff bases derived from diaminomaleonitrile and their metal complexes

    Science.gov (United States)

    Yang, Jianjie; Shi, Rufei; Zhou, Pei; Qiu, Qiming; Li, Hui

    2016-02-01

    Asymmetric Schiff bases, due to its asymmetric structure, can be used as asymmetric catalyst, antibacterial, and mimic molecules during simulate biological processes, etc. In recent years, research on synthesis and properties of asymmetric Schiff bases have become an increase interest of chemists. This review summarizes asymmetric Schiff bases derived from diaminomaleonitrile (DAMN) and DAMN-based asymmetric Schiff bases metal complexes. Applications of DAMN-based asymmetric Schiff bases are also discussed in this review.

  3. Syntheses,Structure Analyses and Thermal Stabilities of Two Schiff Base Metal Complexes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yinli; CHEN Sanping; FAN Guang; ZHAO Zhijie; GAO Shengli

    2009-01-01

    A Schiff base ligand 1-salicylideneamino-l,3,4-triazole(L)was prepared.Two new complexes with Schiff base,takes a mononuclear zinc structure and the coordination geometry of zinc atom exhibits a distorted tetrahedron,in which a zig-zag chain is constructed through hydrogen bonding interactions.A 2D supramolecular network is formed through π-π stacking between triazole planes and phenyl planes of adjacent chains,and a 3D supramolecular network is further constructed by these non-covalent π-π stacking interactions between the triazole planes of neighboring layers.Complex 2 takes a dinuclear structure with the bidentate-bridging Schiff base ligands,and cobalt site exhibits a distorted octahedron.The lattice water molecules and neutral complex 2 units form a dimer with hydrogen bonding interactions.In addition,IR and thermal gravimetric analysis are presented.

  4. Reaction of Nitrosonium (NO+) with Schiff Bases

    Institute of Scientific and Technical Information of China (English)

    Yu Lu ZHOU; Cong De HUO; Shu MIAO; Long Min WU

    2004-01-01

    The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.

  5. Cu(II) complexes of an ionic liquid-based Schiff base [1-{2-(2-hydroxy benzylidene amino) ethyl}-3-methyl­imidazolium]Pf6: Synthesis, characterization and biological activities

    OpenAIRE

    Saha Sanjoy; Brahman Dhiraj; Sinha Biswajit

    2015-01-01

    Two Cu(II) complexes of an ionic liquid based Schiff base 1-{2-(2-hydroxybenzylideneamino) ethyl}-3-methylimidazolium hexaflurophosphate, were prepared and characterized by different analytical and spectroscopic methods such as elemental analysis, magnetic susceptibility, UV-Vis, IR, NMR and mass spectroscopy. The Schiff base ligand was found to act as a potential bidentate chelating ligand with N, O donor sites and formed 1:2 metal chelates with Cu(II) sal...

  6. Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

    OpenAIRE

    Mauro Panunzio; Stefano Biondi; Wenling Qin; Sha Long

    2013-01-01

    The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their “metallo-imines” variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as “privileged” ligands in the organometallic complexes and as biological active Schiff intermed...

  7. Metal-Based Biologically Active Compounds: Synthesis, Spectral, and Antimicrobial Studies of Cobalt, Nickel, Copper, and Zinc Complexes of Triazole-Derived Schiff Bases

    Directory of Open Access Journals (Sweden)

    Kiran Singh

    2011-01-01

    Full Text Available A series of cobalt, nickel, copper, and zinc complexes of bidentate Schiff bases derived from the condensation reaction of 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazole with 2,4-dichlorobenzaldehyde were synthesized and tested as antimicrobial agents. The synthesized Schiff bases and their metal complexes were characterized with the aid of elemental analyses, magnetic moment measurements, spectroscopic and thermogravimetric techniques. The presence of coordinated water in metal complexes was supported by infrared and thermal gravimetric studies. A square planar geometry was suggested for Cu(II and octahedral geometry proposed for Co(II, Ni(II, and Zn(II complexes. The Schiff bases and their metal complexes have been screened for antibacterial (Pseudomonas aeruginosa, Bacillus subtilis and antifungal activities (Aspergillus niger, A. flavus. The metal complexes exhibited significantly enhanced antibacterial and antifungal activity as compared to their simple Schiff bases.

  8. Some Transition Metal Complexes of NO Type Schiff Base: Preparation and Characterization

    Directory of Open Access Journals (Sweden)

    Erdal CANPOLAT

    2016-04-01

    Full Text Available Metal complexes of Schiff base ligand (5-bromo-3-methoxysalicyliden-p-iminoacetophenone oxime derived from 5-bromo-3-methoxsalicylaldehyde and p-aminoacetophenoneoxime is reported. Schiff base was found to be bidentate ligand involving the imino nitrogen and carboxyl oxygen atoms in the complexes. Metal to ligand ratio were found to be 1:2 for all of the complexes. Co(II, Ni(II, and Zn(II complexes have been found tetrahedral geometry and Cu(II complex has been found four coordinated geometry. The complexes are found to have the formulae [M(L2]. The compounds obtained have been characterized by their elemental analyses, IR, 1H-NMR, 13C-NMR, UV spectra, magnetic susceptibility and thermogravimetric analyses (TGA.

  9. Synthetic, Structural, and Biochemical Studies of Organotin(IV With Schiff Bases Having Nitrogen and Sulphur Donor Ligands

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Three bidentate Schiff bases having nitrogen and sulphur donor sequences were prepared by condensing S-benzyldithiocarbazate ( NH 2 NHCS 2 CH 2 C 6 H 5 with heterocyclic aldehydes. The reaction of diphenyltin dichloride with Schiff bases leads to the formation of a new series of organotin(IV complexes. An attempt has been made to prove their structures on the basis of elemental analyses, conductance measurements, molecular weights determinations, UV, infrared, and multinuclear magnetic resonance ( H 1 , C 13 , and S 119 n spectral studies. Organotin(IV complexes were five- and six-coordinate. Schiff bases and their corresponding organotin complexes have also been screened for their antibacterial and antifungal activities and found to be quite active in this respect.

  10. Syntheses, characterizations and structures of NO donor Schiff base ligands and nickel(II) and copper(II) complexes

    Science.gov (United States)

    Şenol, Cemal; Hayvali, Zeliha; Dal, Hakan; Hökelek, Tuncer

    2011-06-01

    New Schiff base derivatives ( L 1 and L 2) were prepared by the condensation of 2-hydroxy-3-methoxybenzaldehyde ( o-vanillin) and 3-hydroxy-4-methoxybenzaldehyde ( iso-vanillin) with 5-methylfurfurylamine. Two new complexes [Ni(L 1) 2] and [Cu(L 1) 2] have been synthesized with bidentate NO donor Schiff base ligand ( L 1). The Ni(II) and Cu(II) atoms in each complex are four coordinated in a square planar geometry. Schiff bases ( L 1 and L 2) and complexes [Ni(L 1) 2] and [Cu(L 1) 2] were characterized by elemental analyses, FT-IR, UV-vis, mass and 1H, 13C NMR spectroscopies. The crystal structures of the ligand ( L 2) and complexes [Ni(L 1) 2] and [Cu(L 1) 2] have also been determined by using X-ray crystallographic technique.

  11. Synthesis and characterization of new azo containing Schiff base macrocycle

    Institute of Scientific and Technical Information of China (English)

    Saeed Malek-Ahmadi; Amir Abdolmaleki

    2011-01-01

    Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition, a one-pot cyclization procedure of four-component without using a template. The condensation reaction of related bis (hydroxybenzaldehyde) with phenylenediamines to prepare a conjugated [2 + 2] Schiff base macrocycle has been investigated and fluorescent [2 + 2] Schiff base macrocycles with N2O2 binding pockets has been prepared and characterized by elemental analysis,' H NMR, IR, fluorescent, UV-visible and MALDI mass spectroscopies.

  12. Synthesis and characterization of Schiff's bases of sulfamethoxazole

    OpenAIRE

    Hussain, Zainab; Yousif, Emad; Ahmed, Ahmed; Altaie, Ali

    2014-01-01

    Background Schiff's bases are excellent ligands which are synthesized from the condensation of primary amines with carbonyl groups. Findings The classical reaction for the synthesis of Schiff's bases in an ethanolic solution and glacial acetic acid as a catalyst was followed in the synthesis of substituted sulfamethoxazole compounds. Conclusions Some Schiff's bases containing sulfamethoxazole nucleus have been synthesized and characterized. The present compounds are hoped to be applied in the...

  13. Schiff bases: A short review of their antimicrobial activities

    Directory of Open Access Journals (Sweden)

    Cleiton M. da Silva

    2011-01-01

    Full Text Available Schiff bases are aldehyde- or ketone-like compounds in which the carbonyl group is replaced by an imine or azomethine group. They are widely used for industrial purposes and also exhibit a broad range of biological activities. This short review compiles examples of the most promising antimalarial, antibacterial, antifungal, and antiviral Schiff bases. An overview of synthetic methodologies used for the preparation of Schiff bases is also described.

  14. Synthesis of Chiral Metal Complexes of Unsymmetrical Schiff Bases

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Recently, in asymmetric catalyst research the great developments of chiral Salen complexes have been made, but the report on unsymmetrical schiff bases is deficient. The unsymmetrical schiff bases complexes are an effective system in catalytically selective Olefin-epoxidations1. At the same time, unsymmetrical schiff bases was immobilized onto polymer supports for heterogenization2. The potential benefits of the catalyst include facilitation of catalyst separation from reagents, simplification of methods for catalyst recycle, and the possible adaptation of the immobilized catalyst to continuous-flow processes. A series of new unsymmetrical schiff bases was synthesized to study the relations between unsymmetry and enantioselectivity and select better catalyst. The following is the route:

  15. Schiff bases: a short survey on an evergreen chemistry tool.

    Science.gov (United States)

    Qin, Wenling; Long, Sha; Panunzio, Mauro; Biondi, Stefano

    2013-10-08

    The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their "metallo-imines" variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as "privileged" ligands in the organometallic complexes and as biological active Schiff intermediates/targets have been reported as well.

  16. Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

    Directory of Open Access Journals (Sweden)

    Mauro Panunzio

    2013-10-01

    Full Text Available The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their “metallo-imines” variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as “privileged” ligands in the organometallic complexes and as biological active Schiff intermediates/targets have been reported as well.

  17. 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.

  18. Synthesis, characterization, and biological evaluation of Schiff base-platinum(II) complexes.

    Science.gov (United States)

    Shiju, C; Arish, D; Bhuvanesh, N; Kumaresan, S

    2015-06-15

    The platinum complexes of Schiff base ligands derived from 4-aminoantipyrine and a few substituted aldehydes were synthesized and characterized by elemental analysis, mass, (1)H NMR, IR, electronic spectra, molar conductance, and powder XRD. The structure of one of the ligands L5 was confirmed by a single crystal XRD analysis. The Schiff base ligand crystallized in the triclinic, space group P-1 with a=7.032(2)Ǻ, b=9.479(3)Ǻ, c=12.425(4)Ǻ, α=101.636(3)°, β=99.633(3)°, γ=94.040(3)°, V=795.0(4)Ǻ(3), Z=2, F(000)=352, Dc=1.405 mg/m(3), μ=0.099 mm(-1), R=0.0378, and wR=0.0967. The spectral results show that the Schiff base ligand acts as a bidentate donor coordinating through the azomethine nitrogen and the carbonyl oxygen atoms. The geometrical structures of these complexes are found to be square planar. Antimicrobial studies indicate that these complexes exhibit better activity than the ligand. The anticancer activities of the complexes have also been studied towards human cervical cancer cell line (HeLa), Colon Cancer Cells (HCT116) and Epidermoid Carcinoma Cells (A431) and it was found that the [Pt(L3)Cl2] complex is more active.

  19. Synthesis and Spectroscopic Studies of New Schiff Bases

    OpenAIRE

    Weaver, W.; Saeed Ahmad; Amjid Iqbal; Hamid Latif Siddiqui

    2006-01-01

    Five novel Schiff bases have been prepared from o-formylphenoxyacetic acidand a series of aminothiazoles to form a number of potentially biologically activecompounds. The structures of these Schiff bases have been characterized using IR and 1H-and 13C-NMR spectroscopy.

  20. Anion recognition by simple chromogenic and chromo-fluorogenic salicylidene Schiff base or reduced-Schiff base receptors.

    Science.gov (United States)

    Dalapati, Sasanka; Jana, Sankar; Guchhait, Nikhil

    2014-08-14

    This review contains extensive application of anion sensing ability of salicylidene type Schiff bases and their reduced forms having various substituents with respect to phenolic OH group. Some of these molecular systems behave as receptor for recognition or sensing of various anions in organic or aqueous-organic binary solvent mixture as well as in the solid supported test kits. Development of Schiff base or reduced Schiff base receptors for anion recognition event is commonly based on the theory of hydrogen bonding interaction or deprotonation of phenolic -OH group. The process of charge transfer (CT) or inhibition of excited proton transfer (ESIPT) or followed by photo-induced electron transfer (PET) lead to naked-eye color change, UV-vis spectral change, chemical shift in the NMR spectra and fluorescence spectral modifications. In this review we have tried to discuss about the anion sensing properties of Schiff base or reduced Schiff base receptors.

  1. Anion recognition by simple chromogenic and chromo-fluorogenic salicylidene Schiff base or reduced-Schiff base receptors

    Science.gov (United States)

    Dalapati, Sasanka; Jana, Sankar; Guchhait, Nikhil

    2014-08-01

    This review contains extensive application of anion sensing ability of salicylidene type Schiff bases and their reduced forms having various substituents with respect to phenolic sbnd OH group. Some of these molecular systems behave as receptor for recognition or sensing of various anions in organic or aqueous-organic binary solvent mixture as well as in the solid supported test kits. Development of Schiff base or reduced Schiff base receptors for anion recognition event is commonly based on the theory of hydrogen bonding interaction or deprotonation of phenolic -OH group. The process of charge transfer (CT) or inhibition of excited proton transfer (ESIPT) or followed by photo-induced electron transfer (PET) lead to naked-eye color change, UV-vis spectral change, chemical shift in the NMR spectra and fluorescence spectral modifications. In this review we have tried to discuss about the anion sensing properties of Schiff base or reduced Schiff base receptors.

  2. Synthesis, Characterization and Antimicrobial Activity of Oxovanadium(IV) Complexes of Schiff Base Hydrazones Containing Quinoxaline Moiety

    Institute of Scientific and Technical Information of China (English)

    Lakshmi, P. V. Anantha; Satyanarayana, T.; Reddy, P. Saritha

    2012-01-01

    The oxovanadium(IV) complexes of the Schiff base hydrazones, synthesized from 3-hydrazinoquinoxaline-2- one (HQO) with salicylaldehyde (HSHQO), o-hydroxyacetophenone (HHAHQO), dehydroacetic acid (HDHAHQO) and o-nitrobenzaldehyde (NBHQO) were synthesized and characterized on the basis of analytical, conductance, magnetic moment, infrared, NMR, ESR and electronic spectral data. The ligands HSHQO, HDHAHQO behaved as monobasic tridentate ONN donors through phenolic oxygen, azomethine nitrogens. The ligand HAHQO acted as a monobasic bidentate ON donor through the phenolic oxygen, azomethine (free) nitrogen and the ligand NBHQO acted as neutral bidentate ON donor through oxygen of the nitro group and azomethine (free) nitrogen.

  3. Anomeric and tautomeric equilibria in D-2-glucosamine Schiff bases

    Science.gov (United States)

    Kołodziej, B.; Grech, E.; Schilf, W.; Kamieński, B.; Makowski, M.; Rozwadowski, Z.; Dziembowska, T.

    2007-11-01

    The structure of some glucosamine Schiff bases has been studied by means of ab initio RHF and DFT calculation and CP/MAS 13C and 15N NMR measurements. The anomeric and tautomeric equilibria in a DMSO solution have been studied by 1H, 13C and 15N NMR spectroscopy. The anomeric composition of D-2-glucosamine Schiff bases in the solid state and in DMSO solution has been shown to depends on the tautomeric form of Schiff bases and electronic properties of substituents on the aromatic ring.

  4. 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.

  5. Antibacterial and antifungal metal based triazole Schiff bases.

    Science.gov (United States)

    Chohan, Zahid H; Hanif, Muhammad

    2013-10-01

    A new series of four biologically active triazole derived Schiff base ligands (L(1)-L(4)) and their cobalt(II), nickel(II), copper(II) and zinc(II) complexes (1-16) have been synthesized and characterized. The ligands were prepared by the condensation reaction of 3-amino-5-methylthio-1H-1,2,4-triazole with chloro-, bromo- and nitro-substituted 2-hydroxybenzaldehyde in an equimolar ratio. The antibacterial and antifungal bioactivity data showed the metal(II) complexes to be more potent antibacterial and antifungal than the parent Schiff bases against one or more bacterial and fungal species.

  6. Phenoxyacetohydrazide Schiff Bases: β-Glucuronidase Inhibitors

    OpenAIRE

    Waqas Jamil; Shagufta Perveen; Syed Adnan Ali Shah; Muhammad Taha; Nor Hadiani Ismail; Shahnaz Perveen; Nida Ambreen; Khan, Khalid M.; Choudhary, Muhammad I.

    2014-01-01

    Phenoxyacetohydrazide Schiff base analogs 1–28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50 = 9.20 ± 0.32 µM), 5 (IC50 = 9.47 ± 0.16 µM), 7 (IC50 = 14.7 ± 0.19 µM), 8 (IC50 = 15.4 ± 1.56 µM), 11 (IC50 = 19.6 ± 0.62 µM), 12 (IC50 = 30.7 ± 1.49 µM), 15 (IC50 = 12.0 ± 0.16 µM), 21 (IC50 = 13.7 ± 0.40 µM) and 22 (IC50 = 22.0 ± 0.14 µM) showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1...

  7. Cu(II complexes of an ionic liquid-based Schiff base [1-{2-(2-hydroxy benzylidene amino ethyl}-3-methyl­imidazolium]Pf6: Synthesis, characterization and biological activities

    Directory of Open Access Journals (Sweden)

    Saha Sanjoy

    2015-01-01

    Full Text Available Two Cu(II complexes of an ionic liquid based Schiff base 1-{2-(2-hydroxybenzylideneamino ethyl}-3-methylimidazolium hexaflurophosphate, were prepared and characterized by different analytical and spectroscopic methods such as elemental analysis, magnetic susceptibility, UV-Vis, IR, NMR and mass spectroscopy. The Schiff base ligand was found to act as a potential bidentate chelating ligand with N, O donor sites and formed 1:2 metal chelates with Cu(II salts. The synthesized Cu(II complexes were tested for biological activity.

  8. Bidentate coordinating behaviour of chalcone based ligands towards oxocations: VO(IV) and Mo(V)

    Science.gov (United States)

    Thaker, B. T.; Barvalia, R. S.

    2013-08-01

    We synthesized and studied the coordinating behaviour of chalcone based ligands derived from DHA and n-alkoxy benzaldehyde and their complexes of VO(IV) and MoO(V). The chalcone ligands are characterized by elemental analyses, UV-visible, IR, 1H NMR, and mass spectra. The resulting oxocation complexes are also characterized by elemental analyses, IR, 1H NMR, electronic, electron spin resonance spectra, magnetic susceptibility measurement and molar conductance studies. The IR and 1H NMR spectral data suggest that the chalcone ligands behave as a monobasic bidentate with O:O donor sequence towards metal ion. The molar conductivity data show them to be non-electrolytes. From the electronic, magnetic and ESR spectral data suggest that all the chalcone ligand complexes of VO(IV) and MoO(V) have distorted octahedral geometry.

  9. Synthesis of Chiral Metal Complexes of Unsymmetrical Schiff Bases

    Institute of Scientific and Technical Information of China (English)

    SONG; Bo

    2001-01-01

    Recently, in asymmetric catalyst research the great developments of chiral Salen complexes have been made, but the report on unsymmetrical schiff bases is deficient. The unsymmetrical schiff bases complexes are an effective system in catalytically selective Olefin-epoxidations1. At the same time, unsymmetrical schiff bases was immobilized onto polymer supports for heterogenization2. The potential benefits of the catalyst include facilitation of catalyst separation from reagents, simplification of methods for catalyst recycle, and the possible adaptation of the immobilized catalyst to continuous-flow processes. A series of new unsymmetrical schiff bases was synthesized to study the relations between unsymmetry and enantioselectivity and select better catalyst. The following is the route:  ……

  10. Synthetic Lubricating Oil Greases Containing Metal Chelates of Schiff Bases

    Science.gov (United States)

    1992-09-15

    greases comprising the addition to said greases of effective amounts of a chelated Schiff base derived from the condensation of approximately stoichiometic amounts of at least one aldehyde and a polyamine.

  11. Syntheses and Structural Studies of Schiff Bases Involving Hydrogen Bonds

    OpenAIRE

    José Elguero; Rosa M. Claramunt; Dionisia Sanz; Almudena Perona

    2006-01-01

    New Schiff bases have been prepared by reacting 3-hydroxy-4-pyridine- carboxaldehyde with various amines. NMR spectroscopic methods provided clear evidence that the Schiff bases exist in the solid state and in solution as hydroxyimino tautomers with the E-configuration. A study of the stabilities of the tautomeric forms and the different conformers has been carried out using density functional calculations at the B3LYP/6-31G** level. © 2006 by MDPI.

  12. Acidichromism in the LB film of bolaform Schiff base

    Institute of Scientific and Technical Information of China (English)

    Mei Fang Yin; Ti Feng Jiao; Ming Hua Liu

    2007-01-01

    A bolaform (BNC10) and single-headed (HNOA) amphiphilic Schiff bases containing naphthyl group were designed and their Langmuir-Blodgett films were investigated. It was found that both the LB films show acidichromism, i.e. a reversible color change upon alternatively exposing the films to HCl and NH3 gases, respectively. It was further found that the bolaform Schiff bases film could trap NH3 gas during the acidichromic process.

  13. Spectrophotometric and spectrofluorimetric studies of novel heterocyclic Schiff base dyes

    OpenAIRE

    2014-01-01

    Novel heterocyclic Schiff base dyes were prepared by the reaction of salicylaldehyde/2-Hydroxy-1-naphthaldehyde with different heterocyclic amines. Results of the newly synthesized compounds established by FT-IR, 1H-NMR, 13C-NMR and GC–MS spectroscopic experiments were consistent with their chemical structures. Resulted heterocyclic Schiff base dyes were found to be pure from data obtained by the elemental analysis. In addition, spectrophotometric and spectrofluorimetric studies showed that t...

  14. Synthesis, Electrochemical, Spectroscopic, Antimicrobial, and Superoxide Dismutase Activity of Nickel (II Complexes with Bidentate Schiff Bases

    Directory of Open Access Journals (Sweden)

    R. N. Patel

    2013-01-01

    Full Text Available Five new nickel (II complexes, namely, [Ni(L12](ClO42(1; [Ni(L22](ClO42(2; [Ni(L32](ClO42(3; [Ni(L42](ClO42(4; [Ni(L52](ClO42(5, where L1 = benzoylhydrazide; L2 = N-[(1-1-(2-methylphenylethylidene]benzohydrazide; L3=N-[(1-1-(4-methylphenylethylidene]benzohydrazide; L4=N-[(1-1-(2-methoxyphenylethylidene]benzohydrazide; L5 = N-[(1-1-(4-methoxy-phenylethylidene]benzohydrazide, have been synthesized and characterized by various physicochemical and spectroscopic techniques. The synthesized complexes are stable powders, insoluble in common organic solvents such as ethanol, benzene, carbon tetrachloride, chloroform, and diethyl ether, and are nonelectrolytes. The magnetic and spectroscopic data indicate a distorted square planar geometry for all complexes. The superoxide dismutase activity of these complexes has been measured and discussed. Antibacterial and antifungal properties of these complexes were also tested.

  15. Phenoxyacetohydrazide Schiff Bases: β-Glucuronidase Inhibitors

    Directory of Open Access Journals (Sweden)

    Waqas Jamil

    2014-06-01

    Full Text Available Phenoxyacetohydrazide Schiff base analogs 1–28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50 = 9.20 ± 0.32 µM, 5 (IC50 = 9.47 ± 0.16 µM, 7 (IC50 = 14.7 ± 0.19 µM, 8 (IC50 = 15.4 ± 1.56 µM, 11 (IC50 = 19.6 ± 0.62 µM, 12 (IC50 = 30.7 ± 1.49 µM, 15 (IC50 = 12.0 ± 0.16 µM, 21 (IC50 = 13.7 ± 0.40 µM and 22 (IC50 = 22.0 ± 0.14 µM showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1,4-lactone, IC50 = 48.4 ± 1.25 µM.

  16. Metal based biologically active compounds: design, synthesis, and antibacterial/antifungal/cytotoxic properties of triazole-derived Schiff bases and their oxovanadium(IV) complexes.

    Science.gov (United States)

    Chohan, Zahid H; Sumrra, Sajjad H; Youssoufi, Moulay H; Hadda, Taibi B

    2010-07-01

    A new series of oxovanadium(IV) complexes have been designed and synthesized with a new class of triazole Schiff bases derived from the reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde and acetyl pyridine-2-carboxaldehyde, respectively. Physical (magnetic susceptibility, molar conductance), spectral (IR, (1)H NMR, (13)C NMR, mass and electronic) and analytical data have established the structures of these synthesized Schiff bases and their oxovanadium(IV) complexes. The Schiff bases, predominantly act as bidentate and coordinate with the vanadium(IV) metal to give a stoichiometric ratio of 1:2 [M:L], forming a general formulae, [M(L-H)(2)] and [M(L)(2)]SO(4) where L = (L(1))-(L(4)) and M = VO(IV) of these complexes in a square-pyramidal geometry. In order to evaluate the biological activity of Schiff bases and to assess the role of vanadium(IV) metal on biological activity, the triazole Schiff bases and their oxovanadium(IV) complexes have been studied for in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexenari, Pseudomonas aeruginosa, Salmonella typhi) and two Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacterial strains, in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glaberata. The simple Schiff bases showed weaker to significant activity against one or more bacterial and fungal strains. In most of the cases higher activity was exhibited upon coordination with vanadium(IV) metal. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina.

  17. Physicochemical Studies of Some Schiff Bases Derived From 6-Ethylbenzene 1,3-diol

    OpenAIRE

    Shipra Baluja

    2004-01-01

    The schiff bases were synthesized and their characterization was done by CHN analysis, IR and NMR spectra. The physicochemical properties such as density, refractive index, conductance, heat of solution etc., of these schiff bases were determined

  18. Physicochemical Studies of Some Schiff Bases Derived From 6-Ethylbenzene 1,3-diol

    Directory of Open Access Journals (Sweden)

    Shipra Baluja

    2004-01-01

    Full Text Available The schiff bases were synthesized and their characterization was done by CHN analysis, IR and NMR spectra. The physicochemical properties such as density, refractive index, conductance, heat of solution etc., of these schiff bases were determined

  19. Spectrophotometric and spectrofluorimetric studies of novel heterocyclic Schiff base dyes

    Directory of Open Access Journals (Sweden)

    Hadi M. Marwani

    2014-11-01

    Full Text Available Novel heterocyclic Schiff base dyes were prepared by the reaction of salicylaldehyde/2-Hydroxy-1-naphthaldehyde with different heterocyclic amines. Results of the newly synthesized compounds established by FT-IR, 1H-NMR, 13C-NMR and GC–MS spectroscopic experiments were consistent with their chemical structures. Resulted heterocyclic Schiff base dyes were found to be pure from data obtained by the elemental analysis. In addition, spectrophotometric and spectrofluorimetric studies showed that these dyes were good absorbent and fluorescent. Fluorescence polarity study data revealed that some of these compounds were sensitive to the polarity of the microenvironment provided by different solvents. Time-based fluorescence steady-state measurements also showed that these heterocyclic Schiff base dyes have high photostability against photobleaching.

  20. Synthesis, characterization, crystal structure determination and catalytic activity in epoxidation reaction of two new oxidovanadium(IV) Schiff base complexes

    Science.gov (United States)

    Tahmasebi, Vida; Grivani, Gholamhossein; Bruno, Giuseppe

    2016-11-01

    The five coordinated vanadium(IV) Schiff base complexes of VOL1 (1) and VOL2 (2), HL1 = 2-{(E)-[2-bromoethyl)imino]methyl}-2- naphthol, HL2 = 2-{(E)-[2-chloroethyl)imino]methyl}-2- naphthol, have been synthesized and they were characterized by using single-crystal X-ray crystallography, elemental analysis (CHN) and FT-IR spectroscopy. Crystal structure determination of these complexes shows that the Schiff base ligands (L1 and L2) act as bidentate ligands with two phenolato oxygen atoms and two imine nitrogen atoms in the trans geometry. The coordination geometry around the vanadium(IV) is distorted square pyramidal in which vanadium(IV) is coordinated by two nitrogen and two oxygen atoms of two independent ligands in the basal plane and by one oxygen atom in the apical position. The catalytic activity of the Schiff base complexes of 1 and 2 in the epoxidation of alkenes were investigated using different reaction parameters such as solvent effect, oxidant, alkene/oxidant ratio and the catalyst amount. The results showed that in the presence of TBHP as oxidant in 1: 4 and 1:3 ratio of the cyclooctene/oxidant ratio, high epoxide yield was obtained for 1 (76%) and 2 (80%) with TON(= mole of substrate/mole of catalyst) of 27 and 28.5, respectively, in epoxidation of cyclooctene.

  1. Synthesis, characterization and biological activity of ferrocene-based Schiff base ligands and their metal (II) complexes

    Science.gov (United States)

    Liu, Yu-Ting; Lian, Gui-Dan; Yin, Da-Wei; Su, Bao-Jun

    Metal (II) complexes derived from S-benzyl-N-(1-ferrocenyl-3-(4-methylbenzene)acrylketone) dithiocarbazate; HL1, S-benzyl-N-(1-ferrocenyl-3-(4-chlorobenzene)acrylketone)dithiocarbazate; HL2, all the compounds were characterized using various spectroscopic techniques. The molar conductance data revealed that the chelates were non-electrolytes. IR spectra showed that the Schiff bases were coordinated to the metal ions in a bidentate manner with N, S donor sites. The ligands and their metal complexes have been screened for in vitro antibacterial, antifungal properties. The result of these studies have revealed that zinc (II) complexes 6 and 13 of both the ligands and copper (II) complexes 9 of the HL2 were observed to be the most active against all bacterial strains, antifungal activity was overall enhanced after complexation of the ligands.

  2. Synthesis and Purification of Porphyrin-Schiff Base Using Ethyl Vanillin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel porphyrin-Schiff base was synthesized via the condensation of 5-(4-aminophenyl)-10,15,20-triphenylporphyrin and ethyl vanillin. After analyzing the level of purification of the porphyrin-Schiff base, it was successfully separated. This porphyrin-Schiff base was characterized by using UV-Vis, IR, 1 H NMR and MS spectroscopy.

  3. Synthesis of Schiff Base Calix[4]arene Crowns

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This letter reports the synthesis of Schiff base calix[4]arene crowns containing m-xylylene phenol subunit, in which calix[4]arene Schiff base crowns 2a, 2b and 2c were formed by 1:1 condensation of calix[4]arene diamine 1 with dialdehydes (2, 6-diformyl-4-chlorophenol 3a, 2, 6-diformyl-4-methylphenol 3b, 2, 6-diformyl-4-tert-butylphenol 3c) under high dilute condition in refluxing anhydrous ethanol in 65-70% yield.

  4. Synthesis and characterization of the polyaniline dopant Schiff base

    Directory of Open Access Journals (Sweden)

    Mirian Y. Matsumoto

    2012-06-01

    Full Text Available The Schiff base, N-salicilidenoanilina was used as dopant to induce polymerization of aniline and thus preparing polyaniline (PAni. The different conditions of preparation, including Schiff base structure, and the dosage of acidity reaction medium, were investigated to discuss the influence of these conditions relative conductivity of the resulting samples. The products were also characterized by Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis, electrochemical impedance spectroscopy (EIE. The results showed the synthesis conditions play an important in the formation and the final properties of the polyaniline

  5. Schiff base functionalized Organopropylsilatranes: Synthesis and structural characterization

    Indian Academy of Sciences (India)

    Gurjaspreet Singh; Promila; Amandeep Saroa; Jandeep Singh; Raj Pal Sharm; V Ferretti

    2016-02-01

    Synthesis of Schiff bases linked to organopropylsilatranes were performed by condensation reaction of post-functionalized silatranes such as aminopropylsilatrane (4), aminopropyl-3,7,10-trimethylsilatrane (5) and N-substituted aminopropylsilatrane (10) with two different aldehydes viz. pyrrole-2-carboxaldehyde and 2-hydroxy-1-napthaldehyde. The resulting Schiff base substituted silatranes were well characterized by elemental analysis, spectroscopic studies [IR, (1H, 13C) NMR, and MS]. The structures of two silatranes were confirmed by single crystal X-ray diffraction analysis.

  6. Synthèse, caractérisation et bioactivité de ligands issus de bases de Schiff dérivées de dithiocarbazate et de leurs complexes métalliques

    OpenAIRE

    Low, May Lee

    2014-01-01

    There is an urgent need to discover new drugs with novel mechanisms of action, higher activity and improved selectivity to address the severe challenge of multidrug resistance in treating bacterial infections and cancer. In view of this, Schiff bases derived from S-substituted dithiocarbazate and their corresponding metal complexes with a plethora of potentially exciting biological activities and coordination chemistry are attractive candidates. Metal complexes of tetradentate NNSS and bident...

  7. Synthesis, Thermochromic Properties and Thermal Behavior of some Schiff Bases. Part I. p, p'-Diaminodiphenylmethane-Schiff Bases and Sulphonamide Schiff Base

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    p, p'-Diaminodiphenylmethane-Schiff bases (SB) of general formula (R)-phCH=N- ph-CH2-ph-N=CHph(R), where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, and sul- phonamide Schiff bases (SB) of general formula (R)-phCH=N-ph-SO2NH2, where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, were synthesized and their structure have been characterized by the melting pointing, 1HNMR, MS, and elemental analysis. They are thermolabile and undergo thermo-chromism and thermal decomposition after melting. The TG. and DSC measurement were recorded in dynamic air and interpreted.

  8. Microwave synthesis, spectral, thermal and antimicrobial studies of some Ni(II and Cu(II Schiff base complexes

    Directory of Open Access Journals (Sweden)

    A P Mishra

    2012-05-01

    Full Text Available Bidentate and tridentate (NO, (ONO Schiff bases have been synthesized by condensing methyl isobutyl ketone with 2-amino-4-chlorophenol and 2-hydroxy acetophenone with isonicotinic acid hydrazide. The 1:1 or 1:2 metal complexes have been prepared by interacting these Schiff bases with metal ions viz. Ni(II, Cu(II. These compounds have been synthesized by conventional as well as microwave methods and characterized by elemental analysis, FT-IR, UV-Vis, ESR, molar conductance, thermal analysis and X-ray diffraction. The complexes are colored and stable in air at room temperature. 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. Crystal data of [Ni(HINH(H2O]Cl.3H2O complex a = b =13.9338Ǻ, c = 34.7975Ǻ, V = 6755.96Ǻ3, Z = 12, Dobs = 1.2421g/cm3, Dcal 1.2847g/cm3, reflect that this complex has crystallized in orthorhombic system. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff bases and metal complexes show 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 are better antimicrobial agents as compared to the Schiff bases.

  9. Mössbauer investigation of novel pentadentate schiff base complexes

    Science.gov (United States)

    Heyer, L.; Dreyer, B.; Preiss, A.; Menze, M.; Klimke, S.; Jahns, M.; Sindelar, R.; Klingelhöfer, G.; O. Costa, B. F.; Renz, F.

    2016-12-01

    We synthesised a series of seven mononuclear and two trinuclear Schiff base coordination compounds. All nine complexes have been analysed by Mössbauer and IR spectroscopy. The Mössbauer spectra reveal a doublet, which are related to the high spin state (S = 5/2) of the iron(III) centres.

  10. Synthesis and Crystal Structures of Schiff Bases Bearing Ferrocenylphenyl Groups

    Institute of Scientific and Technical Information of China (English)

    Yan XU; Yong FU; Mao Ping SONG; Yang Jie WU

    2005-01-01

    The Schiff bases bearing ferrocenylphenyl and diferrocenylphenyl groups were synthesized by the reactions of m-ferrocenylaniline with salicylaldehyde or 1, 4-bis (2'-formylphenyl)-1, 4-dioxabutane. The title compounds were characterized by elemental analysis, IR, 1H NMR and X-ray structural determination.

  11. Synthesis of novel bisindolylmethane Schiff bases and their antibacterial activity.

    Science.gov (United States)

    Imran, Syahrul; Taha, Muhammad; Ismail, Nor Hadiani; Khan, Khalid Mohammed; Naz, Farzana; Hussain, Memona; Tauseef, Saima

    2014-08-06

    In an effort to develop new antibacterial drugs, some novel bisindolylmethane derivatives containing Schiff base moieties were prepared and screened for their antibacterial activity. The synthesis of the bisindolylmethane Schiff base derivatives 3-26 was carried out in three steps. First, the nitro group of 3,3'-((4-nitrophenyl)-methylene)bis(1H-indole) (1) was reduced to give the amino substituted bisindolylmethane 2 without affecting the unsaturation of the bisindolylmethane moiety using nickel boride in situ generated. Reduction of compound 1 using various catalysts showed that combination of sodium borohydride and nickel acetate provides the highest yield for compound 2. Bisindolylmethane Schiff base derivatives were synthesized by coupling various benzaldehydes with amino substituted bisindolylmethane 2. All synthesized compounds were characterized by various spectroscopic methods. The bisindolylmethane Schiff base derivatives were evaluated against selected Gram-positive and Gram-negative bacterial strains. Derivatives having halogen and nitro substituent display weak to moderate antibacterial activity against Salmonella typhi, S. paratyphi A and S. paratyphi B.

  12. 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…

  13. Synthesis and spectroscopic properties of novel asymmetric Schiff bases.

    Science.gov (United States)

    Güngör, Ozlem; Gürkan, Perihan

    2010-09-15

    Three novel diimine Schiff bases including two asymmetric imines (2-OH)R-CHN-C(6)H(4)-CHN-R'(2-OH) type [where R=R'=phenyl for H(2)L(1); R=naphthyl, R'=phenyl for H(2)L(2) and R=R'=naphthyl for H(2)L(3)] have been synthesized with a new two step method. For this purpose, the starting Schiff bases 4-nitrobenzylidene-2-hydroxyaniline (SB(1)-NO(2)) and 4-nitrobenzylidene-2-hydroxy-3-naphthylamine (SB(2)-NO(2)) have been synthesized, previously. Nitro groups of them have been reduced into their amino derivatives (SB(1)-NH(2) and SB(2)-NH(2)) with sodium dithionite as selective reductant and the other imino groups have been formed by adding salicylaldehyde or 2-hydroxy-1-naphthaldehyde to the same solutions. The structures of the diimine Schiff bases were confirmed by elemental analyses, ESI-MS, FT-IR, (1)H NMR and (13)C NMR spectroscopy. The phenol-imine and keto-amine tautomerism of the Schiff bases were investigated by FT-IR, (1)H NMR, (13)C NMR techniques and UV-vis spectra in different solvents (DMSO, methanol, chloroform, toluene and cyclohexane). The effects of acidic and basic media on the tautomeric equilibria were discussed.

  14. Synthesis and Biological Activities of Substituted Triazolethione Schiff Base

    Institute of Scientific and Technical Information of China (English)

    SUN, Xiao-Hong; TAO, Yan; LIU, Yuan-Fa; CHEN, Bang

    2007-01-01

    Six novel Schiff bases have been synthesized by the condensation reaction of 4-amino-5-(4-pyridyl)-2,4-dihydro-1,2,4-triazole-3-thione with various benzaldehydes. The structures of the compounds have been confirmed by 1H NMR, IR and elemental analysis. The preliminary bioassay indicated that the title compounds possessed good fungicidal activities to several vegetable pathogens.

  15. A Schiff base formed from sulfanilic acid and dimethylformamide.

    Science.gov (United States)

    Hempel, A; Camerman, N; Mastropaolo, D; Camerman, A

    1999-04-15

    The crystal structure the Schiff base contains one 4-dimethylaminomethyleneaminobenzenesulfonic acid molecule in zwitterionic form [4-(dimethylaminomethyleneammonio)benzenesulfonate], and one water molecule in the asymmetric unit (C9H12N2O3S.H2O). Protonation occurs at nitrogen atom N1, but the charge is delocalized.

  16. Syntheses, characterization, biological activity and fluorescence properties of bis-(salicylaldehyde)-1,3-propylenediimine Schiff base ligand and its lanthanide complexes

    Science.gov (United States)

    Taha, Ziyad A.; Ajlouni, Abdulaziz M.; Al-Hassan, Khader A.; Hijazi, Ahmed K.; Faiq, Ari B.

    2011-10-01

    Eight new lanthanide metal complexes [Ln L(NO 3) 2]NO 3 {Ln(III) = Nd, Dy, Sm, Pr, Gd, Tb, La and Er, L = bis-(salicyladehyde)-1,3-propylenediimine Schiff base ligand} were prepared. These complexes were characterized by elemental analysis, thermogravimetric analysis (TGA), molar conductivity measurements and spectral studies ( 1H NMR, FT-IR, UV-vis, and luminescence). The Schiff base ligand coordinates to Ln(III) ion in a tetra-dentate manner through the phenolic oxygen and azomethine nitrogen atoms. The coordination number of eight is achieved by involving two bi-dentate nitrate groups in the coordination sphere. Sm, Tb and Dy complexes exhibit the characteristic luminescence emissions of the central metal ions attributed to efficient energy transfer from the ligand to the metal center. Most of the complexes exhibit antibacterial activity against a number of pathogenic bacteria.

  17. Synthesis and Characterization of New Lead(II and Organotin(IV Complexes of Schiff Bases Derived from Histidine and Methionine

    Directory of Open Access Journals (Sweden)

    Har Lal Singh

    2012-01-01

    Full Text Available New Schiff base (HL ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR. The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2 to from metal complexes (Pb(II(L2 and Bu2Sn(L2, where L is the Schiff base ligands of histidine and methionine. The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV and lead(II complexes.

  18. Synthesis, spectroscopic studies and inhibitory activity against bacteria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand.

    Science.gov (United States)

    Abou-Hussein, A A; Linert, Wolfgang

    2015-04-15

    Two series of new mono and binuclear complexes with a Schiff base ligand derived from the condensation of 3-acetylcoumarine and diethylenetriamine, in the molar ratio 2:1 have been prepared. The ligand was characterized by elemental analysis, IR, UV-visible, (1)H-NMR and mass spectra. The reaction of the Schiff base ligand with cobalt(II), nickel(II), copper(II), zinc(II) and oxovanadium(IV) lead to mono or binuclear species of cyclic or macrocyclic complexes, depending on the mole ratio of metal to ligand and as well as on the method of preparation. The Schiff base ligand behaves as a cyclic bidentate, tetradendate or pentaentadentae ligand. The formation of macrocyclic complexes depends significantly on the dimension of the internal cavity, the rigidity of the macrocycles, the nature of its donor atoms and on the complexing properties of the anion involved in the coordination. Electronic spectra and magnetic moments of the complexes indicate that the geometries of the metal centers are either square pyramidal or octahedral for acyclic or macro-cyclic complexes. The structures are consistent with the IR, UV-visible, ESR, (1)H-NMR, mass spectra as well as conductivity and magnetic moment measurements. The Schiff base ligand and its metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

  19. Synthesis, spectroscopic studies and inhibitory activity against bactria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand

    Science.gov (United States)

    Abou-Hussein, A. A.; Linert, Wolfgang

    2015-04-01

    Two series of new mono and binuclear complexes with a Schiff base ligand derived from the condensation of 3-acetylcoumarine and diethylenetriamine, in the molar ratio 2:1 have been prepared. The ligand was characterized by elemental analysis, IR, UV-visible, 1H-NMR and mass spectra. The reaction of the Schiff base ligand with cobalt(II), nickel(II), copper(II), zinc(II) and oxovanadium(IV) lead to mono or binuclear species of cyclic or macrocyclic complexes, depending on the mole ratio of metal to ligand and as well as on the method of preparation. The Schiff base ligand behaves as a cyclic bidentate, tetradendate or pentaentadentae ligand. The formation of macrocyclic complexes depends significantly on the dimension of the internal cavity, the rigidity of the macrocycles, the nature of its donor atoms and on the complexing properties of the anion involved in the coordination. Electronic spectra and magnetic moments of the complexes indicate that the geometries of the metal centers are either square pyramidal or octahedral for acyclic or macro-cyclic complexes. The structures are consistent with the IR, UV-visible, ESR, 1H-NMR, mass spectra as well as conductivity and magnetic moment measurements. The Schiff base ligand and its metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

  20. Synthesis, spectroscopic, cytotoxic aspects and computational study of N-(pyridine-2-ylmethylene)benzo[d]thiazol-2-amine Schiff base and some of its transition metal complexes

    Science.gov (United States)

    Abd El-Aziz, Dina M.; Etaiw, Safaa Eldin H.; Ali, Elham A.

    2013-09-01

    N-(pyridine-2-ylmethylene)benzo[d]thiazol-2-amine Schiff base (L) and its Cu(II), Fe(III), Co(II), Ni(II) and Zn(II) complexes were synthesized and characterized by a set of chemical and spectroscopic measurements using elemental analysis, electrical conductance, mass spectra, magnetic susceptibility and spectral techniques (IR, UV-Vis, 1H NMR). Elemental and mass spectrometric data are consistent with the proposed formula. IR spectra confirm the bidentate nature of the Schiff base ligand. The octahedral geometry around Cu(II), Fe(III), Ni(II) and Zn(II) as well as tetrahedral geometry around Co(II) were suggested by UV-Vis spectra and magnetic moment data. The thermal degradation behavior of the Schiff base and its complexes was investigated by thermogravimetric analysis. The structure of the Schiff base and its transition metal complexes was also theoretically studied using molecular mechanics (MM+). The obtained structures were minimized with a semi-empirical (PM3) method. The in vitro antitumor activity of the synthesized compounds was studied. The Zn-complex exhibits significant decrease in surviving fraction of breast carcinoma (MCF 7), liver carcinoma (HEPG2), colon carcinoma (HCT116) and larynx carcinoma (HEP2) cell lines human cancer.

  1. POLYKETONE FROM ETHYLENE WITH CARBON MONOXIDE CATALYZED BY NOVEL CATALYST SYSTEMS BASED ON COPPER WITH BIDENTATE PHOSPHORUS CHELATING LIGANDS

    Institute of Scientific and Technical Information of China (English)

    Jun Huang; Feng-bo Li; Jin Zou; Guo-qing Yuan; Xiu-li Shi; Ding-sheng Yu

    2003-01-01

    Copolymerization of ethylene with carbon monoxide was performed with Cu catalyst systems. Novel catalyst systems based on Cu (Cu(CH3COO)2/ligand/acid) were firstly reported for the copolymerization of ethylene with carbon monoxide, in which the ligand was a bidentate phosphorus chelating ligand. The experimental results showed that this kind of Cu catalyst system exhibited high activity. When DPPP (1,3-bis(diphenylphosphine)propane) and CH3COOH were used catalyst system had the advantages of high stability and low cost.

  2. Polymerization of isoprene catalyzed by neodymium heterocyclic Schiff base complex

    Institute of Scientific and Technical Information of China (English)

    Lei Zhang; Xu Feng Ni; Wei Lin Sun; Zhi Quan Shen

    2008-01-01

    Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity (ca. 95%) and high molecular weight (ca. 105) in the presence of the triisobutyl aluminium (AliBu3) as cocatalyst. The microstructure of obtained polyisoprene was investigated by FTIR, 1H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.

  3. Novel Synthesis of Ferrocenyl Schiff Bases and Crystal Structure

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Hui-Qing; ZHOU,Zhi-Ming; YU,Cong-Xuan

    2004-01-01

    @@ Ferrocenylimines have attracted additional interest due to their versatile utilities. They have been widely used as plant growth regulator, bactericide, fuel dope and new anticarcinogen.[1] And a large amount of ferrocenyl shiff bases were prepared in the past. However, study on ferrocenylimines as directing ortho metalation group (DMG) in the (-)-sparteine meditated synthesis of planar chiral ferrocene has not been reported. Herein, we synthesized a series of ferrocenyl schiff bases for this study.

  4. Synthesis and degradation of Schiff bases containing heterocyclic pharmacophore.

    Science.gov (United States)

    Ledeţi, Ionuţ; Alexa, Anda; Bercean, Vasile; Vlase, Gabriela; Vlase, Titus; Şuta, Lenuţa-Maria; Fuliaş, Adriana

    2015-01-13

    This paper reports on the synthesis and characterization of two Schiff bases bearing 1,2,4-triazolic moieties, namely 4H-4-(2-hydroxy-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole and 4H-4-(4-nitro-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole using thin layer chromatography, melting interval, elemental analysis, spectroscopy and thermal stability studies.

  5. Syntheses and Structures of Binaphthyl-bridged Schiff Bases

    Institute of Scientific and Technical Information of China (English)

    WANG Bin; LI Min-xiong; XU Shan-sheng; SONG Hai-bin; WANG Bai-quan

    2008-01-01

    The reaction ofdinaphthofuran with lithium in anhydrous diethyl ether led to a solution of the corresponding C,O-dilithiated intermediate which,upon treatment with DMF at -78 ℃,afforded,after hydrolysis,2'-hydroxy-1,1'-binaphthyl-2-carbaldehyde in a good yield.Then binaphthyl-bridged Schiff bases were prepared by the condensation of 2'-hydroxy-1,1'-binaphthyl-2-carbaldehyde with the corresponding aromatic amines.

  6. Oxidative peptide /and amide/ formation from Schiff base complexes

    Science.gov (United States)

    Strehler, B. L.; Li, M. P.; Martin, K.; Fliss, H.; Schmid, P.

    1982-01-01

    One hypothesis of the origin of pre-modern forms of life is that the original replicating molecules were specific polypeptides which acted as templates for the assembly of poly-Schiff bases complementary to the template, and that these polymers were then oxidized to peptide linkages, probably by photo-produced oxidants. A double cycle of such anti-parallel complementary replication would yield the original peptide polymer. If this model were valid, the Schiff base between an N-acyl alpha mino aldehyde and an amino acid should yield a dipeptide in aqueous solution in the presence of an appropriate oxidant. In the present study it is shown that the substituted dipeptide, N-acetyl-tyrosyl-tyrosine, is produced in high yield in aqueous solution at pH 9 through the action of H2O2 on the Schiff-base complex between N-acetyl-tyrosinal and tyrosine and that a great variety of N-acyl amino acids are formed from amino acids and aliphatic aldehydes under similar conditions.

  7. Kinetics of Schiff base on Escherichia coli by microcalorimetry

    Institute of Scientific and Technical Information of China (English)

    许名飞; 李新海; 万洪文; 刘义

    2003-01-01

    The influence of four kinds of Schiff bases on a strain of Escherichia coli was studied by microcalorimetry. Differences in their capabilities of suppressing the metabolism of this bacterium were observed. The results show that the extent and duration of the inhibitory effect on the metabolism as judged from the multiplication rate constant, k, varies with different Schiff bases.The multiplication rate constant k, of Escherichia coli (in log phase) in the presence of Mo-salicylioaldehyde-thiadizole, Mo-piperonaldehyde-thiosemicarbazone and Mo-3-methoxy-salicylicaldehyde-thiadizole decreases with the increase of concentrations of compounds c, and the relationships between k and c, maximum heat production rate Pm and c, peak time of growth curves tp and c are of linearity. For Mo-6-nitro-pieronalde-thiosemicarbazone, the multiplication rate constant is constant irrespective of variation in concentration. The sequence of antibiotic activity of Schiff base is: Mo-salicylioaldehyde-thiadizole>Mo-3-methoxy-salicylicaldehyde-thiadizole>Mo-piperonaldehyde-thiosemicarbazone> 6-nitro-pieronalde-thiosemicarbazone.

  8. Electrochemical Impedance Study of Schiff Base by Means of Self-assembled Monolayer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this work, the self-assembled monolayer of Schiff base was first investigated using electrochemical impedance spectroscopy (ELS). The complexation of Cu2+ with the Schiff base was also detected with EIS method. The approximate linear relationship between Cu2+ and the reaction resistance (Rr) was observed. All the results suggest that the electrochemical property of Schiff base could be studied conveniently by means of forming self-assembled monolayer.

  9. Synthesis and characterization of nickel complexes derived from Schiff-Bases

    OpenAIRE

    Mirian Y. Matsumoto; Keila B. Dias; Vicente L. Kupfer; Elias B. O. Filho; Larisse G. Salazar; Adalberto V. Mezacasa; Persiely P. Rosa; Nelson Luis de Campos Domingues; Andrelson W. Rinaldi

    2012-01-01

    Aromatic Schiff-Bases constitute a large class of organic compounds containing the imine group (C=N) [1-3]. 2-hydroxybenzaldehyde (salicylaldehyde) which has been frequently used for the synthesis of aromatic Schiff-Bases, it has many biological applications, such as analgesics, anti-inflammatory, antibacterial, antiviral and bactericidal activities [4-6]. From above, this project proposed the synthesis of three Schiff bases derived from salicylaldehyde prepared by condensation between salicy...

  10. 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.

  11. Synthesis, spectral, thermal and magnetic studies of Mn(II), Ni(II) and Cu(II) complexes with some benzopyran-4-one Schiff bases.

    Science.gov (United States)

    el-Ansary, Aida L; Abdel-Fattah, Hussein M; Abdel-Kader, Nora S

    2011-08-01

    The Schiff bases of N(2)O(2) dibasic ligands, H(2)La and H(2)Lb are prepared by the condensation of ethylenediamine (a) and trimethylenediamine (b) with 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one. Also tetra basic ligands, H(4)La and H(4)Lb are prepared by the condensation of aliphatic amines (a) and (b) with 6-formyl-5,7-dihydroxy-2-methylbenzopyran-4-one. New complexes of H(4)La and H(4)Lb with metal ions Mn(II), Ni(II) and Cu(II) are synthesized, in addition Mn(II) complexes with ligands H(2)La and H(2)Lb are also synthesized. Elemental and thermal analyses, infrared, ultraviolet-visible as well as conductivity and magnetic susceptibility measurements are used to elucidate the structure of the newly prepared metal complexes. The structures of copper(II) complexes are also assigned based upon ESR spectra study. All the complexes separated with the stoichiometric ratio (1:1) (M:L) except Mn-H(4)La and Mn-H(4)Lb with (2:1) (M:L) molar ratio. In metal chelates of the type 1:1 (M:L), the Schiff bases behave as a dinegative N(2)O(2) tetradentate ligands. Moreover in 2:1 (M:L) complexes, the Schiff base molecules act as mono negative bidentate ligand and binuclear complex is then formed. The Schiff bases were assayed by the disc diffusion method for antibacterial activity against Staphylococcus aureus and Escherichia coli. The antifungal activity of the Schiff bases was also evaluated against the fungi Aspergillus flavus and Candida albicans.

  12. Spectroscopic Characterization and Biological Activity of Mixed Ligand Complexes of Ni(II with 1,10-Phenanthroline and Heterocyclic Schiff Bases

    Directory of Open Access Journals (Sweden)

    Y. Prashanthi

    2012-01-01

    Full Text Available Mixed ligand complexes of Ni(II with 1,10-phenanthroline (1,10-Phen and Schiff bases L1(MIIMP; L2(CMIIMP; L3(EMIIMP; L4(MIIMNP; L5(MEMIIMP; L6(BMIIMP; L7(MMIIMP; L8(MIIBD have been synthesized. These metal chelates have been characterized by elemental analysis, IR, 1H-NMR, 13C-NMR, Mass, UV-Vis, magnetic moments, and thermogravimetric (TG&DTA analysis. Spectral data showed that the 1,10-phenanthroline act as neutral bidentate ligand coordinating to the metal ion through two nitrogen donor atoms and Schiff bases acts as monobasic bidentate coordinating through NO donor atoms. All Ni(II complexes appear to have an octahedral geometry. The antimicrobial activity of mixed ligand complexes has been studied by screening against various microorganisms, it is observed that the activity enhances upon coordination. The DNA binding studies have been investigated by UV-Vis spectroscopy, and the experimental results indicate that these complexes bind to CT DNA with the intrinsic binding constant Kb=2.5±0.2×105 M−1. MTT is used to test the anticancer effect of the complexes with HL60 tumor cell. The inhibition ratio was accelerated by increasing the dosage, and it had significant positive correlation with the medication dosage.

  13. Syntheses, Crystal Structures and Kinetic Mechanisms of Thermal Decomposition of Rare Earth Complexes with Schiff Base Derived from o-Vanillin and p-Toluidine

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Three complexes, [Pr(NO3)3(HL)2] (1), [Nd(NO3)3(HL)2] (2) and [Er(NO3)3(HL)2] ·0.5H2O (3),were synthesized from the reaction of a Schiff base ligand 2-[ (4-methylphenylimino)methyl ]-6-methoxyphenol (C15 H15 mental analysis, molar conductance, FT-IR, UV-Vis, 1H NMR and thermal analysis shows the title complexes are neutral molecules where the central Ln( Ⅲ ) ion is ten-coordinated in biapical anti-hexahedron prism geometry, with four oxygen atoms of the phenolic hydroxy and methoxy groups in the two bidentate Schiff base ligands and six oxygen atoms provided by the three bidentate NO3- anions. Additionally, the kinetic mechanism of thermal decomposition of complex 3 was determined with a TG-DTG curves by both integral and differential methods. The functions of thermal decomposition reaction mechanism and the equation of kinetic compensation effect were obtained.

  14. Antioxidant activity of bovine serum albumin binding amino acid Schiff-bases metal complexes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Glutamic acid-salicylaldehyde Schiff-base metal complexes are bound into bovine serum albumin (BSA), which afforded BSA binding Schiff-base metal complexes (BSA-SalGluM, M=Cu, Co, Ni, Zn). The BSA binding metal complexes were characterized by UV-vis spectra and Native PAGE. It showed that the protein structures of BSA kept after coordinating amino acid Schiff-bases metal complexes. The effect of the antioxidant activity was investigated. The results indicate that the antioxidant capacity of BSA increased more than 10 times after binding Schiff-base metal complexes.

  15. 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.

  16. Antimicrobial salicylaldehyde Schiff bases: synthesis, characterization and evaluation.

    Science.gov (United States)

    Adeel-Sharif, Hafiz Muhammad; Ahmed, Dildar; Mir, Hira

    2015-03-01

    As the pathogens soon develop resistance to the existing antibiotics, the demand for new and more effective anti-microbial agents is a continuous phenomenon. In this paper we are reporting synthesis and spectral data of eight Schiff bases of salicylaldehyde with different amines, and evaluation of their anti-microbial activities against different bacterial strains. The bases were synthesized by reflux method, and their structures were determined based FT-IR, (1)H-NMR, (13)C-NMR and Mass spectrometric data. The Schiff bases synthesized included 2-{[(Z)-(2-hydroxyphenyl) methylidene] amino}benzoicacid (SB1), 4-{[(Z)-(2-hydroxyphenyl) methylidene] amino} benzoic acid (SB2),2-[(naphthalene-2-ylimino)methyl] phenol(SB3),2-2'-[benzene-1,4-diylbis(nitrilomethylylidene)]diphenol (SB4), 2-2'-[benzene-1,2-diylbis (nitrile-(E)-methylylidene)]diphenol (SB5), 2-[(2-phenylhydrazineylidene)methyl]phenol (SB6), 2-2'-[ethene-1,2-diylbis(iminomethanediyl)]diphenol (SB7) and 2-[(Z)-(phenylimino)methyl]phenol (SB8). The anti-microbial activities of synthesized Schiff bases were determined in terms of zones of inhibition and minimum inhibitory concentrations (MICs). All the bases showed moderate to good activities against all the tested microorganisms. The MICs of most compounds were 100-200βg/mL against different microorganisms. However, it was 50βg/mL for SB1 against P. aeruginosa (1), SB3 against P. aurantiaca, P. aeruginosa (1), E. coli (2), S. typhi (2) and C. freundii, SB4against E. coli (2), S. typhi (1) and S. maltophilia, SB5 against K. pneumoniae and S. typhi (2), SB6 against P. aeruginosa (3) and C. freundii, SB7 against E. cloacae and A. lipoferum, and SB8 against E. coli (2). Considerably active bases may prove to be potential candidates for future antibiotic drugs.

  17. Antimicrobial Activity and Spectral, Magnetic and Thermal Studies of Some Transition Metal Complexes of a Schiff Base Hydrazone Containing a Quinoline Moiety

    Directory of Open Access Journals (Sweden)

    Nora H Al-Sha’alan

    2007-05-01

    Full Text Available A series of new copper(II, cobalt(II, nickel(II, manganese(II, iron(III, and uranyl(VI complexes of the Schiff base hydrazone 7-chloro-4-(benzylidene-hydrazoquinoline (HL were prepared and characterized. The Schiff base behaves as a monobasic bidentate ligand. Mononuclear complexes with the general composition [ML2(Clm(H2O2(OEtn]·xEtOH (M = Cu(II, Co(II, Ni(II, Mn(II, Fe(III or UO2(VI; m and n = 0-1; x = 1-3 were obtained in the presence of Li(OH as a deprotonating agent. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, infrared, electronic spectra, magnetic susceptibility and conductivity measurements. An octahedral geometry was suggested for all the complexes except the Cu(II and UO2(VI ones. The Cu(II complex has a square-planar geometry distorted towards tetrahedral, while the UO2(VI complex displays its favored heptacoordination. The Schiff base ligand, HL, and its complexes were tested against one strain Gram +ve bacteria (Staphylococcus aureus, Gram -ve bacteria (Escherichia coli, and Fungi (Candida albicans. The prepared metal complexes exhibited higher antibacterial activities than the parent ligand and their biopotency is discussed.

  18. Synthesis, Characterization and Use of Schiff Bases as Fluorimetric Analytical Reagents (Part II)

    OpenAIRE

    Mohamed N. Ibrahim; Salaheddin A. I. Sharif

    2011-01-01

    Many Schiff bases were prepared by condensation reaction of certain aromatic amines with aromatic aldehydes derivatives and then the fluorescence properties of these Schiff bases were examined in acidic and basic media. It is shown that these compounds can be used for fluorimetric monitoring of small pH changes.

  19. Synthesis, Characterization and Use of Schiff Bases as Fluorimetric Analytical Reagents

    OpenAIRE

    Mohamed N. Ibrahim; Sharif, Salah E. A.

    2007-01-01

    Many Schiff bases were prepared by condensation reaction of certain aromatic amines with aromatic aldehydes derivatives, then the fluorescence properties of these Schiff bases were examined in acidic and basic media. It shows that, these compounds can be used for spectrofluorimetric monitoring of small pH changes.

  20. Synthesis and Characterization of Binuclear Schiff Base Complexes of Nickel, Copper, and Manganese.

    Science.gov (United States)

    1983-11-04

    D-Ri35 493 SYNTHESIS AND CHRACTERILATION OF BINUCLEAR SCHIFF BASE i/i COMPLEXES OF NICK-.U) ROCHESTER UNIV NV DEPT OF CHEMISTRY B C WHITMIORE ET AL...RESEARCH Contract NOO014-83-K-0154 fl Task No. NR 634-742 TECHNICAL REPORT NO. 1 ,Z Synthesis and Characterization of Binuclear Schiff Base Complexes

  1. Synthesis, Characterization and Use of Schiff Bases as Fluorimetric Analytical Reagents (Part II

    Directory of Open Access Journals (Sweden)

    Mohamed N. Ibrahim

    2011-01-01

    Full Text Available Many Schiff bases were prepared by condensation reaction of certain aromatic amines with aromatic aldehydes derivatives and then the fluorescence properties of these Schiff bases were examined in acidic and basic media. It is shown that these compounds can be used for fluorimetric monitoring of small pH changes.

  2. Synthesis, spectroscopic properties and theoretical studies of bis-Schiff bases derived from polyamine and pyrazolones.

    Science.gov (United States)

    Ren, Tiegang; Liu, Shuyun; Li, Guihui; Zhang, Jinglai; Guo, Jia; Li, Weijie; Yang, Lirong

    2012-11-01

    A series of novel bis-Schiff base were synthesized from 1-aryl-3-methyl-4-benzoyl-5-pyrazolones and diethylenetriamine (or triethylenetetramine) as the starting materials. All of these bis-Schiff bases were characterized by means of NMR, IR, and MS. The UV-vis absorption spectra and fluorescent spectra of these bis-Schiff bases were also measured. Moreover, the B3LYP/6-31G(d) method was used to optimize the ground state geometry of the bis-Schiff bases; and the UV-vis spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVDZ basis set of TD-B3LYP method. It has been found that all of these bis-Schiff bases show a remarkable absorption peak in a wavelength range of 270-340 nm; and their maximum emission peaks are around 348 nm.

  3. EPR spectra of four gadolinium complexes with Schiff bases

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 陈德余; 封子先; 李冬成; 冯亚菲; 何玲

    1995-01-01

    EPR spectra of four new gadolinium complexes with Schiff bases in polycrystalline powder and those of these complexes in three organic solvents were investigated at different temperatures. It has been observed for the first time that their freezing solution spectra are quite different from each other. In THF one peak was observed only, but there were three peaks and typical "U" spectral features appearing in DMF and DMSO at low temperatures. On the basis of spin Hamiltonian of S = 7/2 system, the correlations between crystal field strength in complexes and local symmetry around Gd3+ ions are discussed.

  4. SYNTHESIS,CHARACTERIZATION AND SELECTIVITY STUDIES OF POLY(ACRYLAMIDE)INCORPORATING SCHIFF BASES

    Institute of Scientific and Technical Information of China (English)

    Nur(s)en Sarl; Serkan (O)zcan

    2009-01-01

    Three novel polymers incorporating Schiff bases,derived from condensation reactions of poly(acrylamide)with 5-chloro-2-hydroxybenzaldehyde,5-bromo-2-hydroxybenzaldehyde and 5-methyl-2-hydroxybenzaldehyde,have been synthesized,and their Cu(Ⅱ)and Ni(Ⅱ)complexes have been prepared.The 1H-NMR signals of the -CH=N- and -NH2 groups have been utilized to determine the relative abundances of Schiff base and acrylamide groups in the polymers containing Schiff bases.Poly(acrylamide)incorporating Schiff bases and metal complexes thereof have been characterized by molar conductance,magnetic susceptibility and electronic and IR spectral studies.The selectivity of poly(acrylamide)incorporating Schiff bases in forming Ni(Ⅱ)-aldehyde and Cu(Ⅱ)-aldehyde complexes has been studied.The Cu(Ⅱ)and Ni(Ⅱ)contents in the metal-bearing polymer complexes were determined by the ICP-MS technique.

  5. Chemistry and applications of organotin(IV) complexes of Schiff bases.

    Science.gov (United States)

    Nath, Mala; Saini, Pramendra K

    2011-07-21

    Schiff bases are the most widely used versatile ligands, able to coordinate many elements and to stabilize them in various oxidation states. Recently, this class of compounds has been employed as models for biological systems, and in control of stereochemistry in six-coordinate transition metal complexes. Recently, the chemistry of organotin(IV) complexes of Schiff bases has also stemmed from their antitumour, antimicrobial, antinematicidal, anti-insecticidal and anti-inflammatory activities. Furthermore, organotin(IV) complexes of Schiff bases present a wide variety of interesting structural possibilities. Both aliphatic and aromatic Schiff bases in their neutral and deprotonated forms have been used to yield adducts and chelates with variable stoichiometry and different modes of coordination. This critical review (>155 references) focuses upon the chemistry and biological applications of organotin(IV) complexes of Schiff bases reported in the past 15 years. Thermal behavior of these complexes is also discussed.

  6. Synthesis, crystal structure and thermodynamic properties of a new praseodymium Schiff-base complex

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chuan-Hua, E-mail: lichuanhua0526@126.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan (China); Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China); Song, Xiang-Zhi, E-mail: xzsong@csu.edu.cn [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan (China); Jiang, Jian-Hong [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China); Gu, Hui-Wen [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan (China); Tao, Li-Ming; Yang, Ping; Li, Xu; Xiao, Sheng-Xiong; Yao, Fei-Hong; Liu, Wen-Qi; Xie, Jin-Qi; Peng, Meng-Na; Pan, Lan; Wu, Xi-Bin; Jiang, Chao; Wang, Song; Xu, Man-Fen [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China); Li, Qiang-Guo, E-mail: liqiangguo@163.com [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China)

    2014-04-01

    Highlights: • A new mononuclear Schiff base praseodymium complex was synthesized. • Based on Hess's law, thermochemical cycles of two reactions were designed. • The dissolution enthalpies were measured by a solution–reaction calorimeter. • The standard molar enthalpy of formation of the complex was calculated. - Abstract: The title complex [Pr(H{sub 2}vanen)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}·NO{sub 3}] was synthesized reacting of Valen Schiff-base ligand [H{sub 2}vanen = N,N′-ethylene-bis(3-methoxysalicylideneimine)] and Pr(NO{sub 3}){sub 3}·6H{sub 2}O in ethanol at 60 °C. The complex was crystallized in the monoclinic crystal system with space group P21/c. The coordination polyhedron of Pr(III) ion was consisted of two bidentate nitrate ions, two molecules of water and one ligand which coordinated through oxygen atoms of the two phenolic and methoxy groups. After designing two reasonable thermochemical cycles according to Hess's law, the calorimetric experiments were conducted using isoperibol solution–reaction calorimeter at a constant temperature of 298.15 K. The standard molar enthalpy changes of two reactions were determined to be Δ{sub r}H{sub m}{sup θ}(1a)=−(51.94±1.26) kJ mol{sup −1} and Δ{sub r}H{sub m}{sup θ}(1b)=−(8.62±1.34) kJ mol{sup −1}. Then the standard molar enthalpies of formation of the ligand and the title complex were calculated to be Δ{sub f}H{sub m}{sup θ} [H{sub 2}vanen(s), 298.15 K] = −(517.75 ± 2.36) kJ mol{sup −1} and Δ{sub f}H{sub m}{sup θ} [Pr(H{sub 2}vanen)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}·NO{sub 3} (s), 298.15 K] = −(2454.8 ± 2.7) kJ mol{sup −1}, respectively. The rationality of two thermochemical cycles was verified by UV spectra and refractive indexes.

  7. Use of Manganese(II)-Schiff Base Complexes for Carrying Polar Organometallics and Inorganic Ion Pairs.

    Science.gov (United States)

    Gallo, Emma; Solari, Euro; Floriani, Carlo; Chiesi-Villa, Angiola; Rizzoli, Corrado

    1997-05-07

    This report concerns the carrier properties of [Mn(acacen)]-derived compounds toward polar organometallics, inorganic ion pairs, and salts. Such properties are the consequence of Mn(II) behaving as a Lewis acid and the O&arcraise;O bite of the bidentate Schiff base ligand toward alkali cations. The starting compounds, which occur in a dimeric form, [Mn(acac-L-en)](2) [L' = CH(2)CH(2) (1); L" = C(6)H(10) (2); L"' = R,R-C(6)H(10) (3)] have been synthesized either via a metathesis reaction from MnCl(2) or using [Mn(3)Mes(6)]. The reaction of 1-3 with lithium organometallics allowed the isolation of [Mn(acac-L-en)(R)Li(DME)] [R = Me, L = L' (4); R = Ph, L = L' (5); R = Mes, L = L' (6); R = Me, L = L" (7); R = Me, L = L"' (8)] as metalated forms, where the alkyl or aryl group is sigma-bonded to Mn(II), while the lithium cation is anchored to the Schiff base ligand. The metalated forms 4-8 react with PhCHO to give the corresponding lithium alkoxide, which remains bound in its ion-pair form to the [Mn(acacen)] skeleton in [Mn(2)(acac-L'-en)(2)Li(2)(OCH(Ph)Me)(2)](n)() (9). The use of 8, which has a chiral bridge across two nitrogen atoms, did not lead to a significant asymmetric induction in the reaction with PhCHO, because of the long separation between the lithium cation and the stereogenic center. The metalated form 4 was able to transfer the methyl group to the nitrile function to give the corresponding lithium-imide which then remains bonded to [Mn(acacen)] as the ion pair in a dimeric structure, as revealed for [Mn(2)(acac-L'-en)(2)Li(2)(DME){N=C(Ph)Me}(2)](n)() (10). Their reaction with 1 appears to depend on the steric bulkiness of the alkyl group in NaOR, resulting in either monomeric adducts, i.e. in [Mn(acac-L'-en)(2,6-Bu(t)(2)C(6)H(3)O)Na(DME)(2)] (11.2DME), or polymeric structures, like in [Mn(acac-L'-en)Na(DME)(&mgr;-OEt)](n)() (13). All the dimeric units reported in this paper show a slight antiferromagnetic coupling between the two Mn(II) assisted by

  8. Synthesis and characterization of novel Schiff bases containing pyrimidine unit

    Directory of Open Access Journals (Sweden)

    Jumbad H. Tomma

    2014-01-01

    Full Text Available The work involves synthesis of novel Schiff base derivatives containing a pyrimidine unit starting with chalcones. 4-Aminoacetophenone was reacted with 4-nitrobenzaldehyde or 4-chlorobenzaldehyde in basic medium giving chalcones, [I]a and [I]b, respectively, by Claisen-Schemidt reaction. The chalcones [I]a and [I]b were reacted with urea in HCl medium giving oxopyrimidines, [II]a and [II]b. They were also reacted with thiourea in basic medium to give thioxopyrimidines, [III]a and [III]b. The novel mono and bis Schiff bases, [VIII]na, [VIII]nb, [IX]na, [IX]nb, [X]na, [X]nb, [XI]na, and [XI]nb were synthesized by the reaction of pyrimidine derivatives; oxopyrimdines, [II]a and [II]b and thioxopyrimidines, [III]a and [III]b with 4-(4′-n-alkoxybenzoloxybenzaldehyde [VI] and polymethylene-α,ω-bis-4-oxybenzaldehydes [VII]m, respectively, in dry benzene using drops of glacial acetic acid as a catalyst. The synthesized compounds were characterized by melting points, elemental analysis, FTIR, and 1H NMR spectroscopy.

  9. Synthesis, characterization, and spectroscopic investigation of benzoxazole conjugated Schiff bases.

    Science.gov (United States)

    Santos, Fabiano S; Costa, Tania M H; Stefani, Valter; Gonçalves, Paulo F B; Descalzo, Rodrigo R; Benvenutti, Edilson V; Rodembusch, Fabiano S

    2011-11-24

    Two Schiff bases were synthesized by reaction of 2-(4'-aminophenyl)benzoxazole derivatives with 4-N,N-diethylaminobenzaldehyde. UV-visible (UV-vis) and steady-state fluorescence in solution were applied in order to characterize its photophysical behavior. The Schiff bases present absorption in the UV region with fluorescence emission in the blue-green region, with a large Stokes' shift. The UV-vis data indicates that each dye behaves as two different chromophores in solution in the ground state. The fluorescence emission spectra of the dye 5a show that an intramolecular proton transfer (ESIPT) mechanism takes place in the excited state, whereas a twisted internal charge transfer (TICT) state is observed for the dye 5b. Theoretical calculations were performed in order to study the conformation and polarity of the molecules at their ground and excited electronic states. Using density functional theory (DFT) methods at theoretical levels BLYP/Aug-SV(P) for geometry optimizations and B3LYP/6-311++G(2d,p) for single-point energy evaluations, the calculations indicate that the lowest energy conformations are in all cases nonplanar and that the dipole moments of the excited state relaxed structures are much larger than those of the ground state structures, which corroborates the experimental UV-vis absorption results.

  10. Controlling the pKa of the bacteriorhodopsin Schiff base by use of artificial retinal analogues.

    OpenAIRE

    1986-01-01

    Artificial bacteriorhodopsin pigments based on synthetic retinal analogues carrying an electron-withdrawing CF3 substituent group were prepared. The effects of CF3 on the spectra, photocycles, and Schiff base pKa values of the pigments were analyzed. A reduction of 5 units in the pKa of the Schiff base is observed when the CF3 substituent is located at the C-13 polyene position, in the vicinity of the protonated Schiff base nitrogen. The results lead to the unambiguous characterization of the...

  11. Structural, Spectroscopic and Biological Aspects of O, N- Donor Schiff Base Ligand and its Cr(III, Co(II, Ni(II and Cu(II Complexes Synthesized through Green Chemical Approach

    Directory of Open Access Journals (Sweden)

    Kavita Rathore

    2010-01-01

    Full Text Available The monofunctional bidentate Schiff base ligand (o-vanillin p-chloroaniline and its four new complexes of chromium(III, cobalt(II, nickel(II and copper(II have been synthesized by classical thermal and microwave-irradiated techniques. All the new derivatives have been characterized by elemental analysis, molecular weight determinations, molar conductance measurements, UV-Vis, IR and NMR spectral studies. The IR spectral data suggest the involvement of phenolic oxygen after deprotonation and azomethine nitrogen in coordination to the central metal ion. The growth inhibiting potential of the ligands and complexes has been assessed against a variety of fungal and bacterial strains.

  12. Synthesis, characterization and biological activity of Schiff bases based on chitosan and arylpyrazole moiety.

    Science.gov (United States)

    Salama, Hend E; Saad, Gamal R; Sabaa, Magdy W

    2015-08-01

    The Schiff bases of chitosan were synthesized by the reaction of chitosan with 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde. The structure of the prepared chitosan derivatives was characterized by FT-IR spectroscopy, elemental analysis, and X-ray diffraction studies and thermogravimetric analysis (TG). The results show that the specific properties of Schiff bases of chitosan can be altered by modifying the molecular structures with proper substituent groups.TG results reveal that the thermal stability of the prepared chitosan Schiff bases was lower than chitosan. The activation energy of decomposition was calculated using Coats-Redfern model. The antimicrobial activity of chitosan and Schiff bases of chitosan were investigated against Streptococcus pneumonia, Bacillis subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi). The results indicated that the antimicrobial activity of the Schiff bases was stronger than that of chitosan and was dependent on the substituent group. The activity of un-substituted arylpyrazole chitosan derivative toward the investigated bacteria and fungi species was better than the other derivatives.

  13. Double template effect in [4 + 4] Schiff base macrocycle formation; an ESI-MS study.

    Science.gov (United States)

    Barreira-Fontecha, Julia; Kulmaczewski, Rafal; Ma, Xiaomei; McKee, Vickie

    2011-12-07

    The mechanism of self-assembly of a polynuclear complex of a [4 + 4] Schiff base iminomethylenediphenolate macrocycle [BaCu(4)(4 + 4)](2+) via a non-macrocyclic dialdehyde intermediate has been followed using ESI-MS of the reaction solutions. Both assembly of the intermediate and Schiff-base condensation with diamine give rise to single products; formation of the intermediate metallacycle is fast but Schiff-base condensation is much slower. Both intermediate complex and macrocyclic product have been structurally characterised.

  14. Catalytic Asymmetric Carbon-Carbon Forming Reactions Catalyzed Chiral Schiff Base-Metal Complexes

    Institute of Scientific and Technical Information of China (English)

    Takanori; Tanaka; Masahiko; Hayashi

    2007-01-01

    1 Results In 1991, we disclosed the novel asymmetric catalysts prepared from chiral Schiff base and titanium alkoxide in the reaction of asymmetric silylcyanation of aldehydes (eq.1)[1]. Since our first report, chiral Schiff base-metal complex was proven to be efficient in a variety of asymmetric reactions. We reported the first example of enantioselective addition of diketene to aldehydes promoted by chiral Schiff base-titanium alkoxide complexes (eq.2)[2]. The products of this reaction have been cove...

  15. 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.

  16. Synthesis and spectral characterization of Schiff base complexes of Cu(II), Co(II), Zn(II) and VO(IV) containing 4-(4-aminophenyl)morpholine derivatives: antimicrobial evaluation and anticancer studies.

    Science.gov (United States)

    Dhahagani, K; Mathan Kumar, S; Chakkaravarthi, G; Anitha, K; Rajesh, J; Ramu, A; Rajagopal, G

    2014-01-03

    Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by (1)H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M=Cu(II), Co(II)), Zn(II), or VO(IV); MPMP=2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X=Cl, (L1H), X=Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines.

  17. Synthesis of New Schiff Bases Containing Thiophene Moiety

    Institute of Scientific and Technical Information of China (English)

    ZhuWan-ren; HuPei-zhi; LiMei-ying; HuangXiao-ling; WuCheng-tai

    2003-01-01

    Seven new Schiff bases, which are 4,4,4-trifluoro-1- ( 2-thienyl )- 1-butanone-3-Z, Z =-thiosemicarbazone (a) ;-thiocarbohydrazone ( b),-benzoic hydrazone (e), -( o-hydroxyphenyl) imine (d) ,-nicotinic hydrazone (e) ,-salicylic hydrazone ( f), and -(p-fluoro-m-chlorophenyl) imine (g),have been synthesized by reaction of 4, 4, 4-trifluoro-l-(2-thienyl)-l, 3-butanedione (TFTBD) with corresponding hydrazides or anilines, acetic acid or p-toluence sulfonic acid as catalyst, and characterized by Elemental analysis, IR, UV-Vis,1H NMR and MS. The MS spectra confirmed that the —C3=O condensed with primary amino group. Tautomerism of the compounds is discussed.

  18. Langmuir-Blodgett Films from Schiff Base Aluminium ( Ⅲ ) Complex

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The characteristics of the LB films of Schiff base aluminium( Ⅲ ), tris(2-hydroxy-5-nitro N-dodecyl-benzylideneaminato) aluminium ( Ⅲ ) [Al (TA 12) 3], were studied. The surface pres sure-area(r-A) isotherm of Al(TA12)3 in the pure water subphase was investigated. The molec ular area, 0.48 nm2, is one-third of the expected value that indicates the formation of an aggre gate. The Langmuir-Blodgett (LB) films of Al(TA12) 3 were transferred and characterized. The UV-Vis spectra and the AFM image both confirmed that the J-aggregates formed. The polarized UV-Vis spectra indicated that the complex plane had to be oriented with an angle of about 30° to the substrate surface. The IR spectra suggested that the complexation took place between aluminium ions and the oxygen atoms of the ligand rather than the nitrogen atom.

  19. Synthesis of Schiff Bases via Environmentally Benign and Energy-Efficient Greener Methodologies

    Directory of Open Access Journals (Sweden)

    Arshi Naqvi

    2009-01-01

    Full Text Available Non classical methods (water based reaction, microwave and grindstone chemistry were used for the preparation of Schiff bases from 3-chloro-4-fluoro aniline and several benzaldehydes. The key raw materials were allowed to react in water, under microwave irradiation and grindstone. These methodologies constitute an energy-efficient and environmentally benign greener chemistry version of the classical condensation reactions for Schiff bases formation.

  20. Synthesis, characterization and antibacterial activity of biodegradable films prepared from Schiff bases of zein.

    Science.gov (United States)

    Soliman, E A; Khalil, A A; Deraz, S F; El-Fawal, G; Elrahman, S Abd

    2014-10-01

    Pure zein is known to be very hydrophobic, but is still inappropriate for coating and film applications because of their brittle nature. In an attempt to improve the flexibility and the antimicrobial activity of these coatings and films, Chemical modification of zein through forming Schiff bases with different phenolic aldhydes was tried. Influence of this modifications on mechanical, topographical, wetting properties and antimicrobial activity of zein films were evaluated. The chemical structure of the Schiff bases films were characterized by ATR-FTIR spectroscopy. The results indicate an improvement in mechanical properties with chemically modification of zein to form Schiff bases leading to a reduction in the elastic modulus. An increase in the elongation at break has been observed, but with slight influence on tensile strength. Plasticized zein films have similar initial contact angle (∼40°). An increase in reaction temperature and time increases film's affinity towards water. As shown by contact angle measurements, a noticeable relation was found between film composition and the hydrophilicity. Surface topography also varied by forming Schiff bases, becoming rougher than zein-based films. The antibacterial activities of zein and Schiff bases of zein-based films were investigated against gram-positive bacteria (Listeria innocua, Listeria monocytogenes, Bacillus cereus and Clostridium sporogenes) and gram-negative bacteria (Escherichia coli, Yersinia enterocolitica and Salmonella enterica). It was found that the antibacterial activity of the Schiff bases-based films was more effective than that of zein-based films.

  1. Complexes of some 3d-metals with a Schiff base derived from 5-acetamido-1,3,4-thiadiazole-2-sulphonamide and their biological activity

    Directory of Open Access Journals (Sweden)

    Mitu Liviu

    2011-01-01

    Full Text Available Using a bidentate ligand, a Schiff base of 5-acetamido-1,3,4- thiadiazole-2-sulphonamide, complexes of transition metals having the general formula ML2, where M = Mn(II, Fe(II, Ni(II and Cu(II, were synthesized. The complexes were characterized by elemental analysis, molar conductivity, magnetic moment, electronic, ESR and IR spectroscopy, and particle size analysis. The conductivity data of the complexes suggests their non-electrolytic nature. The stability constants and free energy change for the complexes were calculated. Spectral studies and magnetic susceptibility measurements revealed an octahedral geometry for all the complexes. The ligand and its complexes were screened for their fungicidal activity against Aspergillus niger and A. flavus.

  2. New strategy for chemically attachment of Schiff base complexes on Multiwalled Carbon Nanotubes surfaces

    Directory of Open Access Journals (Sweden)

    Leila Moradi

    2014-06-01

    Full Text Available Chemically attachment of Schiff base complexes on multiwalled carbon nanotubes (MWCNTs surfaces through a convenient and simple method was studied. In the first step of this method, we present a new method for preparation of aminated MWCNTs in order to attachment of (new chlorinated salen Schiff bases. Amination of multiwalled carbon nanotubes performed under microwave (MW irradiation through a one pot two step reaction. The chemically attachment of salen Schiff bases on functionalized MWCNTs (salen@MWCNTs performed under a facile simple nucleophilic substitution reaction and complexation of attached salen Schiff bases (salen complex@MWCNTs in last step, have been occurred with reaction of transition metal salts and salen@MWCNTs. The obtained products were characterized in detail, using FTIR, XRD, UV-Vis absorption, SEM and EDX methods.

  3. Synthesis, mechanism and NMR spectra of lanthanide complexes with a novel unsymmetrical Schiff base

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 周文; 鲁桂; 沈联芳

    1999-01-01

    Owing to its two unsymmetrical-NH2 groups sited on different terminals, 2, 6-diaminocaproic acid (lysine) was used as a reactant for synthesizing a novel unsymmetrical Schiff base with salicylaldehyde on one side and ovanillin on the other for the first time. It is a new way to synthesize such a special unsymmetrical Schiff base. It is named "hetero bis-Schiff base" for distinguishing it from others. The synthesis method, formation mechanism as well as twelve new lanthanide complexes with the above ligand are reported and discussed herein. They were characterized by elementary analysis, molar conductivity, IR-spectra and especially by 1H and 13C NMR spectra. The results obtained may provide a new promising method for synthesizing similar unsymmetrical Schiff bases and their complexes.

  4. The Rapid Synthesis of Schiff-Base without Solvent under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A microwave-assisted preparation of a series of Schiff-base via efficient condensation of salicylaldehyde and aryl amines without solvent is described in high yield as well as environmental friendship reaction in organic synthesis.

  5. Reversible Formation and Transmetalation of Schiff-Base Complexes in Subcomponent Self-Assembly Reactions.

    Science.gov (United States)

    Lewing, Dennis; Koppetz, Hannah; Hahn, F Ekkehardt

    2015-08-03

    Dinuclear complexes [Zn2(NS,NS)2] 3 and [Ni2(NS,NS)2] 6 bearing Schiff-base ligands featuring two NS donor groups were obtained in subcomponent self-assembly reactions using nickel or zinc as template metals. Several transmetalation reactions starting from 3 or 6 yielded the complexes [Pd2(NS,NS)2] 4 and [Co2(NS,NS)2] 5, and their molecular structures were determined by X-ray diffraction. Starting from the mononuclear complex [Ni(NS/NOH)2] 9 featuring a coordinated NS Schiff base and a free NOH Schiff base, completely reversible thermodynamically controlled imine bond formation was observed leading to complex [Ni2(NS,NS)2] 6 and the free Schiff -base ligand NOH,NOH 10.

  6. Synthesis, Characterization and Antibacterial Activity of Some Halo Substituted Schiff Bases

    Directory of Open Access Journals (Sweden)

    S. B. Junne

    2010-01-01

    Full Text Available Some new halo substituted Schiff bases have been prepared from different aromatic aldehydes and a series of substituted aromatic amines to form a number of potentially biologically active compounds. The structures of the Schiff bases have been characterized by using IR and 1HNMR spectroscopy. These compounds were screened against human pathogenic bacteria by agar diffusion method. Ampicillin was used as control.

  7. Supramolecular assemblies and molecular recognition of amphiphilic schiff bases with barbituric acid in organized molecular films.

    Science.gov (United States)

    Jiao, Tifeng; Liu, Minghua

    2005-02-24

    A bolaform Schiff base, N,N'-bis(salicylidene)-1,10-decanediamine (BSC10), has been synthesized and its interfacial hydrogen bond formation or molecular recognition with barbituric acid was investigated in comparison with that of a single chain Schiff base, 2-hydroxybenzaldehyde-octadecylamine (HBOA). It has been found that while HBOA formed a monolayer at the air/water interface, the bolaform Schiff base formed a multilayer film with ordered layer structure on water surface. When the Schiff bases were spread on the subphase containing barbituric acid, both of the Schiff bases could form hydrogen bonds with barbituric acid in situ in the spreading films. As a result, an increase of the molecular areas in the isotherms was observed. The in situ H-bonded films could be transferred onto solid substrates, and the transferred multilayer films were characterized by various methods such as UV-vis and FT-IR spectrosopies. Spectral changes were observed for the films deposited from the barbituric acid subphase, which supported the hydrogen bond formation between the Schiff bases and barbituric acid. By measuring the MS-TOF of the deposited films dissolved in CHCl3 solution, it was concluded that a 2:1 complex of HBOA with barbituric acid and a 1:2 complex of BSC10 with barbituric acid were formed. On the other hand, when the multilayer films of both Schiff bases were immersed in an aqueous solution of barbituric acid, a similar molecular recognition through the hydrogen bond occurred. A clear conformational change of the alkyl spacer in the bolaform Schiff base was observed during the complex formation with the barbituric acid.

  8. A review on versatile applications of transition metal complexes incorporating Schiff bases

    OpenAIRE

    Abu-Dief, Ahmed M.; Ibrahim M.A. Mohamed

    2015-01-01

    Schiff bases and their complexes are versatile compounds synthesized from the condensation of an amino compound with carbonyl compounds and widely used for industrial purposes and also exhibit a broad range of biological activities including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory, antiviral, and antipyretic properties. Many Schiff base complexes show excellent catalytic activity in various reactions and in the presence of moisture. Over the past few year...

  9. Preparation and Electronic Property Investigation of Zinc(II)-Schiff Base Complexes in the Confined Space

    OpenAIRE

    Peng Shang; Lei Zhang

    2013-01-01

    Metal-Schiff base complexes have attracted continued research interest regarding their intriguing and useful features, while the electronic properties of these complexes in the confined space have not been sufficiently addressed in previous studies. In this work, a new zinc(II)-Schiff base complex bis(N-dodecyl salicylideneiminato)Zn(II) (1) was synthesized and subsequently loaded in an inorganic solid host. A large red shift (~40 nm) of the absorption onset was recorded, when the microenviro...

  10. Microplate assay for screening the antibacterial activity of Schiff bases derived from substituted benzopyran-4-one.

    Science.gov (United States)

    Amin, Rehab M; Abdel-Kader, Nora S; El-Ansary, Aida L

    2012-09-01

    Schiff bases (SB(1)-SB(3)) were synthesized from the condensation of 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one with 2-aminopyridine (SB(1)), p-phenylenediamine (SB(2)) and o-phenylenediamine (SB(3)), while Schiff bases (SB(4)-SB(6)) were synthesized by condensation of 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one with 2-aminopyridine (SB(4)), p-phenylenediamine (SB(5)) and o-phenylenediamine (SB(6)). Schiff bases were characterized using elemental analysis, IR, UV-Vis, (1)H NMR, (13)C NMR and mass spectroscopy. These compounds were screened for antibacterial activities by micro-plate assay technique. Escherichia coli and Staphylococcus capitis were exposed to different concentrations of the Schiff bases. Results showed that the antibacterial effect of these Schiff bases on Gram-negative bacteria were higher than that on Gram-positive bacteria moreover, the Schiff bases containing substituent OCH(3) on position five have higher antibacterial activity than that containing hydroxy group on the same position.

  11. Schiff bases及配合物的研究进展%The Research Progress of Schiff Bases and their Complexes

    Institute of Scientific and Technical Information of China (English)

    焦元红; 张前

    2007-01-01

    希夫碱配体及与后过渡金属元素所形成的配合物,以其多样的结构和广泛的用途愈来愈受到人们的重视.文章综述了Schiff base 配体及配合物的发展状况以及在生物化学、催化化学、分析化学、材料化学等方面的研究与应用,并指出了它的美好前景.

  12. Synthesis, Structural Diversity and Mimic Superoxide Dismutase of Mn(II) Complexes Derived from N, O-donor Schiff bases.

    Science.gov (United States)

    Qin, Jie; Yin, Qiang; Zhao, Shan-Shan; Wang, Jun-Zheng; Qian, Shao-Song

    2016-01-01

    Two new potentially tetradentate Schiff base ligands N'-(pyridin-2-ylmethylene)nicotinohydrazide (L1), and N'-(pyridin-2-ylmethylene)isonicotinohydrazide (L(2)) were synthesized. Reactions of hydrazone ligands L(1) and L(2) with Mn(NO(3))(2) afford two mononuclear Mn(II) complexes, [Mn(L(1))(NO(3))(H(2)O)(2)]•(NO(3)) (1) and [Mn(L(2))(2)(NO(3))(H(2)O)]•(NO(3)) (2). For complexes 1 and 2, L(1) and L(2) act as pincer-like tridentate or bidentate ligands, respectively. The Mn(II) ions in the two compounds are both in heptacoordinated environment, while the two molecules display diverse solid-state supramolecular structures because of the different orientation of Npyridine and hydrogen bonding patterns of nitrate anions. Complex 1 features 2D supramolecular sheet, while complex 2 is double-chain supramolecular structure. Both of the two complexes exhibit moderate superoxide dismutase (SOD) mimetic activity.

  13. Synthesis, characterization, DNA interaction and pharmacological studies of substituted benzophenone derived Schiff base metal(II complexes

    Directory of Open Access Journals (Sweden)

    P. Subbaraj

    2015-03-01

    Full Text Available A new bidentate NO type Schiff base ligand (HL, derived from 2-hydroxy-4-methoxyphenylphenylmethanone with aniline and its metal(II [M = Mn, Co, Ni, Cu and Zn] complexes has been synthesized. The synthesized ligand and the metal(II complexes were structurally characterized by analytical, spectral (FT-IR, UV–vis., 1H NMR, FAB-Mass, TGA/DTA and EPR as well as molar conductance and magnetic studies. All the complexes are non-electrolytes having 1:2 stoichiometry. They adopt tetrahedral and octahedral geometry. Thermal behavior of metal(II complexes (1a–1c shows loss of coordinated water molecules in the first step followed by the decomposition of ligand moieties in a respective manner and leads to form an air stable metal oxide as the final residue. Micro crystalline nature and the presence of coordinated water molecules have been confirmed by powder XRD, SEM and thermal analyses. The ligand and its complexes have efficient bio-efficacy, DNA binding and cleavage ability.

  14. Chemical reactivity and skin sensitization potential for benzaldehydes: can Schiff base formation explain everything?

    Science.gov (United States)

    Natsch, Andreas; Gfeller, Hans; Haupt, Tina; Brunner, Gerhard

    2012-10-15

    Skin sensitizers chemically modify skin proteins rendering them immunogenic. Sensitizing chemicals have been divided into applicability domains according to their suspected reaction mechanism. The widely accepted Schiff base applicability domain covers aldehydes and ketones, and detailed structure-activity-modeling for this chemical group was presented. While Schiff base formation is the obvious reaction pathway for these chemicals, the in silico work was followed up by limited experimental work. It remains unclear whether hydrolytically labile Schiff bases can form sufficiently stable epitopes to trigger an immune response in the living organism with an excess of water being present. Here, we performed experimental studies on benzaldehydes of highly differing skin sensitization potential. Schiff base formation toward butylamine was evaluated in acetonitrile, and a detailed SAR study is presented. o-Hydroxybenzaldehydes such as salicylaldehyde and the oakmoss allergens atranol and chloratranol have a high propensity to form Schiff bases. The reactivity is highly reduced in p-hydroxy benzaldehydes such as the nonsensitizing vanillin with an intermediate reactivity for p-alkyl and p-methoxy-benzaldehydes. The work was followed up under more physiological conditions in the peptide reactivity assay with a lysine-containing heptapeptide. Under these conditions, Schiff base formation was only observable for the strong sensitizers atranol and chloratranol and for salicylaldehyde. Trapping experiments with NaBH₃CN showed that Schiff base formation occurred under these conditions also for some less sensitizing aldehydes, but the reaction is not favored in the absence of in situ reduction. Surprisingly, the Schiff bases of some weaker sensitizers apparently may react further to form stable peptide adducts. These were identified as the amides between the lysine residues and the corresponding acids. Adduct formation was paralleled by oxidative deamination of the parent

  15. Antimicrobial Activity of Co(II, Ni(II and Cu(II Coordination Compounds with Nitrogen, Oxygen Containing Schiff Base

    Directory of Open Access Journals (Sweden)

    B. K. RAI

    2013-06-01

    Full Text Available A series of complexes of the type [M(EHPQH2X2] where M = Co(II, Ni(II and Cu(II, EHPQH=2-ethyl, [3(hydroxypropyl]-3, 1 4H quinazoline -4-hydrazone, X= Cl-, Br-, I- and No-3 -. The geometry of the complexes have been elucidated in the light of molar mass, elemental analysis, IR, electronic Spectra, molar conductance and magnetic susceptibility. The measured molar conductance value indicates that the complexes are nonelectrolytic in nature. The above observation indicates that Schiff bases EHPQH behave as bidentate ligand and coordination proposes through azomethine N and oxygen atom of alcoholic group of ligand. The remaining coordination sites are satisfied by negative ion such as Ci-, Br-, I- and NB-. The geometry of the Co(II and Ni(II were proposed to be octahedral in geometry whereas Cu(II complexes were proposed to be distorted octahedral. The Schiff bases and its complexes have been evaluated for their antibacterial activity. The complexes show enhanced antibacterial activity than ligand.

  16. Synthesis, structure analysis, anti-bacterial and in vitro anti-cancer activity of new Schiff base and its copper complex derived from sulfamethoxazole

    Indian Academy of Sciences (India)

    I Rama; R Selvameena

    2015-04-01

    A new bidentate Schiff base ligand (HL1), containing O,N donors was prepared by the reaction of sulfamethoxazole with 5-nitrosalicylaldehyde and characterized by elemental analysis, FT-IR, 1H and 13C NMR. The copper complex of this ligand was synthesised by treating DMF-ethanolic mixture solution of the ligand of two equivalents with one equivalent of copper acetate. The complex was characterized on the basis of UV, FT-IR, molar conductance, EPR, magnetic moment and single crystal X-ray diffraction. Interestingly, the crystal structure of the octahedral complex showed two solvent molecules (DMF) as ligands at their axial positions. The molar conductance data revealed that the complex is a non-electrolyte. The Schiff base and its copper complex have been investigated as anti-bacterial and anti-fungal agents against various microorganisms. The in vitro cytotoxicity tests of the ligand and its copper complex were carried out in two different human tumour cell lines, HCT-116 and MDA – MB - 231. The cytotoxicity studies showed that the complex exhibited higher activity than cisplatin and carboplatin towards MDA – MB – 231.

  17. Ligating behaviour of Schiff base ligands derived from heterocyclic β-diketone and ethanol or propanol amine with oxovanadium (IV) metal ion

    Science.gov (United States)

    Thaker, B. T.; Barvalia, R. S.

    2009-12-01

    Synthesis and evaluation of six new oxovanadium (IV) complexes, formed by the interaction of vanadyl sulphate pentahydrate and the Schiff base, viz.; (HL 1)-(HL 3) and (HL 4)-(HL 6) such as 5-hydroxy-3-methyl-1(2-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (I), 5-hydroxy-3-methyl-1(3-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (II) and 5-hydroxy-3-methyl-1(3-sulphoamido)phenyl-1H-pyrazolone-4-carbaldehyde (III) with ethanol amine and propanol amine, respectively, in aqueous ethanol medium. The ligands and their Schiff base ligands have been characterized by elemental analyses, IR and 1H NMR. The resulting complexes have been characterized by elemental analyses, IR, 1H NMR, mass, electronic, electron spin resonance spectra, magnetic susceptibility measurement, molar conductance and thermal studies. The IR spectral data suggest that the ligand behaves as a dibasic bidentate with ON donor sequence towards metal ion. The molar conductivity data show them to be non-electrolytes. From the electronic, magnetic and ESR spectral data suggest that all the oxovanadium (IV) complexes have distorted octahedral geometry.

  18. Ligating behaviour of Schiff base ligands derived from heterocyclic beta-diketone and ethanol or propanol amine with oxovanadium (IV) metal ion.

    Science.gov (United States)

    Thaker, B T; Barvalia, R S

    2009-12-01

    Synthesis and evaluation of six new oxovanadium (IV) complexes, formed by the interaction of vanadyl sulphate pentahydrate and the Schiff base, viz.; (HL(1))-(HL(3)) and (HL(4))-(HL(6)) such as 5-hydroxy-3-methyl-1(2-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (I), 5-hydroxy-3-methyl-1(3-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (II) and 5-hydroxy-3-methyl-1(3-sulphoamido)phenyl-1H-pyrazolone-4-carbaldehyde (III) with ethanol amine and propanol amine, respectively, in aqueous ethanol medium. The ligands and their Schiff base ligands have been characterized by elemental analyses, IR and (1)H NMR. The resulting complexes have been characterized by elemental analyses, IR, (1)H NMR, mass, electronic, electron spin resonance spectra, magnetic susceptibility measurement, molar conductance and thermal studies. The IR spectral data suggest that the ligand behaves as a dibasic bidentate with ON donor sequence towards metal ion. The molar conductivity data show them to be non-electrolytes. From the electronic, magnetic and ESR spectral data suggest that all the oxovanadium (IV) complexes have distorted octahedral geometry.

  19. Spectral characterization, optical band gap calculations and DNA binding of some binuclear Schiff-base metal complexes derived from 2-amino-ethanoic acid and acetylacetone

    Science.gov (United States)

    Hussien, Mostafa A.; Nawar, Nagwa; Radwan, Fatima M.; Hosny, Nasser Mohammed

    2015-01-01

    Bi-nuclear metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H2L) resulted from the condensation of 2-amino-ethanoic acid (glycine) and acetylacetone have been synthesized and characterized by elemental analyses, Raman spectra, FT-IR, ES-MS, UV-Vis., 1H NMR, ESR, thermal analyses (TG, DTG and DTA) and magnetic measurements. The results showed that, the Schiff base ligand can bind two metal ions in the same time. It coordinates to the first metal ion as mono-negative bi-dentate through azomethine nitrogen and enolic carbonyl after deprotonation. At the same time, it binds to the second metal ion via carboxylate oxygen after deprotonation. The thermodynamic parameters E∗, ΔH∗, ΔG∗ and ΔS∗ have been calculated by Coats-Redfern (CR) and Horowitz-Metzger (HM) methods. The optical band gaps of the isolated complexes have been calculated from absorption spectra and the results indicated semi-conducting nature of the investigated complexes. The interactions between the copper (II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA.

  20. Characterizing some gossypol and gossypolone Schiff's bases by studying their fragmentation patterns with electrospray ionization tandem mass spectra

    Institute of Scientific and Technical Information of China (English)

    Long Zhang; Xing Xin Cao; Hai Xia Jiang; Biao Jiang; Yu Xin Cui

    2009-01-01

    To investigate the structural form of gossypol and gossypolone Schiff's bases, seven relevant Schiff's bases were synthesized and the eleetrospray ionization-tandem mass spectrometry (ESI-MS/MS) with low-energy collision-induced dissociation was used to analyze their fragmentations. A common fragmentation pathway with the loss of RNH2 from those schiff's bases quasi-molecular ions was observed and proposed on the basis of their MS/MS spectra data. This common pathway indicated that those Schiff's bases existed mainly as the enamine form not the imine form previously showed in most reports.

  1. A new copper(II) Schiff base complex containing asymmetrical tetradentate N2O2 Schiff base ligand: Synthesis, characterization, crystal structure and DFT study

    Science.gov (United States)

    Grivani, Gholamhossein; Baghan, Sara Husseinzadeh; Vakili, Mohammad; Khalaji, Aliakbar Dehno; Tahmasebi, Vida; Eigner, Václav; Dušek, Michal

    2015-02-01

    A new copper (II) Schiff base complex, CuL1, was prepared from the reaction of asymmetrical Schiff base ligand of L1 and Cu(OAC)2 (L1 = salicylidene imino-ethylimino-pentan-2-one). The Schiff base ligand, L1, and its copper (II) complex, CuL1, have been characterized by elemental analysis (CHN) and FT-IR and UV-vis spectroscopy. In addition, 1H NMR was employed for characterization of the ligand. Thermogrametric analysis of the CuL1 reveals its thermal stability and its decomposition pattern shows that it is finally decomposed to the copper oxide (CuO). The crystal structure of CuL1 was determined by the single crystal X-ray analysis. The CuL1 complex crystallizes in the monoclinic system, with space group P21/n and distorted square planar coordination around the metal ion. The Schiff base ligand of L1 acts as a chelating ligand and coordinates via two nitrogen and two oxygen atoms to the copper (II) ion with C1 symmetry. The structure of the CuL1 complex was also studied theoretically at different levels of DFT and basis sets. According to calculated results the Csbnd O bond length of the salicylate fragment is slightly higher than that in the acetylacetonate fragment of ligand, which could be interpreted by resonance increasing between phenyl and chelated rings in ligand in relative to the acetylacetonate fragment.

  2. A Turn-on and Reversible Fluorescence Sensor for Zinc Ion Based on 4,5-Diazafluorene Schiff Base.

    Science.gov (United States)

    Li, Hui; Zhang, ShuJiang; Gong, ChenLiang; Wang, JianZhi; Wang, Feng

    2016-09-01

    A new 4,5-diazafluorene-based fluorescent chemosensor has been synthesized by Schiff base condensation of 9,9-bis(3,5-dimethyl-4-aminophenyl)-4,5-diazafluorene with salicylaldehyde. The interaction of Schiff base with different metal ions has been studied over photofluorescent spectra. The results showed that Schiff base exhibited 194-fold enhancements in fluorescence at 465 nm after Zn(2+) ions. Such fluorescent responses could be detected by naked eye under UV-lamp. The complex solution (L-Zn(2+)) exhibited reversibility with EDTA.

  3. Synthesis, characterization and antimicrobial studies of Schiff base complexes

    Science.gov (United States)

    Zafar, Hina; Ahmad, Anis; Khan, Asad U.; Khan, Tahir Ali

    2015-10-01

    The Schiff base complexes, MLCl2 [M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized by the template reaction of respective metal ions with 2-acetylpyrrole and 1,3-diaminopropane in 1:2:1 M ratio. The complexes have been characterized by elemental analyses, ESI - mass, NMR (1H and 13C), IR, XRD, electronic and EPR spectral studies, magnetic susceptibility and molar conductance measurements. These studies show that all the complexes have octahedral arrangement around the metal ions. The molar conductance measurements of all the complexes in DMSO indicate their non-electrolytic nature. The complexes were screened for their antibacterial activity in vitro against Gram-positive (Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae) bacteria. Among the metal complexes studied the copper complex [CuLCl2], showed highest antibacterial activity nearly equal to standard drug ciprofloxacin. Other complexes also showed considerable antibacterial activity. The relative order of activity against S. Pyogenes is as Cu(II) > Zn(II) > Co(II) = Fe(II) > Ni(II) and with K. Pneumonia is as Cu(II) > Co(II) > Zn(II) > Fe(II) > Ni(II).

  4. Synthesis and Antibacterial Activities of Some Schiff Bases

    Directory of Open Access Journals (Sweden)

    Mohamed N. Ibrahim

    2011-01-01

    Full Text Available Schiff bases p-hydroxybenzylidene-2-carboxyaniline, p-nitrobenz-ylidene-2-carboxyaniline, p-(N, N-dimethylaminobenzylidene-2-carboxyaniline, N-(4-hydroxybezylidene-benzene-1,2-diamine, N--(4-nitrobezylidenebenzene-1,2-diamine, N-(4-(N, N-dimethylaminobezylidenebenzene-1,2-diamine, N-(4-(N,N-dimethylaminobenzylidenenaphthalen-1-amine,N-(4-nitrobenzylidenenaphthalen-1-amine,N--(4-chlorobenzylidenenaphthalen-1-amine,sodium-4-(4-(N,N-dimethyl aminobenzylideneaminonaphthalene-1-sulfonate,sodium -4-(4-nitrobenzylidene-aminonaphthalene-1-sulfonate and sodium-4-(4-chlorobenzylideneamino naphthalene-1-sulfonate obtained by condensation of aniline and naphthyl-amine derivatives with some aromatic aldehydes were characterized by physical and spectral methods. The biological activity of these products were as antibacterial agents against three species of human pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Klebsiella sp. Nearly 50% of these compounds showed reasonable activity against the bacterial species investigated and we found that the antibacterial activity is dependent on the molecular structure of the compounds.

  5. Excited State Potential Energy Surfaces of Polyenes and Protonated Schiff Bases.

    Science.gov (United States)

    Send, Robert; Sundholm, Dage; Johansson, Mikael P; Pawłowski, Filip

    2009-09-08

    The potential energy surface of the (1)Bu and (1)A' states of all-trans-polyenes and the corresponding protonated Schiff bases have been studied at density functional theory and coupled cluster levels. Linear polyenes and protonated Schiff bases with 4 to 12 heavy atoms have been investigated. The calculations show remarkable differences in the excited state potential energy surfaces of the polyenes and the protonated Schiff bases. The excited states of the polyenes exhibit high torsion barriers for single-bond twists and low torsion barriers for double-bond twists. The protonated Schiff bases, on the other hand, are very flexible molecules in the first excited state with low or vanishing torsion barriers for both single and double bonds. Calculations at density functional theory and coupled cluster levels yield qualitatively similar potential energy surfaces. However, significant differences are found for some single-bond torsions in longer protonated Schiff bases, which indicate a flaw of the employed time-dependent density functional theory methods. The close agreement between the approximate second and third order coupled cluster levels indicates that for these systems calculations at second order coupled cluster level are useful in the validation of results based on time-dependent density functional theory.

  6. Preparation and characterization of high performance Schiff-base liquid crystal diepoxide polymer

    Energy Technology Data Exchange (ETDEWEB)

    Liu Huan; Fu Zien [Key Laboratory of Organic Polymer Material for Electronics, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. BOX 1122, Guangzhou 510650 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Xu Kai, E-mail: xk@gic.ac.cn [Key Laboratory of Organic Polymer Material for Electronics, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. BOX 1122, Guangzhou 510650 (China); Cai Hualun; Liu Xin [Key Laboratory of Organic Polymer Material for Electronics, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. BOX 1122, Guangzhou 510650 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Chen Mingcai [Key Laboratory of Organic Polymer Material for Electronics, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. BOX 1122, Guangzhou 510650 (China)

    2012-02-15

    Graphical abstract: The specific effects of highly conjugated Schiff-base moiety on thermal properties of the Schiff-base epoxy polymer were proposed first by us. From the point of view of structure-properties relationship, it can be considered that owing to the presence of the Schiff-base group, the high performance liquid crystal diepoxide polymer displayed improved thermal stability. Highlights: Black-Right-Pointing-Pointer In this work, we first proposed that specific effects of highly conjugated Schiff-base moiety on thermal properties of the Schiff-base epoxy polymer. Black-Right-Pointing-Pointer As one aim of this study, the thermal and thermal-oxidative stabilities of the thermosets were studied by TGA under nitrogen and under air. Black-Right-Pointing-Pointer The second aim of this study was to further understand the thermal degradation mechanism. Black-Right-Pointing-Pointer For thermal degradation mechanism of this polymer under nitrogen, TG-IR was used to investigate volatile components, and SEM/EDS was used to explore morphologies and chemical components of the residual char. Black-Right-Pointing-Pointer From the point of view of structure-properties relationship, it can be considered that owing to the presence of the Schiff-base group, the high performance liquid crystal diepoxide polymer displayed the improved thermal stability. - Abstract: A novel Schiff-base liquid crystal diepoxide polymer was prepared via a thermal copolymerization of a Schiff-base epoxy monomer (PBMBA) with a diamine co-monomer (MDA). We first proposed that specific effects of highly conjugated Schiff-base moiety on thermal properties of the Schiff-base epoxy polymer (PBMBA/MDA). Thermal degradation behavior of the polymer was characterized using thermogravimetric analysis (TGA) under nitrogen and under air, respectively. Thermogravimetric data obtained from TGA under nitrogen and under air reveal that PBMBA/MDA exhibits higher thermal stability compared with bisphenol-A type

  7. Dimerization of Propylene by Nickel (Ⅱ) and Cobalt (Ⅱ) Catalysts Based on Bidentate Nitrogen-phosphino Chelating Ligands

    Institute of Scientific and Technical Information of China (English)

    Si Zhong WU; Shi Wei LU

    2003-01-01

    The catalytic property of propylene dimerization by several nickel (Ⅱ), cobalt (Ⅱ)complexes containing N-P bidentate ligands was studied in combination with organoaluminumco-catalysts. The effects of the type of aluminum co-catalysts and its relative amount, the natureof precursors in terms of ligand backbone and metal center were investigated. The resultsindicated that precursor I (N,N-dimethyl-2-(diphenylphosphino)aniline nickel (Ⅱ) dichloride)exhibited high activity in propylene dimerization in the presence of the strong Lewis acid Et3Al2Cl3,whereas low productivity by its cobalt analogues was observed under identical reaction conditions.

  8. Stereocontrol of the Schiff Base of Substituted Benzaldehyde to Staudinger Cycloaddition Reaction

    Institute of Scientific and Technical Information of China (English)

    齐传民; 杨凌春; 孙彭利

    2003-01-01

    Syntheses of 4 novel chiral azetidin-2-one derivatives,which were characterized by 1H NMR,IR,specific rotation and elemental analysis,through Staudinger cycloaddition reaction of Schiff base of benzaldehyde with chlorine substitution at different position in benzene ring,were described.For the first time,this type of 3S,4R configuration azetidin-2-one monocrystals with many chiral centers [(3S,4R)-3-hydroxy-N-[(S)-(1-phenyl)ethyl]-4-(2''-chlorophenyl)-azetidin-2-one monocrystal]were obtained,the structures of which were determined by X-ray diffraction analysis.The effects of Schiff base of benzaldehyde with chlorine substitution at different position in benzene ring on stereoselectivity of Staudinger cycloaddition reaction products were discussed and the results are showed as below:2-chlorophenyl Schiff base favored to yield 3S,4R configuration product,but 4-chlorophenyl Schiff base favored to yield 3R,4S configuration product.The reaction orientation of 2,4-dichlorophenyl Schiff base was determined by corporate effect of 2- and 4-chlorine,and that of the 4-chlorine was more obvious.In contrast to 4-chlorophenyl,although the main product was 3R,4S configuration,3-chlorophenyl owned lower selectivity.

  9. A review on versatile applications of transition metal complexes incorporating Schiff bases

    Directory of Open Access Journals (Sweden)

    Ahmed M. Abu-Dief

    2015-06-01

    Full Text Available Schiff bases and their complexes are versatile compounds synthesized from the condensation of an amino compound with carbonyl compounds and widely used for industrial purposes and also exhibit a broad range of biological activities including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory, antiviral, and antipyretic properties. Many Schiff base complexes show excellent catalytic activity in various reactions and in the presence of moisture. Over the past few years, there have been many reports on their applications in homogeneous and heterogeneous catalysis. The high thermal and moisture stabilities of many Schiff base complexes were useful attributes for their application as catalysts in reactions involving at high temperatures. The activity is usually increased by complexation therefore to understand the properties of both ligands and metal can lead to the synthesis of highly active compounds. The influence of certain metals on the biological activity of these compounds and their intrinsic chemical interest as multidentate ligands has prompted a considerable increase in the study of their coordination behaviour. Development of a new chemotherapeutic Schiff bases and their metal complexes is now attracting the attention of medicinal chemists. This review compiles examples of the most promising applied Schiff bases and their complexes in different areas.

  10. 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.

  11. Interactions of some Schiff base compounds with mild steel surface in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Bayol, Emel [Department of Chemistry, Faculty of Science and Art, Nigde University, Nigde 51200 (Turkey); Guerten, Tijen [Department of Chemistry, Faculty of Science and Art, Cukurova University, Adana 01330 (Turkey); Guerten, A. Ali [Department of Chemistry, Faculty of Science and Art, Nigde University, Nigde 51200 (Turkey)], E-mail: agurten@nigde.edu.tr; Erbil, Mehmet [Department of Chemistry, Faculty of Science and Art, Cukurova University, Adana 01330 (Turkey)

    2008-12-01

    The inhibition effect of the Schiff bases N,N'-bis(salicylidene)-1,2-ethylenediamine (Salen), N,N'-bis(5-methoxysalicylidene)-1,2-ethylenediamine (MeO-Salen) and N,N'-bis(5-nitrosalicylidene)-1,2-ethylenediamine (NO{sub 2}-Salen) on the corrosion of the mild steel in 1.0 M HCl has been studied by electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR) and Tafel polarisation measurements. Maximum inhibition for MeO-Salen was obtained. Results showed that the inhibition efficiency have increased when the concentration of the Schiff bases have increased. Polarisation curves revealed that the Schiff bases acted as anodic inhibitors. The surface adsorption of the Schiff bases has lead to a decrease in the double layer capacitance and to an increase in polarisation resistance. The inhibitor performance depended strongly on the type of functional groups on benzene ring. The adsorption process is spontaneous one and follows Langmuir adsorption isotherm model. Scanning electron microscopy (SEM) has been applied to identify the surface morphology of the mild steel both in the absence and presence of the Schiff base molecules.

  12. Syntheses and structural characterization of mercury (II) coordination polymers with neutral bidentate flexible pyrazole-based ligands

    Science.gov (United States)

    Lalegani, Arash; Khaledi Sardashti, Mohammad; Salavati, Hossein; Asadi, Amin; Gajda, Roman; Woźniak, Krzysztof

    2016-03-01

    Mercury(II) coordination compounds [Hg(μ-bbd)(μ-SCN)4]n(1) and [Hg(bpp)(SCN)2] (2) were synthesized by using the neutral flexible bidentate N-donor ligands 1,4-bis(3,5-dimethypyrazol-1-yl)butane (bbd) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp), NCS- ligand and appropriate mercury(II) salts. Compound 1 forms a polymeric network with moieties which are connected by SCN groups and the mercury ions present as HgN3S2 trigonal bipyramides. The crystal structure of 2 is build of monomers and the mercury(II) ion adopts an HgN2S2 tetrahedral geometry. In the complex 1, each bbd acts as bridging ligand connecting Hg(μ-SCN)4 ions, while in the complex 2, the bpp ligand is coordinated to an mercury(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Moreover, in the tetrahedral structure of 2, the neutral molecules form a 1D chain structure through the C-H···N hydrogen bonds, whereas in 1 no hydrogen bonds are observed. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction.

  13. Selective Synthesis of [2+2] Macrocyclic Schiff Bases from Chiral 1,4-Diamines

    Institute of Scientific and Technical Information of China (English)

    ZHU Hai-Bin; HU Da-Hua; DONG Hua-Ze; LI Gen-Xi; GOU Shao-Hua

    2007-01-01

    [2+2] macrocyclic Schiff bases of three kinds have been synthesized from chiral 1,4-diamines by use of different methods. Macrocyclic Schiff bases 1a-1c have been selectively obtained based on a non-templated dilution method from chiral 1,4-diamines a-c and dialdehyde DA1, whereas macrocycles 2a-2c have been selectively produced from reaction of diamines a-c and dialdehyde DA2 in the presence of boric acid as templates. Macrocyclic Schiff bases 3a-3c have been afforded in high selectivity from diamines a-c and dialdehyde DA3 by means of sodium-template. All the titled compounds have been confirmed by 1H NMR and ESI-MS analyses.

  14. Synthesis of Unsymmetrical Bissalicylaldimine Ligands and bis-Schiff Base Cobalt Complexes with Benzo-10-aza-15-crown-5 Pendant

    Institute of Scientific and Technical Information of China (English)

    LI Jian-Zhang; XU Bin; FENG Fa-Mei; ZHOU Bo; QIN Sheng-Ying

    2007-01-01

    Novel unsymmetrical bissalicylaldimine bis-Schiff bases with a benzo-10-aza-15-crown-5 pendant and their cobalt complexes have been synthesized via condensation of 3 or 5-[(benzo-10-aza-15-crown-5)-10-ylmethyl] salicylaldehyde with the half unit Schiff bases and characterized by 1H NMR, IR, mass spectroscopy, elemental analysis, molar conductances and molar magnetic susceptibility.

  15. Fluorescent chemosensor based on sensitive Schiff base for selective detection of Zn2+.

    Science.gov (United States)

    Singh, T Sanjoy; Paul, Pradip C; Pramanik, Harun A R

    2014-01-01

    A Schiff-base fluorescent compound - N, N'-bis(salicylidene)-1,2 - phenylenediamine (LH2) was synthesized and evaluated as a chemoselective Zn(2+) sensor. Addition of Zn(2+) to ethanol solution of LH2 resulted in a red shift with a pronounced enhancement in the fluorescence intensity. Moreover, other common alkali, alkaline earth and transition metal ions failed to induce response or minimal spectral changes. Notably, this chemosensor could distinguish clearly Zn(2+) from Cd(2+). Fluorescence studies on free Schiff base ligand LH2 and LH2 - Zn(2+) complex reveal that the quantum yield strongly increases upon coordination. The stoichiometric ratio and association constant were evaluated using Benesi - Hildebrand relation giving 1:1 stoichiometry. This further corroborated 1:1 complex formation based on Job's plot analyses.

  16. Preparation of six quinazoline schiff bases and their inhibitory effect on HHCC and Bcap-37 cells

    Institute of Scientific and Technical Information of China (English)

    陈惠; 孙晓莉; 刘志红; 张生勇; 药立波

    2003-01-01

    Objective: To prepare six quinazoline schiff bases by six steps of chemistry organic synthesis and test their inhibitory effect on hepatomacellular carcinoma cells HHCC and mammary cancer cell Bcap-37, furthmore,to compare their antitumor activities on these two kinds of cells. Methods: 2-Amino-5-nitro-benzylcarbonitrile was the initial material, and it was under the reaction of hydrolysis, ring-closing, halogenation, addition, reduction and substitution in turn to get the six quinazoline schiff bases, MTT method was adopted to compare their anticancer activities against the two cancer cells. Result and Conclusion: Six 6-imine-4-halo substituted anilinoquinozolines were prepared. The anticancer activities against both HHCC and Bcap-37were found, furthermore, they have more potency that on HHCC than on Bcap-37. In the six compounds, the schiff base Ⅵ is the most potent compound.

  17. Antioxidant properties of phenolic Schiff bases: structure-activity relationship and mechanism of action.

    Science.gov (United States)

    Anouar, El Hassane; Raweh, Salwa; Bayach, Imene; Taha, Muhammad; Baharudin, Mohd Syukri; Di Meo, Florent; Hasan, Mizaton Hazizul; Adam, Aishah; Ismail, Nor Hadiani; Weber, Jean-Frédéric F; Trouillas, Patrick

    2013-11-01

    Phenolic Schiff bases are known for their diverse biological activities and ability to scavenge free radicals. To elucidate (1) the structure-antioxidant activity relationship of a series of thirty synthetic derivatives of 2-methoxybezohydrazide phenolic Schiff bases and (2) to determine the major mechanism involved in free radical scavenging, we used density functional theory calculations (B3P86/6-31+(d,p)) within polarizable continuum model. The results showed the importance of the bond dissociation enthalpies (BDEs) related to the first and second (BDEd) hydrogen atom transfer (intrinsic parameters) for rationalizing the antioxidant activity. In addition to the number of OH groups, the presence of a bromine substituent plays an interesting role in modulating the antioxidant activity. Theoretical thermodynamic and kinetic studies demonstrated that the free radical scavenging by these Schiff bases mainly proceeds through proton-coupled electron transfer rather than sequential proton loss electron transfer, the latter mechanism being only feasible at relatively high pH.

  18. Preparation and Catalytic Properties of Polymer-Bound Schiff Base Ternary Complexes

    Institute of Scientific and Technical Information of China (English)

    HAO Cheng-jun; WANG Rong-min; HE Yu-feng; WANG Yun-pu; XIA Chun-gu

    2004-01-01

    The polymer-bound Schiff base ternary manganese complexes [PS-SalPhe-Mn-L (L = Phen, Bipy and 8HQ)-] have been prepared from the polymer-bound Schiff base ligand, a manganese salt and the second ligand, such as 1,10-phenanthroline(phen), 2,2′-bipyridyl(bipy) and 8-quinolinol(8HQ). The polymer-bound Schiff base ternary manganese complexes were characterized by means of infrared spectrometry and ICPAES. The catalytic activities of the complexes have been studied in the aerobic epoxidation of long-chain linear a[iphatic olefins. It is shown that 1-octene or 1-decene can be directly oxidized by molecular oxygen when catalyzed by PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ), and 1,2-epoxy alkane can be afforded in these reactions.

  19. Preparation and Characterization of Er2O3 Nanocrystals by Schiff Base Salt Combustion Method

    Institute of Scientific and Technical Information of China (English)

    刘建华; 孙杰; 李松梅

    2003-01-01

    The nanocrystals Er2O3 were prepared by using a combustion method with Schiff base as a chelating agent. The Er(Ⅲ) coordanation compound of Schiff base, obtained from erbium nitrate and retinal Schiff base, underwent a combustion process and voluminous ashes formed when calcimining the complex in air. Pure cubic Er2O3 nanocrystals with a diameter of 13 nm were produced. The nanocrystals were homogeneous and rigid coacervation was not observed. The photoluminescence emission spectrum of the erbium(Ⅲ) oxide nanocrystals shows that it has a characteristic peak at 1.54 μm, and some other shoulder peaks appear on both sides of the main peak.

  20. The exceptionally rich coordination chemistry generated by Schiff-base ligands derived from o-vanillin.

    Science.gov (United States)

    Andruh, Marius

    2015-10-14

    Ortho-vanillin became very popular in coordination chemistry because of its Schiff bases, which generate a rich variety of complexes, ranging from oligonuclear species to coordination polymers. Some of these organic molecules are particularly useful in metallosupramolecular chemistry for assembling homo- and heterometallic helicates. The Schiff bases obtained using aminoalcohols open the door to the synthesis of homo- and heterometallic clusters with various nuclearities and surprising topologies of the metal centers. Several relevant structural types are reviewed. The heterobinuclear 3d-3d' and 3d-4f complexes are valuable building-blocks for the synthesis of heterotrimetallic systems. Beyond the richness of this chemistry, the complexes obtained from o-vanillin-based Schiff ligands show interesting properties: magnetism, luminescence, chirality, catalysis, cytotoxicity, and ferroelectricity. This paper reviews recent data that illustrate a very fertile and dynamic research field in coordination chemistry and materials science.

  1. Schiff bases of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and its silatranes: Synthesis and characterization

    Indian Academy of Sciences (India)

    Gurjaspreet Singh; Amandeep Saroa; Sadhika Khullar; Sanjay K Mandal

    2015-04-01

    This paper aims at the introduction of azomethine group by the condensation reaction of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with different compounds containing carbonyl group such as 2’-hydroxyacetophenone, salicylaldehyde, pyrrole-2-carboxaldehyde, acetylacetone and ethyl acetoacetate. Further, transesterification reaction of these Schiff base modified silanes with triethanolamine as a tripodal ligand leads to the synthesis of corresponding silatranes 1–5 bearing Schiff base functionalized long chain in the axial position. All the synthesized compounds are characterized by spectroscopic methods, elemental analysis and mass spectrometry. The authentication of Schiff base modified silatranes is scrutinized by single X-ray crystal structure of silatrane 1. The thermal stability of the five silatranes is studied by thermo-gravimetric analysis (TGA).

  2. SYNTHESIS AND DOCKING STUDIES OF SCHIFF BASES DERIVED FROM 4-AMINOPYRIDINE

    Directory of Open Access Journals (Sweden)

    Jayita Nandi

    2012-10-01

    Full Text Available A Schiff base is a compound with a functional group that contains a carbon-nitrogen double bond with the nitrogen atom connected to aryl or alkyl group. In the present study, schiff bases were synthesized using 4-amino pyridine and different aldehydes, after assessing the drug likeliness properties. The structure of synthesised compounds were characterized by IR, NMR and Mass spectroscopic techniques. Docking studies were carried out for the schiff bases derived from 4-amino pyridine using Molegro Virtual Docker and protein beta-ketoacyl acyl carrier protein synthase II (mtKasB enzyme was selected as the target for M. tuberculosis. The results of docking study was compared with the standard drug isoniazid and the significant results were obtained.

  3. Synthesis, spectroscopy, and thermal study of uranyl unsymmetrical Schiff base complexes.

    Science.gov (United States)

    Kianfar, Ali Hossein; Dostani, Morteza

    2011-11-01

    The new uranyl complexes with tetradentate unsymmetrical N(2)O(2) Schiff base ligands were synthesized and characterized by IR, UV-vis, NMR and elemental analysis. The DMF solvent is coordinated to uranyl complexes. The thermogravimetry (TG) and differential thermoanalysis (DTA) of the uranyl complexes were carried out in the range of 20-700°C. The UO(2)L(1) complex was decomposed in two and the others were decomposed in three stages. Up to 100°C, the coordinated solvent was released then the Schiff base ligands were decomposed in one or two steps. Decomposition of synthesized complexes is related to the Schiff base characteristics. The thermal decomposition reaction is first order for the studied complexes.

  4. An insight into synthetic Schiff bases revealing antiproliferative activities in vitro.

    Science.gov (United States)

    Sztanke, Krzysztof; Maziarka, Agata; Osinka, Anna; Sztanke, Małgorzata

    2013-07-01

    Schiff bases or azomethines are among the most important groups of biomolecules. These compounds have been found to reveal both remarkable biological activities and a variety of valuable practical applications. An interest in the exploration of novel series of synthetic Schiff bases has undoubtedly been growing due to their proven utility as attractive lead structures for the design of novel cytotoxic and cytostatic agents with a mechanism of action that sometimes differs from that of clinically authorized anticancer agents. Therefore, in the present paper we have focussed our attention on the collected synthetic simple Schiff bases of aldimine- and ketimine-types revealing anticancer activities in vitro, that have been described in the scientific literature during the last decade, and on structural variations whose affect the antiproliferative activity in sets of the designed molecules.

  5. Schiff base protonation changes in Siberian hamster ultraviolet cone pigment photointermediates.

    Science.gov (United States)

    Mooney, Victoria L; Szundi, Istvan; Lewis, James W; Yan, Elsa C Y; Kliger, David S

    2012-03-27

    Molecular structure and function studies of vertebrate ultraviolet (UV) cone visual pigments are needed to understand the molecular evolution of these photoreceptors, which uniquely contain unprotonated Schiff base linkages between the 11-cis-retinal chromophore and the opsin proteins. In this study, the Siberian hamster ultraviolet cone pigment (SHUV) was expressed and purified in an n-dodecyl-β-D-maltoside suspension for optical characterization. Time-resolved absorbance measurements, over a spectral range from 300 to 700 nm, were taken for the purified pigment at time delays from 30 ns to 4.64 s after photoexcitation using 7 ns pulses of 355 nm light. The resulting data were fit globally to a sum of exponential functions after noise reduction using singular-value decomposition. Four exponentials best fit the data with lifetimes of 1.4 μs, 210 μs, 47 ms, and 1 s. The first photointermediate species characterized here is an equilibrated mixture similar to the one formed after rhodopsin's Batho intermediate decays into equilibrium with its successor, BSI. The extremely large red shift of the SHUV Batho component relative to the pigment suggests that SHUV Batho has a protonated Schiff base and that the SHUV cone pigment itself has an unprotonated Schiff base. In contrast to SHUV Batho, the portion of the equilibrated mixture's spectrum corresponding to SHUV BSI is well fit by a model spectrum with an unprotonated Schiff base. The spectra of the next two photointermediate species revealed that they both have unprotonated Schiff bases and suggest they are analogous to rhodopsin's Lumi I and Lumi II species. After decay of SHUV Lumi II, the correspondence with rhodopsin photointermediates breaks down and the next photointermediate, presumably including the G protein-activating species, is a mixture of protonated and unprotonated Schiff base photointermediate species.

  6. Photostability and Performance of Polystyrene Films Containing 1,2,4-Triazole-3-thiol Ring System Schiff Bases.

    Science.gov (United States)

    Ali, Gassan Q; El-Hiti, Gamal A; Tomi, Ivan Hameed R; Haddad, Raghad; Al-Qaisi, Alaa J; Yousif, Emad

    2016-12-09

    Series of 4-(4-substituted benzylideneamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole-3-thiols were synthesized and their structures were confirmed. The synthesized Schiff bases were used as photostabilizers for polystyrene against photodegradation. Polystyrene polymeric films containing synthesized Schiff bases (0.5% by weight) were irradiated (λmax = 365 nm and light intensity = 6.43 × 10(-9) ein·dm(-3)·s(-1)) at room temperature. The photostabilization effect of 1,2,4-triazole-3-thiols Schiff bases was determined using various methods. All the additives used enhanced the photostability of polystyrene films against irradiation compared with the result obtained in the absence of Schiff base. The Schiff bases can act as photostabilizers for polystyrene through the direct absorption of UV radiation and/or radical scavengers.

  7. Photostability and Performance of Polystyrene Films Containing 1,2,4-Triazole-3-thiol Ring System Schiff Bases

    Directory of Open Access Journals (Sweden)

    Gassan Q. Ali

    2016-12-01

    Full Text Available Series of 4-(4-substituted benzylideneamino-5-(3,4,5-trimethoxyphenyl-4H-1,2,4-triazole-3-thiols were synthesized and their structures were confirmed. The synthesized Schiff bases were used as photostabilizers for polystyrene against photodegradation. Polystyrene polymeric films containing synthesized Schiff bases (0.5% by weight were irradiated (λmax = 365 nm and light intensity = 6.43 × 10−9 ein·dm−3·s−1 at room temperature. The photostabilization effect of 1,2,4-triazole-3-thiols Schiff bases was determined using various methods. All the additives used enhanced the photostability of polystyrene films against irradiation compared with the result obtained in the absence of Schiff base. The Schiff bases can act as photostabilizers for polystyrene through the direct absorption of UV radiation and/or radical scavengers.

  8. Crossing the Traditional Boundaries: Salen-Based Schiff Bases for Thermal Protective Applications.

    Science.gov (United States)

    Naik, Anil D; Fontaine, Gaëlle; Bellayer, Séverine; Bourbigot, Serge

    2015-09-30

    A broad spectrum of applications of "Salen"-based Schiff bases tagged them as versatile multifunctional materials. However, their applicability is often bounded by a temperature threshold and, thus, they have rarely been used for high temperature applications. Our investigation of a classical Schiff base, N,N'-bis(4-hydroxysalicylidene)ethylenediamine (L2), reveals that it displays an intriguingly combative response to an elevated temperature/fire scenario. L2 resists and regulates thermal degradation by forming an ablative surface, and acts as a thermal shield. A polycondensation via covalent cross-linking, which forms a hyperbranched cross-linked resin is found to constitute the origin of the ablative surface. This is a unique example of a resin formation produced with a Schiff base, that mimicks the operational strategy of a high-heat resistant phenolic resin. Further applicability of L2, as a flame retardant, was tested in an engineering polymer, polyamide-6. It was found that it reinforces the polymer against fire risks by the formation of an intumescent coating. This paves the way for a new strategic avenue in safeguarding polymeric materials toward fire risks. Further, this material represents a promising start for thermal protective applications.

  9. Synthesis, spectroscopy, electrochemistry and thermal study of vanadyl tridentate Schiff base complexes.

    Science.gov (United States)

    Kianfar, Ali Hossein; Paliz, Marzeh; Roushani, Mahmoud; Shamsipur, Mojtaba

    2011-11-01

    The VO(IV) complexes of tridentate ONO Schiff ligands were synthesised and characterized by IR, UV-vis and elemental analysis. The electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. A good correlation was observed between the oxidation potentials and the electron withdrawing character of the substituents on the Schiff base ligands, showing the following trend: MeOcomplexes were carried out in the range of 20-700°C. The VOL(1)(OH(2)) decomposed in two steps whereas the remaining six complexes decomposed in three steps. The thermal decomposition of these complexes is closely related to the nature of the Schiff base ligands and proceeds via first order kinetics.

  10. 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.

  11. Fluorescence Properties and Electrochemical Behavior of Some Schiff Bases Derived from N-Aminopyrimidine.

    Science.gov (United States)

    Gulcan, Mehmet; Doğru, Ümit; Öztürk, Gülsiye; Levent, Abdulkadir; Akbaş, Esvet

    2014-03-01

    A series of Schiff bases (L 1 , L 2 and L 3) were prepared by refluxing aromatic aldehydes with N-Aminopyrimidine derivatives in methanol and ethanol. The structures of synthesized compounds were characterized by FTIR, (1)H NMR, (13)C NMR and microanalysis. The electrochemical behaviors of the Schiff base ligands were also discussed. Moreover, the evaluation of absorption and emission properties of the structures were carried out in five different solvents. The products show visible absorption maxima in the range of 304-576 nm, and emission maxima from 636 to 736 nm in all solvents tested.

  12. Efficient C2-Symmetric Chiral Schiff Bases for Lanthanide-catalyzed Asymmetric Hydrogenation of Acetophenone

    Institute of Scientific and Technical Information of China (English)

    Peng Fei YAN; Wen Bin SUN; Guang Ming LI; Chun Hong NIE; Zheng Yu YUE

    2006-01-01

    An array of C2-symmetric chiral Schiff bases of substituted salicylaldehyde (1R, 2R)-1,2-cyclohexanediamine and (R)-(+)-2, 2'-diamino-1, 1'-binaphthalene, incorporated with lanthanide complexes, have been applied as catalysts for asymmetric hydrogenation of acetophenone for the first time. Highly enantioselective product with 90% enantiomeric excess (e.e.) was obtained when the catalyst, hybridized by the bulky electron-donating 3, 5-di-tert-butyl substituted Schiff base (2) and SmCl3·4THF, was employed.

  13. Synthesis, X-ray crystallography, thermal studies, spectroscopic and electrochemistry investigations of uranyl Schiff base complexes.

    Science.gov (United States)

    Asadi, Zahra; Shorkaei, Mohammad Ranjkesh

    2013-03-15

    Some tetradentate salen type Schiff bases and their uranyl complexes were synthesized and characterized by UV-Vis, NMR, IR, TG, C.H.N. and X-ray crystallographic studies. From these investigations it is confirmed that a solvent molecule occupied the fifth position of the equatorial plane of the distorted pentagonal bipyramidal structure. Also, the kinetics of complex decomposition by using thermo gravimetric methods (TG) was studied. The thermal decomposition reactions are first order for the studied complexes. To examine the properties of uranyl complexes according to the substitutional groups, we have carried out the electrochemical studies. The electrochemical reactions of uranyl Schiff base complexes in acetonitrile were reversible.

  14. Recent advances in cooperative bimetallic asymmetric catalysis: dinuclear Schiff base complexes.

    Science.gov (United States)

    Matsunaga, Shigeki; Shibasaki, Masakatsu

    2014-02-04

    Cooperative catalysis has proven to be a powerful strategy for realizing high reactivity and selectivity in asymmetric transformations. A variety of cooperative asymmetric catalysts have been developed over the last two decades. In this feature article, recent advances from our research on cooperative asymmetric catalysis, focusing on dinuclear Schiff base catalysis, are described. Design of dinuclear Schiff base catalysts and their applications in several asymmetric C-C and C-N bond-forming reactions under simple proton transfer conditions with perfect atom-economy are discussed in detail.

  15. Transition Metal Ion Complexes of Schiff-bases. Synthesis, Characterization and Antibacterial Properties

    OpenAIRE

    Chohan, Zahid H.; Munawar, Asifa; Supuran, Claudiu T

    2001-01-01

    Some novel transition metal [Co(II), Cu(II), Ni(II) and Zn(II)] complexes of substituted pyridine Schiff-bases have been prepared and characterized by physical, spectral and analytical data. The synthesized Schiff-bases act as deprotonated tridentate for the complexation reaction with Co(II), Ni(II) and Zn(II) ions. The new compounds, possessing the general formula [M(L)2] where [M=Co(II), Cu(II), Ni(II) and Zn(II) and HL=HL1, HL2, HL3 and HL4] show an octahedral geometry. In order to evaluat...

  16. Condensation Polymers of Terephthalic Acid and 1,4-Diaminobutane and Their Schiff Base Complexes

    Directory of Open Access Journals (Sweden)

    Sandeep Rai

    2013-01-01

    Full Text Available Amino-terminated oligomeric poly(tetramethylene terephthalamide (PTTA was prepared by condensation of terephthalic acid and 1,4-diaminobutane using phosphorylation technique. Schiff base complexes of this polyamide were synthesized with salicylaldehyde and 2-hydroxy-1-naphthaldehyde complexes of Co(II, Ni(II, and Cu(II. The polyamide as well as Schiff base complexes were characterized by elemental analysis, IR spectroscopy, and magnetic susceptibility measurements. Thermal stabilities of ligand and its various complexes were compared by thermogravimetric analysis.

  17. Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

    Directory of Open Access Journals (Sweden)

    Shahram Golbabapour

    2013-01-01

    Full Text Available Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg, the positive control (Tween 20 5% v/v, 5 mL/kg, and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg. After 1 h, all of the groups received ethanol 95% (5 mL/kg but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg. The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E, immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

  18. Synthesis and characterization of Schiff base contained dextran microgels in water-in-oil inverse microemulsion.

    Science.gov (United States)

    Su, Hongying; Jia, Qingming; Shan, Shaoyun

    2016-11-05

    Polysaccharide-based microgels with high water content, excellent biocompatibility and controllable particle size have been widely studied as ideal candidates for drug release and delivery. In this study, microgels based on dextran were developed via the Schiff base formation between aldehyded dextran and ethylenediamine in a water-in-oil (W/O) microemulsion. Particle size of the resulted microgel was controllable between 800 and 1100nm by modulating the amount of the employed co-surfactants (Span 80/Tween 80). Furthermore, fluoresceins (e.g., aminofluorescein) and drugs (e.g., doxorubicin) with free amino groups can be conjugated onto the network of the dextran-based microgel via Schiff base linkages. Since the Schiff base linkages are degradable via hydrolysis and their stability decreases with the environmental pH decreases, the resulted Schiff bases contained microgel showed a pH dependent degradation profile. These results indicated that the pH-sensitive microgel based on dextran could be used as promising drug delivery systems for biomedical applications.

  19. Crystal structures and spectral properties of two polyoxometalate-based inorganic-organic compounds from silver-azine building blocks with bis-bidentate and tridentate ligands

    Science.gov (United States)

    An, Bing; Zhou, Rui-Min; Sun, Li; Bai, Yan; Dang, Dong-Bin

    2014-07-01

    Two polyoxometalate-based inorganic-organic hybrid compounds constructed from silver(I)-L species and saturated Keggin type polyoxoanion, [Ag2L21]2(SiMo12O40)·1.5DMF·0.5CH3OHṡH2O 1 and [{Ag4L22(DMF)5}(SiMo12O40)] 2 (L1 = phenyl 2-pyridyl ketone azine, L2 = 3-phenyltriazolo[1,5-a]pyridine), have been synthesized and structurally characterized by IR, UV, elemental analysis, XRPD and complete single crystal structure analyses, where the ligands L1 and L2 are bis-bidentate and tridentate azines synthesized with the same materials under different conditions. The structure of 1 exhibits a dinuclear double-helicate with [SiMo12O40]4- anions as counter ions, where all of the Ag centers coordinate to bis-bidentate chelating ligands. Compound 2 displays a two-dimensional sheet formed by the Ag-organic infinite chains and the [SiMo12O40]4- alternately arranged in a “rail-like” fashion. The luminescent properties of 1 and 2 in the solid state were investigated.

  20. Synthesis and crystal structure of the dinuclear copper(II) Schiff base complex μ-hydroxido-μ-chlorido-bis{[bis(trans-2-nitrocinnamaldehyde)ethylenediamine]chloridocopper(II)} dichloromethane sesquisolvate.

    Science.gov (United States)

    Barati, Kazem; Clegg, William; Habibi, Mohammad Hossein; Harrington, Ross W; Lalegani, Arash; Montazerozohori, Morteza

    2016-03-01

    Transition metal complexes of Schiff base ligands have been shown to have particular application in catalysis and magnetism. The chemistry of copper complexes is of interest owing to their importance in biological and industrial processes. The reaction of copper(I) chloride with the bidentate Schiff base N,N'-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, systematic name: (1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]} in a 1:1 molar ratio in dichloromethane without exclusion of air or moisture resulted in the formation of the title complex μ-chlorido-μ-hydroxido-bis(chlorido{(1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ(2)N,N'}copper(II)) dichloromethane sesquisolvate, [Cu2Cl3(OH)(C20H18N4O4)2]·1.5CH2Cl2. The dinuclear complex has a folded four-membered ring in an unsymmetrical Cu2OCl3 core in which the approximate trigonal bipyramidal coordination displays different angular distortions in the equatorial planes of the two Cu(II) atoms; the chloride bridge is asymmetric, but the hydroxide bridge is symmetric. The chelate rings of the two Nca2en ligands have different conformations, leading to a more marked bowing of one of the ligands compared with the other. This is the first reported dinuclear complex, and the first five-coordinate complex, of the Nca2en Schiff base ligand. Molecules of the dimer are associated in pairs by ring-stacking interactions supported by C-H...Cl interactions with solvent molecules; a further ring-stacking interaction exists between the two Schiff base ligands of each molecule.

  1. Physicochemical characterization of novel Schiff bases derived from developed bacterial cellulose 2,3-dialdehyde.

    Science.gov (United States)

    Keshk, Sherif M A S; Ramadan, Ahmed M; Bondock, Samir

    2015-08-20

    The synthesis of two novel Schiff's bases (cellulose-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] (5) & cellulose-2,3-bis-[(4-methylene-amino)-N-(thiazol-2-yl)-benzenesulfonamide] (6) via condensation reactions of periodate oxidized developed bacterial cellulose ODBC (2) with sulfa drugs [sulfanilamide (3) & sulfathiazole (4)] was reported. The physicochemical characterization of the condensation products was performed using FTIR, (1)H NMR, (13)C NMR spectral analyses, X-ray diffraction and DTA. The ODBC exhibited the highest degree of oxidation based on the aldehyde group number percentage (82.9%), which confirms the highest reactivity of developed bacterial cellulose [DBC (1)]. The X-ray diffractograms indicated an increase in the interplanar distance of the cellulose Schiff base (6) compared to ODBC (2) due to sulfathiazole (4) inclusion between ODBC (2) sheets corresponding to the 1 1 0 plane. In addition, the aldehyde content of Schiff base (6) was (20.8%) much lower than that of Schiff base (5) (41.5%). These results confirmed the high affinity of sulfathiazole (4) to the ODBC (2) chain, and the substantial changes in the original properties of ODBC were due to these chemical modifications rather than the sulfanilamide (3).

  2. Synthesis,Crystal Structure and DNA-binding Properties of a New Copper(Ⅱ) Schiff Base Complex

    Institute of Scientific and Technical Information of China (English)

    QIN Bei

    2012-01-01

    A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic space group P2 1 /c with a=11.218(3),b=9.355(3),c=13.449(4),β=108.722(4)°,V=1336.8(6)3,Z=2,Dc=2.008 g/cm 3,μ(MoKα)=7.024 mm-1,F(000)=806,S=0.999,the final R=0.0342 and wR=0.0641for2611observed reflections (I〉2σ(I)).The central copper(Ⅱ) is four-coordinate and bonds to two nitrogen and two oxygen atoms from two Schiff base ligands.The complex is linked into a two-dimensional supramolecular structure by weak intermolecular interactions.In addition,DNA-binding properties of the metal complex were investigated using spectrometric titrations and viscosity measurements.The results show that the complex binds with calf-thymus DNA(CT-DNA),presumably via a partial intercalative mode.The intrinsic binding constant of the Cu(Ⅱ) complex with DNA is 7.335×10 3 M-1.

  3. Synthesis and Crystal Structure of Binuclear and Pentanuclear Nickel(II Complexes Containing 4-(salicylaldiminatoantipyrine Schiff base

    Directory of Open Access Journals (Sweden)

    Mohamed N. EL-Kaheli

    2015-11-01

    Full Text Available The new title binuclear Ni (II compound  (1 and the novel pentanuclear Ni (II cluster {[   } (2 are formed from the reaction of an asymmetric Schiff base ligand L (L = 4-(salicylaldiminatoantipyrine with Ni .4  in the former or Ni(ClO42.6H2O in presence of malonate in the later.  Complex (1 consists of ( ]+ cation and one uncoordinated tetraphenylborate anion.  The cation adopts a distorted octahedral arrangement around each metal center.  In the binuclear unit both Ni(II ions are linked through two phenolate (µ2-O oxygen atoms of L, and two oxygen atoms of a  bridging carboxylate group. Each Ni (II coordinates to four oxygen atoms at the basal plane, two oxygen atoms from two bridging phenolate groups, one from pyrazolone ring and the last of an aqua molecule, and at the axial positions to a bridging carboxylate-O atom and an azomethine nitrogen atom.  In the pentanuclear cluster (2 consisting of [ ]+2 cation and two tetraphenylborate anions, the core of the cation is assembled by four [Ni( ] units, linked to the central Ni-ion by two bridging water molecules. The resulting coordination sphere for the external symmetry related nickel ions is a pseudo octahedron.  The central Ni-atom unusually adopts dodecahedron geometry through its coordination to eight bridging water molecules. In complex (1 each Ni-atom is coordinated to one tridentate L ligand and in complex (2 each [Ni ( ] unit is coordinated to two bidentate L ligands.  Inter-and intramolecular hydrogen bonds are present in both crystal structures.

  4. Kinetics of formation of acrylamide and Schiff base intermediates from asparagine and glucose

    DEFF Research Database (Denmark)

    Hedegaard, Rikke Susanne Vingborg; Frandsen, Henrik; Skibsted, Leif H.

    2008-01-01

    From the concentration of glucose and asparagine as reactants and of acrylamide as product each determined by LC-MS during reaction in an acetonitrile/water (68:32) model system at pH 7.6 (0.04 M phosphate buffer) and from the relative concentration of the Schiff base intermediate......, the decarboxylated Schiff base intermediate, the Amadori product and aminopropionamide determined in the same reaction mixtures at 120 degrees C, 140 degrees C, 160 degrees C and 180 degrees C for up to 16 min, the energy of activation for formation of the Schiff base intermediate was found to have the value 50...... +/- 2 kJ mol(-1), while the apparent activation energy for formation of acrylamide was 64.4 +/- 0.6 kJ mol(-1), for formation of the decarboxylated Schiff base intermediate 92 +/- 2 kJ mol(-1), and for formation of the Amadori compound 59 +/- 4 kJ mol(-1), respectively. At high temperature conditions...

  5. Characterisation of covalent copper and manganese organometallic complexes with Schiff bases by ionspray mass spectrometry

    NARCIS (Netherlands)

    Raffaelli, A.; Minutolo, F.; Feringa, B.L.; Salvadori, P.

    1998-01-01

    Copper and manganese complexes containing Schiff bases as ligands, having potential interest in homogeneous catalysis, have been characterised by mass spectrometry using ionspray ionisation. Single stage mass spectrometry allowed us to confirm the molecular weight of complexes in all cases, providin

  6. 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.

  7. Small-molecule azomethines: organic photovoltaics via Schiff base condensation chemistry

    NARCIS (Netherlands)

    Petrus,M. L.; Bouwer, R. K. M.; Lafont, U.; Athanasopoulos, S.; Greenham, N. C.; Dingemans, T. J.

    2014-01-01

    Conjugated small-molecule azomethines for photovoltaic applications were prepared via Schiff base condensation chemistry. Bulk heterojunction (BHJ) devices exhibit efficiencies of 1.2% with MoOx as the hole-transporting layer. The versatility and simplicity of the chemistry is illustrated by prepari

  8. Synthesis of Tetra-Schiff Base Macrocyclic Compound Containing Benzo-12-crown-4

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Tetra-Schiff base macrocyclic compound containing benzo-12-crown-4 was synthesized via condensation of 2, 6-diformyl-4-methyl-phenol with 4(, 5(- diaminobenzo-12-C- 4 promoted by proton. The compound was characterized by MS, IR 1HNMR spectroscopy and elemental analysis.

  9. Investigation of some Schiff base compounds containing disulfide bond as HCl corrosion inhibitors for mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M., E-mail: m.behpour@kashanu.ac.i [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of); Ghoreishi, S.M.; Mohammadi, N. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of); Soltani, N. [Payame Noor University (PNU), Shahin Shahr Branch, Isfahan (Iran, Islamic Republic of); Salavati-Niasari, M. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2010-12-15

    Research highlights: {yields} All studied Schiff bases are effective inhibitors for mild steel in 2.0 M HCl. {yields} The inhibition is accomplished by adsorption of molecules on the steel surface. {yields} Examined Schiff bases behave as mixed type inhibitor. {yields} Feed back bonds form between the Schiff bases and steel surface. {yields} Quantum chemical calculations were applied to explain the experimental results. - Abstract: The inhibition performance of three Schiff bases containing disulfide bond as corrosion inhibitors for mild steel in 2.0 M HCl has been investigated by weight loss measurements, potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization study showed that all the inhibitors are mixed type. The adsorption of inhibitors on mild steel surface was found to follow Langmuir adsorption isotherm and the adsorption isotherm parameters (K{sub ads}, {Delta}G{sub ads}) were determined. Quantum chemical calculations were further applied to reveal the adsorption structure and explain the experimental results. Some samples of mild steel were examined by SEM.

  10. New mesogenic Schiff base esters comprising benzothiazole moiety:Synthesis and mesomorphic properties

    Institute of Scientific and Technical Information of China (English)

    Sie Tiong Ha; Teck Ming Koh; Guan Yeow Yeap; Hong Cheu Lin; Jun Kit Beh; Yip Foo Win; Peng Lim Boey

    2009-01-01

    A homologous series of Schiff base esters,6-methoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles,comprising a benzothiazole moiety as the core was synthesized.All the members of this series exhibited an enantiotropic nematic phase.The azomethine linkage along with the lateral hydroxyl and terminal methoxyl groups were found to exert an effect on the mesomorphic properties.

  11. Synthesis and Characterization of Lanthanum Complexes with Amino Acid Schiff Base

    Institute of Scientific and Technical Information of China (English)

    张秀英; 张有娟; 杨林

    2001-01-01

    Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, 1H NMR, thermogravimetric and differential thermal analysis.

  12. Synthesis, characterization and antibacterial studies of ruthenium(III) complexes derived from chitosan schiff base.

    Science.gov (United States)

    Vadivel, T; Dhamodaran, M

    2016-09-01

    Chitosan can be modified chemically by condensation reaction of deacetylated chitosan with aldehyde in homogeneous phase. This condensation is carried by primary amine (NH2) with aldehyde (CHO) to form corresponding schiff base. The chitosan biopolymer schiff base derivatives are synthesized with substituted aldehydes namely 4-hydroxy-3-methoxy benzaldehyde, 2-hydroxy benzaldehyde, and 2-hydroxy-3-methoxy benzaldehyde, becomes a complexing agent or ligand. The Ruthenium(III) complexes were obtained by complexation of Ruthenium with schiff base ligands and this product exhibits as an excellent solubility and more biocompatibility. The novel series of schiff base Ruthenium(III) complexes are characterized by Elemental analysis, FT-IR spectroscopy, and Thermo-gravimetric analysis (TGA). The synthesized complexes have been subjected to antibacterial study. The antibacterial results indicated that the antibacterial activity of the complexes were more effective against Gram positive and Gram negative pathogenic bacteria. These findings are giving suitable support for developing new antibacterial agent and expand our scope for applications.

  13. Synthesis and characterization of nickel complexes derived from Schiff-Bases

    Directory of Open Access Journals (Sweden)

    Mirian Y. Matsumoto

    2012-06-01

    Full Text Available Aromatic Schiff-Bases constitute a large class of organic compounds containing the imine group (C=N [1-3]. 2-hydroxybenzaldehyde (salicylaldehyde which has been frequently used for the synthesis of aromatic Schiff-Bases, it has many biological applications, such as analgesics, anti-inflammatory, antibacterial, antiviral and bactericidal activities [4-6]. From above, this project proposed the synthesis of three Schiff bases derived from salicylaldehyde prepared by condensation between salicylaldehyde with different p-substituted anilines (H, NO2 and MeO. Schiff-Bases synthesized were used as starting compound for the synthesis of nickel complexes. The synthesis of nickel complexes were carried out by adding of alcoholic solution of ligands (2 eq. in aqueous solution of NiCl2.6 H2O (1 eq. contain KOH (1eq. 3 hours. After thisMatsumoto et al. time, the reaction was kept to r.t. to obtain a precipitates. The precipitates were filtered under vacuum and they were characterized by GC-MS, FT-IR and UV-Vis

  14. MTO Schiff-base complexes: synthesis, structures and catalytic applications in olefin epoxidation.

    Science.gov (United States)

    Zhou, Ming-Dong; Zhao, Jin; Li, Jun; Yue, Shuang; Bao, Chang-Nian; Mink, Janos; Zang, Shu-Liang; Kühn, Fritz E

    2007-01-01

    Several Schiff-base ligands readily form complexes with methyltrioxorhenium(VII) (MTO) by undergoing a hydrogen transfer from a ligand-bound OH group to a ligand N atom. The resulting complexes are stable at room temperature and can be handled and stored in air without problems. Due to the steric demands of the ligands they display distorted trigonal-bipyramidal structures in the solid state, as shown by X-ray crystallography, with the O(-) moiety binding to the Lewis acidic Re atom and the Re-bound methyl group being located either in cis or trans position to the Schiff base. In solution, however, the steric differences seem not to be maintained, as can be deduced from (17)O NMR spectroscopy. Furthermore, the Schiff-base ligands exchange with donor ligands. Nevertheless, the catalytic behaviour is influenced significantly by the Schiff bases coordinated to the MTO moiety, which lead either to high selectivities and good activities or to catalyst decomposition. A large excess of ligand, in contrast to the observations with aromatic N-donor ligands, is detrimental to the catalytic performance as it leads to catalyst decomposition.

  15. Structural and molecular docking studies of biologically active mercaptopyrimidine Schiff bases

    Science.gov (United States)

    Kirubavathy, S. Jone; Velmurugan, R.; Karvembu, R.; Bhuvanesh, N. S. P.; Enoch, Israel V. M. V.; Selvakumar, P. Mosae; Premnath, D.; Chitra, S.

    2017-01-01

    Novel Schiff bases derived from the treatment of mercapto-diamino pyrimidine with two different aldehydes are characterized using elemental analysis, single crystal X-ray diffraction and 1H NMR spectroscopy. The pharmacological action of the synthesized compounds viz., antimicrobial, anticancer and antitubercular activities is studied. The Schiff bases show a very good activity against various test pathogens. DNA and β-CD binding interactions of the compounds are studied using UV-Visible absorption and fluorescence spectral measurements. The binding constants of the compounds towards β-CD are in the order of 103 to 104. Molecular docking is done using MOE program on the 3D structure of the enzymes, viz., human thymidylate synthase complexed with dump and raltitrex, candida albicans N-myristoyltransferasepeptidic inhibitor, catalytic domain of protein kinase pKnb from mycobacterium tuberculosis in complex with mitoxantrone, pare, topoisomerase atpase inhibitor, E. coli and lactobacillus casdihydrofolatereductase. The MIC/IC50 values of the Schiff bases are compared with the glide scores from the molecular docking studies. The number of hydrogen bonding interactions between the Schiff bases and amino acid residues are also reported.

  16. Spectroscopic characterization, antimicrobial activity, DFT computation and docking studies of sulfonamide Schiff bases

    Science.gov (United States)

    Mondal, Sudipa; Mandal, Santi M.; Mondal, Tapan Kumar; Sinha, Chittaranjan

    2017-01-01

    Schiff bases synthesised from the condensation of 2-(hydroxy)naphthaldehyde and sulfonamides (sufathiazole (STZ), sulfapyridine (SPY), sulfadiazine (SDZ), sulfamerazine (SMZ) and sulfaguanidine (SGN)) are characterized by different spectroscopic data (FTIR, UV-Vis, Mass, NMR) and two of them, (E)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)-N-(thiazol-2-yl)benzenesulfonamide (1a) and (E)-N-(diaminomethylene)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)benzenesulfonamide (1e) have been confirmed by single crystal X-ray structure determination. Antimicrobial activities of the Schiff bases have been evaluated against certified and resistant Gram positive (Staphylococcus aureus, Enterococcus facelis) and Gram negative (Streptococcus pyogenes, Salmonella typhi, Shigella dysenteriae, Shigella flexneri, Klebsiella pneumonia) pathogens. Performance of Schiff base against the resistant pathogens are better than standard stain and MIC data lie 32-128 μg/ml while parent sulfonamides are effectively inactive (MIC >512 μg/ml). The DFT optimized structures of the Schiff bases have been used to accomplish molecular docking studies with DHPS (dihydropteroate synthase) protein structure (downloaded from Protein Data Bank) to establish the most preferred mode of interaction. ADMET filtration, Cytotoxicity (MTT assay) and haemolysis assay have been examined for evaluation of druglike character.

  17. Synthesis and catalytic activity of Ln(III) complexes with an unsymmetrical Schiff base including multigroups

    Institute of Scientific and Technical Information of China (English)

    YAO; Kemin; (

    2003-01-01

    [1]Elder, R. C., Tridentate and unsymmetrical tetradentate Schiff base ligands from salicylaldehydes and dimeric nickel(II) complexes, Aust. J. Chem., 1978, 31:35-45.[2]Atkins, R., Brewer, G., Kokot, G. et al., Copper(II) and nickel(II) complexesof unsymmetrical tetradentate Schiff base ligand, Inorg. Chem., 1985, 24: 127-134.[3]Meng Qingjin, Wang Ruixue, Bu Xiuren et al., New Ni (II) complexes with mixedtrimeric double Schiff ligands, Chemical Journal of Chinese Universities (in Chinese), 1990, 10: 1126-1130.[4]Yao Kemin, Zhou Wen, Lu Gui et al., Synthesis, mechanism and NMR spectra of lanthanide complexes with a novel unsymmetrical Schiff base, Science in China, Series B, 1999, 42(2): 164-169.[5]Yao Kemin, Li Ning, Huang Qiaohong et al., Synthesis and catalytic activity of novel heteronuclear Ln(III)-Cu(II) complexes with noncyclic polyether-amino acid Schiff base, Science in China, Series B, 1999, 42 (1) : 54-81.[6]Li Ning, Yao Kemin, Lou Kaiyan, Synthesis of La(III), Y(III) complexes with polyglycol aldehyde-amino acid Schiff base and their high resolution solid state 13C NMR spectra, Science in China, Series B, 1999, 42(6): 599-604.[7]Lam Berf, J. B., Shurvell, H. F., Verbet, L. et al., Organic Structural Analysis, New York: Macmillan Publishing Co. Inc., 1975, 234-250.[8]Yao Kemin, Cai Lezhen, Shen Liangfang et al., Synthesis and characterization of lanthanide perchlorates with noncyclic polyethylene glycols and their 13C-NMRspectra, Polyhedron, 1992,11(7): 2245-2251.[9]Dewar, M. J. S., Zoebisch, E. G., Healy, E. F., AM1: A new general purpose quantum mechanical molecular model, J. Amer. Chem. Soc., 1985, 107: 3902-3909.[10]Feifer, P., Avnjr, D., Chemistry in noninteger dimensions between two and three, I. Fractal theory of heterogeneous surfaces, J. Chem. Phys., 1983, 79(7): 3558-3565.[11]Yang Haifeng, Wang Hui, Duan Jinxia et al., Ab initio research of organic ligand Schiff base 4-[(2-hydroxyphenyl) imine]-2

  18. Fluorescence Quenching Study on the Interaction of Some Schiff Base Complexes with Bovine Serum Albumin

    Institute of Scientific and Technical Information of China (English)

    MEI,Ping; ZHANG,Li-Xia; LIU,Yi; CAI,Li-Hua; HU,Pei-Zhi

    2008-01-01

    The interaction of Schiff base ligand A and its three metal complexes[A-Fe(Ⅱ), A-Cu(Ⅱ), and A-Zn(Ⅱ)] with bovine serum albumin (BSA) was investigated using a tryptophan fluorescence quenching method. The Schiff base ligand A and its three metal complexes all showed quenching of BSA fluorescence in a Tris-HCl buffer. Quenching constants were determined for quenching BSA by the Schiff base ligand A and its metal complexes in a Tris-HCl buffer (pH=7.4) at different temperatures. The experimental results show that the dynamic quenching constant (KSV) was increased with increasing temperature, whereas the association constant (K) was decreased with the in crease of temperature. The thermodynamic parameters ΔH, ΔG and ΔS at different temperatures were calculated.The ionic strength of the Tris-HCl buffer had a great influence on the wavelength of maximum emission of BSA.Under low ionic strength, the emission spectra of BSA influenced by A-Zn(Ⅱ) had a small blue shift. Compared to A-Zn(Ⅱ), the emission spectra of BSA in the presence of the Schiff base ligand A and A-Cu(Ⅱ) had no significant λem shift. At high ionic strength, the emission spectra of BSA upon addition of the Schiff base A, A-Fe(Ⅱ), and A-Zn(Ⅱ) all had a red shift, but the emission spectra of BSA had λem shift neither at low ionic strength, nor at high ionic strength in the presence of A-Cu(Ⅱ). Furthermore, the temperature did not affect the λem shift of BSA emission spectra.

  19. Inhibition of advanced protein glycation by a Schiff base between aminoguanidine and pyridoxal.

    Science.gov (United States)

    Taguchi, T; Sugiura, M; Hamada, Y; Miwa, I

    1999-08-13

    Aminoguanidine is a well-known inhibitor of the formation of advanced glycation end products and is considered to be promising for the treatment of diabetic complications. We recently reported, however, that administration of aminoguanidine caused the formation of a Schiff base adduct between aminoguanidine and pyridoxal phosphate in the liver and kidney of mice and a concomitant decrease in the amount of liver pyridoxal phosphate. Our study led us to hypothesize that the Schiff base adduct and/or another Schiff base adduct formed from aminoguanidine and pyridoxal might be a better compound than aminoguanidine. In the present study, we examined the in vitro inhibitory potency of the latter adduct against advanced glycation end product formation and its effect on the tissue contents of pyridoxal and its phosphate. Aminoguanidine-pyridoxal phosphate adduct was not employed in this study because of its poor solubility in water. Aminoguanidine-pyridoxal adduct was hydrolyzed by only about 15% during 10 days at pH 7.4 and 37 degrees C. The adduct at 1 mM did not inhibit Amadori product formation induced by incubation of albumin with 100 mM mannose for 10 days. The adduct, when tested at 1 and 2 mM, dose-dependently inhibited advanced glycation end product formation induced by incubation of albumin with mannose; and the inhibitory potency of the adduct was similar to or higher than that of aminoguanidine. The presence of an appreciable amount of aminoguanidine-pyridoxal adduct in the kidney of mice given the adduct suggested that at least part of the adduct administered was absorbed from the gastrointestinal duct. The amounts of pyridoxal and its phosphate in tissues were not at all decreased by administration of the aminoguanidine-pyridoxal Schiff base. We conclude that the Schiff base may be a more promising inhibitor of advanced protein glycation than aminoguanidine.

  20. Molecular Design of Calixarene 5. Syntheses and Cation Selectivities of Novel Schiff' s Base p-tert-Butylcalix[4]arenes

    Institute of Scientific and Technical Information of China (English)

    刘育; 赵邦屯; 王浩; 陈企发; 张衡益

    2001-01-01

    Five novel Schiff's bases p-tert-butylcalix[4]arenes have ben synthesized in high yields by the reaction of 1,3-distally disubstituted p-tert-butyicalix[4]arene amine(1) with the corresponding aromatic aldehydes,and their cation binding abilities and selectivities with alkali and heavy metal ions have been evaluated by solvent extraction of aqueous metal picrates to show the highet Ag+ extractability for Schiff' s base p-tertbutylcalix[4]arene (6) and the best Na+/Li+ and Ag+/Tl+selectivities for Schiff's base p-tert-butylcalix[4]arene (4 and 2) over any other caltx[4]arene derivatives, respectively.

  1. Biological activity of palladium(II) and platinum(II) complexes of the acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate and the X-ray crystal structure of the [Pd(asme)2] (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) complex.

    Science.gov (United States)

    Akbar Ali, Mohammad; Mirza, Aminul Huq; Butcher, Raymond J; Tarafder, M T H; Keat, Tan Boon; Ali, A Manaf

    2002-11-25

    Palladium(II) and platinum(II) complexes of general empirical formula, [M(NS)(2)] (NS=uninegatively charged acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate; M=Pt(II) and Pd(II)) have been prepared and characterized by a variety of physicochemical techniques. Based on conductance, IR and electronic spectral evidence, a square-planar structure is assigned to these complexes. The crystal and molecular structure of the [Pd(asme)(2)] complex (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) has been determined by X-ray diffraction. The complex has a distorted cis-square planar structure with the ligands coordinated to the palladium(II) ions as uninegatively charged bidentate NS chelating agents via the azomethine nitrogen and the mercaptide sulfur atoms. The distortion from a regular square-planar geometry is attributed to the restricted bite angles of the ligands. Antimicrobial tests indicate that the Schiff bases exhibit strong activities against the pathogenic bacteria, Bacillus subtilis (mutant defective DNA repair), methicillin-resistant Staphylococcus aureus, B. subtilis (wild type) and Pseudomonas aeruginosa and the fungi, Candida albicans (CA), Candida lypotica (2075), Saccharomyces cerevisiae (20341) and Aspergillus ochraceous (398)-the activities exhibited by these compounds being greater than that of the standard antibacterial and antifungal drugs, streptomycin and nystatin, respectively. The palladium(II) and platinum(II) complexes are inactive against most of these organisms but, the microbe, Pseudomonas aeruginosa shows strong sensitivity to the platinum(II) complexes. Screening of the compounds for their cytotoxicities against T-lymphoblastic leukemia cancer cells has shown that the acetone Schiff base of S-methyldithiocarbazate (Hasme) exhibits a very weak activity, whereas the S-benzyl derivative (Hasbz) is inactive. However, the palladium(II) complexes exhibit strong cytotoxicities against this cancer; their

  2. Synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory potential of hydrazide based Schiff bases.

    Science.gov (United States)

    Rahim, Fazal; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Nawaz, Mohsan; Ashraf, Muhammad; Ali, Muhammad; Sajid, Muhammad; Ali, Farman; Khan, Muhammad Naseem; Khan, Khalid Mohammed

    2016-10-01

    To discover multifunctional agents for the treatment of Alzheimer's disease, a series of hydrazide based Schiff bases were designed and synthesized based on multitarget-directed strategy. We have synthesized twenty-eight analogs of hydrazide based Schiff bases, characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase and butyrylcholinesterase inhibition. All compounds showed varied degree of acetylcholinesterase and butyrylcholinesterase inhibition when compared with standard Eserine. Among the series, compounds 10, 3 and 24 having IC50 values 4.12±0.01, 8.12±0.01 and 8.41±0.06μM respectively showed potent acetylcholinesterase inhibition when compared with Eserine (IC50=0.85±0.0001μM). Three compounds 13, 24 and 3 having IC50 values 6.51±0.01, 9.22±0.07 and 37.82±0.14μM respectively showed potent butyrylcholinesterase inhibition by comparing with eserine (IC50=0.04±0.0001μM). The remaining compounds also exhibited moderate to weak inhibitory potential. Structure activity relationship has been established. Through molecular docking studies the binding interaction was confirmed.

  3. Synthesis and antibacterial activity of Schiff bases and amines derived from alkyl 2-(2-formyl-4-nitrophenoxy)alkanoates.

    Science.gov (United States)

    Goszczyńska, Agata; Kwiecień, Halina; Fijałkowski, Karol

    A series of novel Schiff bases and secondary amines were obtained in good yields, as a result of the reductive amination of alkyl 2-(2-formyl-4-nitrophenoxy)alkanoates with both aniline and 4-methoxyaniline under established mild reaction conditions. Sodium triacetoxyborohydride as well as hydrogen in the presence of palladium on carbon were used as efficient reducing agents of the Schiff bases, in both direct and stepwise reductive amination processes. The Schiff bases, amines, and amine hydrochlorides were designed as potential antibacterial agents, and structure-activity relationship could be established following in vitro assays against Gram-positive and Gram-negative bacteria. The minimal inhibitory concentration and zone of inhibition were also determined. In these tests, some of Schiff bases and secondary amine hydrochlorides showed moderate-to-good activity against Gram-positive bacteria, including S. aureus, M. luteus, and S. mutans.

  4. Novel symmetric diimine-Schiff bases and asymmetric triimine-Schiff bases as chemosensors for the detection of various metal ions

    Science.gov (United States)

    Özdemir, Özlem

    2016-12-01

    In this study, two symmetric diimine-Schiff bases (D1, D2) containing nitro group were synthesized by a simple one-pot condensation of 4-nitro-o-phenylenediamine with substituted-salicylaldehyde (5-Cl, 5-CH3) in 1:2 ratio. After the selective reduction of nitro group to amino group by using sodium dithionite and forming the new imine bond by adding substituted-salicylaldehyde or 2-hydroxy-1-naphthaldehyde, four asymmetric triimine-Schiff bases (T1s, T1n, T2s, and T2n) were obtained. Results of the newly synthesized compounds established by elemental analyses, FT-IR, UV-vis, 2D NMR (HMQC), 1H-NMR, 13C-NMR and TOF-mass spectroscopic experiments were consistent with their chemical structures. The tautomeric equilibria were also studied. The sensor properties of all Schiff bases were examined upon addition of the metal ions, such as Cr3+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, and Pb2+. The interactions between receptors and ions are easily monitored by UV-vis method. The receptor D2 showed colour changes from yellow to intense deep orange colour for Cu2+, a orange colour for Co2+ and dark yellow colour for other ions. Although metal ions caused no change in colour of T2s, the main absorption band of receptor shifted from 351 nm to 343-372 nm T2n underwent colour changes from yellow to light yellow on gradual addition of Fe3+.

  5. Synthesis, Characterization and Biological Activity of Transition Metals with Schiff Base Derived from Adamantaneamine and o-Vanillin

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Five new solid complexes were synthesized about transition metals with Schiff base(L,C18H23NO2) derived from adamantaneamine and o-vanillin, and characterized by elemental analysis, molar conductance, infrared spectra, UV-vis spectra, thermal analysis. Their chemical formula are [ML2](ClO4)2 (M= Mn,Co,Ni,Cu,Zn),and the coordination numbers are four. The antibacterial activity of Schiff base ligand and its complexes was studied.

  6. Structural characterization of some Schiff base compounds: Investigation of their electrochemical, photoluminescence, thermal and anticancer activity properties

    Energy Technology Data Exchange (ETDEWEB)

    Ceyhan, Gökhan; Köse, Muhammet [Chemistry Department, Kahramanmaraş Sütcü Imam University, 46100 Kahramanmaraş (Turkey); Tümer, Mehmet, E-mail: mtumer@ksu.edu.tr [Chemistry Department, Kahramanmaraş Sütcü Imam University, 46100 Kahramanmaraş (Turkey); Demirtaş, İbrahim; Şahin Yağlioğlu, Ayse [Chemistry Department, Çankırı Karatekin University, 18100 Çankırı (Turkey); McKee, Vickie [Chemistry Department, Loughborough University, LE11 3TU Leics (United Kingdom)

    2013-11-15

    Three Schiff base compounds, N,N′-bis(2,4-dimethoxy benzaldiimine)-1,4-diamino cyclohexane (IGA{sup 1}), N,N′-bis(2,3,4-trimethoxy benzaldiimine)-1,4-diamino cyclohexane (IGA{sup 2}) and N,N′-bis(3,4,5-trimethoxy benzaldiimine)-1,4-diamino cyclohexane (IGA{sup 3}) were synthesized and characterized by the spectroscopic and analytical methods. The electrochemical and photoluminescence properties of the compounds IGA{sup 1}–IGA{sup 3} have been investigated in the different conditions. All the synthesized Schiff base compounds IGA{sup 1}, IGA{sup 2} and IGA{sup 3} were screened for their cytotoxicity (HeLa and Vera cells). The structural characterization of the Schiff base compounds was determined by single crystal X-ray diffraction studies. The molecules IGA{sup 1} and IGA{sup 3} both lie on centers of symmetry but in IGA{sup 2} the molecule has no crystallographically imposed symmetry. In the compound IGA{sup 1}, Schiff base molecules are linked by π stacking interactions. There is no evidence of π stacking in both IGA{sup 2} and IGA{sup 3}, however there are some C–H⋯π and C–H…O interactions in these compounds. The thermal stabilities of the compounds were investigated in the nitrogen atmosphere. -- Highlights: • Schiff base ligands were prepared and fully characterized. • X-ray crystal structures of Schiff base ligands were reported. • Electrochemical properties of Schiff base ligands were investigated. • Absorption and photoluminescence properties of the Schiff bases were examined.

  7. Synthesis, characterization and antioxidant activities of Schiff bases are of cholesterol

    Directory of Open Access Journals (Sweden)

    Madasamy Kumar

    2017-01-01

    Full Text Available A series of new cholesterol based Schiff base derivatives, namely cholesteryl-n-(4-((E-(4′-cyanobiphenyl-4-yliminomethylphenoxyalkanoate (3a–j have been synthesized and characterized by IR, NMR and mass spectral studies. In vitro antioxidant activities of these compounds were evaluated against super oxide anion radical, nitric oxide radical, DPPH radical and hydrogen peroxide and were compared with standard natural antioxidant, ascorbic acid. Our results reveal that these compounds exhibit excellent radical scavenging activities.

  8. New anthracene-based Schiff bases: Theoretical and experimental investigations of photophysical and electrochemical properties

    Science.gov (United States)

    Sek, Danuta; Siwy, Mariola; Grucela, Marzena; Małecki, Grzegorz; Nowak, Elżbieta M.; Lewinska, Gabriela; Santera, Jerzy; Laba, Katarzyna; Lapkowski, Mieczyslaw; Kotowicz, Sonia; Schab-Balcerzak, Ewa

    2017-03-01

    The new Schiff bases bearing anthracene unit were synthesized from 2-aminoanthracene and various aldehydes such as: benzaldehyde, 4-(diphenylamino)benzaldehyde, 9-phenanthrenecarboxaldehyde, 9-anthracenecarboxaldehyde, and biphenyl-4-carboxaldehyde, 2-naphthaldehyde. Resulted azomethines were characterized by IR, NMR (1H and 13C), elemental analysis and UV-vis spectroscopy. The imine consists of anthracene and biphenyl moieties exhibited liquid crystal properties and their nematic phase showed Schlieren texture. The photoluminescence measurements carried out in solution and in solid state as blend with PMMA revealed the ability of the imines to emission of the blue light with quantum yield efficiency in the range of 2.18-6.03% in blend. Based on the electrochemical experiment they showed value of energy gap (Eg) in the range of 2.5-2.7 eV. Additionally, density functional theory (DFT) was applied for calculations of both electronic structure and spectroscopic properties of synthesized Schiff bases. Moreover, the results obtained from preliminary tests of application of the azomethines in organic photovoltaic (OPV) devices confirmed their electron acceptor character.

  9. Electronic Spectrum of different Bis-Schiff bases of Isatin and its Solvatochromism

    Directory of Open Access Journals (Sweden)

    *M. A. K. Tanoli

    2014-09-01

    Full Text Available The influence of a series of organic solvents on the UV spectra on some selected bis-Schiff base derivatives has been studied in a number of organic solvents with diverse polarities. As a part of our efforts to interpret the effects of solvent polarity and hydrogen bonding on the absorption spectra of previously synthesized bis-Schiff base derivatives, the study design was based on the linear solvation energy relationship (LSER concept using Kamlet-Taft solvatochromic parameters: π*, α and β. Correlation of spectroscopic data was carried out by means of multiple linear regression techniques. The fitting coefficient obtained from this analysis allows estimating the contribution of each type of interactions relative to total spectral shifts in solution. The dependence of (max on the solvent parameters indicated that the obtained bands were affected by specific and non-specific solute-solvent interactions.

  10. Lanthanide amino acid Schiff base complexes: synthesis, spectroscopic characterization, physical properties and in vitro antimicrobial studies

    Institute of Scientific and Technical Information of China (English)

    Samir Alghool; M.Sh.Zoromba; Hanan F.Abd El-Halim

    2013-01-01

    Complexes of La (Ⅲ),Nd(Ⅲ),Gd(Ⅲ),Sm(Ⅲ),and Ce(Ⅳ) were synthesized with Schiff base [(3,5-di-tert-butyl-2-hydroxybenzyl) amino] acetic acid (H3L).The ligand and its complexes were synthesized and characterized based on the following analysis:elemental analyses,FAB-mass,molar conductance measurements,magnetic measurement,UV-visible,IR,and NMR spectral studies.The spectral data revealed that the ligand acted as a neutral tridentate coordinating to metal ion through ONO donor sequence.Thermal degradation studies of the ligand and its complexes showed that the previous lanthanide complexes were more thermally stable than the ligand itself.The Schiff base and its complexes were screened for their antibacterial (Escherichia coli,Staphylococcus aureus) and antifungal (Aspergillus flavus and Candida Albicans).

  11. Synthesis and characterization of transition metal(II) complexes with tridentate schiff base in DMF solution

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jeong Geun [Seonam Univ., Namwon (Korea, Republic of); Choi, Yong Kook [Cheonnam National Univ., Kwangju (Korea, Republic of)

    1999-10-01

    Shiff Base ligand such as (NOIPH) have been synthesized from 2-hydroxy-1naph-thaldehyde and arometic amine, Co(II), Ni(II), and Cu(II) complexes from the reaction metal salts with Tridentate Schiff Base (NOIPH) were synthesized. The ligand and metal(II) complexes were characterized by the elementary analysis, IR, UV-Vis, NMR spectra, and thermogravimetric analysis. Metal(II) complexes in solid state have been shown that the mole ratio of Schiff base (NOIPH) as N{sub 2}O type to Metal(II) is 2:1 and the metal(II) complexes of N{sub 2}O ligand type were four-coordinated configurations.

  12. Spectroscopic, docking and molecular dynamics simulation studies on the interaction of two Schiff base complexes with human serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Fani, N. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Bordbar, A.K., E-mail: bordbar@chem.ui.ac.ir [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Ghayeb, Y. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2013-09-15

    This study was designed to examine the interaction of two Schiff base complexes with human serum albumin (HSA), by different kinds of spectroscopic and molecular modeling techniques. Fluorescence quenching and absorption spectra were investigated in order to estimate the binding parameters. The analysis of absorption data at different temperatures were done in order to estimate the thermodynamics parameters of interactions between Schiff base complexes and HSA. The experimental data suggested that both complexes demonstrated a significant binding affinity to HSA and the process is enthalpy driven. Molecular docking study indicated that both Schiff base complexes bind to polar and apolar residues located in the subdomain IB of HSA. Molecular dynamics (MD) simulations were also performed with the GROMACS program package to study the characters of HSA in binding states. Molecular dynamics results suggested that both Schiff base complexes can interact with HSA, without affecting the secondary structure of HSA but probably with a slight modification of its tertiary structure. All the molecular docking and molecular dynamics results kept in good consistence with experimental data. -- Highlights: • The fluorescence of HSA quenched due to reacting with Schiff base complexes. • The absorbance of Schiff base complexes in the presence of HSA changed. • Binding parameters and the pose of the molecules in the binding site were estimated. • Both complexes can interact with HSA, without affecting the secondary structure. • Simulation results predicted slight compactness of tertiary structure for HSA.

  13. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors.

    Science.gov (United States)

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz; Riahi, Siavash

    2008-03-11

    Ionophore incorporated PVC membrane sensors are well-established analyticaltools routinely used for the selective and direct measurement of a wide variety of differentions in complex biological and environmental samples. Potentiometric sensors have someoutstanding advantages including simple design and operation, wide linear dynamic range,relatively fast response and rational selectivity. The vital component of such plasticizedPVC members is the ionophore involved, defining the selectivity of the electrodes' complexformation. Molecular recognition causes the formation of many different supramolecules.Different types of supramolecules, like calixarenes, cyclodextrins and podands, have beenused as a sensing material in the construction of ion selective sensors. Schiff's bases andcrown ethers, which feature prominently in supramolecular chemistry, can be used assensing materials in the construction of potentiometric ion selective electrodes. Up to now,more than 200 potentiometric membrane sensors for cations and anions based on Schiff's bases and crown ethers have been reported. In this review cation binding and anioncomplexes will be described. Liquid membrane sensors based on Schiff's bases and crownethers will then be discussed.

  14. DFT and TDDFT investigation of the Schiff base formed by tacrine and saccharin.

    Science.gov (United States)

    Acar, Nursel; Selçuki, Cenk; Coşkun, Emine

    2017-01-01

    Schiff bases have many chemical and biological applications in medicine and pharmaceuticals due to the presence of an imine group (-C=N-). These bases are used in many different fields of technology, and in photochemistry because of their photochromic properties. Here, the structural and electronic properties of the Schiff base formed by tacrine and saccharin (TacSac) were explored using density functional theory with the B3LYP, M06-2X, M06L, and ωB97XD functionals in combination with the 6-311++G(d,p) basis set. The time-dependent formalism was used at the B3LYP/6-311++G(d,p) level to obtain electronic transitions. The calculations were repeated in an implicit solvent model mimicking water, using the polarizable continuum model in conjunction with a solvation model based on a density approach. The results indicate that TacSac cannot form spontaneously, but can be obtained in mild reactions. However, the resulting Schiff base displays different characteristics to its monomers. It also has the potential for use in photochemical intramolecular charge-transfer systems. Graphical Abstract Intramolecular charge transfer between HOMO and LUMO of TacSac.

  15. SchiffBase Dinuclear Complex Catalyst for Oxidation of Cyclohexene with Molecular Oxygen

    Institute of Scientific and Technical Information of China (English)

    SHAO; DongXu

    2001-01-01

    In the past decades, the oxidation of hydrocarbons by transition metal complexes has been studied extensively. The current progress of the research on synthetic quasiporphyrin catalysts has led to the development of several systems that are able to reproduce the hene-enzyme mediated oxygenation and oxidation reactions[1]. In our group[2,51, the mononuclear complexes of amino acid Schiff base have been synthesized and their catalytic oxidation has been studied. In this paper, two dinuclear complexes, such as Salicylidence-β-alanine-Co(II)-Cu(II) and Salicylidence-β-alanine-Co(II)Mn(II), were prepared with amino acid Schiff bases and metal ions. In the presence of these dinuclear complexes, cyclohexene was effectively oxidized under 1 atm of molecular oxygen without any coreductants. The allylic hydroperoxide was obtained as an important product, which suggested a clear allylic pathway of oxidation of cyclohexene.  ……

  16. Synthesis, Characterization and Bioactivity of Complexes of Rare Earth with Bis-Schiff Base from Furoylpyrazolone

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl)α-furylmethylidyne] ethylenediimine ((HPMαFP)2en) were synthesized. On the basis of elemental analysis and molar conductance, a general formula of the complexes, [RE(HPMαFP)2 en(NO3)2]NO3 (RE=La, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Yb,Y), was given. The complexes were characterized by IR, UV-visible, 1H NMR, 13C NMR and fluorescence. The results show that the bis-Schiff base is a quadridentate ligand and the rare earth ions exhibit coordination of eight in the complexes. The antibacterial experiments indicate that they have high antibacterial activities against S. aureus, B. subtillis, E. coli, E.carotovora, C. flaccumfaciens.

  17. Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers.

    Science.gov (United States)

    Yousif, Emad; Al-Amiery, Ahmed A; Kadihum, Abdulhadi; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2015-11-04

    The photostabilization of polyvinyl chloride (PVC) films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs) for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10(-8). According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV) absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.

  18. Syntheses of Ferrocenyl Schiff Bases Using Molecular Sieves and AlCl3 as Catalysts

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to study the donor ability of ferrocenylimines as directing ortho metalation group(DMG) to lithium alkylide to prepare planar chiral ferrocene, a series of ferrocenyl schiff bases were synthesized by new methods using molecular sieves(0.4nm) and AlCl3 as catalysts. The reaction periods were reduced using these two catalysts in contrast with Al2O3, which was a traditional method used in the literature. In addition, as an important feature of these schiff bases, we found that they were unstable as oils in air or when filtrated through silica gel, but were stable as solids. The structures of the new compounds were confirmed by IR, 1H NMR and HRMS.

  19. Synthesis, spectroscopic characterization and pH dependent photometric and electrochemical fate of Schiff bases.

    Science.gov (United States)

    Rauf, Abdur; Shah, Afzal; Abbas, Saghir; Rana, Usman Ali; Khan, Salah Ud-Din; Ali, Saqib; Zia-Ur-Rehman; Qureshi, Rumana; Kraatz, Heinz-Bernhard; Belanger-Gariepy, Francine

    2015-03-05

    A new Schiff base, 1-((4-bromophenylimino) methyl) naphthalen-2-ol (BPIMN) was successfully synthesized and characterized by (1)H NMR, (13)C NMR, FTIR and UV-Vis spectroscopy. The results were compared with a structurally related Schiff base, 1-((4-chlorophenylimino) methyl) naphthalen-2-ol (CPIMN). The photometric and electrochemical fate of BPIMN and CPIMN was investigated in a wide pH range. The experimental findings were supported by quantum mechanical approach. The redox mechanistic pathways were proposed on the basis of results obtained electrochemical techniques. Moreover, pH dependent UV-Vis spectroscopy of BPIMN and CPIMN was carried out and the appearance of isosbestic points indicated the existence of these compounds in different tautomeric forms.

  20. Characterisation of fluorescent Schiff bases formed during oxidation of pig myofibrils.

    Science.gov (United States)

    Chelh, Ilham; Gatellier, Philippe; Santé-Lhoutellier, Véronique

    2007-06-01

    The aim of this study was to investigate the formation of fluorescent Schiff bases between proteins and lipid oxidation products in myofibrils. Myofibrils were prepared from pig M. longissimus dorsi and oxidized by hydroxyl (OH()) and superoxide (O(2)(-)) radical generating systems. Protein oxidation was measured by the carbonyl content and lipid oxidation was estimated by measurement of thiobarbituric acid reactive substances (TBARS). To avoid any bias due to their low solubility, fluorescent pigments were estimated directly in the solid state by a front-face fluorescence technique. Hydroxyl radicals generated high levels of lipid and protein oxidation as well as fluorescent pigments, whereas only fluorescence was affected by superoxide radicals. The formation of fluorescent pigments was linked not only to aldehyde production, but also to the availability of the amino groups of the myofibrillar protein side chains. Schiff bases could be implicated in protein aggregation with deleterious effect on meat quality.

  1. A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution.

    Science.gov (United States)

    Gündüz, Z Yurtman; Gündüz, C; Özpınar, C; Urucu, O Aydın

    2015-02-05

    A new fluorescent Cu(II) sensor (L) obtained from the Schiff base of 5,5'-methylene-bis-salicylaldehyde with amidol (2,4-diaminophenol) was synthesized and characterized by FT-IR, MS, (1)H NMR, (13)C NMR techniques. In the presence of pH 6.5 (KHPO4-Na2HPO4) buffer solutions, copper reacted with L to form a stable 2:1 complex. Fluorescence spectroscopic study showed that Schiff base is highly sensitive towards Cu(II) over other metal ions (K(+), Na(+), Al(3+), Ni(2+), Co(2+), Fe(3+), Zn(2+), Pb(2+)) in DMSO/H2O (30%, v/v). The sensor L was successfully applied to the determination of copper in standard reference material. The structural properties and molecular orbitals of the complex formed between L and Cu(2+) ions were also investigated using quantum chemical computations.

  2. Studies of Some Lanthanide(III Nitrate Complexes of Schiff Base Ligands

    Directory of Open Access Journals (Sweden)

    Kishor Arora Mukesh Sharma

    2009-01-01

    Full Text Available The studies of 16 new lanthanide(III nitrate complexes of Schiff base ligands are discussed. Schiff bases were obtained by the condensation of 2–methyl–4–N,N–bis–2' –cyanoethyl aminobenzaldehyde with aniline and 3 different substituted anilines. Lanthanide(III nitrates, viz. gadolinium(III nitrate, lanthanum(III nitrate, samarium(III nitrate and cerium(III nitrate were chosen to synthesize new complexes. The complexes were characterized on the basis of physicochemical studies viz. elemental analysis, spectral, viz. IR and electronic spectral and magnetic studies. TGA studies of some of the representative complexes were also done. Some of the representative complexes were also screened for the anti microbial studies.

  3. Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers

    Directory of Open Access Journals (Sweden)

    Emad Yousif

    2015-11-01

    Full Text Available The photostabilization of polyvinyl chloride (PVC films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10−8. According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.

  4. Synthesis, physical characterization and biological evaluation of Schiff base M(II complexes

    Directory of Open Access Journals (Sweden)

    Mahasin Alias

    2014-04-01

    Full Text Available Metal (II complexes of Cu, Ni, and Co with Schiff base derived from potassium 2-N (4-N,N-dimethylaminobenzyliden- 4-trithiocarbonate 1,3,4-thiadiazole (L were synthesized and characterized by standard physico-chemical procedures i.e. (metal analysis A.A, elemental chemical analysis C.H.N.S, FTIR, UV–vis, thermal analysis TGA, magnetic susceptibility and conductometric measurements. On the basis of these studies, a six coordinated octahedral geometry for all these complexes has been proposed. The Schiff base ligand and its complexes were also tested for their antibacterial activity to assess their inhibiting potential against Pseudomonas aeruginosa (as gram negative bacteria and Staphylococcus aureus (as gram positive bacteria using two different concentrations (5 and 10 mM. The results showed the Ni(II complex have the higher rate in antibacterial activity than other complexes and ligand when compared them with ampicillin as standard drug.

  5. Preparation, regulation and biological application of a Schiff base fluorescence probe

    Science.gov (United States)

    Yin, Ninghua; Diao, Haipeng; Liu, Wen; Wang, Jingru; Feng, Liheng

    2016-01-01

    A facile fluorescence switch with Schiff base units was designed and achieved by nucleophilic addition and dehydration reaction. The fluorescence of the probe can be regulated by metal ions (Al3 + and Cu2 +). The whole process shows that the weak fluorescence of the probe enhances with the addition of Al3 +, and then the strong fluorescence of the probe/Al3 + ensemble reduces by introducing Cu2 +. Meanwhile, the solution color changes of the probe with metal ions can be observed under 365 nm UV-vis light from weak light, pale green, green, pale green to weak light. Noticeably, the photo regulation processes of the probe by metal ions can be realized in the biological system and applied in cells imaging. The work provides a new strategy for designing facile regulation probe and develops a new application for Schiff base derivatives.

  6. Characterization and luminescent properties of zinc–Schiff base complexes for organic white light emitting devices

    Directory of Open Access Journals (Sweden)

    Vandna Nishal

    2015-12-01

    Full Text Available Zinc complexes with Schiff base ligands bis(salicylideneethylene-1,2-diamine (salen, bis(salicylidenepropylene-1,3-diamine (salpen, bis(salicylidenebutylene-1,4-diamine (salbutene, bis(salicylidenehexylene-1,6-diamine (salhexene, bis(salicylideneheptylene-1,7-diamine (salheptene were synthesized and characterized. All these metal complexes exhibited high thermal stability. The photo-physical properties of zinc complexes were investigated by taking their UV–vis absorption and photoluminescent spectra. The complexes of Schiff bases with zinc gave blue luminescence (430–450 nm under excitation of ultraviolet energy source which can be efficiently used for the generation of white light for display applications.

  7. Cationic schiff base amphiphiles and their metal complexes: Surface and biocidal activities against bacteria and fungi.

    Science.gov (United States)

    Negm, N A; Zaki, M F; Salem, M A I

    2010-05-01

    A series of cationic surfactants containing schiff base groups was synthesized by condensation of four fatty amines namely: dodecyl, tetradecyl, hexadecyl and octadecyl amine and 4-diethyl aminobenzaldehyde (1-4), as well as their metal complexes with divalent transition metal ions including Co, Cu and Mn (5-16). The surface activities of the synthesized surfactants were influenced by their chemical structures and the type of the transition metals. The biological activity measurements of the parent cationic schiff bases showed high efficacy against Gram positive and Gram negative bacterial strains and fungi. While on complexation, the biocidal activity was increased remarkably. The biocidal activity of the tested compounds against sulfur reducing bacteria showed promising results in the field of biocide applications.

  8. Synthesis and characterization of novel nano-chitosan Schiff base and use of lead (II) sensor.

    Science.gov (United States)

    Kocak, Nuriye; Sahin, Mustafa; Kücükkolbasi, Semahat; Erdogan, Zehra Ozden

    2012-12-01

    A new kind of nano-chitosan Schiff base ligand (CHNS) with particle size of 34 nm was formed by the reaction between the 2-amino groups of glucosamine residue of nano-chitosan and a 2,5-dihydroxybenzaldehyde. The chemical structures of the nano-chitosan and nano-chitosan Schiff base were characterized by FT-IR spectra, particle sizer, zeta potential, and elemental analysis. A new, simple and effective chemically modified carbon paste electrode with CHNS was prepared and used as a lead (II) sensor. The prepared electrode was characterized using scanning electronic microscopy (SEM-EDX) and cyclic voltammetry (CV). The modified electrode showed only one oxidation peak in the anodic scan at -0.34 V (vs. Ag/AgCl) for the oxidation of lead (II). The dedection limit (LOD) was calculated as 1.36×10(-7) for a 10-min preconcentration time at pH 6.0.

  9. Photoresponse of the protonated Schiff-base retinal chromophore in the gas phase

    DEFF Research Database (Denmark)

    Toker, Jonathan; Rahbek, Dennis Bo; Kiefer, H V

    2013-01-01

    The fragmentation, initiated by photoexcitation as well as collisionally-induced excitation, of several retinal chromophores was studied in the gas phase. The chromophore in the protonated Schiff-base form (RPSB), essential for mammalian vision, shows a remarkably selective photoresponse. The sel......The fragmentation, initiated by photoexcitation as well as collisionally-induced excitation, of several retinal chromophores was studied in the gas phase. The chromophore in the protonated Schiff-base form (RPSB), essential for mammalian vision, shows a remarkably selective photoresponse...... modifications of the chromophore. We propose that isomerizations play an important role in the photoresponse of gas-phase retinal chromophores and guide internal conversion through conical intersections. The role of protein interactions is then to control the specificity of the photoisomerization in the primary...

  10. Synthesis, characterization, and anticancer properties of rare earth complexes with Schiff base and o-phenanthroline

    Institute of Scientific and Technical Information of China (English)

    XU Dongfang; MA Shuzhi; DU Guangying; HE Qizhuang; SUN Dazhi

    2008-01-01

    Five novel ternary complexes of the rare earth ions with o-phenanthroline(Phen) and Schiff base salicylaldehyde L-phenyla-lanine(KHL) were synthesized in ethanol. Their compositions were characterized by elemental analysis, molar conductance, 1H NMR, FT-IR,and Raman spectra. The formulas of the complexes were verified to be RE(L)(Phen)Cl(H2O) (RE=La3+, Ce3+, Nd3+, Er3+, and Gd3+; L=Schiff base salicylaldehyde L-phenylalanine; phen=o-phenanthroline). Methyl thiazolyl tetrazolium (MTT) colorimetry and flow cytometry were used to test the anticancer effect of the complexes with K562 tumor cell. The research showed that the complexes could inhibit K562 tumor cell's growth, generation, and induce apoptosis. The inhibition ratio was accelerated by increasing the dosage, and it had significant positive correlation with the medication dosage.

  11. Tridentate Schiff base (ONO) transition metal complexes: Synthesis, crystal structure, spectroscopic and larvicidal studies

    Indian Academy of Sciences (India)

    SUNDARAMURTHY SANTHA LAKSHMI; KANNAPPAN GEETHA; P MAHADEVI

    2016-07-01

    A series of four new Schiff base transition metal complexes [Co(II), Ni(II), Cu(II) and Zn(II)] derived from N-(salicylidene)-L-alanine and N,N,N',N'-tetramethylethylene-1,2-diamine (tmen) were designed, synthesized and tested for larvicidal activity against Culex quinquefasciatus, the southern house mosquito, which is the primary vector of St. Louis encephalitis virus and West Nile virus. All the complexes were characterized by physicochemical and spectral studies such as UV-Visible, FTIR, and EPR. The X-ray crystallographic analysis of Ni(II) complex revealed that, Ni(II) cation is surrounded by nitrogen and oxygen atoms from the Schiff base ligand, the oxygen atom of a water molecule, and two nitrogen atoms from tmen. Intermolecularhydrogen bonding stabilizes the Ni(II) complex. Results indicated that all the complexes exhibited higher mosquito larvicidal activity against C. quinquefasciatus.

  12. Novel polymer anchored Cr(III) Schiff base complexes: Synthesis, characterization and antimicrobial properties

    Science.gov (United States)

    Selvi, Canan; Nartop, Dilek

    2012-09-01

    New polymer-bound Schiff bases and Cr(III) complexes have been synthesized by the reaction of 4-benzyloxybenzaldehyde, polymer-bound with 2-aminophenol, 2-amino-4-chlorophenol and 2-amino-4-methylphenol. The structure of polymeric-Schiff bases and their Cr(III) complexes have been characterized by elemental analyses, magnetic measurements, IR, UV-Vis, TG-DTA and 1H-NMR. All these compounds have also been investigated for antibacterial activity by the well-diffusion method against Staphylococcus aureus (RSKK-07035), Shigella dysenteria type 10 (RSKK 1036), Listeria monocytogenes 4b(ATCC 19115, Escherichia coli (ATCC 1230), Salmonella typhi H (NCTC 901.8394), Staphylococcus epidermis (ATCC 12228), Brucella abortus (RSKK-03026), Micrococcs luteus (ATCC 93419, Bacillus cereus sp., Pseudomonas putida sp. and for antifungal activity against Candida albicans (Y-1200-NIH).

  13. In situ hydrogel constructed by starch-based nanoparticles via a Schiff base reaction.

    Science.gov (United States)

    Li, Yangling; Liu, Chang; Tan, Ying; Xu, Kun; Lu, Cuige; Wang, Pixin

    2014-09-22

    Polysaccharide-based hydrogels are remarkable materials for the biomedical fields because of its excellent biodegradation and biocompatibility. In this work, a novel polysaccharide-based hydrogel was fabricated by in situ crosslinking of starch-based nanoparticles and polyvinylamine. Starch was decorated with cholesterol group and aldehyde groups. TEM and DLS showed that the cholesterol modified oxidation starch (OCS) exhibited a core-shell nanoparticles with mean size of ∼143 nm in aqueous. The hydrogel was then synthesized via Schiff base reaction. Rheological measurements demonstrated the incorporation of cholesterol groups not only reduced the gel time but also improved the storage modulus of the hydrogel compared with the oxide starch crosslinked hydrogel. SEM showed the OCS based hydrogels possess a well-defined porous structure. Furthermore, doxorubicin (DOX) was used as model drug to investigate the control and release properties of OCS hydrogels. This OCS hydrogel would be a promising drug carrier for biomedical applications.

  14. Synthesis, characterization and biological studies of Schiff bases derived from heterocyclic moiety.

    Science.gov (United States)

    Shanty, Angamaly Antony; Philip, Jessica Elizabeth; Sneha, Eeettinilkunnathil Jose; Prathapachandra Kurup, Maliyeckal R; Balachandran, Sreedharannair; Mohanan, Puzhavoorparambil Velayudhan

    2016-11-21

    Some new Schiff bases (H1-H7) have been synthesized by the condensation of 2-aminophenol, 2-amino-4-nitrophenol, 2-amino-4-methylphenol, 2-amino benzimidazole with thiophene-2-carboxaldehyde and pyrrole-2-carboxaldehyde. The structures of newly synthesized compounds were characterized by elemental analysis, FT-IR, (1)H NMR, UV-VIS, and single crystal X-ray crystallography. The in vitro antibacterial activity of the synthesized compounds has been tested against Salmonella typhi, Bacillus coagulans, Bacillus pumills, Escherichia coli, Bacillus circulans, Pseudomonas, Clostridium and Klebsilla pneumonia by disk diffusion method. The quantitative antimicrobial activity of the test compounds was evaluated using Resazurin based Microtiter Dilution Assay. Ampicillin was used as standard antibiotics. Schiff bases individually exhibited varying degrees of inhibitory effects on the growth of the tested bacterial species. The antioxidant activity of the synthesized compounds was determined by the 1,1-diphenyl-2-picrylhydrazyl(DPPH) method. IC50 value of synthesized Schiff bases were calculated and compared with standard BHA.

  15. In vitro anticancer activities of Schiff base and its lanthanum complex.

    Science.gov (United States)

    Neelima; Poonia, Kavita; Siddiqui, Sahabjada; Arshad, Md; Kumar, Dinesh

    2016-02-15

    Schiff base metal complexes are well-known to intercalate DNA. The La(III) complexes have been synthesized such that they hinder with the role of the topoisomerases, which control the topology of DNA during the cell-division cycle. Although several promising chemotherapeutics have been developed, on the basis of Schiff base metal complex DNA intercalating system they did not proceed past clinical trials due to their dose-limiting toxicity. Herein, we discuss an alternative compound, the La(III) complex, [La(L(1))2Cl3]·7H2O based on a Schiff base ligand 2,3-dihydro-1H-indolo-[2,3-b]-phenazin-4(5H)-ylidene)benzothiazole-2-amine (L(1)), and report in vitro cell studies. Results of antitumor activity using cell viability assay, reactive oxygen species (ROS) generation and nuclear condensation in PC-3 (Human, prostate carcinoma) cells show that the metal complex is more potent than ligand. La(III) complexes have been synthesized by reaction of lanthanum(III) salt in 1:2M ratio with ligands L(1) and 3-(ethoxymethylene)-2,3-dihydro-1H-indolo[2,3-b]-phenazin-4(5H)-ylidene)benzathiazole-2-amine (L(2)) in methanol. The ligands and their La(III) complexes were characterized by molar conductance, magnetic susceptibility, elemental analyses, FT-IR, UV-Vis, (1)H/(13)C NMR, thermogravimetric, XRD, and SEM analysis.

  16. Transition Metal(II Complexes with Cefotaxime-Derived Schiff Base: Synthesis, Characterization, and Antimicrobial Studies

    Directory of Open Access Journals (Sweden)

    Aurora Reiss

    2014-01-01

    Full Text Available New [ML2(H2O2] complexes, where M = Co(II, Ni(II, Cu(II, and Zn(II while L corresponds to the Schiff base ligand, were synthesized by condensation of cefotaxime with salicylaldehyde in situ in the presence of divalent metal salts in ethanolic medium. The complexes were characterized by elemental analyses, conductance, and magnetic measurements, as well as by IR and UV-Vis spectroscopy. The low values of the molar conductance indicate nonelectrolyte type of complexes. Based on spectral data and magnetic moments, an octahedral geometry may be proposed for Co(II, Ni(II, and Zn(II complexes while a tetragonal geometry for Cu(II complex. Molecular structure of the Schiff base ligand and its complexes were studied using programs dedicated to chemical modeling and quantomolecular calculation of chemical properties. All the synthesized complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, namely Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains revealed that the metal complexes possess superior antibacterial activity than the Schiff base.

  17. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors

    Directory of Open Access Journals (Sweden)

    Siavash Riahi

    2008-03-01

    Full Text Available Ionophore incorporated PVC membrane sensors are well-established analyticaltools routinely used for the selective and direct measurement of a wide variety of differentions in complex biological and environmental samples. Potentiometric sensors have someoutstanding advantages including simple design and operation, wide linear dynamic range,relatively fast response and rational selectivity. The vital component of such plasticizedPVC members is the ionophore involved, defining the selectivity of the electrodes' complexformation. Molecular recognition causes the formation of many different supramolecules.Different types of supramolecules, like calixarenes, cyclodextrins and podands, have beenused as a sensing material in the construction of ion selective sensors. Schiff's bases andcrown ethers, which feature prominently in supramolecular chemistry, can be used assensing materials in the construction of potentiometric ion selective electrodes. Up to now,more than 200 potentiometric membrane sensors for cations and anions based on Schiff'sbases and crown ethers have been reported. In this review cation binding and anioncomplexes will be described. Liquid membrane sensors based on Schiff's bases and crownethers will then be discussed.

  18. In vitro anticancer activities of Schiff base and its lanthanum complex

    Science.gov (United States)

    Neelima; Poonia, Kavita; Siddiqui, Sahabjada; Arshad, Md; Kumar, Dinesh

    2016-02-01

    Schiff base metal complexes are well-known to intercalate DNA. The La(III) complexes have been synthesized such that they hinder with the role of the topoisomerases, which control the topology of DNA during the cell-division cycle. Although several promising chemotherapeutics have been developed, on the basis of Schiff base metal complex DNA intercalating system they did not proceed past clinical trials due to their dose-limiting toxicity. Herein, we discuss an alternative compound, the La(III) complex, [La(L1)2Cl3]·7H2O based on a Schiff base ligand 2,3-dihydro-1H-indolo-[2,3-b]-phenazin-4(5H)-ylidene)benzothiazole-2-amine (L1), and report in vitro cell studies. Results of antitumor activity using cell viability assay, reactive oxygen species (ROS) generation and nuclear condensation in PC-3 (Human, prostate carcinoma) cells show that the metal complex is more potent than ligand. La(III) complexes have been synthesized by reaction of lanthanum(III) salt in 1:2 M ratio with ligands L1 and 3-(ethoxymethylene)-2,3-dihydro-1H-indolo[2,3-b]-phenazin-4(5H)-ylidene)benzathiazole-2-amine (L2) in methanol. The ligands and their La(III) complexes were characterized by molar conductance, magnetic susceptibility, elemental analyses, FT-IR, UV-Vis, 1H/13C NMR, thermogravimetric, XRD, and SEM analysis.

  19. A novel Schiff base: Synthesis, structural characterisation and comparative sensor studies for metal ion detections.

    Science.gov (United States)

    Köse, Muhammet; Purtas, Savas; Güngör, Seyit Ali; Ceyhan, Gökhan; Akgün, Eyup; McKee, Vickie

    2015-02-05

    A novel Schiff base ligand was synthesized by the condensation reaction of 2,6-diformylpyridine and 4-aminoantipyrine in MeOH and characterised by its melting point, elemental analysis, FT-IR, (1)H, (13)C NMR and mass spectroscopic studies. Molecular structure of the ligand was determined by single crystal X-ray diffraction technique. The electrochemical properties of the Schiff base ligand were studied in different solvents at various scan rates. Sensor ability of the Schiff base ligand was investigated by colorimetric and fluorometric methods. Visual colour change of the ligand was investigated in MeOH solvent in presence of various metal ions Na(+), Mg(2+), Al(3+), K(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+). Upon addition of Al(3+) ion into a MeOH solution of the ligand, an orange colour developed which is detectable by naked eye. Fluorescence emission studies showed that the ligand showed single emission band at 630-665nm upon excitation at 560nm. Addition of metal ions Na(+), Mg(2+), K(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+) (1:1M ratio) cause fluorescence quenching, however addition of Al(+3) resulted in an increase in fluorescence intensity. No significant variation was observed in the fluorescence intensity caused by Al(3+) in presence of other metal ions. Therefore, the Schiff base ligand can be used for selective detection of Al(3+) ions in the presence of the other metal ions studied.

  20. Synthesis and characterization of rare earth complexes with Phthalaldehyde-lysine Schiff base

    Institute of Scientific and Technical Information of China (English)

    Hu Meixian; Li Ning; Yao Kemin

    2006-01-01

    Ten new rare earth complexes with Schiff base (HL) derived from phthalaldehyde with two -CHO groups and lysine,which has unsymmetrical α-and ε-NH2 groups,were synthesized and characterized by elemental analysis,TG-DTA analysis,UV-Vis,IR,and 1H NMR spectra.They spectively.Furthermore,their coordination mechanism,spectral properties and probable molecular structures were also discussed.

  1. Synthesis and Antimicrobial Activity of New Schiff Base Compounds Containing 2-Hydroxy-4-pentadecylbenzaldehyde Moiety

    Directory of Open Access Journals (Sweden)

    Gadada Naganagowda

    2014-01-01

    Full Text Available Various novel Schiff base compounds have been synthesized by reaction of 2-hydroxy-4-pentadecylbenzaldehyde with substituted benzothiophene-2-carboxylic acid hydrazide and different substituted aromatic or heterocyclic amines in the presence of acetic acid in ethanol. The structures of all these compounds were confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR, and mass spectral data and have been screened for antibacterial and antifungal activity.

  2. Mesomorphic behavior of new benzothiazole liquid crystals having Schiff base linker and terminal methyl group

    Institute of Scientific and Technical Information of China (English)

    Sie Tiong Ha; Kok Leei Foo; Hong Cheu Lin; Masato M.Ito; Kazuma Abe; Kenji Kunbo; S.Sreehari Sastry

    2012-01-01

    A homologous series of heterocycles,6-methyl-2-(4-alkoxybenzylidenamino)benzothiazoles,were synthesized and characterized using FT-IR,1H and 13C NMR and mass spectrometric analysis.Enantiotropic nematic phase was observed for shorter members.Smectic A phase only emerged from octyloxy derivative onwards.The terminal methyl group at the benzothiazole fragment and the Schiff base linkage influenced the mesomorphic behavior of the present series.

  3. In-vitro Evaluation and Molecular Docking Studies of Some Schiff Bases as Cholinesterase Inhibitor

    OpenAIRE

    2015-01-01

    Some new Schiff bases of 4-aminopyridine were synthesized and evaluated for antiamnesic and cognition enhancing activity. In the current study to further understand the mechanism of action of these derivatives we have evaluated in-vitro acetycholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity. Enzyme kinetics and docking studies were performed for all compounds to observe their nature of inhibition. The IC50 value of synthesized compounds showed maximum activity of comp...

  4. Spectroscopic, structural and theoretical studies of copper(II) complexes of tridentate NOS Schiff bases

    Science.gov (United States)

    Olalekan, Temitope E.; Ogunlaja, Adeniyi S.; VanBrecht, Bernardus; Watkins, Gareth M.

    2016-10-01

    Two newly synthesized Schiff bases (L4 and L5) were derived from the condensation reaction of 2-(methylthiomethyl)anilines and 4-methoxysalicylaldehyde. Coordination complexes of these and four previously reported NOS Schiff bases, Cu(L1)2-Cu(L6)2, were synthesized via the reflux reaction of the various Schiff base ligands with CuCl2·2H2O. The compounds were characterized by means of elemental analysis, FTIR and UV-Vis. The crystal structures of Cu(L1)2 and Cu(L2)2 were obtained by X-ray diffraction. The Schiff bases were coordinated to copper ion as monobasic tridentate ligands through the phenolic oxygen, azomethine nitrogen and thioether sulfur. The microanalyses of the coordination complexes were agreeable with bimolar binding of the ligands to the copper metal ion. The crystal structures of the copper complexes confirmed an octahedral geometry around the metal centre and showed they are mononuclear. The magnetic moment values indicated the presence of a lone electron in each copper(II) orbital and confirmed the mononuclearity of the complexes. The electronic spectra of the coordination compounds consist of the intraligand, charge transfer and d→d bands. Molecular modeling studies on the complexes (Cu(L1)2-Cu(L6)2) by employing DFT revealed that complex Cu(L5)2 possessed the smallest optimization energy as well as a small HOMO-LUMO energy gap which may best explain its higher polarizability as well as reactivity in comparison to the other complexes.

  5. EPR character of gadolinium complexes with noncyclic polyether Schiff bases and its solvent effects

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 陈德余; 王晓南; 邓宁

    1996-01-01

    EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The ’single peak effect’ due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated.

  6. Lanthanum heterocyclic Schiff-base complex initiated ring-opening polymerization of ε-caprolactone

    Institute of Scientific and Technical Information of China (English)

    Wen Lin; Wei Lin Sun; Zhi Quan Shen

    2007-01-01

    Lanthanum complex supported by the heterocyclic Schiff-base ligand of N-(2-pyridyl)-3,5-di-tert-butyl-salicylaldimine was prepared and employed for the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The polymers obtained with this initiator showed a unimodal molecular weight distribution implied that only one active species was present. Mechanism study revealed that the polymerization proceeds via acyl-oxygen bond cleavage.

  7. Synthesis, characterization and antibacterial activity of biodegradable films prepared from Schiff bases of zein

    OpenAIRE

    Soliman, E. A.; KHALIL, A.A.; Deraz, S. F.; El-Fawal, G.; Elrahman, S. Abd

    2012-01-01

    Pure zein is known to be very hydrophobic, but is still inappropriate for coating and film applications because of their brittle nature. In an attempt to improve the flexibility and the antimicrobial activity of these coatings and films, Chemical modification of zein through forming Schiff bases with different phenolic aldhydes was tried. Influence of this modifications on mechanical, topographical, wetting properties and antimicrobial activity of zein films were evaluated. The chemical struc...

  8. In vitro anti-glycation and anti-oxidant properties of synthesized Schiff bases.

    Science.gov (United States)

    Jhaumeer-Laulloo, Sabina; Bhowon, Minu Gupta; Mungur, Shabneez; Mahomoodally, Mohamad Fawzi; Subratty, Anwar Hussein

    2012-05-01

    A series of mono, bis and mixed Schiff bases (1-7) were synthesised and evaluated for potential anti-glycation and anti-oxidant activities using the bovine serum albumin-glucose assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay respectively. All compounds showed significant (papplications that warrant further investigation as potential anti-glycation and anti-oxidant agents which could be of importance in metabolic diseases including diabetes mellitus.

  9. Characterization and luminescent properties of zinc–Schiff base complexes for organic white light emitting devices

    OpenAIRE

    Vandna Nishal; Devender Singh; Raman Kumar Saini; Vijeta Tanwar; Sonika Kadyan; Ritu Srivastava; Pratap Singh Kadyan

    2015-01-01

    Zinc complexes with Schiff base ligands bis(salicylidene)ethylene-1,2-diamine (salen), bis(salicylidene)propylene-1,3-diamine (salpen), bis(salicylidene)butylene-1,4-diamine (salbutene), bis(salicylidene)hexylene-1,6-diamine (salhexene), bis(salicylidene)heptylene-1,7-diamine (salheptene) were synthesized and characterized. All these metal complexes exhibited high thermal stability. The photo-physical properties of zinc complexes were investigated by taking their UV–vis absorption and photolu...

  10. Synthesis and mesomorphic properties of new Schiff base esters with different alkyl chains

    Institute of Scientific and Technical Information of China (English)

    Sie Tiong Ha; Lay Khoon Ong; Siew Teng Ong; Guan Yeow Yeap; Joanna Pik Wan Wong; Teck Ming Koh; Hong Cheu Lin

    2009-01-01

    A new series of Schiff base esters, 4-(dimethylamino)benzylidene-4'-alkanoyloxyanilines containing even number of carbons at the end group of the molecules (Cn-1H2n-1COO, n =6, 8, 10, 12, 14, 16, 18) were synthesized. The present compounds were monotropic liquid crystals. It was also found that the end groups of the molecules had effect on the mesomorphic properties.

  11. 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.

  12. Tetrameric Self-Assembly of a Cu(II) Complex Containing Schiff-Base Ligand and Its Unusually High Catecholase-like Activity

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Shuranjan; Lee, Hongin [Kyungpook National Univ., Daegu (Korea, Republic of); Lee, Woo Ram; Hong, Chang Seop [Korea Univ., Seoul (Korea, Republic of)

    2013-09-15

    We report a new tetrameric supramolecular Cu(II) complex (Cu{sub 4}L{sub 4} = tetrakis(N,N'-bis(salicylidene)-2,2'-ethylenedianiline) Copper(II)) with a Schiff-base ligand (H{sub 2}L = N,N'-bis (salicylaldimine)-1,2-ethylenediamine) containing two N,O-bidentate chelate groups. Though the copper sites of Cu{sub 4}L{sub 4} are non-coupled, the complex exhibits a unusually high catecholase-like activity (k{sub cat} = 935 h{sup -1}) when the Cu{sub 4}L{sub 4} solution is treated with 3,5-di-tert-butylcatechol (3,5-DTBC) at basic condition in the presence of air. Combined information obtained from UV-VIS and EPR measurements could lead the suggestion of the reaction pathway in which the substrate may bind to Cu(II) ions by anti-anti didentate bridging mode.

  13. Synthesis, characterization, and antipathogenic studies of some transition metal complexes with N,O-chelating Schiff's base ligand incorporating azo and sulfonamide Moieties

    Science.gov (United States)

    Alaghaz, Abdel-Nasser M. A.; Bayoumi, Hoda A.; Ammar, Yousry A.; Aldhlmani, Sharah A.

    2013-03-01

    Chromium(III), Manganese(II), Cobalt(II), nickel(II), copper(II) and cadmium(II) complexes of 4-[4-hydroxy-3-(phenyliminomethyl)-phenylazo]benzenesulfonamide, were prepared and characterized on the basis of elemental analyses, spectral, magnetic, molar conductance and thermal analysis. Square planar, tetrahedral and octahedral geometries have been assigned to the prepared complexes. Dimeric complexes are obtained with 2:2 molar ratio except chromium(III) complex is monomeric which is obtained with 1:1 molar ratios. The IR spectra of the prepared complexes were suggested that the Schiff base ligand(HL) behaves as a bi-dentate ligand through the azomethine nitrogen atom and phenolic oxygen atom. The crystal field splitting, Racah repulsion and nepheloauxetic parameters and determined from the electronic spectra of the complexes. Thermal studies suggest a mechanism for degradation of HL and its metal complexes as function of temperature supporting the chelation modes. Also, the activation thermodynamic parameters, such as ΔE*, ΔH*, ΔS* and ΔG* for the different thermal decomposition steps of HL and its metal complexes were calculated. The pathogenic activities of the synthesized compounds were tested in vitro against the sensitive organisms Staphylococcus aureus (RCMB010027), Staphylococcus epidermidis (RCMB010024) as Gram positive bacteria, Klebsiella pneumonia (RCMB 010093), Shigella flexneri (RCMB 0100542), as Gram negative bacteria and Aspergillus fumigates (RCMB 02564), Aspergillus clavatus (RCMB 02593) and Candida albicans (RCMB05035) as fungus strain, and the results are discussed.

  14. 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.

  15. Synthesis, characterization, thermal study and biological evaluation of Cu(II), Co(II), Ni(II) and Zn(II) complexes of Schiff base ligand containing thiazole moiety

    Science.gov (United States)

    Nagesh, G. Y.; Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

    2015-01-01

    The novel Schiff base ligand 2-(4-(dimethylamino)benzylidene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 4-dimethylaminobenzaldehyde and its newly synthesized Cu(II), Co(II), Ni(II) and Zn(II) complexes have been characterized by microanalysis, magnetic susceptibility, molar conductance, thermal analysis, FT-IR, 1H NMR, ESI mass, UV-Visible, ESR spectroscopy and powder X-ray diffraction data. The newly synthesized ligand behaves as a bidentate ON donor. The IR results confirmed the bidentate binding of the ligand involving oxygen atom of amide carbonyl and azomethine nitrogen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. In order to evaluate the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties of all the compounds against Artemia salina. Furthermore, the antioxidant activity of the ligand (L) and its metal complexes were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH), the ligand exhibited potent in vitro - antioxidant activity than its metal complexes.

  16. New Thiazolyl-triazole Schiff Bases: Synthesis and Evaluation of the Anti-Candida Potential.

    Science.gov (United States)

    Stana, Anca; Enache, Alexandra; Vodnar, Dan Cristian; Nastasă, Cristina; Benedec, Daniela; Ionuț, Ioana; Login, Cezar; Marc, Gabriel; Oniga, Ovidiu; Tiperciuc, Brîndușa

    2016-11-22

    In the context of the dangerous phenomenon of fungal resistance to the available therapies, we present here the chemical synthesis of a new series of thiazolyl-triazole Schiff bases B1-B15, which were in vitro assessed for their anti-Candida potential. Compound B10 was found to be more potent against Candida spp. when compared with the reference drugs Fluconazole and Ketoconazole. A docking study of the newly synthesized Schiff bases was performed, and results showed good binding affinity in the active site of co-crystallized Itraconazole-lanosterol 14α-demethylase isolated from Saccharomyces cerevisiae. An in silico ADMET (absorption, distribution, metabolism, excretion, toxicity) study was done in order to predict some pharmacokinetic and pharmacotoxicological properties. The Schiff bases showed good drug-like properties. The results of in vitro anti-Candida activity, a docking study and ADMET prediction revealed that the newly synthesized compounds have potential anti-Candida activity and evidenced the most active derivative, B10, which can be further optimized as a lead compound.

  17. Ni(II) complexes of arginine Schiff-bases and its interaction with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Sallam, S.A., E-mail: shehabsallam@yahoo.com [Chemistry Department, Faculty of Science, Suez Canal University, Isamilia (Egypt); Abbas, A.M. [Chemistry Department, Faculty of Science, Suez Canal University, Isamilia (Egypt)

    2013-04-15

    Ni(II) complexes with Schiff-bases obtained by condensation of arginine with salicylaldehyde; 2,3-; 2,4-; 2,5-dihydroxybenzaldehyde and o-hydroxynaphthaldehyde have been synthesized using the template method in ethanol or ammonia media. They were characterized by elemental analyses, conductivity measurements, magnetic moment, UV, IR and {sup 1}H NMR spectra as well as thermal analysis (TG, DTG and DTA). The Schiff-bases are dibasic tridentate donors and the complexes have diamagnetic square planar and octahedral structures. The complexes decompose in three steps where kinetic and thermodynamic parameters of the decomposition steps were computed. The interactions of the formed complexes with FM-DNA were monitored by UV and fluorescence spectroscopy. -- Highlights: ► Arginine Schiff-bases and their nickel(II) complexes have been synthesized. ► Magnetic and spectral data show diamagnetic square planar and octahedral complexes. ► The complexes thermally decompose in three stages. Interaction with FM-DNA shows hyperchromism with blue shift.

  18. Multichromic Bis-Axially Extended Perylene Chromophore with Schiff Bases: Synthesis, Characterization and Electrochemical Studies.

    Science.gov (United States)

    Shabir, Ghulam; Saeed, Aamer; Arshad, Muhammad; Zahid, Muhammad

    2016-11-01

    In the present paper a novel way of symmetric conjugation extension along molecular axes of perylene dianhydride chromophore has been devised to achieve lengthy delocalized electronic species exhibiting red shifted absorption and emission of UV-Visible radiations. During synthetic pathway free amino Schiff bases of novel aldehydes with 4-amino acetanilide have been condensed with perylene dianhydride in quinoline at high temperature. Bis perylene diimide Schiff bases (5a-e) have been synthesized which showed absorption λmax at 461-526 nm and emission at 525-550 nm. Structures of newly obtained compounds have been confirmed by (1)H and (13)C-NMR studies. Cyclic voltammetric analysis of these dyes exhibited oxidation and reduction peaks which provide indirect evidence for their potential utility as n-type material for sensitization of semiconductors in solar cells. LUMO and HOMO energy levels were found in the range of -4.21 to -5.20 and -6.75 to -7.57 eV, respectively. Graphical Abstract Multi chromic bis-axially extended perylene chromophore with Schiff bases, synthesis characterization and electrochemical studies. Ghulam Shabir, Aamer Saeed, Muhammad Arshad and Muhammad Zahid.

  19. A novel schiff base zinc coordination compound inhibits proliferation and induces apoptosis of human osteosarcoma cells.

    Science.gov (United States)

    Yan, Ming; Pang, Li; Ma, Tan-tan; Zhao, Cheng-liang; Zhang, Nan; Yu, Bing-xin; Xia, Yan

    2015-10-01

    Various kinds of schiff base metal complexes have been proven to induce apoptosis of tumor cells. However, it remains largely unknown whether schiff base zinc complexes induce apoptosis in human cancer cells. Here, we synthesized a novel schiff base zinc coordination compound (SBZCC) and investigated its effects on the growth, proliferation and apoptosis of human osteosarcoma MG-63 cells. A novel SBZCC was synthesized by chemical processes and used to treat MG-63 cells. The cell viability was determined by CCK-8 assay. The cell cycle progression, mitochondrial membrane potential and apoptotic cells were analyzed by flow cytometry. The apoptosis-related proteins levels were determined by immunoblotting. Treatment of MG-63 cells with SBZCC resulted in inhibition of cell proliferation and cell cycle arrest at G1 phase. Moreover, SBZCC significantly reduced the mitochondrial membrane potential and induced apoptosis, accompanied with increased Bax/Bcl-2 and FlasL/Fas expression as well as caspase-3/8/9 cleavage. Our results demonstrated that the synthesized novel SBZCC could inhibit the proliferation and induce apoptosis of MG-63 cells via activating both the mitochondrial and cell death receptor apoptosis pathways, suggesting that SBZCC is a promising agent for the development as anticancer drugs.

  20. Synthesis, X-ray Structure, Spectroscopic Properties and DFT Studies of a Novel Schiff Base

    Directory of Open Access Journals (Sweden)

    Kew-Yu Chen

    2014-10-01

    Full Text Available A series of Schiff bases, salicylideneaniline derivatives 1–4, was synthesized under mild conditions and characterized by 1H NMR, HRMS, UV-Vis and fluorescence spectra, and single-crystal X-ray diffraction. In solid and aprotic solvents 1–4 exist mainly as E conformers that possess an intramolecular six-membered-ring hydrogen bond. A weak intramolecular C–H×××F hydrogen bond is also observed in fluoro-functionalized Schiff base 4, which generates another S(6 ring motif. The C–H×××F hydrogen bond further stabilizes its structure and leads it to form a planar configuration. Compounds 1–3 exhibit solely a long-wavelength proton-transfer tautomer emission, while dipole-functionalized Schiff base 4 shows remarkable dual emission originated from the excited-state intramolecular charge transfer (ESICT and excited-state intramolecular proton transfer (ESIPT states. Furthermore, the geometric structures, frontier molecular orbitals (MOs and the potential energy curves for 1–4 in the ground and the first singlet excited state were fully rationalized by density functional theory (DFT and time-dependent DFT calculations.

  1. Microcalorimetric Study on the Inhibition of Escherichia coil by Some Novel Pyridine Amide Schiff Base Derivatives

    Institute of Scientific and Technical Information of China (English)

    LI Chao-Hong; ZHANG Li-Xia; CAI Li-Hua; LIU Yi; HU Pei-Zhi

    2008-01-01

    The antibacterial effect of a series of novel pyridine amide Schiff base compounds on Escherichia coli was investigated by a microcalorimetric method at 37℃.The metabolic power-time curves of the bacteria treated by the compounds were obtained,and the thermokinetic parameters were analyzed,from which the antibacterial activities of these compounds were evaluated.The results show that two compounds F and G have good activity on aerobic multiplying metabolism of E.coli,with the value of IC50 106 and 113 mg/L respectively,but have no effective action on the fermentation metabolism of E.coli.The action of the compounds on the non-multiplying metabolism was investigated by taking the heat output of E.coli in the stationary phase as the guideline of the activity.The experimental results revealed that the hydrophilicity of these Schiff bases had a great influence on their antibacterial activity,which results from the bacterial cell wall structure.The antibacterial structure-activity relationship of these Schiff base derivatives was also briefly discussed.The antibacterial activity of the compounds against E.coli was as follows:compound F>G>C>D>E>B>A.

  2. 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.

  3. One-step electrochemical deposition of Schiff base cobalt complex as effective water oxidation catalyst

    Science.gov (United States)

    Huang, Binbin; Wang, Yan; Zhan, Shuzhong; Ye, Jianshan

    2017-02-01

    Schiff base metal complexes have been applied in many fields, especially, a potential homogeneous catalyst for water splitting. However, the high overpotential, time consumed synthesis process and complicated working condition largely limit their application. In the present work, a one-step approach to fabricate Schiff base cobalt complex modified electrode is developed. Microrod clusters (MRC) and rough spherical particles (RSP) can be obtained on the ITO electrode through different electrochemical deposition condition. Both of the MRC and RSP present favorable activity for oxygen evolution reaction (OER) compared to the commercial Co3O4, taking an overpotential of 650 mV and 450 mV to drive appreciable catalytic current respectively. The highly active and stable RSP shows a Tafel plot of 84 mV dec-1 and negligible decrease of the current density for 12 h bulk electrolysis. The synthesis strategy of effective and stable catalyst in this work provide a simple method to fabricate heterogeneous OER catalyst with Schiff base metal complex.

  4. Spectroscopic studies and biological activity of some transition metal complexes of unusual Schiff base

    Science.gov (United States)

    Abu Al-Nasr, Ahmad K.; Ramadan, Ramadan M.

    2013-03-01

    Unusual Schiff base ligand, 4-ethanimidoyl-6-[(1E)-N-(2-hydroxy-4-methylphenyl)ethanimidoyl]benzene-1,3-diol, L, was synthesized via catalytic process involving the interaction of some metal ions with a macrocyclic Schiff base (MSB). The transition metal derivatives [ML(H2O)4](NO3)3, M = Cr(III) and Fe(III), [NiL(H2O)4](NO3)2, [ML(H2O)2](NO3)2, M = Zn(II) and Cd(II), [Cl2Pd(μ-Cl)2PdL], [PtL(Cl)2] and [PtL(Cl)4] were also synthesized from the corresponding metal species with L. The Schiff bases and complexes were characterized by elemental analysis, mass spectrometry, IR and 1H NMR spectroscopy. The crystal structure of L was determined by X-ray analysis. The spectroscopic studies revealed a variety of structure arrangements for the complexes. The biological activities of L and metal complexes against the Escherchia coli as Gram-negative bacteria and Staphylococcus aureus as Gram-positive bacteria, and the two fungus Aspergillus flavus and Candida albicans were screened. The cytotoxicity of [PtL(Cl)2] complex, a cis-platin analogous, was checked as an antitumor agent on two breast cancer cell lines (MCF7 and T47D) and human liver carcinoma cell line (HepG2).

  5. A comparative study of electrochemical reduction of isatin and its synthesized Schiff bases at HMDE

    Indian Academy of Sciences (India)

    Alpana K Gupta; Rajendra S Sindal

    2009-05-01

    The electrochemical behaviour of a series of Schiff base i.e. 3-[5-phenylpyrazol-3-ylimino]indol-2-ones (IIa-e) synthesized by the reaction of various 5-substituted isatins with 3-amino-5-phenyl-pyrazole has been investigated and compared with corresponding isatin in dimethylformamide in 0.1 M LiCl using cyclic voltammetry at Hanging Mercury Drop Electrode. All synthesized Schiff bases exhibit a single irreversible two-electron reduction wave in contrast with the two discrete one-electron transfer reduction waves observed for isatin in this medium. Observation of a well-developed single reduction wave can be attributed to the higher basicity of the nitrogen species of the imine bond of Schiff bases, making proton abstraction as well as second electron transfer both rapid. The compounds are subjected to constant potential preparative electrolysis. The products are identified as secondary amines by spectroscopic methods. A mechanism for the electro-reduction process has been proposed. Kinetic parameters have also been calculated.

  6. Synthesis, structural investigation and kinetic studies of uranyl(VI) unsymmetrical Schiff base complexes

    Indian Academy of Sciences (India)

    Zahra Asadi; Mozaffar Asadi; Azade Zeinali; Mohammad Ranjkeshshorkaei; Karla Fejfarova; Vaclav Eigner; Michal Dusek; Aliakbar Dehnokhalaji

    2014-11-01

    Uranyl(VI) complexes with unsymmetrical N2O2 Schiff base ligands were synthesized and characterized. Their characterization was performed using UV-Vis, 1H NMR, cyclic voltammetry, single-crystal X-ray crystallography, IR, TG and C.H.N. techniques. X-ray crystallography of the complexes show that beside coordination of the tetradentate Schiff base, one DMF molecule is also coordinated. In order to investigate the effect of the substitutional groups of the Schiff base on the oxidation and reduction potentials, we used the cyclic voltammetry method. Electrochemistry of these complexes showed that the presence of electron releasing groups accelerates oxidation of the complexes. The kinetics of thermal decomposition was studied using thermal gravimetric method (TG) and Coats-Redfern equation. According to Coats-Redfern plots, the kinetics of thermal decomposition of the studied complexes is first-order in all stages. Also the kinetics and mechanism of the exchange reaction of the coordinated solvent with tributylphosphine was carried out in solution, using spectrophotometric method. As a result, the second order rate constants at four temperatures and the activation parameters were calculated showing an associative mechanism for all corresponding complexes. It was concluded that the steric and the electronic properties of the complexes influence the reaction rate significantly.

  7. Influence of Schiff base and lanthanide metals on the synthesis, stability, and reactivity of monoamido lanthanide complexes bearing two Schiff bases.

    Science.gov (United States)

    Han, Fubin; Teng, Qiaoqiao; Zhang, Yong; Wang, Yaorong; Shen, Qi

    2011-03-21

    The monoamido lanthanide complexes stabilized by Schiff base ligand L(2)LnN(TMS)(2) (L = 3,5-Bu(t)(2)-2-(O)-C(6)H(2)CH═N-8-C(9)H(6)N, Ln = Yb (1), Y (2), Eu (3), Nd (4), and La (5)) were synthesized in good yields by the reactions of Ln[N(TMS)(2)](3) with 1.8 equiv of HL in hexane at room temperature. It was found that the stability of 1-5 depends greatly on the size of the lanthanide metals with the increasing trend of Yb ≈ Y metals of Y and Yb, L''(2)LnN(TMS)(2) (Ln = Yb (13) and Y (14)), and the more stable tris-Schiff base complexes with the large metals of La and Nd, yielded L''(3)Ln as the only product. Complexes 1-14 were fully characterized including X-ray crystal structural analysis. Complexes 1-5, 10, and 14 can serve as the efficient catalysts for addition of amines to carbodiimides, and the catalytic activity is greatly affected by the lanthanide metals with the active sequence of Yb < Y < Eu ≈ Nd ≈ La.

  8. Proton transfer assisted charge transfer phenomena in photochromic Schiff bases and effect of -NEt2 groups to the anil Schiff bases.

    Science.gov (United States)

    Jana, Sankar; Dalapati, Sasanka; Guchhait, Nikhil

    2012-11-15

    Photochromic Schiff bases 5-diethylamino-2-[(4-diethylamino-benzylidene)-hydrazonomethyl]-phenol (DDBHP) and N,N'-bis(4-N,N-diethylaminosalisalidene) hydrazine (DEASH) with both the proton and charge transfer moieties have been synthesized, and their photophysical properties such as excited state intramolecular charge transfer (ICT) and proton transfer (ESIPT) processes have been reported on the basis of steady-state and time-resolved spectral measurement in various solvents. The ground-state six-membered intramolecular hydrogen bonding network at the proton transfer site accelerates the ESIPT process for these compounds. Both the compounds show large Stokes-shifted emission bands for proton transfer and charge transfer processes. The hydrogen bonding solvents play a crucial role in these photophysical processes. Excited-state dipole moment of DDBHP and DEASH calculated by the solvatochromic method supports the polar character of the charge transfer excited state. Introduction of -NEt(2) groups to the reported salicylaldehyde azine (SAA) Schiff base results an increase in fluorescence lifetime from femtosecond to picosecond time scale for the proton transfer process.

  9. Synthesis, spectral studies, thermal behavior, and antibacterial activity of Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) complexes with an ONO tridentate Schiff base

    Institute of Scientific and Technical Information of China (English)

    Mohammad Azarkish; Tahereh Sedaghat

    2012-01-01

    Three new transition metal complexes have been synthesized with a Schiff base,3-(2-hydroxy-5-chlorophenylimino)-1,3-diphenylpropen- 1-one.In all complexes Schiff base is completely deprotonated and coordinated to metal as tridentate ligand via phenolic and enolic oxygens and imine nitrogen.Thermal decomposition of the complexes has been studied by thermogravimetry.The in vitro antibacterial activity of Schiff bases and their complexes has been evaluated and compared with the standard drugs.

  10. Design and Synthesis of New Series of One Pot Schiff Bases of 4-Aminobenzenesulfon- Amideas Potent Antibacterial and Anti-Fungal Agents

    OpenAIRE

    Gideon A. Shallangwa; Haliru Musa; Elizabeth Ogbe; http://scitecresearch.com/journals/index.php/jprc/article/view/157

    2015-01-01

    Schiff bases are imines formed by the condensation of a primary amine and a carbonyl compound. These classes of compounds are very important due to their wide range of biological activities and industrial applications. In this study, some Schiff bases (coded GAS1-5) were synthesized by condensation of 4–Aminobenzenesulfonamide and some selected carbonyl molecules via MW irradiation for 1 minute at 385 watt power; and were characterized by FT-IR and elemental analyses. These Schiff bases...

  11. Syntheses, structures and properties of two dinuclear mercury(II) iodide compounds containing tetradentate tripodal amine/pentadentate N-donor Schiff base: Control of molecular and crystalline architectures by varying ligand matrices

    Indian Academy of Sciences (India)

    Subhasis Roy; Soumi Chattopadhyay; Somnath Choubey; Kishalay Bhar; Partha Mitra; Barindra Kumar Ghosh

    2014-05-01

    Two dinuclear mercury(II) iodide complexes of the types [(L1)Hg(-I)HgI3] (1) and [Hg2(L2) (I)4]·H2O (2) [L1 = tris(2-aminoethyl)amine and L2 = N,N'-(bis-(pyridin-2-yl)benzylidene)diethylenetriamine] have been synthesized and characterized usingmicroanalytical, spectroscopic, thermal and other physicochemical results. Structures of both the compounds are solved by X-ray diffraction measurements. Structural analyses show that one mercury (II) centre in 1 adopts a distorted tetrahedral geometry with an HgI4 chromophore surrounded by four iodides, while the other has a distorted trigonal bipyramidal environment with an HgN4I chromophore bound by four N atoms of L1 and one bridging iodide. Pentadentate Schiff base (L2) in 2 shows unusual binucleating bis(bidentate) behaviour to bind two different mercury(II) centres—Hg1 with an HgN3I2 chromophore in a distorted square pyramidal geometry and Hg2 with an HgN2I2 chromophore in a tetrahedral environment. Weak intermolecularN-H…I hydrogen bonds in 1 and cooperative C-H$\\ldots$ and $\\ldots$ interactions in 2 promote dimensionalities. The Schiff base complex, 2, shows intraligand (-*) fluorescence in DMF solution at room temperature, whereas compound 1 containing tripodal amine is fluorescent-inactive.

  12. Light activation of the isomerization and deprotonation of the protonated Schiff base retinal.

    Science.gov (United States)

    Kubli-Garfias, Carlos; Salazar-Salinas, Karim; Perez-Angel, Emily C; Seminario, Jorge M

    2011-10-01

    We perform an ab initio analysis of the photoisomerization of the protonated Schiff base of retinal (PSB-retinal) from 11-cis to 11-trans rotating the C10-C11=C12-C13 dihedral angle from 0° (cis) to -180° (trans). We find that the retinal molecule shows the lowest rotational barrier (0.22 eV) when its charge state is zero as compared to the barrier for the protonated molecule which is ∼0.89 eV. We conclude that rotation most likely takes place in the excited state of the deprotonated retinal. The addition of a proton creates a much larger barrier implying a switching behavior of retinal that might be useful for several applications in molecular electronics. All conformations of the retinal compound absorb in the green region with small shifts following the dihedral angle rotation; however, the Schiff base of retinal (SB-retinal) at trans-conformation absorbs in the violet region. The rotation of the dihedral angle around the C11=C12 π-bond affects the absorption energy of the retinal and the binding energy of the SB-retinal with the proton at the N-Schiff; the binding energy is slightly lower at the trans-SB-retinal than at other conformations of the retinal.

  13. Antimicrobial Activity and Urease Inhibition of Schiff Bases Derived from Isoniazid and Fluorinated Benzaldehydes and of Their Copper(II Complexes

    Directory of Open Access Journals (Sweden)

    Ladislav Habala

    2016-12-01

    Full Text Available In order to evaluate the influence of substitution on biological properties of Schiff bases and their metal complexes, a series of differently substituted fluorine-containing Schiff bases starting from the drug isoniazid (isonicotinylhydrazide were prepared and their structures were established by single-crystal X-ray diffraction. Also, four copper(II complexes of these Schiff bases were synthesized. The prepared compounds were evaluated for their antimicrobial activity and urease inhibition. Two of the Schiff bases exerted activity against C. albicans. All copper(II complexes showed excellent inhibitory properties against jack bean urease, considerably better than that of the standard inhibitor acetohydroxamic acid.

  14. Antimicrobial Activity and Urease Inhibition of Schiff Bases Derived from Isoniazid and Fluorinated Benzaldehydes and of Their Copper(II) Complexes.

    Science.gov (United States)

    Habala, Ladislav; Varényi, Samuel; Bilková, Andrea; Herich, Peter; Valentová, Jindra; Kožíšek, Jozef; Devínsky, Ferdinand

    2016-12-17

    In order to evaluate the influence of substitution on biological properties of Schiff bases and their metal complexes, a series of differently substituted fluorine-containing Schiff bases starting from the drug isoniazid (isonicotinylhydrazide) were prepared and their structures were established by single-crystal X-ray diffraction. Also, four copper(II) complexes of these Schiff bases were synthesized. The prepared compounds were evaluated for their antimicrobial activity and urease inhibition. Two of the Schiff bases exerted activity against C. albicans. All copper(II) complexes showed excellent inhibitory properties against jack bean urease, considerably better than that of the standard inhibitor acetohydroxamic acid.

  15. 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.

  16. Colorimetric chemosensor for multi-signaling detection of metal ions using pyrrole based Schiff bases.

    Science.gov (United States)

    Udhayakumari, Duraisamy; Velmathi, Sivan

    2014-03-25

    Pyrrole based Schiff bases act as a highly sensitive probe for metal ions in aqueous medium. Both receptors R1 and R2 are sensitive towards Fe(3+), Cu(2+), Hg(2+) and Cr(3+) among the other metal ions. The sensing ability of the receptors are investigated via colorimetric, optical and emission spectroscopic studies. The binding stoichiometries of R1 and R2 with metal ions have been determined as 2:1 by using Job's plot. The colorimetric receptors exhibited high sensitivity with a low detection limit of μM levels. In the presence of metal ions both receptors shows fluorescence quenching. This might be due to the photo induced electron transfer mechanism. The quenching constant was further determined using Stern-Volmer plot.

  17. Synthesis of Some Salicylaldehyde-Based Schiff Bases in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Sunita Bhagat

    2013-01-01

    Full Text Available A new efficient and environmental friendly procedure for the synthesis of a series of salicylaldehyde-based schiff bases under microwave irradiation is described. The method is compared with the conventional method also. The present work involves condensation of salicylaldehyde with various aromatic amines in water under microwave irradiation. A judicious choice of the solvent and reaction conditions allowed the final products to be generated in excellent yields in a one-step procedure, whereas experiments under thermal conditions led to lower yields with tedious work-up. Microwave irradiation method gives advantages like reduction in reaction time, increase in conversion, reduced wastes, and good yields. The structures of synthesized compounds were confirmed by IR, 1HNMR, and Mass Spectra data.

  18. Synthesis and antioxidant activity of thymol and carvacrol based Schiff bases.

    Science.gov (United States)

    Beena; Kumar, Deepak; Rawat, Diwan S

    2013-02-01

    Thymol and carvacrol are well known antioxidants found in the extract of the plants of thyme species. The Schiff bases of 2-iso-propyl-5-methyl-phenol (thymol/1a), 2-tert-butyl-5-methyl-phenol (1b) and 5-iso-propyl-2-methyl-phenol (carvacrol/1c) exhibited much better antioxidant activity than thymol and carvacrol in DPPH assay. Ten compounds (4k, 4l, 4r, 5k, 5l, 5q, 5r, 6k, 6l and 6r) showed better or similar activity as compared to the reference compound ascorbic acid. Twenty-four most active compounds were also screened by ABTS method and showed 60-90% inhibition at 5 μg/mL concentration.

  19. Extraction and functionalization of bagasse cellulose nanofibres to Schiff-base based antimicrobial membranes.

    Science.gov (United States)

    Bansal, Monica; Chauhan, Ghanshyam S; Kaushik, Anupama; Sharma, Avantika

    2016-10-01

    The work reported in this paper involves synthesis of a nanocellulose/chitosan composite and its further modification to antimicrobial films. Bagasse, an easily available biowaste, was used as source to extract nanocellulose fibres (CNFs) by subjecting it to mechanical and chemical treatments including alkaline steam explosion and high shear homogenization. The CNFs were subjected to periodate oxidation to obtain nanocellulose dialdehyde (CDA). The aldehyde groups of CDA were reacted with amino groups of chitosan to form Schiff-base. The resulting CDA/chitosan composite fibres were characterized at various steps. The fibres were then cast into films using cellulose acetate as a binder. The films have good physical strength. The composite films show excellent antimicrobial properties when tested against Staphylococcus aureus and Escherichia coli. Such antimicrobial films have potential applications in the formation of antimicrobial packaging material.

  20. Crystal structure characterization as well as theoretical study of spectroscopic properties of novel Schiff bases containing pyrazole group.

    Science.gov (United States)

    Guo, Jia; Ren, Tiegang; Zhang, Jinglai; Li, Guihui; Li, Weijie; Yang, Lirong

    2012-09-01

    A series of novel Schiff bases containing pyrazole group were synthesized using 1-aryl-3-methyl-4-benzoyl-5-pyrazolone and phenylenediamine as the starting materials. All as-synthesized Schiff bases were characterized by means of NMR, FT-IR, and MS; and the molecular geometries of two Schiff bases as typical examples were determined by means of single crystal X-ray diffraction. In the meantime, the ultraviolet-visible light absorption spectra and fluorescent spectra of various as-synthesized products were also measured. Moreover, the B3LYP/6-1G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases; and the spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVTZ basis set of TD-B3LYP method. It has been found that all as-synthesized Schiff bases show a remarkable absorption peak in a wavelength range of 270-370 nm; and their maximum emission peaks are around 344 nm and 332 nm, respectively.

  1. Experimental evidence for secondary protein-chromophore interactions at the Schiff base linkage in bacteriorhodopsin: molecular mechanism for proton pumping

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, A.; Marcus, M.A.; Ehrenberg, B.; Crespi, H.

    1978-10-01

    Resonance Raman spectroscopy of the retinylidene chromophore in various isotopically labeled membrane environments together with spectra of isotopically labeled model compounds demonstrates that a secondary protein interaction is present at the protonated Schiff base linkage in bacteriorhodopsin. The data indicate that although the interaction is present in all protonated bacteriorhodopsin species it is absent in unprotonated intermediates. Furthermore, kinetic resonance Raman spectroscopy has been used to monitor the dynamics of Schiff base deprotonation as a function of pH. All results are consistent with lysine as the interacting group. A structure for the interaction is proposed in which the interacting protein group in an unprotonated configuration is complexed through the Schiff base proton to the Schiff base nitrogen. These data suggest a molecular mechanism for proton pumping and ion gate molecular regulation. In this mechanism, light causes electron redistribution in the retinylidene chromophore, which results in the deprotonation of an amino acid side chain with pK > 10.2 +- 0.3 (e.g., arginine). This induces subsequent retinal and protein conformational transitions which eventually lower the pK of the Schiff base complex from > 12 before light absorption to 10.2 +- 0.3 in microseconds after photon absorption. Finally, in this low pK state the complex can reprotonate the proton-deficient high pK group generated by light, and the complex is then reprotonated from the opposite side of the membrane.

  2. Schiff base: A high affinity chemical agent to decrease the concentration of aflatoxin M1 in raw milk contaminated artificially

    Directory of Open Access Journals (Sweden)

    Frane Delaš

    2012-03-01

    Full Text Available In the present study were conducted the effect of pH (5.5, 6.0 and 6.5 and concentration of new synthesized 3-/2-aminophenylimino-(p-toluoyl/-4-hydroxy-6-(p-tolyl-2H-pyrane-2-one (Schiff base on decrease the concentration of aflatoxin M1 (AFM1 in raw milk contaminated with known concentration of this toxin. Experiments were carried out at temperature of 4 °C during 35 days. At pH 5.5 Schiff base concentration of 0.1 µmol/L was lessening the concentration of AFM1 after 35 days by 55 %. However, at pH 6.5 the most effective concentration for lessening of AFM1 was 0.5 µmol/L. Schiff base was not effective at pH value of 7 or higher. The ability of Schiff base to act as antimycotoxigenic agent provides new perspective for possibly using this compound to control AFM1 contamination in milk and to extent shelf lives of this food. Detection of toxicity of investigated Schiff base was performed by using the brine shrimp (Artemia salina larvae as an biological indicator to determine their sensitivity to this chemical agent.

  3. Synthesis of New Schiff Base from Natural Products for Remediation of Water Pollution with Heavy Metals in Industrial Areas

    Directory of Open Access Journals (Sweden)

    Reham Hassan

    2013-01-01

    Full Text Available A resin of [5-((E-1-(ethylimino ethyl-4, 7-dimethoxy benzofuran-6-ol] Schiff base (EEDB was prepared, characterized, and successfully applied in the removal of Cu (II ions from aqueous real samples. While the metal cation was detected using ICP-OES, the prepared Schiff base resin was characterized by means of FTIR, 1HNMR, mass spectral data, and elemental analysis. Various factors affecting the uptake behavior such as pH (2–12, contact time, effect of initial metal concentration (10–250 ppm, and effect of Schiff base weight (0.1–1.5 gm were studied. The adsorption process was relatively fast and equilibrium was established after about 60 min. The optimum initial pH was 8.0 at a metal ion concentration (100 ppm. Under the optimized conditions, the removal of Cu (II from real samples of tap water was applied and the removal efficiency reached nearly 85%. The biological activity for Schiff base was also investigated. The results showed that there is no significant difference between the effects of Schiff base on serum (alanine amino transferase ALT and creatinine concentration activities in treated mice and control, at confidence limits 95%.

  4. Oxovanadium(IV complexes of bioinorganic and medicinal relevance: Synthesis, characterization and 3D molecular modeling of some oxovanadium(IV complexes involving O, N-donor environment of salicylaldehyde-based sulfa drug Schiff bases

    Directory of Open Access Journals (Sweden)

    R.C. Maurya

    2016-11-01

    Full Text Available The present paper reports the synthesis and characterization of some new sulfa drug based Schiff base oxovanadium(IV complexes of composition, [VO(sal-sdz2(H2O]·H2O, [VO(sal-sgn2(H2O]·H2O, [VO(sal-snm(H2O]·H2O, [VO(sal-smr2(H2O]·H2O and [VO(dadps(H2O]2·2H2O, where sal-sdzH = N-(salicylidenesulfadizine, sal-sgnH = N-(salicylidenesulfaguanidine, sal-snmH = N-(salicylidenesulfanilamide, sal-smrH = N-(salicylidenesulfamerizine, sal-dadpsH2 = N,N′-bis(salicylidene-4,4′-diaminodiphenylsulfone, respectively. Complexes, (1–(4 were prepared by the reaction of VOSO4·5H2O with the Schiff bases in 1:2 metal-ligand ratio while complex (5 in 2:2 metal-ligand ratio in DMF-ethanol medium. The compounds so obtained were characterized by different physico-chemical studies, such as, elemental analysis, molar conductance and magnetic measurements, infrared, ESR, thermogravimetric studies, mass and electronic spectral studies. The overall IR studies conclude that the ligand in complex (1–(4 behave as monobasic bidentate ON donor, while the ligand in the complex (5 behaves as dibasic tetradentate O2N2 donor. The 3D-molecular modeling and analysis for bond lengths and bond angles have also been carried out for two representative compounds, [VO(sal-snm2(H2O]·H2O (3 and [VO(dadps(H2O]2·2H2O (5 to substantiate the proposed structures. Based on these studies suitable octahedral structures have been proposed for these complexes.

  5. Synthesis and Application of Zeolite-encapsulated Nickel Schiff-base Complex

    Institute of Scientific and Technical Information of China (English)

    FENG; HuiXi

    2001-01-01

    Transition-metal complex-catalyzed oxidation of organic substrates with molecular oxygen is gaining importance as a viable alternative to the environmentally hazardous metal-oxide-based reagents. The complexes have received much attention recently due to the potential application of these complexes as oxidation catalysts for the oxidation of alkene, enolizable, aldehydes and other organic substrates. Recent studies of our group showed that metal complexes catalyzed the oxidation of organic substrates selectively in the presence of molecular oxygen 1,5. Here, it is reported that zeolite-encapsulated Ni (I) Schiff-base complex exhibit a catalytic activity and selectivity for the oxidation of styrene.  ……

  6. Synthesis and Application of Zeolite-encapsulated Nickel Schiff-base Complex

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Transition-metal complex-catalyzed oxidation of organic substrates with molecular oxygen is gaining importance as a viable alternative to the environmentally hazardous metal-oxide-based reagents. The complexes have received much attention recently due to the potential application of these complexes as oxidation catalysts for the oxidation of alkene, enolizable, aldehydes and other organic substrates. Recent studies of our group showed that metal complexes catalyzed the oxidation of organic substrates selectively in the presence of molecular oxygen 1,5. Here, it is reported that zeolite-encapsulated Ni (I) Schiff-base complex exhibit a catalytic activity and selectivity for the oxidation of styrene.

  7. Synthesis and characterization of chromium(III) Schiff base complexes: Antimicrobial activity and its electrocatalytic sensing ability of catechol

    Science.gov (United States)

    Praveen Kumar, S.; Suresh, R.; Giribabu, K.; Manigandan, R.; Munusamy, S.; Muthamizh, S.; Narayanan, V.

    2015-03-01

    A series of acyclic Schiff base chromium(III) complexes were synthesized with the aid of microwave irradiation method. The complexes were characterized on the basis of elemental analysis, spectral analysis such as UV-Visible, Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) spectroscopies and electrospray ionization (ESI) mass spectrometry. Electrochemical analysis of the complexes indicates the presence of chromium ion in +3 oxidation state. Cr (III) ion is stabilized by the tetradentate Schiff base ligand through its nitrogen and phenolic oxygen. From the spectral studies it is understood that the synthesized chromium(III) complexes exhibits octahedral geometry. Antimicrobial activity of chromium complexes was investigated towards the Gram positive and Gram negative bacteria. In the present work, an attempt was made to fabricate a new kind of modified electrode based on chromium Schiff base complexes for the detection of catechol at nanomolar level.

  8. Hybrid scaffold bearing polymer-siloxane Schiff base linkage for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Bindu P., E-mail: bindumelekkuttu@gmail.com; Gangadharan, Dhanya; Mohan, Neethu; Sumathi, Babitha; Nair, Prabha D., E-mail: pdnair49@gmail.com

    2015-07-01

    Scaffolds that can provide the requisite biological cues for the fast regeneration of bone are highly relevant to the advances in tissue engineering and regenerative medicine. In the present article, we report the fabrication of a chitosan–gelatin–siloxane scaffold bearing interpolymer-siloxane Schiff base linkage, through a single-step dialdehyde cross-linking and freeze-drying method using 3-aminopropyltriethoxysilane as the siloxane precursor. Swelling of the scaffolds in phosphate buffered saline indicates enhancement with increase in siloxane concentration, whereas compressive moduli of the wet scaffolds reveal inverse dependence, owing to the presence of siloxane, rich in silanol groups. It is suggested that through the strategy of dialdehyde cross-linking, a limiting siloxane loading of 20 wt.% into a chitosan-gelatin matrix should be considered ideal for bone tissue engineering, because the scaffold made with 30 wt.% siloxane loading degrades by 48 wt.%, in 21 days. The hybrid scaffolds bearing Schiff base linkage between the polymer and siloxane, unlike the stable linkages in earlier reports, are expected to give a faster release of siloxanes and enhancement in osteogenesis. This is verified by the in vitro evaluation of the hybrid scaffolds using rabbit adipose mesenchymal stem cells, which revealed osteogenic cell-clusters on a polymer-siloxane scaffold, enhanced alkaline phosphatase activity and the expression of bone-specific genes, whereas the control scaffold without siloxane supported more of cell-proliferation than differentiation. A siloxane concentration dependent enhancement in osteogenic differentiation is also observed. - Highlights: • A hybrid scaffold bearing interpolymer-siloxane Schiff base linkage • A limiting siloxane loading of 20 wt.% into chitosan–gelatin matrix • A siloxane concentration dependent enhancement in osteogenic differentiation.

  9. Synthesis and Chromatographic Properties of New β-Cyclodextrin Derivatives with α-Schiff Base Groups for HPLC

    Institute of Scientific and Technical Information of China (English)

    Min FANG; Zhi Ming ZHOU; Ai Qin LUO

    2005-01-01

    β-Cyclodextrin 1 was directly oxidized to the corresponding monoaldehyde 2 on their primary faces by cyclized 2-iodoxybenzoic acid(IBX) in DMSO, followed by the synthesis of β-cyclodextrin derivatives bearing Schiff-base group 3. A new chiral stationary phase(BCDS 6)was then prepared by immobilization of β-cyclodextrin derivative with α-Schiff base group onto the surface of sillica gel. A series of compounds with amino groups were readily separated using this CSP. Methanol and acetonitrile were tested as the mobile phase while the influence of temperature and the addition of aqueous triethylammonium acetate buffer to the mobile phase was also innvestigated. Ferrocene ligand with Schiff-based groups have been separated satisfactorilly on BCDS column.

  10. In vitro antibacterial, antifungal and cytotoxic activities of some triazole Schiff bases and their oxovanadium(IV) complexes.

    Science.gov (United States)

    Sumrra, Sajjad H; Chohan, Zahid H

    2013-12-01

    The condensation reaction of 3,5-diamino-1,2,4-triazole with methoxy-, chloro-, bromo-, iodo- and nitro-substituted 2-hydroxybenzaldehydes formed triazole Schiff bases (L(1))-(L(6)). The synthesized ligands have been characterized through physical, spectral and analytical data. Furthermore, the reaction of synthesized Schiff bases with the oxovanadium(IV) sulphate in (1:2) (metal:ligand) molar ratio afforded the oxovanadium(IV) complexes (1)-(6). All the complexes were non-electrolytic and showed a square-pyramidal geometry. The synthesized compounds have been screened for in-vitro antibacterial, antifungal and brine shrimp bioassay. The bioactivity data showed the complexes to be more active than the original Schiff bases.

  11. An electrochemical procedure coupled with a Schiff base method; application to electroorganic synthesis of new nitrogen-containing heterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Dowlati, Bahram; Othman, Mohamed Rozali [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2013-11-27

    The synthesis of Nitrogen-containing heterocycles has been achieved using chemical and electrochemical methods, respectively. The direct chemical synthesis of nucleophiles proceeds through the Schiff base chemical reaction. This procedure offers an alternate reaction between dicarbonyl compounds and diamines leads to the formation of products. The results indicate that the Schiff base chemical method for synthesis of the product has successfully performed in excellent overall yield. In the electrochemical step, a series of Nitrogen-containing compounds were electrosynthesized. Various parameters such as the applied potential, pH of the electrolytic solution, cell configuration and also purification techniques, were carried out to optimize the yields of corresponding products. New Nitrogen-containing heterocycle derivatives were synthesized using an electrochemical procedure coupled with a Schiff base as a facile, efficient and practical method. The products have been characterized after purification by IR, {sup 1}H NMR, {sup 13}C NMR and ESI-MS{sup 2}.

  12. Synthesis, characterization and antibacterial activity of a tridentate Schiff base derived from cephalothin and sulfadiazine, and its transition metal complexes.

    Science.gov (United States)

    Anacona, J R; Noriega, Natiana; Camus, Juan

    2015-02-25

    Metal(II) coordination compounds of a cephalothin Schiff base (H2L) derived from the condensation of cephalothin antibiotic with sulfadiazine were synthesized. The Schiff base ligand, mononuclear [ML(H2O)3] (M(II)=Mn,Co,Ni,Zn) complexes and magnetically diluted dinuclear copper(II) complex [CuL(H2O)3]2 were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and (1)H NMR spectral studies. The cephalothin Schiff base ligand H2L behaves as a dianionic tridentate NOO chelating agent. The biological applications of complexes have been studied on two bacteria strains (Escherichia coli and Staphylococcus aureus) by agar diffusion disc method.

  13. Synthesis, characterization and antibacterial activity of a Schiff base derived from cephalexin and sulphathiazole and its transition metal complexes.

    Science.gov (United States)

    Anacona, J R; Rodriguez, Juan Luis; Camus, Juan

    2014-08-14

    Metal(II) coordination compounds of a cephalexin Schiff base (HL) derived from the condensation of cephalexin antibiotic with sulphathiazole were synthesized. The Schiff base ligand, mononuclear [ML(OAc)(H2O)2] (M(II)=Mn, Co, Ni, Zn) complexes and magnetically diluted trinuclear copper(II) complex [Cu3L(OH)5] were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and (1)H NMR spectral studies. The analytical and molar conductance values indicated that the acetate ions coordinate to the metal ions. The Schiff base ligand HL behaves as a monoanionic tridentate NNO and tetradentate NNOO chelating agent in the mono and trinuclear complexes respectively.

  14. Synthesis, characterization and antibacterial activity of a Schiff base derived from cephalexin and sulphathiazole and its transition metal complexes

    Science.gov (United States)

    Anacona, J. R.; Rodriguez, Juan Luis; Camus, Juan

    2014-08-01

    Metal(II) coordination compounds of a cephalexin Schiff base (HL) derived from the condensation of cephalexin antibiotic with sulphathiazole were synthesized. The Schiff base ligand, mononuclear [ML(OAc)(H2O)2] (M(II) = Mn, Co, Ni, Zn) complexes and magnetically diluted trinuclear copper(II) complex [Cu3L(OH)5] were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The analytical and molar conductance values indicated that the acetate ions coordinate to the metal ions. The Schiff base ligand HL behaves as a monoanionic tridentate NNO and tetradentate NNOO chelating agent in the mono and trinuclear complexes respectively.

  15. Synthesis, characterization and antibacterial activity of a tridentate Schiff base derived from cephalothin and sulfadiazine, and its transition metal complexes

    Science.gov (United States)

    Anacona, J. R.; Noriega, Natiana; Camus, Juan

    2015-02-01

    Metal(II) coordination compounds of a cephalothin Schiff base (H2L) derived from the condensation of cephalothin antibiotic with sulfadiazine were synthesized. The Schiff base ligand, mononuclear [ML(H2O)3] (M(II) = Mn, Co, Ni, Zn) complexes and magnetically diluted dinuclear copper(II) complex [CuL(H2O)3]2 were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The cephalothin Schiff base ligand H2L behaves as a dianionic tridentate NOO chelating agent. The biological applications of complexes have been studied on two bacteria strains (Escherichia coli and Staphylococcus aureus) by agar diffusion disc method.

  16. An electrochemical procedure coupled with a Schiff base method; application to electroorganic synthesis of new nitrogen-containing heterocycles

    Science.gov (United States)

    Dowlati, Bahram; Othman, Mohamed Rozali

    2013-11-01

    The synthesis of Nitrogen-containing heterocycles has been achieved using chemical and electrochemical methods, respectively. The direct chemical synthesis of nucleophiles proceeds through the Schiff base chemical reaction. This procedure offers an alternate reaction between dicarbonyl compounds and diamines leads to the formation of products. The results indicate that the Schiff base chemical method for synthesis of the product has successfully performed in excellent overall yield. In the electrochemical step, a series of Nitrogen-containing compounds were electrosynthesized. Various parameters such as the applied potential, pH of the electrolytic solution, cell configuration and also purification techniques, were carried out to optimize the yields of corresponding products. New Nitrogen-containing heterocycle derivatives were synthesized using an electrochemical procedure coupled with a Schiff base as a facile, efficient and practical method. The products have been characterized after purification by IR, 1H NMR, 13C NMR and ESI-MS2.

  17. An expeditious synthetic approach towards the synthesis of Bis-Schiff bases (aldazines) using ultrasound.

    Science.gov (United States)

    Khan, Khalid M; Jamil, Waqas; Ambreen, Nida; Taha, Muhammad; Perveen, Shahnaz; Morales, Guillermo A

    2014-05-01

    Aldazines (Bis-Schiff bases) 1-24 were synthesized using aromatic aldehydes (heterocyclic and benzaldehydes) and hydrazine hydrate under reflux using conventional heating and/or via ultrasound irradiation using BiCl3 as catalyst. Ultrasonication conditions with cat. BiCl3 proved to be an effective, environmentally friendly synthetic procedure. This methodology is robust in the presence of electron donating and electron withdrawing groups affording desired products with high yields (>95%) in just a couple of minutes vs. hours using conventional heating.

  18. Metal complexes of Schiff bases derived from dicinnamoylmethane and aliphatic diamines

    Directory of Open Access Journals (Sweden)

    K. KRISHNANKUTTY

    2008-04-01

    Full Text Available (Received 26 July, revised 10 December 2007Two new Schiff bases containing olefinic linkages have been synthesized by condensing aliphatic diamines with dicinnamoylmethane under specified conditions. The existence of these compounds predominantly in the intramolecularly hydrogen bonded keto-enamine form was well demonstrated by their IR, 1H-NMR and mass spectral data. Dibasic tetradentate N2O2 coordination of the compounds in their [ML] complexes (M = Ni(II, Cu(II and Zn(II was established on the basis of analytical and spectral data.

  19. Co (II) Complexes with Schiff Base Ligands: Synthesis and EXAFS Study

    Science.gov (United States)

    Mishra, Ashutosh; Mansuri, Amantulla; Ninama, Samrath; Trivedi, Apurva; Patidar, Sushma; Jamod, Mahesh; Awate, Ruchita

    2016-10-01

    Thesynthesis of transition metal Schiff base complexes of Co(II) are prepared by chemical root method. Obtained by the condensation of O-phenylenediamine, salicylaldehyde and isatin / 2-hydroxy- 1 Naphthaldehyde is presented. The complexes were characterized by Co- K- edge EXAFS measurements using the dispersive beam line at 2.5GeV energy of Indus-2 synchrotron radiation source RRCAT Indore. The recorded EXAFS data were analyzed using the computer software Athena for determine the nearest neighboring distances (bond lengths) of these complexes with conventional methods and were compared with Fourier transform (FT) analysis.

  20. Synthesis and electrochromic, acidochromic properties of Schiff bases containing triphenylamine and thiophene units.

    Science.gov (United States)

    Wu, Xiaotong; Wang, Wen; Li, Bin; Hou, Yanjun; Niu, Haijun; Zhang, Yanhong; Wang, Shuhong; Bai, Xuduo

    2015-04-05

    A series of Schiff bases (SBs) were designed and prepared from 2-thiophenecarboxaldehyde and different triphenylamine (TPA) derivatives. The structures of the compounds were characterized by Fourier transform infrared (FT-IR), hydrogen nuclear magnetic resonance (1H NMR). The optical and electrochemical properties were tested by ultraviolet-visible (UV-vis) spectroscopy and cyclic voltammetry (CV) techniques. The SBs exhibited stable and reversible electrochromic properties. Furthermore, multiple reversible colors states were also observed with the change of pH. Consequently, the SBs can be used as electrochromic and acidochromic materials.

  1. Microwave-Assisted Synthesis of Some Quinoxaline-Incorporated Schiff Bases and Their Biological Evaluation

    Directory of Open Access Journals (Sweden)

    L. Achutha

    2013-01-01

    Full Text Available Quinoxaline-incorporated Schiff bases (4a–j were synthesized by the condensation of 2-[(3-methylquinoxalin-2-yloxy]acetohydrazide (3 with indole-3-carbaldehyde, furfuraldehyde, 5-(4-nitrophenyl-2-furfuraldehyde, and substituted benzaldehydes under conventional and microwave irradiation methods. The microwave method was found to be remarkably successful with higher yields, less reaction time, and environmentally friendly compared to conventional heating method. The chemical structures of the synthesized compounds have been confirmed by analytical and spectral data. All the compounds have been evaluated for antitubercular and anti-inflammatory activities.

  2. Corrosion inhibition of mild steel in hydrochloric acid solution by some double Schiff bases

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, N. [Payame Noor University (PNU), Shahin Shahr Branch, Isfahan (Iran, Islamic Republic of)], E-mail: N.Soltani@kashanu.ac.ir; Behpour, M.; Ghoreishi, S.M.; Naeimi, H. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2010-04-15

    The inhibition effect of four double Schiff bases on the corrosion of mild steel in 2 M HCl has been studied by polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The inhibitors were adsorbed on the steel surface according to the Langmuir adsorption isotherm model. From the adsorption isotherm, some thermodynamic data for the adsorption process were calculated and discussed. Kinetic parameters activation such as E{sub a}, {delta}H*, {delta}S* were evaluated from the effect of temperature on corrosion and inhibition processes. Quantum chemical calculations have been performed and several quantum chemical indices were calculated and correlated with the corresponding inhibition efficiencies.

  3. The Aggregates in LB Films of Schiff base Aluminium (III) Complex

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The surface pressure-area (p -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TA12)3), on pure water subphase was investigated. The molecular area, 0.48 nm2 , is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TA12)3 was transferred and characterized. The AFM image confirmed the formation of aggregates.

  4. Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays

    Directory of Open Access Journals (Sweden)

    Patrícia M. Dias

    2010-01-01

    Full Text Available Herein, the immobilization of some Schiff base-copper(II complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations.

  5. Synthesis, oxygenation and catalytic performance of manganese complex with p-aminomethyl benzoic acid Schiff base

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy,dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-keto-dehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60℃C, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.

  6. Photochromism and thermochromism of Schiff bases in the solid state: structural aspects.

    Science.gov (United States)

    Hadjoudis, Eugene; Mavridis, Irene M

    2004-11-30

    This tutorial review describes in a brief historical perspective the most important organic compounds that exhibit photochromism in the crystalline state since its discovery in 1867 up to now and considers in detail Schiff bases of salicylaldehyde with amines (anils). The latter comprise a chemical system undergoing hydrogen-atom tautomerism between enol and keto forms and show the phenomena of solid state photochromism and thermochromism. The system has been investigated extensively. Thus it has been shown that the photochromic property is a characteristic of the molecules but their chromobehaviour is influenced by the crystal structure of the compounds. Anils, apart from their fundamental interest, have potential for various applications.

  7. STM and XPS study on the self-assembled films of Schiff base on copper surface

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    SAMs (self-assembled monolayers) of Schiff base were prepared on the copper surface, and characterized by the modern technique of surface analysis. The results demonstrated that the well-ordered and densely packed SAMs of N-2-hydroxyphenyl-(3-methoxy-salicylidenimine), designated as V-bso, were formed on the Cu(111) surface. And two benzene rings in the V-bso molecule were not flat on the copper surface, but tilted at a certain angle. The development of this new system of self-assembly would be of significance to the application of the SAMs in the field of metal corrosion and protection.

  8. Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

    OpenAIRE

    Saeed Taghvaee Ganjali; Karim Akbari Dilmaghani; Behrouz Shaabani; Abdol Ali Alemi

    2001-01-01

    Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2) is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these lig...

  9. Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

    Directory of Open Access Journals (Sweden)

    Saeed Taghvaee Ganjali

    2001-03-01

    Full Text Available Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2 is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these ligands indicates their potential for NLO applications.

  10. Synthesis and mesomorphic properties of Schiff base esters possessing terminal chloro substituent

    Institute of Scientific and Technical Information of China (English)

    Sie

    2010-01-01

    A homologous series of Schiff base esters, 4-chlorobenzylidene-4'-n-alkanoyloxyanilines, containing even number of carbons at the end groups of the molecules (Cn-1H2n-1COO-, n = 4,6,8,10,12,14,16) were synthesized. The mesomorphic properties were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that the end groups of the molecules had an effect on the mesomorphic properties. n-Butanoyloxy was found non-mesogenic, whilst n-hexanoyloxy exhibited monotropic smectic phase. The higher members in this homologous series were enantiotropic smectogens.

  11. Synthesis and characterization of copper complexes of Schiff base derived from isatin and salicylic hydrazide

    Energy Technology Data Exchange (ETDEWEB)

    Lekshmy, R. K., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com; Thara, G. S., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com [Department of Chemistry, University College, Thiruvananthapuram- 695 034, Kerala (India)

    2014-10-15

    A series of novel metal complexes of Schiff base have been prepared by the interaction of Cu(II) with isatin salicylic hydrazide. All the new compounds were characterized by elemental analysis, conductance measurement, magnetic moment determination, IR, UV, NMR, Mass and EPR spectral studies, thermal studies and microbial activities. The results indicate that the ligand acts as a tridentate chelating ligand coordinating through nitrogen and oxygen atoms. The ligand and complexes show inactive against Escherichia coli and active against Staphylococcus aureus and B.substilis. By analyzing the results of spectral, thermal and elemental analysis square planar geometry is proposed for all the complexes.

  12. Recyclable copper nanoparticles: Efficient catalyst for selective cyclization of Schiff bases

    Directory of Open Access Journals (Sweden)

    Sulekh Chandra

    2016-07-01

    Full Text Available Recyclable Cu-nanoparticles provide an efficient, economic and novel method for the synthesis of imine Schiff bases via condensation of salicylaldehyde and aliphatic amines using 25 mol% of Cu-nanoparticles in the presence of K2CO3/KHCO3/Na2CO3 in MeOH at 80 °C. This method provides a wide range of substrate applicability and avoids the use of heavy metal co-catalysts and gives satisfactory yields.

  13. Palladium catalysed asymmetric alkylation of benzophenone Schiff base glycine esters in ionic liquids

    Indian Academy of Sciences (India)

    Dae Hyun Kim; Jin Kyu Im; Dae Won Kim; Minserk Cheong; Hoon Sik Kim; Deb Kumar Mukherjee

    2011-07-01

    Asymmetric alkyl substitution of various benzophenone Schiff base substrates under biphasic conditions proceeded using optically active Palladium(II) complexes. The corresponding products were obtained in high yields but with moderate enantiomeric excess (ee). Addition of specific ionic liquids to the reaction medium enhanced reactivity and selectivity for phase transfer catalytic (PTC) glycine alkylation. It has been found that there is an anionic influence of the ionic liquids that modify the steric environment around the enolate ion. A computer-assisted molecular design of enantioselective phase-transfer catalysis with the palladium complex and the ionic liquid has been done.

  14. An expeditious green synthesis of Schiff bases and azetidinones derivatised with 1,2,4-triazoles

    Indian Academy of Sciences (India)

    Tasneem Taj; Ravindra R Kamble; Tegginamath Gireesh; Bharathi V Badami

    2011-09-01

    An efficient green approach to the synthesis of Schiff bases (11-21) of 1-amino-2-aryl-3-oxo-1,2,4-triazoles (1-3) have been reported under Mg(ClO4)2 as catalyst followed by the reaction with chloroacetyl chloride in solvent-free conditions to yield the azetidinones (22-32) with excellent yields. The synthesized compounds were evaluated for the extent of penetration into biological membranes ($clogP$), drug-likeliness and finally drug score was calculated and also screened for antitubercular and antimicrobial activities.

  15. A -cyanostilbene-modified Schiff base as efficient turn-on fluorescent chemosensor for Zn2+

    Indian Academy of Sciences (India)

    Aixiang Ding; Fang Tang; Tao Wang; Xutang Tao; Jiaxiang Yang

    2015-03-01

    A novel Schiff base derivative (Z)-3-(4-(hexyloxy)phenyl)-2-(4-((E)-2-hydroxybenzylidene amino)phenyl)acrylonitrile (L) was designed, synthesized and characterized. L was used as a Zn2+ selective, turn-on, fluorescent chemosensor with a detection limit of 0.1M in DMF. 1:1 stoichiometric complex formation of L wih Zn2+ was confirmed through fluorescent titration experiments and Job’s plot. The enhancement of fluorescence intensity of L with addition of Zn2+ is the consequence of the inhibited isomerization of the C=N bond, namely chelation-enhanced fluorescence (CHEF) effect.

  16. A chiral photochromic Schiff base: (R-4-methoxy-2-[(1-phenylethyliminomethyl]phenol

    Directory of Open Access Journals (Sweden)

    Yukie Miura

    2009-10-01

    Full Text Available The title chiral photochromic Schiff base compound, C16H17NO2, was synthesized from (R-1-phenylethylamine and 5-methoxysalicylaldehyde. The molecule of the title compound exists in the phenol–imine tautomeric form. The dihedral angle between the two aromatic rings is 62.61 (11°. An intramolecular O—H...N hydrogen bond with an O...N distance of 2.589 (2 Å is observed. The crystal packing is stabilized by C—H...π interactions involving the aromatic ring.

  17. Laser-induced absorption and fluorescence studies of photochromic Schiff bases

    DEFF Research Database (Denmark)

    Kownacki, K.; Mordzinski, A.; Wilbrandt, R.

    1994-01-01

    Three photochromic Schiff bases: N-salicylideneaniline (SA), N-salicylidene-1-naphthylamine (SN), and N,N-bis-(salicylidene)-p-phenylenediamine (Bsp), were studied in acetonitrile by means of steady-state and time-resolved absorption and fluorescence spectroscopy, as well as semiempirical quantum...... chemical calculations. In all these molecules, the transient absorption and two-step laser-induced fluorescence spectra of long-lived transients are remarkably similar. The photochromic species is tentatively assigned to the non-hydrogen bonded form of the proton transfer reaction product...

  18. Synthesis, Structure and Antibacterial Activities of 4-BBTS Schiff Base and Its Complexes

    Institute of Scientific and Technical Information of China (English)

    LI Pei-Fan; LIU Bin; WANG Jin-Ling

    2007-01-01

    4-Bromobenzaldehyde thiosemicarbazone Schiff base (4-BBTS) and its Cu(Ⅱ),Zn(Ⅱ), Co(Ⅱ) and Ni(Ⅱ) complexes were synthesized and characterized by elemental analysis, UV,IR, MS, 1H NMR, and molar conductivity. Using disc diffusion method, the antibacterial activity tests were conducted. The results revealed that the ligand as well as all the complexes exhibits good antibacterial activities against E. Coli. and S. Aureus. Moreover, Cu(Ⅱ) complex shows the best antibacterial activity, which provides beneficial reference for studying the relationship between the structures and performances.

  19. Reaction of pyridoxal phosphate with amino acids Electrochemical study of the Schiff bases from pyridoxal phosphates with L-leucine. Reaccion de piridoxal fosfate con aminoacido. Estudio electroquimico de las bases de Schiff de piridoxal y piridoxal fosfato con L- lencina

    Energy Technology Data Exchange (ETDEWEB)

    Pineda, T.; Blazquez, M.; Dominguez, M.; Garcia-Blanco, F. (Departamento de Quimica Fisica y Termodinamica Aplicada. Facultad de Ciencias. Cordoba (Spain))

    1994-01-01

    The formation of the Schiff bases derived from pyridoxal (PL) and pyridoxal phosphate (PLP) with l-leucine is followed by UV-visible absorption spectroscopy. On the basis of electrochemical study of the reaction mixtures the apparent formation constant of the un protonated and mono protonated species of the Schiff base is estimated. The stability increases from Ala to Leu amino acid residues and comparatively, the Schiff base derived from PLP and hexilamine is more stable than with amino acid. The Schiff base derived from PL show the same sequence although the stability of the un protonated species shows a higher relative stability. (Author) 10 refs.

  20. Synthesis, Structure and Characterization of Schiff Base Metal Complexes and Their Electrochemical Properties of Thionyl Chloride Reduction

    Institute of Scientific and Technical Information of China (English)

    CHE,Tu-Lin; GAO,Quan-Chang; ZHAO,Jian-She; ZHANG,Gai

    2008-01-01

    A symmetric tetradentate Schiff base ligand bis(3-methoxysalicylidene)-o-phenylenediamine (H2L) was prepared.A series of transition metal complexes with this Schiff base ligand have been synthesized and structurally characterized by IR and elemental analysis.The catalysis for reduction of thionyl chloride was studied by means of coristant resistance discharge.The result shows that [Mn(Ⅲ)LCI(H2O)]CH3OH and [Co(Ⅱ)HLCI(H2O)] have a good catalytic activity for the reduction of thionyl chloride,which improves the cell voltage,the rate of discharge,and the lifetime of Li/SOCl2 batteries.

  1. Synthesis of 4-aminoantipyrine derived Schiff bases and their evaluation for antibacterial, cytotoxic and free radical scavenging activity

    Directory of Open Access Journals (Sweden)

    Mohammad Shoaib

    2015-06-01

    Full Text Available The work was aimed to synthesize 4-Aminoantipyrine derived Schiff bases in economical way and to screen it for study the effect of nitro group on its antibacterial potential, conduct antitumor preliminary study, the effects of group presence in benzylidene phenyl ring on the cytotoxic potentials and study the effects of electron withdrawing and donating group on antioxidant potential. We used green method with 75% reduction in general synthesis time of Schiff bases. Synthesized compound possess antibacterial potentials and nitro group presence enhances this potential. G2, G3, G4, G5, G6, G7 and G8 have significant cytotoxic and no significant antioxidant activity.

  2. Synthesis and Antimicrobial Activity of Some Novel Schiff Bases Containing 1,2,4-Triazole-3-thione

    Directory of Open Access Journals (Sweden)

    M. M. Çalisir

    2010-01-01

    Full Text Available A series of Schiff bases (4a-j were prepared by reacting 4-amino-5-(1-phenylethyl-2,4-dihydro-3H-1,2,4-triazole-3-thione and substituted aromatic aldehydes. The chemical structures were confirmed by means of UV, 1H NMR, IR, MS(API-ES spectral data and elemental analysis. All the synthesized compounds were screened for their antimicrobial activity. Among the tested compounds, Schiff bases with 4-OH and 4-NO2 substituent exhibited remarkable antimicrobial activity against all the tested microorganism.

  3. SYNTHESIS, SPECTROSCOPIC, THERMAL STUDIES AND BIOLOGICAL ACTIVITY OF A NEW SULFAMETHOXAZOLE SCHIFF BASE AND ITS COPPER COMPLEXES

    Directory of Open Access Journals (Sweden)

    A. M. Abu-Yamin et al.

    2011-12-01

    Full Text Available A new Sulfamethoxazole Schiff base (E-4-(4-methoxybenzylideneamino-N-(5-methylis-oxazol-3-yl benzenesulfonamide (C18H17N3O4S, and its copper complex were synthesized and the structures elucidated on the basis of Physiochemical methods. The studies indicate an octahedral structure for the complexes with the (C22H27N3O10SCu formula. The IR spectra suggest that the ligand act as tridentate (from oxygen and two nitrogen atoms donor. Also the biological activity of the Schiff base and its Cu complex were studied.

  4. Synthesis and antitumor and antibacterial evaluation of fluoroquinolone derivatives (Ⅲ) : Mono-and bis-Schiff-bases

    Institute of Scientific and Technical Information of China (English)

    Guo Qiang Hu; Wen Long Huang; Xiao Kui Wu; Guo Qiang Wang; Nan Nan Duan; Xiao Yi Wen; Tie Yao Cao; Yin Jun; Wang Wei; Song Qiang Xie

    2012-01-01

    To further explore an efficient modified route for the shift from an antibacterial fluoroquinolone to an antitumor one,monoSchiff bases 6a-6h related to ciprofloxacin C3 carbonylhydrazone and bis-Schiff bases 4a-4h corresponding to C3/C7 carbonylhydrazone/hydrazone attached on a skeleton of ciprofloquinolone were designed and synthesized,and their in vitro antitumor activity against CHO,HL60,L1210 cells and antibacterial activity against Staphylococcus aureus and Escherichia coli were also reported.

  5. Synthesis of New Schiff Base from Natural Products for Remediation of Water Pollution with Heavy Metals in Industrial Areas

    OpenAIRE

    Reham Hassan; Hassan Arida; Manal Montasser; Nehad Abdel Latif

    2013-01-01

    A resin of [5-((E)-1-(ethylimino) ethyl)-4, 7-dimethoxy benzofuran-6-ol] Schiff base (EEDB) was prepared, characterized, and successfully applied in the removal of Cu (II) ions from aqueous real samples. While the metal cation was detected using ICP-OES, the prepared Schiff base resin was characterized by means of FTIR, 1HNMR, mass spectral data, and elemental analysis. Various factors affecting the uptake behavior such as pH (2–12), contact time, effect of initial metal concentration (10–250...

  6. 新型Schiff碱缓蚀剂的研究进展%Development of Novel Schiff Base Inhibitors

    Institute of Scientific and Technical Information of China (English)

    方晓君; 张娟涛; 陈长风; 白真权; 张国超

    2012-01-01

    综述了Schiff碱缓蚀剂在金属腐蚀与防护领域的研究进展,为Schiff碱作为缓蚀剂的应用提供了实验和理论基础,也为缓蚀剂的进一步开发进行了有益的探索。%The recent developments of novel Schiff base inhibitors in corrosion and protection field are reviewed in this paper, in order to provide theoretical and experimental foundation for the application of novel Schiff base inhibitors, and offer exploration for further exploitation of inhibitors.

  7. Triorganotin(IV) complexes with biologically potent schiff bases: infrared, ¹¹⁹Sn spectral characteristics and antimicrobial applications.

    Science.gov (United States)

    Rehman, W; Khan, J; Muhammad, B; Shah, S W H; Rashid, R

    2012-05-01

    This review paper has attempted information specific to the title compound. This survey of the literature data provides useful information about the design and stabilities of the triorganotin with biologically active ligands. Up to now, considerable efforts have been made to synthesize and characterize triorganotin(IV) schiff base complexes with the general formulae R3ML [R = organic group, M: Sn and L: schiff base] and many studies have been focused in order to understand bioassay results. Users with an interest in this substance are strongly encouraged for future research that this is still a very open field.

  8. Catalytic Oxidative Decarboxylation of Some Benzylcarboxylic Acid Derivatives by a New Iron(Ill) Schiff Base Complex

    Institute of Scientific and Technical Information of China (English)

    MONTAZEROZOHORI,Morteza; NASR-ESFAHANI,Masoud; AKHLAGHI,Parisa

    2009-01-01

    A quadridentate Schiff base ligand of N,N'-bis(2-hydroxy-a-methylbenzylidene)ethylenediamine (HMBEDA) and its new iron(Ⅲ) complex were synthesized and identified by analytical, spectral data (1H NMR, 13C NMR FT-IR and UV-visible) and molar conductance. A rapid and efficient homogeneous oxidative decarboxylatio n ofsome benzylcarboxylic acid derivatives was carried out by a catalytic amount of iron(Ⅲ) Schiff base complex in chloroform, using tetrabutylammonium periodate as a mild oxidant in good to excellent yields at room temperature.

  9. A new MoVI Schiff base complex: methanol[N′-(3-methoxy-2-oxidobenzylidenebenzohydrazidato]dioxidomolybdenum(VI

    Directory of Open Access Journals (Sweden)

    Iran Sheikhshoaie

    2011-07-01

    Full Text Available In the title benzilidene Schiff base molybdenum(VI complex, [Mo(C15H12N2O3O2(CH3OH], the MoVI ion is coordinated by two oxide O atoms and by two O atoms and one N atom of the tridentate N′-(3-methoxy-2-oxidobenzylidenebenzohydrazidate (L Schiff base ligand. The methanol O atom completes the distorted octahedral configuration of the MoVI atom. Strong O—H...N hydrogen bonds form a C(5 chain around a 21 screw axis. Weak C—H—O hydrogen bonds are also present.

  10. Formation of Schiff base adduct between acetaldehyde and rat liver microsomal phosphatidylethanolamine.

    Science.gov (United States)

    Kenney, W C

    1984-01-01

    Recent studies have established the formation of acetaldehyde adducts of proteins even at low concentrations of acetaldehyde expected to occur in vivo under conditions of ethanol metabolism. Although formation of acetaldehyde adducts with phospholipids has been obtained at high pH values and at high concentrations of acetaldehyde, the occurrence of such adducts under more physiological conditions had yet to be demonstrated. Rat liver microsomes were incubated with 0.2 mM [14C]acetaldehyde at pH 7.4 and 37 degrees C. After treatment with sodium borohydride to reduce any Schiff bases formed, the phospholipids were isolated. The major radioactive component within the phospholipid fraction had chromatographic properties identical to N-ethylphosphatidylethanolamine. In addition, the nitrogenous base derived therefrom by acid hydrolysis was identical to N-ethylethanolamine. These results indicate that a Schiff base adduct between acetaldehyde and microsomal phosphatidylethanolamine had been formed during incubation of low concentrations of acetaldehyde with rat liver microsomes.

  11. Exploring DNA binding and nucleolytic activity of few 4-aminoantipyrine based amino acid Schiff base complexes: a comparative approach.

    Science.gov (United States)

    Raman, N; Sakthivel, A; Pravin, N

    2014-05-05

    A series of novel Co(II), Cu(II), Ni(II) and Zn(II) complexes were synthesized from Schiff base(s), obtained by the condensation of 4-aminoantipyrine with furfural and amino acid (glycine(L1)/alanine(L2)/valine(L3)) and respective metal(II) chloride. Their structural features and other properties were explored from the analytical and spectral methods. The binding behaviors of the complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The intrinsic binding constants for the above synthesized complexes are found to be in the order of 10(2) to 10(5) indicating that most of the synthesized complexes are good intercalators. The binding constant values (Kb) clearly indicate that valine Schiff-base complexes have more intercalating ability than alanine and glycine Schiff-base complexes. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. The IC50 values of [Ni(L1)2] and [Zn(L1)2] complexes imply that these complexes have preferable ability to scavenge hydroxyl radical.

  12. Exploring DNA binding and nucleolytic activity of few 4-aminoantipyrine based amino acid Schiff base complexes: A comparative approach

    Science.gov (United States)

    Raman, N.; Sakthivel, A.; Pravin, N.

    A series of novel Co(II), Cu(II), Ni(II) and Zn(II) complexes were synthesized from Schiff base(s), obtained by the condensation of 4-aminoantipyrine with furfural and amino acid (glycine(L1)/alanine(L2)/valine(L3)) and respective metal(II) chloride. Their structural features and other properties were explored from the analytical and spectral methods. The binding behaviors of the complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The intrinsic binding constants for the above synthesized complexes are found to be in the order of 102 to 105 indicating that most of the synthesized complexes are good intercalators. The binding constant values (Kb) clearly indicate that valine Schiff-base complexes have more intercalating ability than alanine and glycine Schiff-base complexes. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. The IC50 values of [Ni(L1)2] and [Zn(L1)2] complexes imply that these complexes have preferable ability to scavenge hydroxyl radical.

  13. The Zinc-Schiff Base-Novicidin Complex as a Potential Prostate Cancer Therapy

    Science.gov (United States)

    Milosavljevic, Vedran; Haddad, Yazan; Merlos Rodrigo, Miguel Angel; Moulick, Amitava; Polanska, Hana; Hynek, David; Heger, Zbynek; Kopel, Pavel; Adam, Vojtech

    2016-01-01

    Prostate cancer cells control energy metabolism by chelating intracellular zinc. Thus, zinc delivery has been a popular therapeutic approach for prostate cancer. Here, we propose the use of the membrane-penetrating peptide Novicidin connected to zinc-Schiff base as a carrier vehicle for the delivery of zinc to prostate cells. Mass spectrometry, electrochemistry and spectrophotometry confirmed the formation/stability of this complex and provided insight regarding the availability of zinc for complex interactions. This delivery system showed minor toxicity in normal PNT1A cells and high potency towards PC3 tumor cells. The complex preferentially penetrated PC3 tumor cells in contrast to confinement to the membranes of PNT1A. Furthermore, zinc uptake was confirmed in both cell lines. Molecular analysis was used to confirm the activation of zinc stress (e.g., ZnT-1) and apoptosis (e.g., CASP-1). Our results strongly suggest that the zinc-Schiff base-Novicidin complex has great potential as a novel anticancer drug. PMID:27727290

  14. Synthesis and Crystal Structure of a Novel Fe(Ⅲ) Schiff Base Complex

    Institute of Scientific and Technical Information of China (English)

    JIANG Guang-Qi; ZHANG Dai-Yu; YANG Zheng-Feng

    2012-01-01

    A novel Fe(Ⅲ) Schiff base complex,FeⅢ(HL) {H4L = 1,1,1,1-tetrakis[(salicylaldimino)methyl]methane},has been prepared and characterized by elemental analyses,IR spectrum,and single-crystal X-ray diffraction analysis.The crystal belongs to the monoclinic system,space group P21/n with a = 12.569(3),b = 12.955(3),c = 17.647(4) ,β = 91.896(9)°,V = 2871.9(1) 3,Z = 4,Dc = 1.391 g/cm3,F(000) = 1252.0,Mr = 601.45,R = 0.0383 and wR = 0.1025.The structural analysis reveals that the Fe(Ⅲ) ions are six-coordinated by imine nitrogen atoms and phenolic oxygen atoms form three pendant arms of Schiff base ligands,and one of the salicylaldimine chelating units remains uncoordinated.Discrete complex molecules were further assembled into 1D supramolecular aggregations by C-H…O hydrogen bonding and C-H…π interactions.

  15. Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases.

    Science.gov (United States)

    Hanif, Muhammad; Chohan, Zahid H

    2013-03-01

    A new series of three biologically active triazole derived Schiff base ligands L(1)-L(3) have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination.

  16. Chalcogenated Schiff bases: Complexation with palladium(II) and Suzuki coupling reactions

    Indian Academy of Sciences (India)

    Pradhumn Singh; G K Rao; Mohd Salman Karim; Ajai K Singh

    2012-11-01

    Chalcogenated Schiff bases of 5-chloroisatin (L1-L3), 2-(methythio)benzaldehyde (L4), 2-acetylpyridine (L5) and benzaldehyde (L6-L7) have been synthesized. Both the carbonyl groups of 5- chloroisatin appear to be reactive (noticed for the first time) for making >C=N bond, of course one at a time only. The 1H, 13C{1H}, 77Se{1H} and 125Te{1H} NMR spectroscopy have been used to establish the coexistence of two products, which were found in the ratio 53:47 (E = S), 55:45 (E = Se) and 81:19 (E = Te). The larger amount is of the one in which C=O group away from NH is derivatized. The two products are not separable. Palladium complexes (1-4) of Schiff bases of other three aldehydes were synthesized. The ligands as well as complexes were characterized by multinuclear NMR spectroscopy. The crystal structures of [Pd(L4/L5)Cl][ClO4] (1/2) have been solved. The Pd-Se bond lengths are 2.4172(17) and 2.3675(4) Å, respectively for 1 and 2. The Pd-complexes (3-4) of L6-L7 were explored for Suzuki-Miyaura coupling and found promising as 0.006 mol % of 3 is sufficient to obtain good conversion with TON up to 1.58 × 104.

  17. 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.

  18. A study of in vitro antibacterial activity of lanthanides complexes with a tetradentate Schiff base ligand

    Institute of Scientific and Technical Information of China (English)

    Waleed Mahmoud Al Momani; Ziyad Ahmed Taha; Abdulaziz Mahmoud Ajlouni; Qasem Mohammad Abu Shaqra; Muaz Al Zouby

    2013-01-01

    Objective: To establish the antibacterial activity of lanthanides complexes with a tetradentate Schiff base ligand L. Methods: (N, N'-bis (1-naphthaldimine)-o-phenylenediamine) was prepared from the condensation of 2-hydroxy-1-naphthaldehyde with o-phenylenediamine in a molar ratio of 2:1. The antimicrobial activity of the resultant Ln (III) complexes was investigated using agar well diffusion and micro-broth dilution techniques; the latter was used to establish the minimum inhibitory concentrations for each compound investigated. Results: Most of Ln (III) complexes were found to exhibit antibacterial activities against a number of pathogenic bacteria with MICs ranging between 1.95-250.00 μg/mL. Staphylococcus aureus was the most susceptible bacterial species to [LaL(NO3)2(H2O)](NO3) complex while Shigella dysenteriae andEscherichia coli required a relatively higher MIC (250 μg/mL). The complexes La (III) and Pr (III) were effective inhibitors against Staphylococcus aureus, whereas Sm (III) complex was effective against Serratia marcescens. On the other hand, Gd (III), La (III) and Nd (III) were found to be more potent inhibitors against Pseudomonas aeruginosa than two of commonly used antibiotics. The remaining Ln (III) complexes showed no remarkable activity as compared to the two standard drugs used. Conclusions: Tetradentate Schiff base ligand L and its complexes could be a potential antibacterial compounds after further investigation.

  19. Gelatin Nanofiber Matrices Derived from Schiff Base Derivative for Tissue Engineering Applications.

    Science.gov (United States)

    Jaiswal, Devina; James, Roshan; Shelke, Namdev B; Harmon, Matthew D; Brown, Justin L; Hussain, Fazle; Kumbar, Sangamesh G

    2015-11-01

    Electrospinning of water-soluble polymers and retaining their mechanical strength and bioactivity remain challenging. Volatile organic solvent soluble polymers and their derivatives are preferred for fabricating electrospun nanofibers. We report the synthesis and characterization of 2-nitrobenzyl-gelatin (N-Gelatin)--a novel gelatin Schiff base derivative--and the resulting electrospun nanofiber matrices. The 2-nitrobenzyl group is a photoactivatable-caged compound and can be cleaved from the gelatin nanofiber matrices following UV exposure. Such hydrophobic modification allowed the fabrication of gelatin and blend nanofibers with poly(caprolactone) (PCL) having significantly improved tensile properties. Neat gelatin and their PCL blend nanofiber matrices showed a modulus of 9.08 ± 1.5 MPa and 27.61 ± 4.3 MPa, respectively while the modified gelatin and their blends showed 15.63 ± 2.8 MPa and 24.47 ± 8.7 MPa, respectively. The characteristic infrared spectroscopy band for gelatin Schiff base derivative at 1560 cm(-1) disappeared following exposure to UV light indicating the regeneration of free NH2 group and gelatin. These nanofiber matrices supported cell attachment and proliferation with a well spread morphology as evidenced through cell proliferation assay and microscopic techniques. Modified gelatin fiber matrices showed a 73% enhanced cell attachment and proliferation rate compared to pure gelatin. This polymer modification methodology may offer a promising way to fabricate electrospun nanofiber matrices using a variety of proteins and peptides without loss of bioactivity and mechanical strength.

  20. Ligational behavior of Schiff bases towards transition metal ion and metalation effect on their antibacterial activity.

    Science.gov (United States)

    Devi, Jai; Batra, Nisha; Malhotra, Rajesh

    2012-11-01

    New Schiff bases pyrazine-2-carboxylicacid (phenyl-pyridin-2-yl-methylene)-hydrazide (Hpch-bp) HL(1) and pyrazine-2-carboxylicacid (pyridin-2-ylmethylene)-hydrazide (Hpch-pc) HL(2) derived from condensation of pyrazine carboxylic hydrazide (Hpch) with 2-benzoyl pyridine (bp) or pyridine 2-carbaldehyde (pc) and their transition metal complexes of type ML((1-2)2) have been synthesized, where M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). Characterization of ligands and their metal complexes was carried out by elemental analysis, conductimetric studies, magnetic susceptibility, spectroscopic techniques (IR, UV-VIS, NMR, ESR, Mass) and thermogravimetric analysis. The physico-chemical studies revealed octahedral geometry or distorted octahedral geometry around metal ion. These azomethine Schiff base ligands acted as tridentate coordinating through carbonyl, azomethine and pyridine nitrogen present in the ligand. The thermodynamic and thermal properties of the complexes have been investigated and it was observed on the basis of these studies that thermal stability of complexes follows the order Mnantibacterial activity at different concentrations against bacteria viz. Gram positive Bacillus subtilis, Micrococcus luteus and Gram negative Pseudomonas aeruginosa, Pseudomonas mendocina. A marked enhancement in biocidal activity of the ligands under similar experimental conditions was observed as a consequence of coordination with metal ions. The trend of growth inhibition in the complexes was found to be in the order: Cu>Mn>Ni>Co>Zn.

  1. Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases

    Science.gov (United States)

    Hanif, Muhammad; Chohan, Zahid H.

    2013-03-01

    A new series of three biologically active triazole derived Schiff base ligands L1-L3 have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination.

  2. Ligational behavior of Schiff bases towards transition metal ion and metalation effect on their antibacterial activity

    Science.gov (United States)

    Devi, Jai; Batra, Nisha; Malhotra, Rajesh

    2012-11-01

    New Schiff bases pyrazine-2-carboxylicacid (phenyl-pyridin-2-yl-methylene)-hydrazide (Hpch-bp) HL1 and pyrazine-2-carboxylicacid (pyridin-2-ylmethylene)-hydrazide (Hpch-pc) HL2 derived from condensation of pyrazine carboxylic hydrazide (Hpch) with 2-benzoyl pyridine (bp) or pyridine 2-carbaldehyde (pc) and their transition metal complexes of type ML(1-2)2 have been synthesized, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). Characterization of ligands and their metal complexes was carried out by elemental analysis, conductimetric studies, magnetic susceptibility, spectroscopic techniques (IR, UV-VIS, NMR, ESR, Mass) and thermogravimetric analysis. The physico-chemical studies revealed octahedral geometry or distorted octahedral geometry around metal ion. These azomethine Schiff base ligands acted as tridentate ? coordinating through carbonyl, azomethine and pyridine nitrogen present in the ligand. The thermodynamic and thermal properties of the complexes have been investigated and it was observed on the basis of these studies that thermal stability of complexes follows the order Mn complexes were tested for in vitro antibacterial activity at different concentrations against bacteria viz. Gram positive Bacillus subtilis, Micrococcus luteus and Gram negative Pseudomonas aeruginosa, Pseudomonas mendocina. A marked enhancement in biocidal activity of the ligands under similar experimental conditions was observed as a consequence of coordination with metal ions. The trend of growth inhibition in the complexes was found to be in the order: Cu > Mn > Ni > Co > Zn.

  3. Antibacterial and Antifungal Studies on Some Schiff Base Complexes of Zinc(II).

    Science.gov (United States)

    Joseyphus, R Selwin; Nair, M Sivasankaran

    2008-06-01

    Two Schiff base ligands L1and L2 were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1: 1electrolytes. The IR data demonstrate the tetradentate binding of L1and tridentate binding of L2. The XRD data show that Zn(II) complexes with L1and L2 have the crystallite sizes of 53 and 61nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.

  4. Preparation and Electronic Property Investigation of Zinc(II-Schiff Base Complexes in the Confined Space

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    Peng Shang

    2013-01-01

    Full Text Available Metal-Schiff base complexes have attracted continued research interest regarding their intriguing and useful features, while the electronic properties of these complexes in the confined space have not been sufficiently addressed in previous studies. In this work, a new zinc(II-Schiff base complex bis(N-dodecyl salicylideneiminatoZn(II (1 was synthesized and subsequently loaded in an inorganic solid host. A large red shift (~40 nm of the absorption onset was recorded, when the microenvironment of 1 changed from the solvent ethanol to the inorganic solid medium, evidencing the confined space effect. The marked shift of the absorption onset was associated with a band-gap reduction between the highest occupied molecular orbital (HOMO and the lowest unoccupied molecular orbital (LUMO. Theoretical calculation results showed that the confined space effect is distance dependent and exerts a more profound influence on the HOMO than the LUMO within an effective distance range. An initial study implied that the confined space effect is also accompanied with the electron density variation.

  5. Supramolecular Influence on Keto-Enol Tautomerism and Thermochromic Properties of o-Hydroxy Schiff Bases

    Directory of Open Access Journals (Sweden)

    Marija Zbačnik

    2016-06-01

    Full Text Available This work presents a study on thermo-optical properties of three Schiff bases (imines in the solid state. The Schiff bases were obtained by means of mechanochemical synthesis using monosubstituted o-hydroxy aromatic aldehydes and monosubstituted aromatic amines. The keto-enol tautomerism and proton transfer via intramolecular O∙∙∙N hydrogen bond of the reported compounds was found to be influenced more by supramolecular interactions than by a temperature change. All products were characterised by powder X-ray diffraction (PXRD, FT-IR spectroscopy, thermogravimetric (TG analysis and differential scanning calorimetry (DSC. Molecular and crystal structures of compounds 1, 2 and 3 were determined by single crystal X-ray diffraction (SCXRD. The molecules of 1 appear to be present as the enol-imine, the molecules of 2 as the keto-amine tautomer and the molecules of 3 exhibit keto-enol tautomeric equilibrium in the solid state. An analysis of Cambridge structural database (CSD data on similar imines has been used for structural comparison. This work is licensed under a Creative Commons Attribution 4.0 International License.

  6. Synthesis, characterization, crystal structure, DNA- and HSA-binding studies of a dinuclear Schiff base Zn(II) complex derived from 2-hydroxynaphtaldehyde and 2-picolylamine

    Science.gov (United States)

    Kazemi, Zahra; Rudbari, Hadi Amiri; Mirkhani, Valiollah; Sahihi, Mehdi; Moghadam, Majid; Tangestaninejad, Sharam; Mohammadpoor-Baltork, Iraj

    2015-09-01

    A tridentate Schiff base ligand NNO donor (HL: 1-((E)-((pyridin-2-yl)methylimino)methyl)naphthalen-2-ol was synthesized from condensation of 2-hydroxynaphtaldehyde and 2-picolylamine. Zinc complex, Zn2L2(NO3)2, was prepared from reaction of Zn(NO3)2 and HL at ambient temperature. The ligand and complex were characterized by FT-IR, 1H NMR, 13C NMR and elemental analysis (CHN). Furthermore, the structure of dinuclear Zn(II) complex was determined by single crystal X-ray analysis. The complex, Zn2L2(NO3)2, is centrosymmetric dimer in which deprotonated phenolates bridge the two Zn(II) atoms and link the two halves of the dimer. In the structure, Zinc(II) ions have a highly distorted six-coordinate structure bonded to two oxygen atoms from a bidentate nitrate group, the pyridine nitrogen, an amine nitrogen and phenolate oxygens. The interaction of dinuclear Zn(II) complex with fish sperm DNA (FS-DNA) and HSA was investigated under physiological conditions using fluorescence quenching, UV-Vis spectroscopy, molecular dynamics simulation and molecular docking methods. The estimated binding constants for the DNA-complex and HSA-complex were (3.60 ± 0.18) × 104 M-1 and (1.35 ± 0.24) × 104 M-1, respectively. The distance between dinuclear Zn(II) complex and HSA was obtained based on the Förster's theory of non-radiative energy transfer. Molecular docking studies revealed the binding of dinuclear Zn(II) complex to the major groove of FS-DNA and IIA site of protein by formation of hydrogen bond, π-cation and hydrophobic interactions.

  7. Solvatochromism of isatin based Schiff bases: An LSER and LFER study

    Directory of Open Access Journals (Sweden)

    Brkić Dominik R.

    2016-01-01

    Full Text Available The derivatives of isatin have already been reported to show a variety of biological activities. However, there has been no report on solvatochromic effect of isatin derivatives so far, and that could be of interest to study and relate to their electronic structure, as a part of the characterisation of these compounds. Linear solvation energy relationships (LSER were used to analyze solvent influence on the UV absorption maxima shifts of investigated isatin derivatives, i.e. isatin based Schiff bases, by using Kamlet-Taft model. Linear free energy relationships (LFER were applied to the substituent-induced NMR chemical shifts (SCS using SSP (single substituent parameter. The obtained correlations together with theoretical calculations gave insight into the influence of the molecular conformation on the transmission of substituent effects, as well as on solute/solvent interactions. The molecular electrostatic potential (MEP surface map was plotted over the optimized geometry of the molecules in order to visualize electron density distribution and explain origin of solvent/solute interactions. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  8. Highly Selective Perchlorate Membrane Electrode Based on Cobalt(Ⅲ) Schiff Base as a Neutral Carrier

    Institute of Scientific and Technical Information of China (English)

    SHOKROLLAHI Ardeshir; GHAEDI Mehrorang; RAJABI, Harold Reza; KIANFAR, Ali Hossein

    2009-01-01

    A highly selective poly(vinyl chloride) (PVC) membrane electrode based on Co(Ⅲ)-Schiff base [Co(5-NO2-Salen)(PBu3)]ClO4·H2O (where 5-NO2-SalenH=bis(5-nitrosalycilaldehyde)ethylenediamine) as a new carrier for construction of perchlorate-selective electrode by incorporating the membrane ingredients on the surface of a graphite electrodes has been reported. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0×10-6 to 5.0×10-1 mol·L-1 with a slope of (59.4±0.9) mV per decade of perchlo-rate concentration with a low detection limit of 5.0×10-7 mol·L-1 and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (<5 s) and a wide pH independent range (3.0-12.0) in comparison with recent reported electrodes and can be used for at least 2 months without any considerable divergence in their potential response. This electrode was used for the determination of perchlorate in river water, drinking water, sludgy water and human urine with satisfactory results without complicated and time consuming pretreatment.

  9. Synthesis of new 1,2,4-triazole compounds containing Schiff and Mannich bases (morpholine) with antioxidant and antimicrobial activities.

    Science.gov (United States)

    Ünver, Yasemin; Deniz, Sadik; Çelik, Fatih; Akar, Zeynep; Küçük, Murat; Sancak, Kemal

    2016-01-01

    Compound 2 was synthesized by reacting CS2/KOH with compound 1. The treatment of compound 2 with hydrazine hydrate produced compound 3. Then, compound 3 was converted to Schiff bases (4a-d) by the handling with several aromatic aldehydes. The treatment of triazole compounds 4a-d containing Schiff base with morpholine gave compounds 5a-d. All compounds were tested for their antioxidant and antimicrobial activities. The antioxidant test results of DPPH• radical scavenging and ferric reducing/antioxidant power methods showed good antioxidant activity. The triazole-thiol (3) was the most active, and the effect of the substituent type of the thiophene ring on the activity was same for both Schiff bases (4a-d) and Mannich bases (5a-d). Among the newly synthesized triazole derivatives, the Schiff base 4d and the Mannich base 5d carrying nitro substituent on the thiophene ring showed promising antibacterial and antifungal activity, with lower MIC values than the standard antibacterial ampicillin.

  10. Autoensamblaje de metalosupramoléculas de bases de Schiff

    OpenAIRE

    Portela García, Cristina

    2013-01-01

    La tesis doctoral titulada “Autoensamblaje de metalosupramoléculas de bases de Schiff” es un trabajo de investigación que gira en torno a la obtención de compuestos metálicos, mayoritariamente dinucleares, mediante la asociación espontánea de ligandos tridentados e iones metálicos, a través de interacciones reversibles no covalentes de diferente fortaleza (enlace de coordinación, enlace de hidrógeno, interacciones p-p y C-H%%%p). Ejemplos destacados de metalosupramolécula...

  11. Synthesis, characterization and the interaction of some new water-soluble metal Schiff base complexes with human serum albumin.

    Science.gov (United States)

    Asadi, Mozaffar; Asadi, Zahra; Sadi, Somaye Barzegar; Zarei, Leila; Baigi, Fatemeh Moosavi; Amirghofran, Zahra

    2014-03-25

    Some new water-soluble Schiff base complexes of Na2[M(L)(H2O)n]; (M=Zn, Cu, Ni, Mn) with a new water-soluble Schiff base ligand where L denotes an asymmetric N2O2 Schiff base ligands; N,N'-bis(5-sulfosalicyliden)-3,4-diaminobenzophenone (5-SO3-3,4-salbenz) were synthesized and characterized. The formation constants of the water soluble Schiff base complexes were calculated by Ketelaar's equation. The theoretical molecular structure for the complexes was computed by using the HF method and the 6-311G basis set. The mechanism of binding of Na2[M(L)(H2O)n] with human serum albumin (HSA) was studied by fluorescence spectroscopic technique. The results of fluorescence titration showed that the intrinsic fluorescence of HSA was quenched by the complexes; which was rationalized in terms of the dynamic quenching mechanism. The values of Stern-Volmer constants, quenching rate constants, binding constants, binding sites and average aggregation number of HSA have been determined. The thermodynamic parameters, were calculated by van't Hoff equation, indicate that the binding is entropy driven and enthalpically disfavored. Based on the Förster theory of non-radiation energy transfer, the efficiency of energy transfer and the distance between the donor (Trp residues) and the acceptor (complex) were obtained. Finally, the growth inhibitory effects of the complexes toward the K562 cancer cell line were measured.

  12. Six-coordinate high-spin iron(ii) complexes with bidentate PN ligands based on 2-aminopyridine - new Fe(ii) spin crossover systems.

    Science.gov (United States)

    Holzhacker, Christian; Calhorda, Maria José; Gil, Adrià; Carvalho, Maria Deus; Ferreira, Liliana P; Stöger, Berthold; Mereiter, Kurt; Weil, Matthias; Müller, Danny; Weinberger, Peter; Pittenauer, Ernst; Allmaier, Günter; Kirchner, Karl

    2014-08-01

    Several new octahedral iron(ii) complexes of the type [Fe(PN(R)-Ph)2X2] (X = Cl, Br; R = H, Me) containing bidentate PN(R)-Ph (R = H, Me) (1a,b) ligands based on 2-aminopyridine were prepared. (57)Fe Mössbauer spectroscopy and magnetization studies confirmed in all cases their high spin nature at room temperature with magnetic moments very close to 4.9μB reflecting the expected four unpaired d-electrons in all these compounds. While in the case of the PN(H)-Ph ligand an S = 2 to S = 0 spin crossover was observed at low temperatures, complexes with the N-methylated analog PN(Me)-Ph retain an S = 2 spin state also at low temperatures. Thus, [Fe(PN(H)-Ph)2X2] (2a,3a) and [Fe(PN(Me)-Ph)2X2] (2b,3b) adopt different geometries. In the first case a cis-Cl,P,N-arrangement seems to be most likely, as supported by various experimental data derived from (57)Fe Mössbauer spectroscopy, SQUID magnetometry, UV/Vis, Raman, and ESI-MS as well as DFT and TDDFT calculations, while in the case of the PN(Me)-Ph ligand a trans-Cl,P,N-configuration is adopted. The latter is also confirmed by X-ray crystallography. In contrast to [Fe(PN(Me)-Ph)2X2] (2b,3b), [Fe(PN(H)-Ph)2X2] (2a,3a) is labile and undergoes rearrangement reactions. In CH3OH, the diamagnetic dicationic complex [Fe(PN(H)-Ph)3](2+) (5) is formed via the intermediacy of cis-P,N-[Fe(κ(2)-P,N-PN(H)-Ph)2(κ(1)-P-PN(H)-Ph)(X)](+) (4a,b) where one PN ligand is coordinated in a κ(1)-P-fashion. In CH3CN the diamagnetic dicationic complex cis-N,P,N-[Fe(PN(H)-Ph)2(CH3CN)2](2+) (6) is formed as a major isomer where the two halide ligands are replaced by CH3CN.

  13. Synthesis, X-ray, and Spectroscopic Study of Dissymmetric Tetrahedral Zinc(II) Complexes from Chiral Schiff Base Naphthaldiminate Ligands with Apparent Exception to the ECD Exciton Chirality.

    Science.gov (United States)

    Enamullah, Mohammed; Makhloufi, Gamall; Ahmed, Rifat; Joy, Baitul Alif; Islam, Mohammad Ariful; Padula, Daniele; Hunter, Howard; Pescitelli, Gennaro; Janiak, Christoph

    2016-07-01

    Bidentate enantiopure Schiff base ligands, (R or S)-N-1-(Ar)ethyl-2-oxo-1-naphthaldiminate (R- or S-N^O), diastereoselectively provide Λ- or Δ-chiral-at-metal four-coordinated Zn(R- or S-N^O)2 {Ar = C6H5; Zn-1R or Zn-1S and p-C6H4OMe; Zn-2R or Zn-2S}. Two R- or S-N^O-chelate ligands coordinate to the zinc(II) in a tetrahedral mode and induce Λ- or Δ-configuration at the zinc metal center. In the solid state, the R- or S-ligand diastereoselectively gives Λ- or Δ-Zn configuration, respectively, and forms enantiopure crystals. Single crystal structure determinations show two symmetry-independent molecules (A and B) in each asymmetric unit to give Z' = 2 structures. Electronic circular dichroism (ECD) spectra show the expected mirror image relationship resulting from diastereomeric excess toward the Λ-Zn for R-ligands and Δ-Zn for S-ligands in solution. ECD spectra are well reproduced by TDDFT calculations, while the application of the exciton chirality method, in the common point-dipole approximation, predicts the wrong sign for the long-wavelength couplet. A dynamic diastereomeric equilibrium (Λ vs Δ) prevails for both R- and S-ligand-metal complexes in solution, respectively, evidenced by (1)H NMR spectroscopy. Variable temperature (1)H NMR spectra show a temperature-dependent shift of the diastereomeric equilibrium and confirm Δ-Zn configuration (for S-ligand) to be the most stable one and favored at low temperature. DSC analyses provide quantitative diastereomeric excess in the solid state for Zn-2R and Zn-2S, which is comparable to the results of solution studies.

  14. Investigation of the antioxidant and radical scavenging activities of some phenolic Schiff bases with different free radicals.

    Science.gov (United States)

    Marković, Zoran; Đorović, Jelena; Petrović, Zorica D; Petrović, Vladimir P; Simijonović, Dušica

    2015-11-01

    The antioxidant properties of some phenolic Schiff bases in the presence of different reactive particles such as (•)OH, (•)OOH, (CH2=CH-O-O(•)), and (-•)O2 were investigated. The thermodynamic values, ΔH BDE, ΔH IP, and ΔH PA, were used for this purpose. Three possible mechanisms for transfer of hydrogen atom, concerted proton-electron transfer (CPET), single electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) were considered. These mechanisms were tested in solvents of different polarity. On the basis of the obtained results it was shown that SET-PT antioxidant mechanism can be the dominant mechanism when Schiff bases react with radical cation, while SPLET and CPET are competitive mechanisms for radical scavenging of hydroxy radical in all solvents under investigation. Examined Schiff bases react with the peroxy radicals via SPLET mechanism in polar and nonpolar solvents. The superoxide radical anion reacts with these Schiff bases very slowly.

  15. Synthesis and Biological Activities of Schiff Bases of 3-Amino-1H-1,2,4-triazole

    Institute of Scientific and Technical Information of China (English)

    SUN,Xiaohong; LIU,Yuanfa; CHEN,Shuzhe; CHEN,Bang; JIA,Yingqi; ZENG,Zhengfang

    2009-01-01

    Eight Schiff bases of 3-amino-1H-1,2,4-triazole have been synthesized by glacial acetic acid catalyzed conden- sation of 3-amino-1H-1,2,4-triazole with substituted benzaldehyde and structurally confirmed by IR, 1H NMR and elemental analysis. The preliminary bioassay showed that the title compounds exhibited good fungicidal activities.

  16. 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.

  17. Characteristic spectral studies and in vitro antifungal activity of some Schiff bases and their organotin (Ⅳ) complexes

    Institute of Scientific and Technical Information of China (English)

    Wajid Rehman; Musa Kaleem Baloch; Bakhtiar Muhammad; Amin Badshah; Khalid M. Khan

    2004-01-01

    The synthesis and in vitro antifungal activity of some Schiff bases and their Sn (Ⅳ) complexes has been tested against plant pathogenic fungi and it is found that they possess excellent fungicidal activity. On the basis of 1H-, 13C-, 119Sn NMR-, 119Sn Mossbauer, IR and Elemental analysis the tetrahedral geometry is proposed for the synthesized compounds.

  18. 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.

  19. Asymmetric Cyclopropanation Catalyzed by Four Stereoisomers of a Copper-(Schiff-base) Complex with Double Chiral Centers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiomeric excess of up to 91.8%. A mechanism that predicts the observed results accurately was proposed.

  20. Synthesis of novel chiral tridentate Schiff-base ligands and their applications in catalytic asymmetric Henry reaction.

    Science.gov (United States)

    Qiang, Gen-Rong; Shen, Tian-Hua; Zhou, Xiao-Cong; An, Xiao-Xia; Song, Qing-Bao

    2014-12-01

    A series of chiral tridentate Schiff-bases were prepared and used as ligands in the catalytic asymmetric Henry reaction. Under the optimal conditions, a variety of arylaldehydes were smoothly converted into corresponding adducts with high yields (up to 98%) and excellent enantioselectivities (up to 97% ee).

  1. Origin of SMM behaviour in an asymmetric Er(III) Schiff base complex: a combined experimental and theoretical study.

    Science.gov (United States)

    Das, Chinmoy; Upadhyay, Apoorva; Vaidya, Shefali; Singh, Saurabh Kumar; Rajaraman, Gopalan; Shanmugam, Maheswaran

    2015-04-11

    An asymmetric erbium(III) Schiff base complex [Er(HL)2(NO3)3] was synthesized which shows SMM behaviour with an Ueff of 5.2 K. Dipolar interaction in 1 significantly reduced upon dilution which increases the barrier height to 51.5 K. Ab initio calculations were performed to shed light on the mechanism of magnetization relaxation.

  2. A combined spectroscopic, docking and molecular dynamics simulation approach to probing binding of a Schiff base complex to human serum albumin.

    Science.gov (United States)

    Fani, N; Bordbar, A K; Ghayeb, Y

    2013-02-15

    The molecular mechanism of a Schiff base complex ((E)-((E)-2-(3-((E)-((E)-3(mercapto (methylthio) methylene)cyclopentylidene) amino) propylimino) cyclopentylidene) (methylthio) methanethiol) binding to Human Serum Albumin (HSA) was investigated by fluorescence quenching, absorption spectroscopy, molecular docking and molecular dynamics (MD) simulation procedures. The fluorescence emission of HSA was quenched by this Schiff base complex that has been analyzed for estimation of binding parameters. The titration of Schiff base solution by various amount of HSA was also followed by UV-Vis absorption spectroscopy and the corresponding data were analyzed by suitable models. The results revealed that this Schiff base has an ability to bind strongly to HSA and formed 1:1 complex. Energy transfer mechanism of quenching was discussed and the value of 5.45 ± 0.06 nm was calculated as the mean distance between the bound complex and the Trp residue. This is implying the high possibility of energy transfer from HSA to this Schiff base complex. Molecular docking results indicated that the main active binding site for this Schiff base complex is site III in subdomain IB. Moreover, MD simulation results suggested that this Schiff base complex can interact with HSA, without affecting the secondary structure of HSA but probably with a slight modification of its tertiary structure. MD simulations, molecular docking and experimental data reciprocally supported each other.

  3. Chromogenic and fluorogenic Schiff base chemosensor for nano scale level fluoride detection with logical interpretation

    Science.gov (United States)

    Ghosh, Pritam; Banerjee, Priyabrata

    2016-10-01

    Schiff base Organic Frameworks (SOFs) based chemosensor have been synthesized and utilized for recognization of biologically relevant fluoride anion. The chemosensor is selective for fluoride (F-) and exhibits reversible UV-Vis response with alternate addition of aluminum (Al3+). Interestingly a fluorescence 'turn on' response has been noticed with concomitant addition of fluoride. TICT, PTTS and restricted Cdbnd N isomerization has been taken into account in order to explain the florescence 'turn on' phenomenon. Significantly, the limit of fluoride detection is nano molar level (∼10 nM). The reversible UV-Vis phenomena have been used for designing AND-NAND-NOT-NOR-OR-XOR-XNOR based complex logic circuit to prepare potential feedstock as 'Lab-on a-Molecule'.

  4. Studies on PNPP Hydrolysis Catalyzed by Schiff Base Cobalt(Ⅱ) Complexes

    Institute of Scientific and Technical Information of China (English)

    HU Wei; LI Jian-Zhang; WANG Ying; LI Ci; DU Juana; MENG Xiang-Guang; HU Chang-Wei; ZENG Xian-Cheng

    2006-01-01

    Two cobalt(Ⅱ) complexes of the Schiff base with morpholino or aza-crown ether pendants, CoL1 and CoL2, as mimic hydrolytic metalloenzyme, were used in catalytic hydrolysis of carboxylic ester (PNPP). The analysis of specific absorption spectra of the hydrolytic reaction systems indicates that key intermediates, made up of PNPP and Co(Ⅱ)complexes, have been formed in reaction processes of the PNPP catalytic hydrolysis. The mechanism of PNPP catalytic hydrolysis has been proposed based on the analytic result of specific absorption spectrum. A kinetic mathematical model, applied to the calculation of the kinetic parameter of PNPP catalytic hydrolysis, has been established based on the mechanism proposed. The acid effect of buffer solution, structural effect of the complexes,and effect of temperature on the rate of PNPP hydrolysis catalyzed by the complexes have been also discussed.

  5. 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.

  6. Mixed (phthalocyaninato)(Schiff-base) di-dysprosium sandwich complexes. Effect of magnetic coupling on the SMM behavior.

    Science.gov (United States)

    Wang, Hailong; Liu, Chenxi; Liu, Tao; Zeng, Suyuan; Cao, Wei; Ma, Qi; Duan, Chunying; Dou, Jianmin; Jiang, Jianzhuang

    2013-11-21

    Reaction between Schiff-base ligand and half-sandwich complex M(Pc)(acac) led to the isolation of new sandwich-type mixed (phthalocyaninato)(Schiff-base) di-lanthanide compounds M2(Pc)2(L)H2O (M = Dy, Gd) (1, 2) [H2Pc = metal free phthalocyanine, Hacac = acetylacetone, H2L = N,N'-bis(3-methyloxysalicylidene)benzene-1,2-diamine] with the triple-decker molecular structure clearly revealed by single crystal X-ray diffraction analysis. For the comparative studies, sandwich triple-decker analogues with pure Schiff-base ligand M2(L)3H2O (M = Dy, Gd) (3, 4) were also prepared. Dynamic magnetic measurement result reveals the single-molecule magnet (SMM) nature of the di-dysprosium derivative 1, while the static magnetic investigation over both pure and the diamagnetic diluted samples of this compound discloses the interionic ferromagnetic coupling between the two dysprosium ions, which in turn effectively suppresses the QTM and enhances the energy barrier of this SMM. Nevertheless, comparative studies over the static magnetic properties of the di-dysprosium triple-decker complexes 1 and 3 indicate the stronger magnetic coupling between the two lanthanide ions in mixed (phthalocyaninato)(Schiff-base) species than in the pure Schiff-base triple-decker analogue, suggesting the special coordination sphere around the dysprosium ions in the former compound over the latter one on the more intense inter-ionic ferromagnetic coupling. As a very small step towards understanding the structure-property relationship, the present result will be surely helpful for the design and synthesis of the multinuclear lanthanide-based SMMs with good properties.

  7. The hydrogen sulfate recognition properties of azo-salicylaldehyde schiff base receptors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Azo-salicylaldehyde Schiff base-typed receptors containing an acidic H-bond donor moiety were syn-thesized and characterized. The UV-Vis data indicate that these receptors could act as selective col-orimetric sensors for basic anions and acidic species hydrogen sulfate by different color changes in a water-containing medium. The experiment of Brφnsted acid-base reaction by adding the sodium hy-droxide or perchloric acid revealed that the mechanism of recognition of anions might be deprotona-tion/protonation of the OH fragments by interacting with different anions and that the deprotona-tion/protonation process is fully reversible. The deprotonation/protonation of the receptors is respon-sible for the dramatic color change.

  8. The hydrogen sulfate recognition properties of azo-salicylaldehyde schiff base receptors

    Institute of Scientific and Technical Information of China (English)

    WEI TaiBao; WANG Jun; ZHANG YouMing

    2008-01-01

    Azo-salicylaldehyde Schiff base-typed receptors containing an acidic H-bond donor moiety were syn-thesized and characterized. The UV-Vis data indicate that these receptors could act as selective col-orimetric sensors for basic anions and acidic species hydrogen sulfate by different color changes in a water-containing medium, The experiment of Brφnsted acid-base reaction by adding the sodium hy-droxide or perchloric acid revealed that the mechanism of recognition of anions might be deprotona-tion/protonation of the OH fragments by interacting with different anions and that the deprotona-tion/protonation process is fully reversible. The deprotonation/protonation of the receptors is respon-sible for the dramatic color change.

  9. Synthesis, Characterization and Spectroscopic Studies of A Novel 2-[(E-[(2,4-dichlorophenylimino]methyl]phenol Schiff Base and Its Metal Complexes

    Directory of Open Access Journals (Sweden)

    Eman Turky Shamkhy

    2012-01-01

    Full Text Available A novel Schiff base 2-{(E-[(2,4-dichlorophenylimino]methyl}phenol (LB was synthesized from the condensation reaction of 2,4-dichloroaniline with salicyladehyde in [1:1] ratio in the presence of glacial acetic acid as catalyst. Complexation reaction of this Schiff base with copper (II, cobalt (II as nitrate salts and with Rhodium (III as chloride salt to produce three coordinate metal complexes, with a Schiff base: Metal ion ratio of 2:1. These compounds have been characterized by a variety of physico-chemical and spectroscopic techniques. The ligand and its metal complexes were expected to show an interesting bioactivity and cytotoxicity.

  10. Click on silica: systematic immobilization of Co(II) Schiff bases to the mesoporous silica via click reaction and their catalytic activity for aerobic oxidation of alcohols.

    Science.gov (United States)

    Rana, Bharat S; Jain, Suman L; Singh, Bhawan; Bhaumik, Asim; Sain, Bir; Sinha, Anil K

    2010-09-07

    The systematic immobilization of cobalt(II) Schiff base complexes on SBA-15 mesoporous silica via copper catalyzed [3 + 2] azide-alkyne cycloaddition (CuAAC) "click reaction" involving either step-wise synthesis of silica-bound Schiff base ligand followed by its subsequent complexation with cobalt ions, or by the direct immobilization of preformed Co(II) Schiff base complex to the silica support is described. The catalytic activity of the prepared complexes was studied for the oxidation of alcohols to carbonyl compounds using molecular oxygen as oxidant. The immobilized complexes were recycled for several runs without loss in catalytic activity and no leaching was observed during this course.

  11. Synthesis and Characterization of Schiff Base Containing Thiocarbohydrazide%含硫脲基Schiff碱的合成与表征

    Institute of Scientific and Technical Information of China (English)

    李琳; 王麟生; 郝振文

    2005-01-01

    Symmetric and asymmetric derivatives of thiocarbohydrazide have broadly been studied due to their potential utility as analytical reagents. Symmetric Schiff base can be easily obtained by direct reaction.while there have many troubles in obtaining asymmetric Schiff base. The obvious difficulty in the synthesis of asymmetric Schiff base is that the straight condensation methodology used for symmetric Schiffbase is no longer applicable when some symmetric dia mines were adopted as the parent reactants in the condensation reaction. As ketone has lower chemical activities than that of the aldehyde,

  12. Ion recognition: application of symmetric and asymmetric schiff bases and their complexes for the fabrication of cationic and anionic membrane sensors to determine ions in real samples.

    Science.gov (United States)

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz

    2007-08-01

    Schiff base compounds refer to the branch of supra-molecules and can be used as sensing material in the construction of potentiometric ion selective electrodes (ISEs). This relatively modern field has been subject to extensive research in the period of 1999-2007 when more than 100 ISEs employing Schiff bases were constructed. The quantitative high-throughput detection of 29 cations and 7 anions has been demonstrated in various scientific branches, such as biomedicine, pharmacy, biochemistry, pharmacology, environmental chemistry, food technology, and agriculture. This review discusses Schiff base compounds and their applications in the design and development of ion selective sensors and microsensors.

  13. Synthesis, spectroscopic characterization and catalytic oxidation properties of ONO/ONS donor Schiff base ruthenium(III) complexes containing PPh3/AsPh3

    Indian Academy of Sciences (India)

    Priyarega; M Muthu Tamizh; R Karvembu; R Prabhakaran; K Natarajan

    2011-05-01

    Six different ruthenium(III) complexes of Schiff bases derived from 2-hydroxy-1-naphthaldehyde and -aminophenol/-aminothiophenol have been synthesized. The compounds with the general formula [RuX(EPh3)2(L)] (X = Cl or Br; E = P or As; L = bifunctional tridentate ONO/ONS donor Schiff base ligand) were characterized by infrared, electronic, electron paramagnetic resonance spectroscopy and elemental analyses. Spectroscopic investigation reveals coordination of Schiff base ligand through ONO/ONS donor atoms and octahedral geometry around ruthenium metal. Redox property of complexes has been examined by using cyclic voltammetry. The catalytic oxidation property of ruthenium(III) complexes were also investigated.

  14. Antipathogenic effects of structurally-related Schiff base derivatives: Structure–activity relationship

    Directory of Open Access Journals (Sweden)

    Soleiman Hisaindee

    2015-11-01

    Full Text Available Eighteen structurally-related Schiff base derivatives, which belong to salicylidenebenzylamine and 2-hydroxy-1-naphthylidenebenzylamine families were prepared and characterized by spectroscopic techniques. All the synthesized compounds were screened in vitro for their antibacterial and antifungal activities. Human pathogenic gram-negative (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcescens, gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus and Bacillus subtilis, and fungi (Alternaria alternata, Aspergillus niger, Penicillium roqueforti, and Saccharomyces cerevisiae were evaluated based on their toxicity to different concentrations of Schiff base compounds. For assessment of toxicity to pathogens, a disc diffusion assay was used to test the antimicrobial properties. The results revealed some antimicrobial activities of some of the synthesized compounds. Among the tested pathogens, the synthesized salicylidinaniline derivatives show highly potent action towards Alternaria alternata. Interestingly, a compound which contains the –Cl group is only effective against gram negative bacteria, but not gram positive bacteria. No remarkable antibacterial or antifungal activities were observed in the presence of –CH3 or –Br group. Furthermore, most of the naphthalene-containing compounds show no growth retardation towards bacterial or fungal pathogens. On the other hand, the presence of –OH or –SH group at para or ortho position, respectively, on the aniline site is correlated with an increased inhibitory drug effect on all pathogens. The importance of our findings to the drug research and developments is discussed in the context of finding a correlation between the structural properties of the new drugs and their biological activities.

  15. Inhibition of copper-mediated aggregation of human γD-crystallin by Schiff bases.

    Science.gov (United States)

    Chauhan, Priyanka; Muralidharan, Sai Brinda; Velappan, Anand Babu; Datta, Dhrubajyoti; Pratihar, Sanjay; Debnath, Joy; Ghosh, Kalyan Sundar

    2017-01-05

    Protein aggregation, due to the imbalance in the concentration of Cu(2+) and Zn(2+) ions is found to be allied with various physiological disorders. Copper is known to promote the oxidative damage of β/γ-crystallins in aged eye lens and causes their aggregation leading to cataract. Therefore, synthesis of a small-molecule 'chelator' for Cu(2+) with complementary antioxidant effect will find potential applications against aggregation of β/γ-crystallins. In this paper, we have reported the synthesis of different Schiff bases and studied their Cu(2+) complexation ability (using UV-Vis, FT-IR and ESI-MS) and antioxidant activity. Further based on their copper complexation efficiency, Schiff bases were used to inhibit Cu(2+)-mediated aggregation of recombinant human γD-crystallin (HGD) and β/γ-crystallins (isolated from cataractous human eye lens). Among these synthesized molecules, compound 8 at a concentration of 100 μM had shown ~95% inhibition of copper (100 μM)-induced aggregation. Compound 8 also showed a positive cooperative effect at a concentration of 5-15 μM on the inhibitory activity of human αA-crystallin (HAA) during Cu(2+)-induced aggregation of HGD. It eventually inhibited the aggregation process by additional ~20%. However, ~50% inhibition of copper-mediated aggregation of β/γ-crystallins (isolated from cataractous human eye lens) was recorded by compound 8 (100 μM). Although the reductive aminated products of the imines showed better antioxidant activity due to their lower copper complexing ability, they were found to be non-effective against Cu(2+)-mediated aggregation of HGD.

  16. Manganese(III) Schiff base complexes: chemistry relevant to the copolymerization of epoxides and carbon dioxide.

    Science.gov (United States)

    Darensbourg, Donald J; Frantz, Eric B

    2007-07-23

    Schiff base complexes of the form (acacen)Mn(III)X (acacen = N,N'-bis(acetylacetone)-1,2-ethylenediimine), where X = OAc, Cl, or N(3), have been evaluated for their ability to couple CO(2) and cyclohexene oxide in the presence of a variety of cocatalysts to provide cyclic or polycarbonates. These complexes proved to be ineffective at catalyzing this process; however, valuable information related to the coordination chemistry of these manganese Schiff bases was elucidated. Of importance, mechanistic findings as revealed by comprehensive studies involving structurally related (salen)CrX and (salen)CoX complexes strongly support the requirement of six-coordinate metal species for the effective copolymerization of CO(2) and epoxides. In the case of these Mn(III) complexes, it was determined that in chloroform or toluene solution a five-coordinate species was greatly favored over a six-coordinate species even in the presence of 20 equiv or more of various Lewis bases. Significantly epoxide monomers such as propylene oxide and cyclohexene oxide displayed no tendency to bind to these (acacen)MnX derivatives, even when used as solvents. Only in the case of excessive quantities of heterocyclic amines such as pyridine, DMAP, and DBU was spectral evidence of a six-coordinate Mn derivative observed in solution. X-ray crystal structures are provided for many of the complexes involved in this study, including the one-dimensional polymeric structures of [(acacen)MnOAc x 2H(2)O](n), [(acacen)MnN(3)](n) (mu(1,3)-N(3)), and a rare mixed bridging species [(acacen)MnN(3)](n) (mu(1,3)-N(3)/mu(1,1)-N(3)). In addition, a structure was obtained in which the unit cell contains both a (acacen)MnN(3)(DMAP) and a (acacen)MnN(3) species.

  17. Structural and antimicrobial studies of coordination compounds of VO(II, Co(II, Ni(II and Cu(II with some Schiff bases involving 2-amino-4-chlorophenol

    Directory of Open Access Journals (Sweden)

    A. P. MISHRA

    2009-05-01

    Full Text Available Complexes of tailor-made ligands with life essential metal ions may be an emerging area to answer the problem of multi-drug resistance (MDR. The coordination complexes of VO(II, Co(II, Ni(II and Cu(II with the Schiff bases derived from 2-hydroxyacetophenone/2-chlorobenzaldehyde with 2-ami¬no-4-chlorophenol were synthesized and characterized by elemental analysis, molar conductance, electronic spectra, FT-IR, ESR, FAB mass, thermal and magnetic susceptibility measurements. The FAB mass and thermal data show degradation of the complexes. The ligand A (2-hydroxyacetophenone-2amino-4-chlorophenol behaved as tridentate and ligand B (2-chlorobenzylidene-2-amino-4-chlorophenol as bidentate, coordinating through O and N donors. The complexes [VO(A(H2O]×xH2O, [M(A(H2On]×xH2O for Co and Ni, [Cu(A(H2O] and [VO(B2]×xH2O, [M(B2(H2On] for Co and Cu and [Ni(B2] exhibited coordination numbers 4, 5 or 6. X-ray powder diffraction data (a = 11.00417 Å, b = 11.706081 Å and c = 54.46780 Å showed that [Cu(CACP2(H2O2], complex 8, crystallized in the orthorhombic system. The in vitro biological screening effects of the investigated compounds were tested against the bacteria Escherichia coli, Staphylococcus aureus and Streptococcus fecalis and the fungi Aspergillus niger, Trichoderma polysporum and Candida albicans by the serial dilution method. A comparative study of the MIC values of the Schiff base and their [M(B2(H2O2] complexes (Co(II, complex 6 and Cu(II, complex 8, indicated that the metal complexes exhibited a higher or lower antimicrobial activity than 2-chlorobenzylidene-2-amino-4-chlorophenol as the free ligand (B.

  18. SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF SCHIFF BASE DERIVATIVES OF 4-CHLORO-3-NITROBENZOIC ACID

    Directory of Open Access Journals (Sweden)

    Kumari Santosh

    2012-12-01

    Full Text Available 4-chloro-3-nitrobenzoic acid was selected as nucleus structure having good antibacterial property. It was thought worthwhile to synthesize Schiff base derivatives of 4-chloro-3-nitrobenzoic acid in search of better antibacterial agents. The compounds were synthesized by first reducing nitro group in presence of Sn/HCl to 3-amino-4-chlorobenzoic acid, which on treatment with substituted benzaldehyde afforded the synthesis of the envisaged compounds. The synthesized compounds were purified and chemically characterized. They were screened for their antibacterial activity and result suggested that SKY-1, SKY-5 and SKY-8 were highly active against both Gram (+ and Gram(- bacteria like B.subtilis, S.aureus and E.coli whereas all are were found moderately to inactive against P.aeruginosa.

  19. Molecular docking study, synthesis and biological evaluation of Schiff bases as Hsp90 inhibitors.

    Science.gov (United States)

    Dutta Gupta, Sayan; Snigdha, D; Mazaira, Gisela I; Galigniana, Mario D; Subrahmanyam, C V S; Gowrishankar, N L; Raghavendra, N M

    2014-04-01

    Heat shock protein 90 (Hsp90) is an emerging attractive target for the discovery of novel cancer therapeutic agents. Docking methods are powerful in silico tools for lead generation and optimization. In our mission to rationally develop novel effective small molecules against Hsp90, we predicted the potency of our designed compounds by Sybyl surflex Geom X docking method. The results of the above studies revealed that Schiff bases derived from 2,4-dihydroxy benzaldehyde/5-chloro-2,4-dihydroxy benzaldehyde demonstrated effective binding with the protein. Subsequently, a few of them were synthesized (1-10) and characterized by IR, (1)HNMR and mass spectral analysis. The synthesized molecules were evaluated for their potential to suppress Hsp90 ATPase activity by Malachite green assay. The anticancer studies were performed by 3-(4,5-dimethythiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method. The software generated results was in satisfactory agreement with the evaluated biological activity.

  20. Synthesis, Characterization and Antimicrobial Activities of Some New Heterocyclic Schiff Bases Derived from Thiocarbohydrazide.

    Science.gov (United States)

    El-Mahdy, Kamelia; El-Kazak, Azza; Abdel-Megid, Mohamed; Seada, Magdyand; Farouk, Osama

    2016-01-01

    The reaction of prazolobenzothienopyrimidine-3-carbaldehyde 1 with thiocarbohydrazide afforded the Schiff's base 3. The latter compound reacted with some electrophilic reagents to give 1,2,4-triazoles 4-6 and 1,2,4-triazines 7-9. Treatment of compound 3 with 2-cyano-3,3-bis(methylthio)acrylonitrile gave the corresponding 5-amino-4-cyano-3-methylthiopyrazole derivative 11. The reaction of pyrazole 11 with carbon disulfide afforded dithioxopyrazolopyrimidine 12. Acylation of compound 11 by using acetic anhydride yielded acetamide 13. On the other hand, the cyclocondensation of pyrazole 11 with acetic anhydride in pyridine yielded pyrazolopyrimidine derivative 14. The reactivity of compound 11 towards formamide and phenylisothiocyanate to give the pyrazolopyrimidines 15 and 16 was studied. The newly synthesized compounds were screened for their antimicrobial activity.

  1. In-vitro Evaluation and Molecular Docking Studies of Some Schiff Bases as Cholinesterase Inhibitor

    Directory of Open Access Journals (Sweden)

    Saurabh Kumar Sinha

    2015-09-01

    Full Text Available Some new Schiff bases of 4-aminopyridine were synthesized and evaluated for antiamnesic and cognition enhancing activity. In the current study to further understand the mechanism of action of these derivatives we have evaluated in-vitro acetycholinesterase (AChE and butyrylcholinesterase (BChE inhibitory activity. Enzyme kinetics and docking studies were performed for all compounds to observe their nature of inhibition. The IC50 value of synthesized compounds showed maximum activity of compound 4APg compared to standard drug donepezil and rivastigmine whereas its kinetic analysis of enzyme inhibition demonstrated non-competitive inhibition for both enzymes AChE and BChE. The docking study confirmed their consensual interaction with AChE and BChE active sites justifying the experimental outcome.

  2. Polycyclic aromatic hydrocarbons connected with Schiff base linkers: Experimental and theoretical photophysical characterization and electrochemical properties

    Science.gov (United States)

    Sęk, Danuta; Siwy, Mariola; Małecki, Jan Grzegorz; Kotowicz, Sonia; Golba, Sylwia; Nowak, Elżbieta M.; Sanetra, Jerzy; Schab-Balcerzak, Ewa

    2017-03-01

    A series of polyaromatic hydrocarbons with anthracene, phenanthrene and pyrene units connected with Schiff base junctions were synthesized via condensation of p-phenylenediamine and hydrazine with selected aldehydes. The effect of both hydrocarbon structures and presence of N-N- or phenyl- linked diimines on properties of the prepared azines and azomethines was analyzed. The obtained compounds were soluble in common organic solvents and melted in the range of 226-317 °C. Their photophysical and electrochemical properties were investigated by UV-vis, photoluminescence spectroscopies and cyclic voltammetry (CV), respectively. Moreover, a density functional theory (DFT) was applied for calculation of their electronic and geometric structures as well as absorption and emission spectra. Additionally, their electron acceptor activity was preliminary tested in photovoltaic experiment.

  3. Synthesis of triazole Schiff bases: novel inhibitors of nucleotide pyrophosphatase/phosphodiesterase-1.

    Science.gov (United States)

    Khan, Khalid Mohammed; Siddiqui, Salman; Saleem, Muhammad; Taha, Muhammad; Saad, Syed Muhammad; Perveen, Shahnaz; Choudhary, M Iqbal

    2014-11-15

    A series of Schiff base triazoles 1–25 was synthesized and evaluated for their nucleotide pyrophosphatase/phosphodiesterase-1 inhibitory activities. Among twenty-five compounds, three compounds 10 (IC50 = 132.20 ± 2.89 lM), 13 (IC50 = 152.83 ± 2.39 lM), and 22 (IC50 = 251.0 ± 6.64 lM) were identified as potent inhibitors with superior activities than the standard EDTA (IC50 = 277.69 ± 2.52 lM). The newly identified inhibitors may open a new avenue for the development of treatment of phosphodiesterase-I related disorders. These compounds were also evaluated for carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase inhibitory potential and were found to be inactive. The compounds showed non-toxic effect towards PC3 cell lines.

  4. Synthesis, catalytic and biological activity of novel dinuclear copper complex with Schiff base

    Institute of Scientific and Technical Information of China (English)

    WEI; Danyi; LI; Ning; LU; Gui; YAO; Kemin

    2006-01-01

    A novel dinuclear copper complex with tetraglycol aldehyde-phenylalanine Schiff base has been synthesized. It was characterized and formulated as [Cu2L(NO3)]NO3 by elemental analysis,magnetic susceptibility, TG-DTA, IR, EPR and 1H NMR spectra. The obtained complex can be used as a good catalyst for the polymerization of methyl methacrylate (MMA). The optimum polymerization conditions are: MMNcatalyst = 500 (molar ratio); [catalyst] = 7.5×10-3 mol. L-1; dioxane as solvent;80℃; 6 h. Polymethyl methacrylate (PMMA) with 80% conversion, 7.2×105 viscosity-average molecular weight and 60.5% syndiotacticity was obtained. This complex has also been shown to play an important role in scavenging O-·2.

  5. Catecholase activity investigations using in situ copper complexes continuing Schiff base derivatives with a theoretical calculation

    Directory of Open Access Journals (Sweden)

    A. Djedouani

    2015-03-01

    Full Text Available The study of catecholase activity of a series of Schiff base compounds using in situ copper complexes of 4-hydroxy-6-methyl-3-(1-(phenyliminoethyl-2H-pyran-2-one derivatives has been reported. The reaction rate depends on four parameters: The nature of the substitution in para position to the benzene ring, the nature of counter anion, the concentration of ligand and the nature of solvent. The highest rate activity is given by complex resulting from one equivalent of ligand L2 and two equivalents of copper acetate in methanol, which equal to 62.25 µmol.min-1.L-1.In other part, a theoretical study of such ligands using the semi-empirical method AM1 were also investigated. A good relationship founded between the maximal reaction rate (Vmax and the HOMO energy (Pearson correlation: r=-0.794.

  6. Study on EPR Spectra of Three Gadolinium Complexes With Noncyclic Polyether Schiff Bases

    Institute of Scientific and Technical Information of China (English)

    陈德余; 姚克敏; 封子先; 蔡乐真; 周佩芬; 薛祺

    1994-01-01

    The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR spectra of nine and four peaks of Gd(Ⅲ) complexes in polycrystalline powder and freezing samples appeared at low temperature respectively for the first time. The interpretations of these results obtained on the basis of spin Hamiltonian of s = 7/2 system are satisfactory. The correlations of EPR feature between crystal-field strength in complexes and local symmetry around Gd3+ ions were revealed. The crystal-field parameters b20 and the asymmetry parameters λ’ of complexes were estimated. A series of interesting regularity and new results were obtained.

  7. 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.

  8. Schiff base triphenylphosphine palladium (II) complexes: Synthesis, structural elucidation, electrochemical and biological evaluation

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Shafiq, Maryam; Mirza, Bushra; McKee, Vickie; Munawar, Khurram Shahzad; Ashraf, Ahmad Raza

    2016-08-01

    The complexes N-(2-oxidophenyl)salicylideneiminatotriphenylphosphine palladium(II) (1) and N-(2-sulfidophenyl)salicylideneiminato triphenylphosphine palladium(II) (2) of tridentate Schiff bases derived from salicylaldehyde and an amino- or thiophenol, have been synthesized and characterized by various spectroscopic, analytical and electro-analytical techniques. X-ray single crystal analysis of complex 1 has revealed its square planar geometry. The thermal analysis has shown the absence of coordinated water and final degradation product is PdO. The alkaline phosphatase studies have indicated that enzymatic activity is concentration dependent which is inversely proportional to the concentration of the compounds. The biological assays (brine shrimp cytotoxicity, DPPH) have reflected their biologically active and mild antioxidant nature. However, results of DNA protection assay have shown that they possess moderate protective activity against hydroxyl free radicals (rad OH). The voltammetric studies ascertain two-electron reduction of the compounds through purely diffusion controlled process and reveal intercalative mode of drug DNA interactions.

  9. Syntheses and Characterization of Some Tetradentate Schiff-Base Complexes and Their Heteroleptic Analogues

    Directory of Open Access Journals (Sweden)

    A. A. Osowole

    2008-01-01

    Full Text Available VO(IV, Ni(II and Cu(II complexes of the asymmetric Schiff base [(HOC6H3(OCH3C(C6H5:N(CH2CH2N:C(CH3CH:C(C6H5OH], and their heteroleptic analogues with triphenyl phosphine and 2,2’-bipyridine have been synthesized and characterized by elemental analyses, conductance, magnetic, infrared and electronic spectral measurements. The ligand is tetradentate coordinating via the imine N and enolic O atoms. The Ni(II and Cu(II complexes adopt a four coordinate square planar geometry, the VO(IV complex is five coordinate square-pyramidal and the heteroleptic complexes are 6-coordinate, octahedral. The assignment of geometry is collaborated by magnetic moments and electronic spectra measurements. The compounds are non-electrolyte in nitromethane and are magnetically dilute.

  10. Synthesis and antimicrobial activity of new crown ethers of Schiff base type

    Directory of Open Access Journals (Sweden)

    MUSTAFA YILDIZ

    2007-03-01

    Full Text Available New crown ether ligands of the Schiff base type (4a–d were synthesized by the reaction of 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxy-1-naphthaldehyde with 6,7-dihydro-13H-dibenzo [e,h] [1,4]dioxonin-2,11-diamine (3. The structures of ligands were investigated by elemental analysis as well as IR, UV–visible, 1H-NMR, 13C-NMR and MS spectroscopic data. The antimicrobial and anti-yeast activities of the ligands were screened in vitro against the organisms Escherichia coli ATCC 11230, Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae UC57, Micrococcus luteus La 2971, Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853, Mycobacterium smegmatis CCM 2067, Bacillus cereus ATCC 7064, Listeria monocytogenes ATCC 15313, Candida albicans ATCC 10231, Kluyveromyces fragilis NRRL 2415, Rhodotorula rubra DSM 70403, Debaryomyces hansenii DSM 70238 and Hanseniaspora guilliermondii DSM 3432.

  11. Synthesis and Application of Lanthanide Complexes with Schiff Base of Pridoxylidence-Glycine

    Institute of Scientific and Technical Information of China (English)

    黄晓华; 周青; 王玉红; 王云翔; 李奚; 王小锋; 李邨

    2002-01-01

    A series of novel rare earths complexes with Schiff base of pridoxylidence-glycine acid (HL) were synthesized in absolute methanol under argon atmosphere. The complexes were characterized by elemental analysis, molar conductivity, IR, UV spectra, and H-NMR spectra et al. Data indicate that the complexes have a general formula Ln LCl2*3H2O (Ln=La, Y, Sm, Gd, Dy, Yb; L=C10H11N2O4). Effects of the complexes (Ln=La) on physiological and biochemical indexes of plants under Pb stress were studied. The experiments shown that the complexes obviously mitigated Pb pollution results in decreasing of chlorophyll content, rising of cell membrane permeability, changing catalase(CAT) and distribution of Pb.

  12. Covalent grafting of the RGD-peptide onto polyetheretherketone surfaces via Schiff base formation.

    Science.gov (United States)

    Becker, Marc; Lorenz, Steffen; Strand, Dennis; Vahl, Christian-Friedrich; Gabriel, Matthias

    2013-01-01

    In recent years, the synthetic polymer polyetheretherketone (PEEK) has increasingly been used in a number of orthopedic implementations, due to its excellent mechanical properties, bioinertness, and chemical resistance. For in vivo applications, the surface of PEEK, which does not naturally support cell adhesion, has to be modified to improve tissue integration. In the present work we demonstrate a novel wet-chemical modification of PEEK to modify the surface, enabling the covalent grafting of the cell-adhesive RGD-peptide. Modification of the polymer surface was achieved via Schiff base formation using an aliphatic diamine and subsequent crosslinker-mediated immobilization of the peptide. In cell culture experiments with primary osteoblasts it was shown that the RGD-modified PEEK not only significantly promoted cellular adhesion but also strongly enhanced the proliferation of osteoblasts on the modified polymer surface.

  13. Synthesis, characterization and third-order nonlinear optical properties of symmetrical ferrocenyl Schiff base materials

    Science.gov (United States)

    Yu, Weiguo; Jia, Jianhong; Gao, Jianrong; Han, Liang; Li, Yujin

    2015-03-01

    Six symmetrical ferrocenyl Schiff base materials were synthesized and characterized by UV, 1H NMR, mass spectrometry (MS) and elemental analysis. Their off-resonant third-order nonlinear optical properties were measured using femtosecond laser and degenerate four-wave mixing (DFWM) technique. The third-order nonlinear optical susceptibilities χ(3) were 1.961-6.363 × 10-13 esu. The nonlinear refractive indexes n2 were 3.609-11.716 × 10-12 esu. The second-order hyperpolarizabilities γ of these molecules were 1.967-6.388 × 10-31 esu. The response time were 45.759-73.079 fs. The results indicate that these materials have potential nonlinear optical applications.

  14. Large negative hyperpolariza-bilities (b) of the protonated Schiff bases of the azulenic retinal analogues

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The molecular first hyperpolarizabilities (b) and electronic properties of some azulenic retinal analogues and their derivatives have been investigated theoretically by employing semiempirical approaches. The results indicate that the protonated Schiff bases (PSB) of the 2-substituted azulenic retinal analogues possess extremely large negative b values and very good transparency. These can be attributed to the large difference between the ground state dipole moment and the first excited state dipole moment according to the electronic property analysis. The characteristic blue- shifted absorption in polar solvents of the 2-substituted PSB chromophores can be well explained by the negative solvato-chromic effects. The largest calculated |mb | value can reach the magnitude of 10-44 esu, which is close to the highest re-ported values of synthesized chromophores.

  15. Isolation and characterization of unusual multinuclear Schiff base complexes: rearrangements reactions and octanuclear cluster formation.

    Science.gov (United States)

    Martínez Belmonte, Marta; Escudero-Adán, Eduardo C; Martin, Eddy; Kleij, Arjan W

    2012-05-07

    The isolation and full characterization of multinuclear Schiff base complexes is reported, and their relevance as precursors for octanuclear Zn(8) salen cluster complex formation is discussed. Starting from simple precursors, three tetranuclear Zn(4) complexes were accessed that incorporate typical half-salen units and comprise of bridging acetates. The use of alternative reaction conditions or a step-wise approach smoothly leads to Zn(8) cluster formation. In addition, the tetranuclear Zn(4) complexes themselves may also serve as precursors toward Zn(8) cluster formation when treated under appropriate reaction conditions. The influence of the solvent medium in the latter Zn(4) → Zn(8) conversion was separately studied and revealed the formation of unusual pyridine-ligated multinuclear structures with fully condensed salen coordination pockets, providing a possible prelude to octanuclear cluster formation.

  16. Bioinorganic Relevance of Some Cobalt(II Complexes with Thiophene-2-glyoxal Derived Schiff Bases

    Directory of Open Access Journals (Sweden)

    Prashant Singh

    2009-01-01

    Full Text Available Complexes of Co(II with two new Schiff bases TEAB [2-hydroxy-4-{[2-oxo-2-(thiophen-2-ylethylidene]amino}benzoic acid] and TEPC [N-[2-oxo-2-(thiophen-2-ylethylidene]pyridine-3-carboxamide] have been synthesized and characterized with the help of elemental analysis, magnetic, mass, 1H-NMR, 13C-NMR, IR and electronic spectral data. IR spectra manifest the coordination of the ligand to the metal ion through the carbonyl oxygen, azomethine nitrogen and thienyl sulphur atoms. With the help of electronic spectral data various ligand field parameters were also calculated. All these studies reveal the distorted octahedral Co(II complexes. Synthesized compounds have also been screened against some micro organisms viz, Escherichia coli, Proteus vulgaris, Aspergillus niger and Aspergillus flavus with the help of ‘filter paper disc’ technique. It has been observed that the antimicrobial activities of metal complexes are higher than that of the free ligand.

  17. HETEROCYCLIC SCHIFF BASE NEODYMIUM COMPLEX AS CATALYST FOR RING-OPENING POLYMERIZATION OF ε-CAPROLACTONE

    Institute of Scientific and Technical Information of China (English)

    Lei Zhang; Xu-feng Ni; Wei-lin Sun; Zhi-quan Shen

    2008-01-01

    An aromatic heterocyclic Schiff base neodymium complex bearing thizole was synthesized and its activity in the ring-opening polymerization of ε-caprolactone (CL) was examined. The conditions of the CL/Nd molar ratio, monomer concentration, polymerization time and temperature were investigated. Activities of ca.171 kg/Nd·h were obtained under the optimum condition (CL/Nd = 1600 (molar ratio), |CL] = 2.26 mol L-1, 1 h at 50℃), giving a poly(ε-caprolactone) (PCL) of number-average molecular weight Mn = 5.4 × 104 and molecular weight distribution MWD = 1.96. The conversion of CL monomer as high as 94% was observed after polymerized for one hour. The mechanism of coordination polymerization has also been illustrated.

  18. Synthesis, characterization and biocidal activities of Schiff base polychelates containing polyurethane links in the main chain

    Science.gov (United States)

    Hasnain, Sumaiya; Nishat, Nahid

    The concept of combining metallo-polymers with urethanes offers a versatile approach for the synthesis of new polymeric materials. Polyurethane containing transition metals was synthesized by the reaction of Schiff base metal complex with toluene 2,4 diisocyanate. The proposed structures were confirmed by elemental analysis, 1H NMR, 13C NMR and FT-IR. The geometry is determined by UV-Visible spectra and magnetic moment measurements, which reveals that the Mn(II), Co(II) and Ni(II) complexes have octahedral geometry while square planer geometry is reported for Cu(II) and tetrahedral for Zn(II) complex. The antimicrobial activities are determined using the agar well diffusion method with Staphylococcus aureus, Escherichia coli, Bacillus subtilis (bacteria), Aspergillus niger, Candida albicans and Aspergillus flavus (yeast). All the polymeric metal complexes show comparatively good biocidal activity, which is further enhanced after polymerization.

  19. Synthesis, Characterization, Anticancer, and Antioxidant Studies of Ru(III) Complexes of Monobasic Tridentate Schiff Bases

    Science.gov (United States)

    Ejidike, Ikechukwu P.

    2016-01-01

    Mononuclear Ru(III) complexes of the type [Ru(LL)Cl2(H2O)] (LL = monobasic tridentate Schiff base anion: (1Z)-N′-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)-N-phenylethanimidamide [DAE], 4-[(1E)-N-{2-[(Z)-(4-hydroxy-3-methoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [HME], 4-[(1E)-N-{2-[(Z)-(3,4-dimethoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [MBE], and N-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)benzenecarboximidoyl chloride [DEE]) were synthesized and characterized using the microanalytical, conductivity measurements, electronic spectra, and FTIR spectroscopy. IR spectral studies confirmed that the ligands act as tridentate chelate coordinating the metal ion through the azomethine nitrogen and phenolic oxygen atom. An octahedral geometry has been proposed for all Ru(III)-Schiff base complexes. In vitro anticancer studies of the synthesized complexes against renal cancer cells (TK-10), melanoma cancer cells (UACC-62), and breast cancer cells (MCF-7) was investigated using the Sulforhodamine B assay. [Ru(DAE)Cl2(H2O)] showed the highest activity with IC50 valves of 3.57 ± 1.09, 6.44 ± 0.38, and 9.06 ± 1.18 μM against MCF-7, UACC-62, and TK-10, respectively, order of activity being TK-10 [Ru(HME)Cl2(H2O)] > [Ru(DAE)Cl2(H2O)] > [Ru(MBE)Cl2(H2O)]. PMID:27597814

  20. A new Schiff base based on vanillin and naphthalimide as a fluorescent probe for Ag+ in aqueous solution

    Science.gov (United States)

    Zhou, Yanmei; Zhou, Hua; Ma, Tongsen; Zhang, Junli; Niu, Jingyang

    2012-03-01

    A new Schiff base based on vanillin and naphthalimide was designed and synthesized as fluorescent probe. The probe showed high selectivity for Ag+ over other metal ions such as Pb2+, Na+, K+, Cd2+, Ba2+, Cr3+, Zn2+, Cu2+, Ni2+, Ca2+, Al3+ and Mg2+ in aqueous solution. A new fluorescence emission was observed at 682 nm in the presence of Ag+ ion. The fluorescence intensity quenched with increasing the concentration of Ag+ at 682 nm. The method of job's plot confirmed the 1:2 complex between Ag+ and probe, and the mechanism was proposed.

  1. Silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases-Novel noncompetitive α-glucosidase inhibitors.

    Science.gov (United States)

    Zheng, Jingwei; Ma, Lin

    2015-01-01

    A series of silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases were designed and tested for α-glucosidase inhibition. Our results indicate that all the silver complexes (4a-18a) possessed strong inhibitory activity at μmolL(-1) level, especially glutamine (12a) and histidine (18a) Schiff base silver(I) complexes exhibited an IC50 value of less than 0.01μmolL(-1). This series of compounds exhibited noncompetitive inhibition characteristics in kinetic studies. In addition, we investigated the mechanism of inhibition and the structure-activity relationships of the amino acid Schiff base silver complexes. Our results reveal that Schiff base silver complexes may be explored for their therapeutic potential as alternatives of α-glucosidase inhibitors.

  2. Immobilization of cobalt(II) Schiff base complexes on polystyrene resin and a study of their catalytic activity for the aerobic oxidation of alcohols.

    Science.gov (United States)

    Jain, Suman; Reiser, Oliver

    2008-01-01

    The copper-catalyzed [3+2] azide-alkyne cycloaddition and the Staudinger ligation are readily applicable and highly efficient for the immobilization of cobalt Schiff base complexes onto polystyrene resins. Stepwise synthesis of polymer-bound Schiff bases followed by their subsequent complexation with metal ions were successfully carried out. Direct covalent attachment of preformed homogeneous cobalt Schiff base complexes to the resins was also possible. The catalytic efficiency of the so-prepared polystyrene-bound cobalt Schiff bases was studied for the oxidation of alcohols to carbonyl compounds using molecular oxygen as oxidant. The immobilized complexes were highly efficient and even more reactive than the corresponding homogenous analogues, thus affording better yields of oxidized products within shorter reaction times. The supported catalysts could easily be recovered from the reaction mixture by simple filtration and reused for subsequent experiments with consistent catalytic activity.

  3. Synthesis of Three Novel Chiral Binuclear Mn(Ⅲ)-Schiff-base Complexes and the Application in Asymmetric Epoxidation of trans-Stilbene

    Institute of Scientific and Technical Information of China (English)

    Yang SUN; Ning TANG; Xin Wen LIU; Wei Sheng LIU

    2004-01-01

    Three novel chiral binuclear Mn(Ⅲ)-Schiff-base complexes have been synthesized and the application of these complexes in the asymmetric epoxidation of trans-stilbene is described, catalytic mechanism is also discussed briefly.

  4. Synthesis and Characterization of New Amino Acid-Schiff Bases and Studies their Effects on the Activity of ACP, PAP and NPA Enzymes (In Vitro

    Directory of Open Access Journals (Sweden)

    Zahraa Salim M. Al-Garawi

    2012-01-01

    Full Text Available In this study, two new Schiff base compounds derived from the condensation reaction of L-glycine and L-tryptophan with 4-methylbenzal-dehyde have been synthesized. The Schiff base compounds were characterized by FT-IR, UV and 1H NMR spectroscopy. Their effects on the activity of total (ACP, prostatic (PAP and non prostatic (NPA acid phosphatase enzymes were studied. The Schiff base derived from L-glycine (A demonstrated inhibition effect on the ACP and NPA activities and activation effect on PAP activity. The Schiff base derived from L-tryptophan (B demonstrated semi fixed inhibition effects on the ACP and NPA activities at high concentrations (5.5×10-2, 5.5×10-3 and 5.5×10-4 M and activator effect at low concentration (5.5×10-5 M while it was exhibits as activator on PAP activity.

  5. NHN-tautomerism in Schiff base derived from pyridoxal 5‧-phosphate and isoniazid: Could it exist?

    Science.gov (United States)

    Gamov, G. A.; Aleksandriiskii, V. V.; Sharnin, V. A.

    2017-02-01

    Structures of Schiff base derived from pyridoxal 5‧-phosphate and isoniazid differing by the quantity of accepted/donated protons were studied by means of quantum chemical calculations (DFT). Based on the total energy and Gibbs energy values the novel intramolecular tautomeric equilibrium consisting in the proton transfer within NHN-group was proposed. The geometry of transition structures was optimized and the values of Gibbs energy of activation of this intramolecular hydrogen transfer were estimated. In the aqueous solution at pH 1 two different NHN-tautomers of Schiff base were found to coexist basing on the comparison of the calculated (TD-SCF) and experimental UV-Vis spectra.

  6. Benzaldehyde Schiff bases regulation to the metabolism, hemolysis, and virulence genes expression in vitro and their structure-microbicidal activity relationship.

    Science.gov (United States)

    Xia, Lei; Xia, Yu-Fen; Huang, Li-Rong; Xiao, Xiao; Lou, Hua-Yong; Liu, Tang-Jingjun; Pan, Wei-Dong; Luo, Heng

    2015-06-05

    There is an urgent need to develop new antibacterial agents because of multidrug resistance by bacteria and fungi. Schiff bases (aldehyde or ketone-like compounds) exhibit intense antibacterial characteristics, and are therefore, promising candidates as antibacterial agents. To investigate the mechanism of action of newly designed benzaldehyde Schiff bases, a series of high-yielding benzaldehyde Schiff bases were synthesized, and their structures were determined by NMR and MS spectra data. The structure-microbicidal activity relationship of derivatives was investigated, and the antibacterial mechanisms were investigated by gene assays for the expression of functional genes in vitro using Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The active compounds were selective for certain active groups. The polar substitution of the R2 group of the amino acids in the Schiff bases, affected the antibacterial activity against E. coli and S. aureus; specific active group at the R3 or R4 groups of the acylhydrazone Schiff bases could improve their inhibitory activity against these three tested organisms. The antibacterial mechanism of the active benzaldehyde Schiff bases appeared to regulate the expression of metabolism-associated genes in E. coli, hemolysis-associated genes in B. subtilis, and key virulence genes in S. aureus. Some benzaldehyde Schiff bases were bactericidal to all the three strains and appeared to regulate gene expression associated with metabolism, hemolysis, and virulence, in vitro. The newly designed benzaldehyde Schiff bases possessed unique antibacterial activity and might be potentially useful for prophylactic or therapeutic intervention of bacterial infections.

  7. Binuclear Schiff Base Complexes of m-Xylylenebis(2-(1,3-Propanedi (2-Pyridinealdmine))) and M-Xylylenebis(2-(1,3-Propanedi(2-Pyrrolealdmine))).

    Science.gov (United States)

    1983-11-04

    H;-13 50 I LEAR SCHIFF BASE COMPLEXES OF / M-XYLYLENEBIS(2-(IiC-PROPRNEOI (2-PYRID. (U) ROCHESTER UNIV NY DEPT OF CHEMIISTRY B C WHITMORE ET AL S...1963-A %4. •N V OFFICE OF NAVAL RESEARCH Contract NOO014-83-K-0154 Task No. NR 634-742 TECHNICAL REPORT NO. 2 Binuclear Schiff Base Complexes of m

  8. Spectroscopic studies on two mono nuclear iron (III) complexes derived from a schiff base and an azodye

    Energy Technology Data Exchange (ETDEWEB)

    Mini, S., E-mail: sadasivan.v@gmail.com; Sadasivan, V., E-mail: sadasivan.v@gmail.com [University College, M G Road, Palayam, Thiruvananthapuram 695 034 Kerala (India); Meena, S. S., E-mail: ssingh@barc.gov.in; Bhatt, Pramod, E-mail: ssingh@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-10-15

    Two new mono nuclear Fe(III) complexes of an azodye (ANSN) and a Schiff base (FAHP) are reported. The azodye is prepared by coupling diazotized 1-amino-2-naphthol-4-sulphonicacid with 2-naphthol and the Schiff base is prepared by condensing 2-amino-3-hydroxy pyridine with furfural. The complexes were synthesized by the reaction of FeCl{sub 3}Ðœ‡2H{sub 2}O with respective ligands. They were characterized on the basis of elemental analysis and spectral studies like IR, NMR, Electronic and M.ssbauer. Magnetic susceptibility and Molar conductance of complexes at room temperature were studied. Based on the spectroscopic evidences and other analytical data the complexes are formulated as[Fe(ANSN)Cl(H{sub 2}O){sub 2}] and [Fe(FAHP)Cl{sub 2}(H{sub 2}O){sub 2}].

  9. Crystal structures of type I dehydroquinate dehydratase in complex with quinate and shikimate suggest a novel mechanism of Schiff base formation.

    Science.gov (United States)

    Light, Samuel H; Antanasijevic, Aleksandar; Krishna, Sankar N; Caffrey, Michael; Anderson, Wayne F; Lavie, Arnon

    2014-02-11

    A component of the shikimate biosynthetic pathway, dehydroquinate dehydratase (DHQD) catalyzes the dehydration of 3-dehydroquniate (DHQ) to 3-dehydroshikimate. In the type I DHQD reaction mechanism a lysine forms a Schiff base intermediate with DHQ. The Schiff base acts as an electron sink to facilitate the catalytic dehydration. To address the mechanism of Schiff base formation, we determined structures of the Salmonella enterica wild-type DHQD in complex with the substrate analogue quinate and the product analogue shikimate. In addition, we determined the structure of the K170M mutant (Lys170 being the Schiff base forming residue) in complex with quinate. Combined with nuclear magnetic resonance and isothermal titration calorimetry data that revealed altered binding of the analogue to the K170M mutant, these structures suggest a model of Schiff base formation characterized by the dynamic interplay of opposing forces acting on either side of the substrate. On the side distant from the substrate 3-carbonyl group, closure of the enzyme's β8-α8 loop is proposed to guide DHQ into the proximity of the Schiff base-forming Lys170. On the 3-carbonyl side of the substrate, Lys170 sterically alters the position of DHQ's reactive ketone, aligning it at an angle conducive for nucleophilic attack. This study of a type I DHQD reveals the interplay between the enzyme and substrate required for the correct orientation of a functional group constrained within a cyclic substrate.

  10. Comparative Study of Aluminum Complexes Bearing N,O- and N,S-Schiff Base in Ring-Opening Polymerization of ε-Caprolactone and L-Lactide.

    Science.gov (United States)

    Chang, Meng-Chih; Lu, Wei-Yi; Chang, Heng-Yi; Lai, Yi-Chun; Chiang, Michael Y; Chen, Hsing-Yin; Chen, Hsuan-Ying

    2015-12-07

    A series of Al complexes bearing Schiff base and thio-Schiff base ligands were synthesized, and their application for the ring-opening polymerization of ε-caprolactone (CL) and l-lactide (LA) was studied. It was found that steric effects of the ligands caused higher polymerization rate and most importantly the Al complexes with N,S-Schiff base showed significantly higher polymerization rate than Al complexes with N,O-Schiff base (5-12-fold for CL polymerization and 2-7-fold for LA polymerization). The reaction mechanism of CL polymerization was investigated by density functional theory (DFT). The calculations predicted a lower activation energy for a process involved with an Al complex bearing an N,S-Schiff base ligand (17.6 kcal/mol) than for that of an Al complex bearing an N,O-Schiff base ligand (19.0 kcal/mol), and this magnitude of activation energy reduction is comparable to the magnitude of rate enhancement observed in the experiment. The reduction of activation energy was attributed to the catalyst-substrate destabilization effect. Using a sulfur-containing ligand to decrease the activation energy in the ring-opening polymerization process may be a new strategy to design a new Al complex with high catalytic activity.

  11. 1-Amino-2-hydroxy-4-naphthalenesulfonic acid based Schiff bases or naphtho[1,2-d]oxazoles: selective synthesis and photophysical properties.

    Science.gov (United States)

    Atahan, Alparslan; Durmus, Sefa

    2015-06-05

    A series of Schiff base and naphtho[1,2-d]oxazole derivatives were selectively synthesized via condensation reaction of 1-amino-2-hydroxy-4-naphthalenesulfonic acid and benzaldehyde derivatives at same conditions. The synthesized compounds were then characterized by using (1)HNMR, (13)CNMR, FTIR spectroscopies and elemental analyses. It was seen that the Schiff bases generated in the presence of OH group at ortho position of benzaldehyde derivatives. However, the products were naphtho[1,2-d]oxazoles in other cases. Then, the synthesized compounds were photophysically investigated by UV absorption and fluorescence emission spectroscopies. As a result, these Schiff bases have shown long wavelength absorption (λ(max): 386 nm) and emission (λ(max): 429-437 nm) effect while synthesized naphtho[1,2-d]oxazole derivatives have a set of absorption (λ(max): about 296, 308, 320 nm) and emission maxima (λ(max): 378-395 nm) at lower wavelength.

  12. Protein changes associated with reprotonation of the Schiff base in the photocycle of Asp96-->Asn bacteriorhodopsin. The MN intermediate with unprotonated Schiff base but N-like protein structure

    Science.gov (United States)

    Sasaki, J.; Shichida, Y.; Lanyi, J. K.; Maeda, A.

    1992-01-01

    The difference Fourier transform infrared spectrum for the N intermediate in the photoreaction of the light-adapted form of bacteriorhodopsin can be recorded at pH 10 at 274 K (Pfefferle, J.-M., Maeda, A., Sasaki, J., and Yoshizawa, T. (1991) Biochemistry 30, 6548-6556). Under these conditions, Asp96-->Asn bacteriorhodopsin gives a photoproduct which shows changes in protein structure similar to those observed in N of wild-type bacteriorhodopsin. However, decreased intensity of the chromophore bands and the single absorbance maximum at about 400 nm indicate that the Schiff base is unprotonated, as in the M intermediate. This photoproduct was named MN. At pH 7, where the supply of proton is not as restricted as at pH 10, Asp96-->Asn bacteriorhodopsin yields N with a protonated Schiff base. The Asn96 residue, which cannot deprotonate as Asp96 in wild-type bacteriorhodopsin, is perturbed upon formation of both MN at pH 10 and N at pH 7. We suggest that the reprotonation of the Schiff base is preceded by a large change in the protein structure including perturbation of the residue at position 96.

  13. Specific inhibition of the transcription factor Ci by a cobalt(III) Schiff base-DNA conjugate.

    Science.gov (United States)

    Hurtado, Ryan R; Harney, Allison S; Heffern, Marie C; Holbrook, Robert J; Holmgren, Robert A; Meade, Thomas J

    2012-02-06

    We describe the use of Co(III) Schiff base-DNA conjugates, a versatile class of research tools that target C2H2 transcription factors, to inhibit the Hedgehog (Hh) pathway. In developing mammalian embryos, Hh signaling is critical for the formation and development of many tissues and organs. Inappropriate activation of the Hedgehog (Hh) pathway has been implicated in a variety of cancers including medulloblastomas and basal cell carcinomas. It is well-known that Hh regulates the activity of the Gli family of C2H2 zinc finger transcription factors in mammals. In Drosophila the function of the Gli proteins is performed by a single transcription factor with an identical DNA binding consensus sequence, Cubitus Interruptus (Ci). We have demonstrated previously that conjugation of a specific 17 base-pair oligonucleotide to a Co(III) Schiff base complex results in a targeted inhibitor of the Snail family C2H2 zinc finger transcription factors. Modification of the oligonucleotide sequence in the Co(III) Schiff base-DNA conjugate to that of Ci's consensus sequence (Co(III)-Ci) generates an equally selective inhibitor of Ci. Co(III)-Ci irreversibly binds the Ci zinc finger domain and prevents it from binding DNA in vitro. In a Ci responsive tissue culture reporter gene assay, Co(III)-Ci reduces the transcriptional activity of Ci in a concentration dependent manner. In addition, injection of wild-type Drosophila embryos with Co(III)-Ci phenocopies a Ci loss of function phenotype, demonstrating effectiveness in vivo. This study provides evidence that Co(III) Schiff base-DNA conjugates are a versatile class of specific and potent tools for studying zinc finger domain proteins and have potential applications as customizable anticancer therapeutics.

  14. Near infrared organic light-emitting diodes based on acceptor-donor-acceptor (ADA) using novel conjugated isatin Schiff bases

    Energy Technology Data Exchange (ETDEWEB)

    Taghi Sharbati, Mohammad, E-mail: m.t.sharbati@sutech.ac.i [Department of Electrical and Electronics Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Soltani Rad, Mohammad Navid, E-mail: soltani@sutech.ac.i [Department of Chemistry, Shiraz University of Technology, Shiraz 71555-313 (Iran, Islamic Republic of); Behrouz, Somayeh [Department of Chemistry, Shiraz University of Technology, Shiraz 71555-313 (Iran, Islamic Republic of); Gharavi, Alireza [Photonics Lab, Department of Electrical and Computer Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Emami, Farzin [Department of Electrical and Electronics Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of)

    2011-04-15

    Fabrications of a single layer organic light emitting diodes (OLEDs) based on two conjugated acceptor-donor-acceptor (ADA) isatin Schiff bases are described. The electroluminescent spectra of these materials range from 630 to 700 nm and their band gaps were measured between 1.97 and 1.77 eV. The measured maximum external quantum efficiencies (EQE) for fabricated OLEDs are 0.0515% and 0.054% for two acceptor-donor-acceptor chromophores. The Commission International De L'Eclairage (CIE) (1931) coordinates of these two compounds were attained and found to be (0.4077, 0.4128) and (0.4411, 0.4126) for two used acceptor-donor-acceptor chromophores. The measured I-V curves demonstrated the apparent diode behavior of two ADA chromophores. The turn-on voltages in these OLEDs are directly dependent on the thickness. These results have demonstrated that ADA isatin Schiff bases could be considered as promising electroluminescence-emitting materials for fabrication of OLEDs.

  15. Chitosan-based Schiff base-metal complexes (Mn, Cu, Co) as heterogeneous, new catalysts for the -isophorone oxidation

    Indian Academy of Sciences (India)

    C S Thatte; M V Rathnam; A C Pise

    2014-05-01

    A new chitosan-based Schiff base was prepared and complexed with manganese, cobalt and copper. These Schiff base metal complexes were used as heterogeneous catalysts for the air oxidation of -isophorone to ketoisophorone. The obtained complexes were characterized by means of FT-IR, 1HNMR spectroscopy, elemental analysis, powder X-ray diffraction, field emission gun scanning electron microscopy, electron spin resonance spectroscopy, ICP-AES and solubility tests. Thermal properties were also investigated using thermal gravimetric analysis. Data obtained by thermal analysis revealed that these complexes showed good thermal stability. The conversion and selectivity of -isophorone to ketoisophorone for each prepared catalyst was studied using a batch reactor and gas chromatography for product identification and quantification. The results were compared against the homogeneous bis-salicylaldehyde ethylenedi-imine-Mn catalyst. The use of methanol, acetone, methyl isobutyl ketone and -hexane as solvent and its effect on conversion and selectivity was also investigated. Acetone was found to be a promising solvent for the -isophorone oxidation. The role of triethyl amine and acetyl acetone in the oxidation reaction has also been investigated.

  16. Synthesis of Some New Pyridine-2,6-carboxamide-derived Schiff Bases as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Abd El-Galil E. Amr

    2010-07-01

    Full Text Available A series of pyridine-bridged 2,6-bis-carboxamide Schiff's bases has been prepared starting from 2,6-pyridinedicarbonyl dichloride (1 and L-alanine or 2-methyl-alanine methyl ester.The coupling of acid chloride 1 with L-alanine methyl ester hydrochloride -or 2-methylalanine methyl ester hydrochloride gave the corresponding 2,6-bis-carboxamide pyridine methyl esters 2a,b.Hydrazonolysis of 2 with hydrazine hydrate afforded the corresponding bis-hydrazides 3a,b. Treatment of 3a,b with appropriate aromatic or heterocyclic aldehydes afforded the corresponding pyridine- bridged 2,6-bis-carboxamide Schiff's bases 4a-f and 5a-f, respectively. The newly synthesized compounds 2-5 were screened for their bactericidal and fungicidal activities. Many of the obtained compounds exhibited significant antimicrobial activity, comparable to streptomycin and fusidic acid, which were used as reference antibiotic drugs.

  17. Schiff Bases of Indoline-2,3-dione: Potential Novel Inhibitors of Mycobacterium Tuberculosis (Mtb DNA Gyrase

    Directory of Open Access Journals (Sweden)

    Jane Thanassi

    2011-09-01

    Full Text Available In the present study a series of Schiff bases of indoline-2,3-dione were synthesized and investigated for their Mtb gyrase inhibitory activity. Promising inhibitory activity was demonstrated with some of these derivatives, which exhibited IC50 values ranging from 50–157 mM. The orientation and the ligand-receptor interactions of such molecules within the Mtb DNA gyrase A subunit active site were investigated applying a multi-step docking protocol using Molecular Operating Environment (MOE and Autodock4 docking software. The results revealed the importance of the isatin moiety and the connecting side chain for strong interactions with the enzyme active site. Among the tested compounds the terminal aromatic ring benzofuran showed the best activity. Promising new leads for developing a novel class of Mtb gyrase inhibitors were obtained from Schiff bases of indoline-2,3-dione.

  18. Design, Synthesis and Antitumor Activity of Asymmetric Bis(s-triazole Schiff-base)s Bearing Functionalized Side-Chain

    Institute of Scientific and Technical Information of China (English)

    HU,Guo-Oiang; HOU,Li-Li; XIE,Song-Oiang; HUANG,Wen-Long

    2008-01-01

    1-Amino-2-pyrid-3-yl-5-(2-benzoylethylthio)-s-triazole (1) was condensed with 1-amino-3-mercapto-5-[(un)substituted phenyl]-s-triazoles and subsequently substituted with chloroacetic acid to afford bis-s-triazole sulfanylacetic acid mono-Schiff bases (3a-3e),which were condensed with 9-formylanthracene to produce asymmetric bis(s-triazole Schiff base) sulfanylacetic acids (4a-4e).The structures of new synthesized compounds were characterized by elemental analysis and spectral data,and their in vitro antitumor activity against L1210,CHO and HL60 cell lines was evaluted via the respective IC50 values by methylthiazole trazolium (MTT) assay.

  19. Antioxidant, electrochemical, thermal, antimicrobial and alkane oxidation properties of tridentate Schiff base ligands and their metal complexes

    Science.gov (United States)

    Ceyhan, Gökhan; Çelik, Cumali; Uruş, Serhan; Demirtaş, İbrahim; Elmastaş, Mahfuz; Tümer, Mehmet

    2011-10-01

    In this study, two Schiff base ligands (HL 1 and HL 2) and their Cu(II), Co(II), Ni(II), Pd(II) and Ru(III) metal complexes were synthesized and characterized by the analytical and spectroscopic methods. Alkane oxidation activities of the metal complexes were studied on cyclohexane as substrate. The ligands and their metal complexes were evaluated for their antimicrobial activity against Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus and Enterococcus faecalis (as Gram-positive bacteria) and Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica, Klebsiella fragilis, Saccharomyces cerevisiae, and Candida albicans (as Gram-negative bacteria). The antioxidant properties of the Schiff base ligands were evaluated in a series of in vitro tests: 1,1-diphenyl-2-picrylhydrazyl (DPPH rad ) free radical scavenging and reducing power activity of superoxide anion radical generated non-enzymatic systems. Electrochemical and thermal properties of the compounds were investigated.

  20. Chemical modification of silica gel with synthesized new Schiff base derivatives and sorption studies of cobalt (II) and nickel (II)

    Energy Technology Data Exchange (ETDEWEB)

    Kursunlu, Ahmed Nuri, E-mail: ankursunlu@gmail.com [Department of Chemistry, Selcuk University, Campus, 42075, Konya (Turkey); Guler, Ersin; Dumrul, Hakan; Kocyigit, Ozcan; Gubbuk, Ilkay Hilal [Department of Chemistry, Selcuk University, Campus, 42075, Konya (Turkey)

    2009-08-15

    In this study, three Schiff base ligands and their complexes were synthesized and characterized by infrared spectroscopy (IR), thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR), elemental analysis and magnetic susceptibility apparatuses. Silica gel was respectively modified with Schiff base derivatives, (E)-2-[(2-chloroethylimino)methyl]phenol, (E)-4-[(2-chloroethylimino)methyl]phenol and N,N'-[1,4-phenilendi(E)methylidene]bis(2-chloroethanamine), after silanization of silica gel by (3-aminopropyl)trimethoxysilane (APTS) by using a suitable method. Characterization of the surface modification was also performed with IR, TGA and elemental analysis. The immobilized surfaces were used for Co(II) and Ni(II) sorption from aqueous solutions and values of sorption were detected by atomic absorption spectrometer (AAS).

  1. Development and cytotoxicity of Schiff base derivative as a fluorescence probe for the detection of L-Arginine

    Science.gov (United States)

    Shang, Xuefang; Li, Jie; Guo, Kerong; Ti, Tongyu; Wang, Tianyun; Zhang, Jinlian

    2017-04-01

    Inspired from biological counter parts, chemical modification of Schiff base derivatives with function groups may provide a highly efficient method to detect amino acids. Therefore, a fluorescent probe involving Schiff base and hydroxyl group has been designed and prepared, which showed high response and specificity for Arginine (Arg) among normal eighteen standard kinds of amino acids (Alanine, Valine, Leucine, Isoleucine, Methionine, Asparticacid, Glutamicacid, Arginine, Glycine, Serine, Threonine, Asparagine, Phenylalanine, Histidine, Tryptophan, Proline, Lysine, Glutamine, Tyrosine and Cysteine). Furthermore, theoretical investigation further illustrated the possible binding mode in the host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. In addition, the synthesized fluorescent probe exhibited high binding ability for Arg and low cytotoxicity to MCF-7 cells over a concentration range of 0-200 μg mL-1 which can be also used as a biosensor for the Arg detection in vivo.

  2. In-vitro antibacterial, antifungal and cytotoxic properties of sulfonamide--derived Schiff's bases and their metal complexes.

    Science.gov (United States)

    Chohan, Zahid H; Mahmood-Ul-Hassan; Khan, Khalid M; Supuran, Claudiu T

    2005-04-01

    A series of new antibacterial and antifungal Schiff's bases derived from sulfonamides, as well as their transition metal complexes incorporating cobalt (II), copper (II), nickel (II) and zinc (II) were synthesized, characterized and screened for their in-vitro antibacterial activity against six Gram-negative (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi and Shigella dysentriae) and four Gram-positive (Bacillus cereus, Corynebacterium diphtheriae, Staphylococcus aureous and Streptococcus pyogenes) bacterial strains and for in-vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, Candida glaberata. The results of these studies show the metal complexes to be more antibacterial and antifungal as compared to the uncomplexed Schiffs' bases. The brine shrimp bioassay was also carried out to study the in-vitro cytotoxic properties of these synthesized ligands and their complexes.

  3. Synthesis of Schiff base 24-membered trivalent transition metal derivatives with their anti-inflammation and antimicrobial evaluation

    Science.gov (United States)

    Kumar, Gajendra; Devi, Shoma; Kumar, Dharmendra

    2016-03-01

    The paper presents the synthesis of macrocyclic complexes [{M(C52H36N12O4)X}X2] of Cr(III), Mn(III) and Fe(III) with Schiff base ligand (C52H36N12O4) obtained through the condensation of 1,4-dicarbonyl phenyl dihydrazide with 1,2-di(1H-indol-1-yl)ethane-1,2-dione. The newly formed Schiff base and its complexes have been characterized with the help of elemental analysis, condensation measurements, magnetic measurements and their structure configuration have been determined by various spectroscopic (electronic, IR, 1H NMR, 13C NMR, GCMS) techniques. The electronic spectra of the complexes indicate a five coordinate square pyramidal geometry of the center metal ion. These metal complexes and ligand were tested for their anti-inflammation and antimicrobial inhibiting potential and compared with standard drugs Phenyl butazone (anti-inflammation), Imipenem (antibacterial) and Miconazole (antifungal).

  4. Synthesis, Crystal Structure and Thermoanalysis of Complex of Zn(Ⅱ) with Aminomethanesulfonic Acid-5-bromosalicylaldelyde Schiff Base

    Institute of Scientific and Technical Information of China (English)

    DENG Yi-Fang; KUANG Dai-Zhi; ZHANG Chun-Hua; CHEN Man-Sheng; PENG Yun-Lin; YANG Ying-Qun; LI Wei

    2006-01-01

    The title complex [Zn(L)(phen)(CH3OH)] (L= C8H6BrO4NS, aminomethanesulfonic acid 5-bromo-salicylaldelyde schiff base; phen = 1,10-phenanthroline) has been synthesized and characterized by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 1.8712(3), b = 1.38008(19), c = 0.83685(12) nm, β = 97.791 (2)°, Mr = 569.72, V = 2.1411(5)nm3,Z= 4, Dc = 1.767 g/cm3, μ = 3.151 mm-1, F(000) = 1144, the final R = 0.0402 and wR = 0.0885. The central Zn(Ⅱ) is six-coordinated by one nitrogen and two oxygen atoms from the Schiff base, two nitrogen atoms from 1,10-phenanthroline and one oxygen from methanol to form a distorted octahedral coordination geometry.

  5. Microwave assisted synthesis and characterization of unsymmetrical tetradentate Schiff base complexes of VO(IV) and MoO(V).

    Science.gov (United States)

    Thaker, B T; Barvalia, R S

    2011-12-15

    Microwave synthesis, is green chemical method, simple, sensitive, reducing solvent amount and reaction time. The attempt was made to synthesize the unsymmetrical tetradentate N(2)O(2) ligands and their VO(IV) and MoO(V) unsymmetrical tetradentate Schiff base complexes by classical and microwave techniques using domestic microwave oven. The resulting unsymmetrical Schiff base ligands L(1)-L(3) characterized by different spectral methods. Their complexes with oxocations of VO(IV) and MoO(V) have been synthesized and characterized by elemental analyses, conductometric measurements, infrared and electronic absorption, (1)H NMR spectra, mass spectrometry, ESR spectra, magnetic susceptibility measurement and thermal study. The study suggests that the oxo metal ion is bonded to the ligand through the oxygen and imino nitrogen and the geometry around metal ion is distorted octahedral.

  6. Antioxidative Effect of Schiff Bases with o-Hydroxybenzylidene Groupon Free Radical Induced Hemolysis of Human Red Blood Cell

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The hemolysis of human red blood cells was initiated by a water-soluble free radical initiator, 2,2′-azobis-(2-amidinopropane hydrochloride)(AAPH), at 37 ℃ in phosphate buffered saline(pH=7.4). The respective addition of 1-[N-(o-hydroxybenzylidene)amino]tetradecane(TDCA), 1,2-di[N-(o-hydroxybenzylidene)amino]cyclohexane(DACH), 4-[N-(o-hydroxybenzylidene)amino]benzoic acid(PABA), 4-nitro[N-(o-hydroxybenzylidene)]aniline(APNA) or N-(o-hydroxybenzylidene)aniline(APA) can all prolong the inhibition period of hemolysis, indicating that the above Schiff bases play an antioxidative role in free radical induced hemolysis. It can be concluded that Schiff base with an alkyl group or a conjugated system in the molecule protect red blood cells against free radical induced hemolysis efficiently. This information may be useful for antioxidant drug design.

  7. Synthesis and antimicrobial activities of new higher amino acid Schiff base derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid

    Science.gov (United States)

    Özdemir (nee Güngör), Özlem; Gürkan, Perihan; Özçelik, Berrin; Oyardı, Özlem

    2016-02-01

    Novel β-lactam derivatives (1c-3c) (1d-3d) were produced by using 6-aminopenicillanic acid (6-APA), 7-aminocephalosporanic acid (7-ACA) and the higher amino acid Schiff bases. The synthesized compounds were characterized by elemental analysis, IR, 1H/13C NMR and UV-vis spectra. Antibacterial activities of all the higher amino acid Schiff bases (1a-3a) (1b-3b) and β-lactam derivatives were screened against three gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii RSKK 02026), three gram positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 07005, Bacillus subtilis ATCC 6633) and their drug-resistant isolates by using broth microdilution method. Two fungi (Candida albicans and Candida krusei) were used for antifungal activity.

  8. Theoretical Studies on Electronic Spectra and Second-order Nonlinear Optical Properties of Barbituric Acid Derivatives Substituted with Schiff Base

    Institute of Scientific and Technical Information of China (English)

    SUN,Gang(孙刚); QIU,Yong-Qing(仇永清); SUN,Hai-Zhu(孙海珠); SU,Zhong-Min(苏忠民); FENG,Jing-Dong(冯静东); ZHU,Yu-Lan(朱玉兰)

    2004-01-01

    The structures of barbituric acid derivatives substituted with Schiff base were optimized using ab initio HF method at 6-31G basis set.Based on the optimized structures,the electronic spectra were obtained by INDO/CI method.The second-order nonlinear optical (NLO) coefficients βu were calculated according to the sum-over-states (SOS) formula.In addition,the effect of conjugation on electronic spectra and second-order NLO coefficients was investigated.The influence of exchange between C and N atoms as well as the substituted effect on the barbituric acid was discussed.It was indicated that the exchange between C and N atoms on Schiff base is important for enhancing the NLO coefficient of the whole molecule with donor and acceptor (D-A).Meanwhile significant changes in electron donation and acception were observed as substituents changes positions.Among the designed models,molecule 1b has maximal βμ value of 124.65 × 10-30 esu.About molecule 1b,barbituric acid is considered as an accepted electronic group and the position of N atom on Schiff base is close to it.

  9. A semiempirical study of the optimized ground and excited state potential energy surfaces of retinal and its protonated Schiff base

    Science.gov (United States)

    Parusel, A. B.; Pohorille, A.

    2001-01-01

    The electronic ground and first excited states of retinal and its Schiff base are optimized for the first time using the semiempirical AM1 Hamiltonian. The barrier for rotation about the C(11)-C(12) double bond is characterized by variation of both the twist angle delta(C(10)-C(11)-C(12)-C(13)) and the bond length d(C(11)-C(12)). The potential energy surface is obtained by varying these two parameters. The calculated ground state rotational barrier is equal to 15.6 kcal/mol for retinal and 20.5 kcal/mol for its Schiff base. The all-trans conformation is more stable by 3.7 kcal/mol than the 11-cis geometry. For the first excited state, S(1,) the 90 degrees twisted geometry represents a saddle point for retinal with the rotational barrier of 14.6 kcal/mol. In contrast, this conformation is an energy minimum for the Schiff base. It can be easily reached at room temperature from the planar minima since it is separated from them by a barrier of only 0.6 kcal/mol. The 90 degrees minimum conformation is more stable than the all-trans by 8.6 kcal/mol. We are thus able to present a reaction path on the S(1) surface of the retinal Schiff base with an almost barrier-less geometrical relaxation into a twisted minimum geometry, as observed experimentally. The character of the ground and first excited singlet states underscores the need for the inclusion of double excitations in the calculations.

  10. Synthesis and Biological Activity of 4,5-Dihydro-1,2,4-triazole-5-thione Schiff Base

    Institute of Scientific and Technical Information of China (English)

    SUN, Xiaohong; BAI, Yan; LIU, Yuanfa; CHEN, Bang; JIA, Yingqi; ZENG, Zhenfang

    2009-01-01

    The 4,5-dihydro-1,2,4-triazole Schiff base derivatives were synthesized with 4-amino-4,5-dihydro-3-(phenoxy- methyl)-1H-1,2,4-triazole-5-thione and substituted benzaidehydes. The chemical structures of the compounds have been confirmed by 1H NMR, IR spectra and elemental analysis. Their biological activities were investigated, and the results showed that they exhibited good fungicidal activities.

  11. Physicochemical Investigations of Th(IV and UO2(VI Complexes with New Schiff Bases Along with their Toxic Effects

    Directory of Open Access Journals (Sweden)

    Sonal Agnihotri

    2010-01-01

    Full Text Available Schiff bases were obtained using p-trimethoxy benzaldehyde, p-hydroxyl benzaldehyde and 2-amino pyridine to prepare new complexes of thorium(IV and dioxouranium(VI metals by various anions. The synthesized ligands and complexes were analytically studied through spectral studies, elemental analysis conductance measurements along with semi empirical and thermogravimetric methods. The complexes were assigned various coordination numbers ranging from 6-10 on the basis of these studies.

  12. Aspartic acid-96 is the internal proton donor in the reprotonation of the Schiff base of bacteriorhodopsin.

    Science.gov (United States)

    Otto, H; Marti, T; Holz, M; Mogi, T; Lindau, M; Khorana, H G; Heyn, M P

    1989-01-01

    Above pH 8 the decay of the photocycle intermediate M of bacteriorhodopsin splits into two components: the usual millisecond pH-independent component and an additional slower component with a rate constant proportional to the molar concentration of H+, [H+]. In parallel, the charge translocation signal associated with the reprotonation of the Schiff base develops a similar slow component. These observations are explained by a two-step reprotonation mechanism. An internal donor first reprotonates the Schiff base in the decay of M to N and is then reprotonated from the cytoplasm in the N----O transition. The decay rate of N is proportional to [H+]. By postulating a back reaction from N to M, the M decay splits up into two components, with the slower one having the same pH dependence as the decay of N. Photocycle, photovoltage, and pH-indicator experiments with mutants in which aspartic acid-96 is replaced by asparagine or alanine, which we call D96N and D96A, suggest that Asp-96 is the internal proton donor involved in the re-uptake pathway. In both mutants the stoichiometry of proton pumping is the same as in wild type. However, the M decay is monophasic, with the logarithm of the decay time [log (tau)] linearly dependent on pH, suggesting that the internal donor is absent and that the Schiff base is directly reprotonated from the cytoplasm. Like H+, azide increases the M decay rate in D96N. The rate constant is proportional to the azide concentration and can become greater than 100 times greater than in wild type. Thus, azide functions as a mobile proton donor directly reprotonating the Schiff base in a bimolecular reaction. Both the proton and azide effects, which are absent in wild type, indicate that the internal donor is removed and that the reprotonation pathway is different from wild type in these mutants. PMID:2556706

  13. Spectroscopic characterization of metal complexes of novel Schiff base. Synthesis, thermal and biological activity studies.

    Science.gov (United States)

    Omar, M M; Mohamed, Gehad G; Ibrahim, Amr A

    2009-07-15

    Novel Schiff base (HL) ligand is prepared via condensation of 4-aminoantipyrine and 2-aminobenzoic acid. The ligand is characterized based on elemental analysis, mass, IR and (1)H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, (1)H NMR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TGA, DrTGA and DTA). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a uninegatively tridentate manner with NNO donor sites of the azomethine N, amino N and deprotonated caroxylic-O. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral. 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*, DeltaH*, DeltaS* and DeltaG* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia Coli, Pseudomonas aeruginosa, Staphylococcus Pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Shciff base ligand against one or more bacterial species.

  14. Structural characterization of new Schiff bases of sulfamethoxazole and sulfathiazole, their antibacterial activity and docking computation with DHPS protein structure.

    Science.gov (United States)

    Mondal, Sudipa; Mandal, Santi M; Mondal, Tapan Kumar; Sinha, Chittaranjan

    2015-01-01

    New Schiff bases (1, 2) of substituted salicylaldehydes and sulfamethoxazole (SMX)/sulfathiazole (STZ) are synthesized and characterized by elemental analysis and spectroscopic data. Single crystal X-ray structure of one of the compounds (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(5-methylisoxazol-3-yl)benzenesulfonamide (1c) has been determined. Antimicrobial activities of the Schiff bases and parent sulfonamides (SMX, STZ) have been examined against several Gram-positive and Gram-negative bacteria and sulfonamide resistant pathogens; the lowest MIC is observed for (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(thiazol-2-yl)benzene sulfonamide (2c) (8.0 μg mL(-1)) and (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(5-methylisoxazol-3-yl)benzene sulfonamide (1c) (16.0 μg mL(-1)) against sulfonamide resistant pathogens. DFT optimized structures of the Schiff bases have been used to carry out molecular docking studies with DHPS (dihydropteroate synthase) protein structure (downloaded from Protein Data Bank) using Discovery Studio 3.5 to find the most preferred binding mode of the ligand inside the protein cavity. The theoretical data have been well correlated with the experimental results. Cell viability assay and ADMET studies predict that 1c and 2c have good drug like characters.

  15. A Quantum Chemical and Statistical Study of Phenolic Schiff Bases with Antioxidant Activity against DPPH Free Radical.

    Science.gov (United States)

    Anouar, El Hassane

    2014-04-21

    Phenolic Schiff bases are known as powerful antioxidants. To select the electronic, 2D and 3D descriptors responsible for the free radical scavenging ability of a series of 30 phenolic Schiff bases, a set of molecular descriptors were calculated by using B3P86 (Becke's three parameter hybrid functional with Perdew 86 correlation functional) combined with 6-31 + G(d,p) basis set (i.e., at the B3P86/6-31 + G(d,p) level of theory). The chemometric methods, simple and multiple linear regressions (SLR and MLR), principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to reduce the dimensionality and to investigate the relationship between the calculated descriptors and the antioxidant activity. The results showed that the antioxidant activity mainly depends on the first and second bond dissociation enthalpies of phenolic hydroxyl groups, the dipole moment and the hydrophobicity descriptors. The antioxidant activity is inversely proportional to the main descriptors. The selected descriptors discriminate the Schiff bases into active and inactive antioxidants.

  16. Synthesis and spectral characterization of trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes with Schiff bases.

    Science.gov (United States)

    Singh, Atresh Kumar; Singh, Alok Kumar

    2012-10-01

    Some novel trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes of the general formula [Fe(3)O(OOCR)(3)(SB)(3)L(3)] (where R=C(13)H(27), C(15)H(31) or C(17)H(35,) HSB=Schiff bases and L=Ethanol) have been synthesized by the stepwise substitutions of acetate ions from μ(3)-oxo-hexa(acetato)tri(aqua)iron(II)diiron(III), first with straight chain carboxylic acids and then with Schiff bases. The complexes were characterized by elemental analyses, molecular weight determinations and spectral (electronic, infrared, FAB mass, Mössbauer and powder XRD) studies. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bridging nature of carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Mössbauer spectroscopic studies indicated two quadrupole-split doublets due to Fe(II) and Fe(III) ions at 80, 200 and 295K, confirming the complexes are mixed-valence species. This was also supported by the observed electronic spectra of the complexes. Magnetic susceptibility measurements displayed octahedral geometry around iron in mixed-valence state and a net antiferromagnetic exchange coupling via μ-oxo atom. Trinuclear nature of the complexes was confirmed by their molecular weight determination and FAB mass spectra. A plausible structure for these complexes has been established on the basis of spectral and magnetic moment data.

  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.

    2015-02-01

    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.

  18. 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.

  19. Polydentate Schiff Base Ligands and Their La(III Complexes: Synthesis, Characterization, Antibacterial, Thermal, and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Ali E. Şabik

    2012-01-01

    Full Text Available We synthesized the Schiff base ligands H2L1–H2L4 and their La(III complexes and characterized them by the analytical and spectroscopic methods. We investigated their electrochemical and antimicrobial activity properties. The electrochemical properties of the ligands H2L1–H2L4 and their La(III complexes were studied at the different scan rates (100 and 200 mV, different pH ranges (pH=2−12, and in the different solvents. The electrooxidation of the Schiff base ligands involves a reversible transfer of two electrons and two protons in solutions of pH up to 5.5, in agreement with the one-step two-electron mechanism. In solutions of pH higher than 5.5, the process of electrooxidation reaction of the Schiff base ligands and their La(III complexes follows an ECi mechanism. The antimicrobial activities of the ligands and their complexes were studied. The thermal properties of the metal complexes were studied under nitrogen atmosphere in the range of temperature 20–1000°C.

  20. Adsorptive removal of lead and cadmium ions using Cross -linked CMC Schiff base: Isotherm, Kinetics and Catalytic Activity

    Directory of Open Access Journals (Sweden)

    P. Moganavally

    2016-03-01

    Full Text Available Water plays a vital role to human and other living organisms. Due to the effluent coming from chemical industries, the industrial activity, contamination of ground water level is goes on increasing nowadays. Therefore, there is a need to develop technologies that can remove toxic pollutants in wastewater. Hence the cross linked Carboxymethyl chitosan(CMC/ 2,3-dimethoxy Benzaldehyde Schiff base complex has been synthesized and characterized by using FT-IR and SEM analysis. All these results revealed that cross linked Schiff base has formed with high adsorption capacity. The prepared effective adsorbent used for the removal of heavy metals like lead (II and cadmium (II ions from aqueous solution and the adsorption data follow the Freundlich model, which follows pseudo first order kinetics. Effect of various parameters like solution pH, adsorbent dose and contact time for the removal of heavy metals has been studied. The synthesized sample undergoes catalytic oxidation process significantly at 24 hrs. The results showed that cross linked Schiff base is an effective, eco-friendly, low-cost adsorbent.

  1. Green Chemistry Approach for Efficient Synthesis of Schiff Bases of Isatin Derivatives and Evaluation of Their Antibacterial Activities

    Directory of Open Access Journals (Sweden)

    Jnyanaranjan Panda

    2013-01-01

    Full Text Available Microwave-assisted organic synthesis, a green chemistry approach, is nowadays widely used in the drug synthesis. Microwave-assisted synthesis improves both throughput and turnaround time for medicinal chemists by offering the benefits of drastically reduced reaction times, increased yields, and pure products. Schiff bases are the important class of organic compounds due to their flexibility, and structural diversities due to the presence of azomethine group which is helpful for elucidating the mechanism of transformation and rasemination reaction in biological system. This novel compound could also act as valuable ligands for the development of new chemical entities. In the present work, some Schiff bases of Isatin derivatives was synthesized using microwave heating method. Schiff base of Isatin were synthesized by condensation of the keto group of Isatin with different aromatic primary amines. They were characterized by means of spectral data and subsequently subjected to the in vitro antibacterial activities against gram positive and gram negative strains of microbes. It was observed that the compound with electron withdrawing substituents exhibited good antibacterial activities against almost all the micro organisms.

  2. Synthesis and Crystal Structures of Copper(II) Complexes with Schiff Base Ligands: [Cu{sub 2}(acpy-mdtc){sub 2}(HBA)(ClO{sub 4})]·H{sub 2}O and [Cu{sub 2}(acpy-phtsc){sub 2}(HBA)]·ClO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-15

    Two new Cu(II) complexes, [Cu{sub 2}(acpy-mdtc){sub 2}(HBA)(ClO{sub 4})]·H{sub 2}O (1) (acpy-mdtc{sup -} = 2-acetylpyridine S-methyldithiocarbamate and HBA{sup -} = benzilic acid anion) and [Cu{sub 2}(acpy-phtsc){sub 2}(HBA)]·ClO{sub 4} (2) (acpy-phtsc{sup -} = 2-acetylpyridine 4-phenyl-3-thiosemicarbazate) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear copper(II) complexes bridged by two thiolate sulfur atoms of Schiff base ligand and bidentate bridging HBA{sup -} anion. For 1, each of the two copper atoms has different coordination environments. Cu1 adopts a five-coordinate square-pyramidal with a N{sub 2}OS{sub 2} donor, while Cu{sub 2} exhibits a distorted octahedral geometry in a N{sub 2}O{sub 2}S{sub 2} manner. For 2, two Cu(II) ions all have a five-coordinate square-pyramidal with a N{sub 2}OS{sub 2} donor. In each complex, the Schiff base ligand is coordinated to copper ions as a tridentate thiol mode.

  3. Structural, spectroscopic and DFT study of 4-methoxybenzohydrazide Schiff bases. A new series of polyfunctional ligands.

    Science.gov (United States)

    Ferraresi-Curotto, Verónica; Echeverría, Gustavo A; Piro, Oscar E; Pis-Diez, Reinaldo; González-Baró, Ana C

    2015-02-25

    Five Schiff bases obtained from condensation of 4-methoxybenzohydrazide with related aldehydes, namely o-vanillin, vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde were prepared. A detailed structural and spectroscopic study is reported. The crystal structures of four members of the family were determined and compared with one another. The hydrazones obtained from 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde resulted to be isomorphic to each other. The solid-state structures are stabilized by intra-molecular O-H⋯N interactions in salicylaldehyde derivatives between the O-H moiety from the aldehyde and the hydrazone nitrogen atom. All crystals are further stabilized by inter-molecular H-bonds mediated by the crystallization water molecule. A comparative analysis between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. The structure is predicted for the compound for which the crystal structure was not determined. Infrared and electronic spectra were measured and assigned with the help of data obtained from computational methods based on the Density Functional Theory.

  4. Synthesis, characterization, biological and catalytic applications of transition metal complexes derived from Schiff base.

    Science.gov (United States)

    Bushra Begum, A; Rekha, N D; Vasantha Kumar, B C; Lakshmi Ranganatha, V; Khanum, Shaukath Ara

    2014-08-01

    A novel series of Cu(II), Ni(II), Zn(II), Co(II), and Cd(II) complexes have been synthesized from the Schiff base. Structural features were determined by analytical and spectral techniques like IR, (1)H NMR, UV-vis, elemental analysis, molar electric conductibility, magnetic susceptibility and thermal studies. The complexes are found to be soluble in dimethylformamide and dimethylsulfoxide. Molar conductance values in dimethylformamide indicate the non-electrolytic nature of the complexes. Binding of synthesized complexes with calf thymus DNA (CT DNA) was studied. There is significant binding of DNA in lanes 2, 3, and 5. Lanes 4 and 6 are showing more florescence when compared to the control indicating that these molecules are strongly bound to the DNA by inserting themselves between the two stacked base pairs and exhibiting their original property of fluorescence. Angiogenesis study has revealed that the compounds B-2, B-4 and B-5 have potent antitumor efficacy and activation of antiangiogenesis could be one of the possible underlying mechanisms of tumor inhibition.

  5. Structural, spectroscopic and DFT study of 4-methoxybenzohydrazide Schiff bases. A new series of polyfunctional ligands

    Science.gov (United States)

    Ferraresi-Curotto, Verónica; Echeverría, Gustavo A.; Piro, Oscar E.; Pis-Diez, Reinaldo; González-Baró, Ana C.

    2015-02-01

    Five Schiff bases obtained from condensation of 4-methoxybenzohydrazide with related aldehydes, namely o-vanillin, vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde were prepared. A detailed structural and spectroscopic study is reported. The crystal structures of four members of the family were determined and compared with one another. The hydrazones obtained from 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde resulted to be isomorphic to each other. The solid-state structures are stabilized by intra-molecular Osbnd H⋯N interactions in salicylaldehyde derivatives between the Osbnd H moiety from the aldehyde and the hydrazone nitrogen atom. All crystals are further stabilized by inter-molecular H-bonds mediated by the crystallization water molecule. A comparative analysis between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. The structure is predicted for the compound for which the crystal structure was not determined. Infrared and electronic spectra were measured and assigned with the help of data obtained from computational methods based on the Density Functional Theory.

  6. Four Thermochromic o-Hydroxy Schiff Bases of α-Aminodiphenylmethane: Solution and Solid State Study

    Directory of Open Access Journals (Sweden)

    Marija Zbačnik

    2017-01-01

    Full Text Available More than a hundred years after the first studies of the photo- and thermochromism of o-hydroxy Schiff bases (imines, it is still an intriguing topic that fascinates several research groups around the world. The reasons for such behavior are still under investigation, and this work is a part of it. We report the solution-based and mechanochemical synthesis of four o-hydroxy imines derived from α-aminodiphenylmethane. The thermochromic properties were studied for the single crystal and polycrystalline samples of the imines. The supramolecular impact on the keto-enol tautomerism in the solid state was studied using SCXRD and NMR, while NMR spectroscopy was used for the solution state. All four imines are thermochromic, although the color changes of the single crystals are not as strong as of the polycrystalline samples. One of the imines shows negative thermochromism, and that one is in keto-amine tautomeric form, both in the solid state as in solution.

  7. Noncovalent interactions from electron density topology and solvent effects on spectral properties of Schiff bases

    Science.gov (United States)

    Gandhimathi, S.; Balakrishnan, C.; Theetharappan, M.; Neelakantan, M. A.; Venkataraman, R.

    2017-03-01

    Two Schiff bases were prepared by the condensation of o-allyl substituted 2,4-dihydroxy acetophenone with 1,2-diaminopropane (L1) and ethanediamine (L2) and characterized by elemental analysis, and ESI-MS, IR, UV-Vis, 1H and 13C NMR spectral techniques. The effect of solvents with respect to different polarities on UV-Vis and emission spectra of L1 and L2 was investigated at room temperature show that the compounds exist in keto and enol forms in solution and may be attributed to the intramolecular proton transfer in the ground state. The solute-solvent interactions, change in dipole moment and solvatochromic properties of the compounds were studied based on the solvent polarity parameters. For L1 and L2, the ground and excited state electronic structure calculations were carried out by DFT and TD-DFT at B3LYP/6-311G (d,p) level, respectively. The IR, NMR and electronic absorption spectra computed were compared with the experimental observations. The intramolecular charge transfer within the molecule is evidenced from the HOMO and LUMO energy levels and surface analysis. The noncovalent interactions like hydrogen bonding and van der Waals interactions were identified from the molecular geometry and electron localization function. These interactions in molecules have been studied by using reduced density gradient and graphed by Multiwfn.

  8. Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles

    Indian Academy of Sciences (India)

    MAGDALENA BARWIOLEK; ROBERT SZCZĘSNY; EDWARD SZŁYK

    2016-07-01

    Cu(II) complexes with Schiff bases derived from ethylenediamine (en) and 2-pyridinecarboxaldehyde (pyca), 2,5-dimethoxybenzaldehyde (dmbaH) or 4-imidazolecarboxaldehyde (4Him) were obtained and studied by elemental analysis, UV-VIS and IR spectra. Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers of the studied Cu(II) complexes were deposited on Si(111) or ZnO/Si(111) substrates by a spin coating method and characterized with a scanningelectron microscopy (SEM/EDS), atomic force microscopy (AFM) and fluorescence spectroscopy. For Cu(II) layers the most intensive fluorescence bands due to intra-ligand transitions were observed between 462 and 503 nm. The fluorescence intensity of thin layers was corelated to the rotation speed. In the case of the [Cu(II)(en(4Him)₂)Cl₂](2a)/ZnO/Si and [Cu(en(dmbaH)₂)Cl₂](3a)/ZnO/Si layers the quenching of the emission band from ZnO at 440 nm (λex = 330 nm) associated with various intrinsic or extrinsic lattice defects was noted.

  9. Investigation of two o-hydroxy Schiff bases in terms of prototropy and radical scavenging activity

    Science.gov (United States)

    Albayrak Kaştaş, Çiğdem; Kaştaş, Gökhan; Güder, Aytaç; Gür, Mahmut; Muğlu, Halit; Büyükgüngör, Orhan

    2017-02-01

    Two Schiff bases, namely (E)-4,6-dibromo-3-methoxy-2-[(phenylimino)methyl]phenol (1) and (Z)-2,4-dibromo-6-[(4-buthylphenylamino)methylene]-5-methoxycyclohexa-2,4-dienone (2), have been investigated by considering solvent, substituent and temperature dependence of prototropy, and scavenging activities. Experimental (X-ray diffraction, UV-vis and NMR) and computational (DFT) techniques have been used to obtain key data on prototropy and other properties of interest. X-ray and UV-vis results underline the variability in the structural preferences of the compounds with respect to the phase and solvent media conditions. This kind of tautomeric behavior has been elaborated by 1H NMR and 13C NMR experiments performed at room and low temperatures. Radical scavenging properties of two compounds have been probed for their usage potentials as therapeutic agent and ingredient in medicinal and food industries, respectively. For this purpose, three different test methods (DPPH, ABTS•+ and DMPD•+) have been used. It has been found from in vivo and in vitro studies that the compound 2 could be interesting as an active component in pharmaceutical industry or as an additive in food industry when its antiradical activity is considered.

  10. A chromone Schiff-base as Al(III) selective fluorescent and colorimetric chemosensor

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Long; Qin, Jing-can; Li, Tian-rong; Wang, Bao-dui; Yang, Zheng-yin, E-mail: yangzy@lzu.edu.cn

    2014-11-15

    A novel and simple chromone Schiff-base receptor 7-methoxychromone-3-carbaldehyde-(indole-2-formyl) hydrazone (MCIH) was prepared. Among the various metal ions, only Al{sup 3+} induces the fluorescence enhancement and results in “OFF–ON” type sensing with excellent selectivity and high sensitivity in ethanol system. Upon binding of Al{sup 3+}, a significant fluorescence enhancement with an “OFF–ON” ratio over 500-fold was triggered and it features visible light excitation (423 nm) and emission (507 nm) profiles. However, other metal ions had no such significant effect on the fluorescence. Also, MCIH can severe as a highly selective chemodosimeter for Al{sup 3+} with “naked-eye” detection, which is easily observed from colorless to yellow–green. The detection limit of MCIH for Al{sup 3+} detection was as low as 5×10{sup −8} M level. - Highlights: • An easy-to-make colorimetric and fluorescent sensor for Al{sup 3+} was developed. • The sensor exhibits higher selectivity and sensitivity for Al{sup 3+} than other metal ions. • Al{sup 3+} resulted in an instant color change of MCIH from colorless to yellow–green. • The Al{sup 3+} detection limit reaching at 5×10{sup −8} M level in ethanol. • This sensor features visible light excitation (423 nm) and emission (507 nm) profiles.

  11. Photoisomerization action spectrum of retinal protonated Schiff base in the gas phase

    Energy Technology Data Exchange (ETDEWEB)

    Coughlan, N. J. A.; Catani, K. J.; Adamson, B. D.; Wille, U.; Bieske, E. J., E-mail: evanjb@unimelb.edu.au [School of Chemistry, The University of Melbourne, Victoria 3010 (Australia)

    2014-04-28

    The photophysical behaviour of the isolated retinal protonated n-butylamine Schiff base (RPSB) is investigated in the gas phase using a combination of ion mobility spectrometry and laser spectroscopy. The RPSB cations are introduced by electrospray ionisation into an ion mobility mass spectrometer where they are exposed to tunable laser radiation in the region of the S{sub 1} ← S{sub 0} transition (420–680 nm range). Four peaks are observed in the arrival time distribution of the RPSB ions. On the basis of predicted collision cross sections with nitrogen gas, the dominant peak is assigned to the all-trans isomer, whereas the subsidiary peaks are assigned to various single, double and triple cis geometric isomers. RPSB ions that absorb laser radiation undergo photoisomerization, leading to a detectable change in their drift speed. By monitoring the photoisomer signal as a function of laser wavelength an action spectrum, extending from 480 to 660 nm with a clear peak at 615 ± 5 nm, is obtained. The photoisomerization action spectrum is related to the absorption spectrum of isolated retinal RPSB molecules and should help benchmark future electronic structure calculations.

  12. Synthesis and antibacterial activity of some Schiff bases derived from 4-aminobenzoic acid

    Directory of Open Access Journals (Sweden)

    JIGNA PAREKH

    2005-10-01

    Full Text Available The following Schiff bases have been synthesized: (1 4-[(2-chlorobenzylidene amino]benzoic acid [JP1], (2 4-[(furan-2-ylmethyleneamino]benzoic acid [JP2], (3 4-[(3-phenylallylideneamino]benzoic acid [JP3], (4 4-[(2-hydroxybenzylidene amino]benzoic acid [JP4], (5 4-[(4-hydroxy-3-methoxybenzylideneamino]benzoic acid [JP5] and (6 4-[(3-nitrobenzylideneamino]benzoic acid [JP6]. They were screened as potential antibacterial agents against a number of medically important bacterial strains. The antibacterial activity was studied against A. faecalis ATCC 8750, E. aerogenes ATCC 13048, E. coli ATCC 25922, K. pneumoniae NCIM 2719, S. aureus ATCC 25923, P. vulgaris NCIM 8313, P. aeruginosa ATCC 27853 and S. typhimurium ATCC 23564. The antibacterial activity was evaluated using the Agar Ditch method. The solvents used were 1,4-dioxane and dimethyl sulfoxide. Different effects of the compounds were found in the bacterial strains investigated and the solvents used, suggesting, once again, that the antibacterial activity is dependent on the molecular structure of the compound, the solvent used and the bacterial strain under consideration. In the present work, 1,4-dioxane proved to be a good solvent in inhibiting the above stated bacterial strains.

  13. Synthesis and Anti-Bacterial Activities of Some Novel Schiff Bases Derived from Aminophenazone

    Directory of Open Access Journals (Sweden)

    Salman A Khan

    2010-10-01

    Full Text Available A series of 1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one-containing Schiff bases were synthesized, characterized and screened for their antibacterial activities. The structures of the synthesized compounds were established by spectroscopic (FT-IR, 1H-NMR, 13C-NMR, MS and elemental analyses. The anti-bacterial activities (with MIC values of compounds were evaluated. The anti-bacterial screening results reveal that among the six compounds screened, four compounds showed moderate to good anti-bacterial activity. Among the tested compounds, the most effective compounds against four bacterial strains, viz. Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Streptococcus pyogenes, are [(2-Chlorobenzylideneamino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one (4 and [(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yliminomethyl]benzonitrile (5 with MIC values of 6.25 μg/mL.

  14. Photoisomerization for a model protonated Schiff base in solution: Sloped/peaked conical intersection perspective

    Energy Technology Data Exchange (ETDEWEB)

    Malhado, Joao Pedro [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05314-970 Sao Paulo, SP (Brazil); Hynes, James T. [Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 (United States); Chemistry Department, Ecole Normale Superieure, UMR ENS-CNRS-UPMC 8640, 24 rue Lhomond, 75005 Paris (France)

    2012-12-14

    The topographical character of conical intersections (CIs)-either sloped or peaked-has played a fundamental and important role in the discussion of the efficiency of CIs as photochemical 'funnels.' Here this perspective is employed in connection with a recent study of a model protonated Schiff base (PSB) cis to trans photoisomerization in solution [Malhado et al., J. Phys. Chem. A 115, 3720 (2011)]. In that study, the calculated reduced photochemical quantum yield for the successful production of trans product versus cis reactant in acetonitrile solvent compared to water was interpreted in terms of a dynamical solvent effect related to the dominance, for the acetonitrile case, of S{sub 1} to S{sub 0} nonadiabatic transitions prior to the reaching the seam of CIs. The solvent influence on the quantum yield is here re-examined in the sloped/peaked CI topographical perspective via conversion of the model's two PSB internal coordinates and a nonequilibrium solvent coordinate into an effective branching space description, which is then used to re-analyze the generalized Langevin equation/surface hopping results. The present study supports the original interpretation and enriches it in terms of topographical detail.

  15. Crystal structures, spectroscopic and theoretical study of novel Schiff bases of 2-(methylthiomethyl)anilines.

    Science.gov (United States)

    Olalekan, Temitope E; Adejoro, Isaiah A; VanBrecht, Bernardus; Watkins, Gareth M

    2015-03-15

    New Schiff bases derived from p-methoxysalicylaldehyde and 2-(methylthiomethyl)anilines (substituted with methyl, methoxy, nitro) were synthesized and characterized by elemental analyses, FT-IR, NMR, electronic spectra and quantum chemical calculations. X-ray crystallography of two compounds showed the solid structures are stabilized by intramolecular and intermolecular H-bonds. The effect of OH⋯N interaction between the phenolic hydrogen and imine nitrogen on the proton and carbon NMR shifts, and the role of CH⋯O and CH⋯S contacts are discussed. The bond lengths and angles, (1)H and (13)C NMR data, E(LUMO-HOMO), dipole moments and polarizability of the compounds were predicted by density functional theory, DFT (B3LYP/6-31G∗∗) method. The experimental geometric parameters and the NMR shifts were compared with the calculated values, which gave good correlations. The electronic effects of aryl ring substituents (methyl, methoxy and nitro) on the properties of the resulting compounds, such as the color, NMR shifts, electronic spectra and the calculated energy band gaps, dipole moments and polarizability are discussed. Increase in electron density shifted the phenolic proton resonance to lower fields. The methoxy-substituted compound has a small dipole moment and subsequent large polarizability value. Highest polarity was indicated by the nitro compound which also showed high polarizability due to its larger size. The energy gaps obtained from E(LUMO-HOMO) calculations suggest these compounds may have applications as organic semiconducting materials.

  16. Synthesis of Phthalyl Substituted Imidazolones and Schiff Bases as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Pramilla Sah

    2011-01-01

    Full Text Available A new series of phthalyl substituted imidazolones (4a–g and Schiff bases (5a–d were synthesized from 2-methyl-(m-nitro-1,3-dioxo-1,3-dihydro-(2H-isoindole-2-yl-5-amino-1,3,4-thiadiazole (3a–b. Compounds (3a–b were prepared by cyclisation of 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H-isoindole-2-ylmethyl ethanoate (2 with thiosemicarbazide. 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H-isoindole-2-ylethanoic acid (1 in presence of thionyl chloride and methanol gave the ester (2 while compound (1 was synthesized by aminolysis of phthalic anhydride with glycine. The compounds were characterized by spectral techniques of IR, 1H NMR, Mass and elemental analysis. All the synthesized compounds (4a–g and (5a–d were screened for their antibacterial activity against the pathogenic strains E. coli, P. aureus, C. freundii while antifungal activity was evaluated against A. niger, A. flavus, Penicillium sp. and C. albicans.

  17. Photocytotoxic ternary copper(II) complexes of histamine Schiff base and pyridyl ligands

    Indian Academy of Sciences (India)

    Samya Banerjee; Akanksha Dixit; K Sesha Maheswaramma; Basudev Maity; Sanjoy Mukherjee; Arun Kumar; Anjali A Karande; Akhil R Chakravarty

    2016-02-01

    Ternary copper(II) complexes of salicylaldehyde-histamine Schiff base (HL) and pyridyl ligands, viz. [Cu(bpy)(L)](ClO4) (1) and [Cu(dppz)(L)](ClO4) (2), where bpy is 2,2′-bipyridine (in 1) and dppz is dipyrido[3,2-a:2′,3′-c]phenazine (in 2), were synthesized, characterized and their DNA binding, photo-activated DNA cleavage activity and photocytotoxicity studied. The 1:1 electrolytic one-electron paramagnetic complexes showed a d-d band near 670 nm in aqueous DMF (1:1 v/v). The crystal structure of complex 1 showed the metal in CuN4O distorted square-pyramidal geometry. Complex 2 intercalatively binds to calf-thymus (ct) DNA with a binding constant (b) of ∼105 M−1. It exhibited moderate chemical nuclease activity but excellent DNA photocleavage activity in red light of 647 nm forming $^{\\bullet}\\text{OH}$ radicals. It showed remarkable photocytotoxicity in human cervical cancer cells (HeLa) giving IC50 of 1.6 M in visible light (400-700 nm) with low dark toxicity. The photo-induced cell death is via generation of oxidative stress by reactive oxygen species.

  18. Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2014-01-01

    Full Text Available The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidene hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization (PD and electrochemical frequently modulation (EFM in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM. The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidenehydrazinecarbothioamide was also verified by scanning electron microscope (SEM.

  19. Synthesis, Characterization, Fluorescence, Photocatalytic and Antibacterial Activity of CdS Nanoparticles Using Schiff Base.

    Science.gov (United States)

    Ayodhya, Dasari; Venkatesham, M; Kumari, A Santoshi; Reddy, G Bhagavanth; Ramakrishna, D; Veerabhadram, G

    2015-09-01

    Cadmium sulfide nanoparticles (CdS NPs) were successfully prepared using sonochemical method by employing Schiff-base, (2-[(4-methoxy-phenylimino)-methyl]-4-nitro phenol) as a complexing agent. Here, SB is used as a ligand to control the morphology of NPs. XRD patterns and TEM images show that the synthesized CdS NPs have cubic structures with a diameter of about 2-10 nm. The formation of CdS NPs and their optical, structure, thermal and morphologies were studied by means of UV-vis DRS, fluorescence, FTIR, zeta potential, XRD, SEM and TEM. The interactions between CdS NPs and SB were investigated in an aqueous solution using fluorescence spectroscopy. The fluorescence quenching studies suggest that SB quenches the fluorescence of CdS NPs effectively. The degradation kinetics of methyl red (MR) by the photocatalyst was followed by Langmuir-Hinshelwood model. The results revealed that photocatalytic degradation of MR by SB capped CdS NPs could be considered as a practical and reliable technique for the removal of environmental pollutants. The antibacterial activity of samples was evaluated against E. coli, S. aureus and P. aeruginosa and the results were compared. SB and SB capped CdS NPs could be a potential antibacterial compounds after further investigation.

  20. Preparation and biodistribution of copper-67 complexes with tetradentate Schiff-base ligands.

    Science.gov (United States)

    John, E K; Bott, A J; Green, M A

    1994-04-01

    Uncharged, lipophilic, low molecular weight copper complexes labeled with generator-produced copper-62 are of interest as potential radiopharmaceutials for imaging the brain with positron emission tomography (PET). We report here the synthesis and biodistribution of a series of [67Cu]copper(II) complexes with tetradentate N2O2(2-)Schiff-base ligands. The compounds studied varied in lipophilicity from log P = 1.7 to log P = 3.6, where P is the octanol/water partition coefficient. In rat biodistribution studies the tracers were generally found to penetrate the blood-brain barrier following intravenous injection, but some far better than others. For closely related compounds brain uptake at 1 min postinjection increased with increasing lipophilicity, although log P was clearly not the sole determinant of high brain uptake. Substantial variations were also observed in the rate at which these various compounds are cleared from brain, with a few exhibiting the prolonged cerebral retention of tracer that would be desired for imaging with 62Cu and PET.

  1. 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.

  2. Synthesis, Spectroscopic Characterization and Biological Activities of Transition Metal Complexes Derived from a Tridentate Schiff Base

    Directory of Open Access Journals (Sweden)

    J. Senthil Kumaran

    2013-01-01

    Full Text Available A new series of Cu (II, Ni (II, Co (II and Zn (II complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis, 1H-NMR, 13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2 type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–H⋯O and C–H⋯N hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such as Bacillus subtilis, Staphylococcus aureus, Proteus vulgaris and fungal species such as Candida albicans by the well-diffusion method.

  3. Synthesis, structure and antidiabetic activity of chromium(III) complexes of metformin Schiff-bases

    Science.gov (United States)

    Mahmoud, M. A.; Zaitone, S. A.; Ammar, A. M.; Sallam, S. A.

    2016-03-01

    A series of Cr3+ complexes with Schiff-bases of metformin with each of salicylaldehyde (HL1); 2,3-dihydroxybenzaldehyde (H2L2); 2,4-dihydroxybenzaldehyde (H2L3); 2,5-dihydroxybenzaldehyde (H2L4); 3,4-dihydroxybenzaldehyde (H2L5) and 2-hydroxynaphthaldehyde (HL6) were synthesized by template reaction. The new compounds were characterized through elemental analysis, conductivity and magnetic moment measurements, IR, UV-Vis., NMR and mass spectroscopy. The complexes have octahedral structure with μ value of hexacoordinated chromium ion. TGA, DTG and DTA analysis confirm the proposed stereochemistry and a mechanism for thermal decomposition was proposed. Thermodynamic parameters are calculated for the second and third decomposition steps. [CrL4Cl(H2O)2].3H2O and [CrL5Cl(H2O)2].2½H2O were able to produce significant decreases in the blood glucose level.

  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. Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

    Directory of Open Access Journals (Sweden)

    Poomalai Jayaseelan

    2016-09-01

    Full Text Available A novel Schiff base ligand has been prepared by the condensation between butanedione monoxime with 3,3′-diaminobenzidine. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, 1H NMR, conductivity measurements, EPR and magnetic studies. The molar conductance studies of Cu(II, Ni(II, Co(II and Mn(II complexes showed non-electrolyte in nature. The ligand acts as dibasic with two N4-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and oxyimino nitrogen atoms. The binuclear metal complexes exhibit octahedral arrangements. DNA binding properties of copper(II metal complex have been investigated by electronic absorption spectroscopy. Results suggest that the copper(II complex bind to DNA via an intercalation binding mode. The nucleolytic cleavage activities of the ligand and their complexes were assayed on CT-DNA using gel electrophoresis in the presence and absence of H2O2. The ligand showed increased nuclease activity when administered as copper complex and copper(II complex behave as efficient chemical nucleases with hydrogen peroxide activation. The anti-microbial activities and thermal studies have also been studied. In anti-microbial activity all complexes showed good anti-microbial activity higher than ligand against gram positive, gram negative bacteria and fungi.

  6. Synthesis, Characterization, and Magnetic and Thermal Studies on Some Metal(II Thiophenyl Schiff Base Complexes

    Directory of Open Access Journals (Sweden)

    Aderoju Amoke Osowole

    2011-01-01

    Full Text Available 4-(Thiophen-3-yl-aniline undergoes condensation with o-vanillin to form an ONS donor Schiff base, 2-methoxy-6-[(4-thiophene-3-yl-phenylimino-methyl]-phenol, which forms complexes of the type [ML2]xH2O (where M = Mn, Co, Ni, Cu, Zn, Pd. These complexes are characterized by elemental analysis, 1H nmr, electronic, mass, and IR spectroscopies and conductance measurements. The electronic, IR and CHN data are supportive of a 4-coordinate tetrahedral geometry for Mn(II, Co(II, Ni(II, and Zn(II complexes and square-planar geometry for Cu(II and Pd(II complexes, with the chromophores N2O2. The magnetic data reveals that the complexes are magnetically dilute and mononuclear with exception of the Cu(II complex, which exhibits some anti-ferromagnetisms. The complexes are air-stable solids, and none is an electrolyte in nitro methane.

  7. Two new heterodinuclear Schiff base complexes: synthesis, crystal structure and thermal studies.

    Science.gov (United States)

    Yardan, Alper; Hopa, Cigdem; Yahsi, Yasemin; Karahan, Ahmet; Kara, Hulya; Kurtaran, Raif

    2015-02-25

    Two new heterodinuclear Schiff base complexes, [Hg(L)NiCl2(DMF)2] 1, and [Zn(L)NiCl2(DMF)2] 2, where H2L = N,N'-bis(salicylidene)-1,3-diaminopropane and DMF = dimethylformamide have been synthesized and characterized using elemental analysis, IR spectroscopy, thermal analysis and X-ray diffraction. Structural studies on 1 and 2 reveal the presence of a heterodinuclear [Ni(II)Hg(II)] unit and [Zn(II)Ni(II)] in which the central metal ions are connected to each other by two phenolate oxygen bridges. For complex 1 the Ni(II) ion adopts an elongated octahedral geometry (NiN2O4) while the Hg(II) ion assumes a distorted tetrahedral arrangement (HgO2Cl2) whereas for complex 2 the Zn(II) ion adopts an elongated octahedral geometry (ZnN2O4) while the Ni(II) ion assumes a distorted tetrahedral arrangement (NiO2Cl2). There are intermolecular C-H···Cl-M interactions among the dinuclear complexes which are interconnected for 1 and 2. These intermolecular interactions result in the formation of a three dimensional structure for 1 and one dimensional zig-zag chains for 2.

  8. 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.

  9. Investigation of Antibacterial Activity of Two Kinds of Novel Schiff Bases on Escherichia coli by Microcalorimetry

    Institute of Scientific and Technical Information of China (English)

    ZHU Jun-Cheng; LIU Yi; WONG Wai-Kwok; ZHOU Bo; YIN Jun

    2006-01-01

    The microcalorimetric method was used to study the antibacterial activity of two newly synthesized Schiff base compounds (H2L3' and H2L3) on Escherichia coli, trying to obtain the action on both of multiplying bacteria and non-multiplying bacteria at one experiment. The metabolic power-time curves of the bacteria treated with the compounds were obtained, and the thermokinetic parameters were analyzed, from which the antibacterial activities of these compounds were evaluated. The results showed that both of the two compounds have good activity on aerobic multiplying metabolism of E. coli, with the value of IC50 75.8 and 168.8 mg/L respectively, but have not effective action on fermentation metabolism of E. coli. The action of the compounds on the non-multiplying metabolism was investigated by taking the heat output of E. coli in the stationary phase as the guideline of the activity. The value of MSC50 (minimum stationary-cidal concentration 50) of them is 118 and 187.5 mg/L, respectively. So, H2L3' has stronger antibacterial action on E. coli than H2L3 either for multiplying bacteria or non-multiplying bacteria, and their activity on the aerobic multiplying bacteria of E. coli is mainly shown. It does strongly suggest that the calorimetric method should play an important role in the fight against the drug-resistant bacteria.

  10. Study of third-order nonlinear susceptibility of polySchiff base containing triphenylamine

    Institute of Scientific and Technical Information of China (English)

    NIU HaiJun; WANG Wen; HUANG YuDong; ZHANG YunDong; ZHANG YunJun; BAI XuDuo; LIU Yuan

    2007-01-01

    PolySchiff base containing triphenylamine has been synthesized by polycondensation and characterized by FT-IR, NMR, UV-visible spectrometer. Measurements of the third-order optical nonlinear susceptibility x(3)by Z-scan technique have shown that the large nonlinearity is dominated by the two-photon absorption in PSB. The sign and size of real part Rex(3), nonlinear refractive index n2 have been measured with the condition of 532 nm, 8 ns-duration pulses to be -1.23x10-10esu, -3.06x10-12esu;nonlinear absorption index β and size of image part Imx(3) to be 3.63x10-10 m/W, 1.15x10-11 esu, respectively, so the third-order nonlinear susceptibility x(3) is 1.19x10-11 esu. The value is larger than other polymers reported. PSB is self-focusing material and has potential application in nonlinear optic field.

  11. Study of third-order nonlinear susceptibility of polySchiff base containing triphenylamine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    PolySchiff base containing triphenylamine has been synthesized by polycondensation and character-ized by FT-IR,NMR,UV-visible spectrometer. Measurements of the third-order optical nonlinear sus-ceptibility χ(3) by Z-scan technique have shown that the large nonlinearity is dominated by the two-photon absorption in PSB. The sign and size of real part Reχ(3) ,nonlinear refractive index n2 have been measured with the condition of 532 nm,8 ns-duration pulses to be -1.23×10-10 esu,-3.06×10-12 esu;nonlinear absorption index β and size of image part Imχ(3) to be 3.63×10-10 m/W,1.15×10-11 esu,respec-tively,so the third-order nonlinear susceptibility χ(3) is 1.19×10-11 esu. The value is larger than other polymers reported. PSB is self-focusing material and has potential application in nonlinear optic field.

  12. Crystal structures, spectroscopic and theoretical study of novel Schiff bases of 2-(methylthiomethyl)anilines

    Science.gov (United States)

    Olalekan, Temitope E.; Adejoro, Isaiah A.; VanBrecht, Bernardus; Watkins, Gareth M.

    2015-03-01

    New Schiff bases derived from p-methoxysalicylaldehyde and 2-(methylthiomethyl)anilines (substituted with methyl, methoxy, nitro) were synthesized and characterized by elemental analyses, FT-IR, NMR, electronic spectra and quantum chemical calculations. X-ray crystallography of two compounds showed the solid structures are stabilized by intramolecular and intermolecular H-bonds. The effect of OH⋯N interaction between the phenolic hydrogen and imine nitrogen on the proton and carbon NMR shifts, and the role of CH⋯O and CH⋯S contacts are discussed. The bond lengths and angles, 1H and 13C NMR data, ELUMO-HOMO, dipole moments and polarizability of the compounds were predicted by density functional theory, DFT (B3LYP/6-31G∗∗) method. The experimental geometric parameters and the NMR shifts were compared with the calculated values, which gave good correlations. The electronic effects of aryl ring substituents (methyl, methoxy and nitro) on the properties of the resulting compounds, such as the color, NMR shifts, electronic spectra and the calculated energy band gaps, dipole moments and polarizability are discussed. Increase in electron density shifted the phenolic proton resonance to lower fields. The methoxy-substituted compound has a small dipole moment and subsequent large polarizability value. Highest polarity was indicated by the nitro compound which also showed high polarizability due to its larger size. The energy gaps obtained from ELUMO-HOMO calculations suggest these compounds may have applications as organic semiconducting materials.

  13. Substituent effects on anion sensing of salicylidene Schiff base derivatives: Tuning sensitivity and selectivity.

    Science.gov (United States)

    Zang, Libin; Jiang, Shimei

    2015-11-05

    A series of colorimetric anion sensors using the salicylidene Schiff bases with different substituents, including electron donating group (tert-butyl, in sensor 2), conjugated group (naphthyl, in sensor 3) and electron withdrawing group (chlorine, in sensor 4), respectively, have been developed. The substituents can not only impact chromogenic signal output, but also tune the sensitivity and selectivity of the anion sensing by their specific electron push-pull features. In particular, both 1 (without substituent) and 2 show high selectivity for F(-) over Cl(-), Br(-), I(-), AcO(-) and H2PO4(-), but the sensitivity of 2 is poorer than 1 due to the effect of electron donating groups. Sensor 3 exhibits higher sensitivity for F(-) than 1, but it is disturbed by the weak response to AcO(-) and H2PO4(-). Sensor 4 has the highest sensitivity for F(-), but shows the significant response to AcO(-) and H2PO4(-), which also decreases the selectivity for F(-). Finally, analytical applications of 1 for the detection of F(-) in aqueous medium and toothpaste have been studied.

  14. Coordination geometry around copper in a Schiff-base trinuclear copper complex using EXAFS spectroscopy

    Science.gov (United States)

    Gaur, Abhijeet; Shrivastava, B. D.; Gaur, D. C.; Prasad, J.; Srivastava, K.; Jha, S. N.; Bhattacharyya, D.; Poswal, A.

    2012-05-01

    In the present investigation, we have studied extended X-ray absorption fine structure (EXAFS) spectra of a trinuclear Schiff-base copper complex tetraaqua-di-μ3-(N-salicylidene-DL-glutamato)-tricopper(II)heptahydrate, [Cu3(C12H10NO5)2 (H2O)4]. 7H2O, in which three metal sites are present. One metal site is square-pyramidal (4+1) and other two similar metal sites are tetragonally distorted octahedral (4+2). EXAFS has been recorded at the K-edge of copper in the complex at the dispersive EXAFS beamline at 2 GeV Indus-2 synchrotron source at RRCAT, Indore, India. The analysis of EXAFS spectra of multinuclear metal complexes pose some problems due to the presence of many absorbing atoms, even when the absorbing atoms may be of the same element. Hence, using the available crystal structure of the complex, theoretical models have been generated for the different copper sites separately, which are then fitted to the experimental EXAFS data. The two coordination geometries around the copper sites have been determined. The contributions of the different copper sites to the experimental spectrum have been estimated. The structural parameters, which include bond-lengths, coordination numbers and thermal disorders, for the two types of copper sites have been reported. Further, copper has been found to be in +2 oxidation state at these metal sites.

  15. Syntheses, characterization, biological activities and photophysical properties of lanthanides complexes with a tetradentate Schiff base ligand

    Science.gov (United States)

    Taha, Ziyad A.; Ajlouni, Abdulaziz M.; Al Momani, Waleed; Al-Ghzawi, Abeer A.

    2011-10-01

    A tetradentate Schiff base ligand L (N,N'-bis(1-naphthaldimine)-o-phenylenediamine) was prepared from the condensation of 2-hydroxy-1-naphthaldehyde with o-phenylenediamine in a molar ratio of 2:1. New eight lanthanide metal complexes [Ln L(NO 3) 2(H 2O) x](NO 3) {Ln(III) = Nd, Dy, Sm, Pr, Gd, Tb, La and Er, x = 0 for Nd, Sm, 1 for La, Gd, Pr, Nd, Dy, and 2 for Tb} were prepared. The characterization and nature of bonding of these complexes were elucidated by elemental analysis, spectral analysis ( 1H NMR, FT-IR, UV-vis), molar conductivity measurements, luminescence spectra and thermogravimetric studies. Analytical and spectral data revealed that the ligand L coordinates to the central Ln(III) ions by its two imine nitrogen atoms and two phenolic oxygen atoms with 1:1 stoichiometry. Under the excitation with 329 nm at room temperature, Tb and Dy complexes exhibited characteristic luminescence of the central metal ions attributed to efficient energy transfer from the ligand to the metal center. Most of Ln(III) complexes found to exhibit antibacterial activities against a number of pathogenic bacteria. We found that the antioxident activity of Ln(III) complexes on DPPH rad is concentration dependent and higher than that of the free ligand L.

  16. Irreversible covalent modification of type I dehydroquinase with a stable Schiff base.

    Science.gov (United States)

    Tizón, Lorena; Maneiro, María; Peón, Antonio; Otero, José M; Lence, Emilio; Poza, Sergio; van Raaij, Mark J; Thompson, Paul; Hawkins, Alastair R; González-Bello, Concepción

    2015-01-21

    The irreversible inhibition of type I dehydroquinase (DHQ1), the third enzyme of the shikimic acid pathway, is investigated by structural, biochemical and computational studies. Two epoxides, which are mimetics of the natural substrate, were designed as irreversible inhibitors of the DHQ1 enzyme and to study the binding requirements of the linkage to the enzyme. The epoxide with the S configuration caused the covalent modification of the protein whereas no reaction was obtained with its epimer. The first crystal structure of DHQ1 from Salmonella typhi covalently modified by the S epoxide, which is reported at 1.4 Å, revealed that the modified ligand is surprisingly covalently attached to the essential Lys170 by the formation of a stable Schiff base. The experimental and molecular dynamics simulation studies reported here highlight the huge importance of the conformation of the C3 carbon of the ligand for covalent linkage to this type of aldolase I enzyme, revealed the key role played by the essential His143 as a Lewis acid in this process and show the need for a neatly closed active site for catalysis.

  17. Schiff base switch II precedes the retinal thermal isomerization in the photocycle of bacteriorhodopsin.

    Directory of Open Access Journals (Sweden)

    Ting Wang

    Full Text Available In bacteriorhodopsin, the order of molecular events that control the cytoplasmic or extracellular accessibility of the Schiff bases (SB are not well understood. We use molecular dynamics simulations to study a process involved in the second accessibility switch of SB that occurs after its reprotonation in the N intermediate of the photocycle. We find that once protonated, the SB C15 = NZ bond switches from a cytoplasmic facing (13-cis, 15-anti configuration to an extracellular facing (13-cis, 15-syn configuration on the pico to nanosecond timescale. Significantly, rotation about the retinal's C13 = C14 double bond is not observed. The dynamics of the isomeric state transitions of the protonated SB are strongly influenced by the surrounding charges and dielectric effects of other buried ions, particularly D96 and D212. Our simulations indicate that the thermal isomerization of retinal from 13-cis back to all-trans likely occurs independently from and after the SB C15 = NZ rotation in the N-to-O transition.

  18. Synthesis, anticancer activity and molecular docking study of Schiff base complexes containing thiazole moiety

    Directory of Open Access Journals (Sweden)

    Mokhles M. Abd-Elzaher

    2016-03-01

    Full Text Available A Schiff base ligand 1 was prepared from condensation of salicyaldehyde with 2-amino-4-phenyl-5-methyl thiazole. The ligand forms complexes with CoII, NiII, CuII, and ZnII in good yield. The synthesized compounds were characterized by elemental analysis, magnetic susceptibility, molar conductance, infrared spectra, 1H and 13C NMR, mass, electronic absorption and ESR spectroscopy. The anticancer activity of the synthesized compounds was studied against different human tumor cell lines: breast cancer MCF-7, liver cancer HepG2, lung carcinoma A549 and colorectal cancer HCT116 in comparison with the activity of doxorubicin as a reference drug. The study showed that ZnII complex showed potent inhibition against human TRK in the four cell lines (HepG2, MCF7, A549, HCT116 by the ratio 80, 70, 61 and 64% respectively as compared to the inhibition in the untreated cells. Moreover, the molecular docking into TRK (PDB: 1t46 was done for the optimization of the aforementioned compounds as potential TRK inhibitors.

  19. Novel Schiff-base-derived FabH inhibitors with dioxygenated rings as antibiotic agents.

    Science.gov (United States)

    Zhou, Yang; Du, Qian-Ru; Sun, Jian; Li, Jing-Ran; Fang, Fei; Li, Dong-Dong; Qian, Yong; Gong, Hai-Bin; Zhao, Jing; Zhu, Hai-Liang

    2013-03-01

    Fatty acid biosynthesis plays a vital role in bacterial survival and several key enzymes involved in this biosynthetic pathway have been identified as attractive targets for the development of new antibacterial agents. Of these promising targets, β-ketoacyl-acyl carrier protein (ACP) synthase III (FabH) is the most attractive target that could trigger the initiation of fatty acid biosynthesis and is highly conserved among Gram-positive and -negative bacteria. Designing small molecules with FabH inhibitory activity displays great significance for developing antibiotic agents, which should be highly selective, nontoxic and broad-spectrum. In this manuscript, a series of novel Schiff base compounds were designed and synthesized, and their biological activities were evaluated as potential inhibitors. Among these 21 new compounds, (E)-N-((3,4-dihydro-2H-benzo[b][1,4]dioxepin-7-yl)methylene)hexadecan-1-amine (10) showed the most potent antibacterial activity with a MIC value of 3.89-7.81 μM(-1) against the tested bacterial strains and exhibited the most potent E. coli FabH inhibitory activity with an IC(50) value of 1.6 μM. Docking simulation was performed to position compound 10 into the E. coli FabH active site to determine the probable binding conformation.

  20. Synthesis, Catalysis of Rare Earth Complexes with Aliphatic Noncyclic Polyether-Amino Acid Schiff Base

    Institute of Scientific and Technical Information of China (English)

    Li Ning; Yao Kemin; Shen Lianfang

    2005-01-01

    Eleven new rare earth complexes with aliphatic Schiff base, condensed from diglycol aldehyde and bis-arginine, were synthesized and characterized. They are confirmed as Ln(H2DAAR)(NO3)3·7H2O (Ln=La, Pr, Nd, Gd), Ln3(H2DAAR)2(NO3)9·5H2O (Ln=Dy, Y) and Ln2(H2DAAR)(NO3)6·3H2O (Ln=La, Nd, Sm, Gd), Ln3(DAAR)(NO3)7·4H2O (Ln=Dy, Yb, Y) respectively under different molar ratios of metal to ligand (DAAR=diglycol aldehyde bis-arginine). The present paper deals with a synthetic method and catalytic properties of obtained complexes. The result shows that proper pH value is important for synthesis of the complexes and compositions of the lighter and the heavier rare earth complexes are different under the same reaction condition. Some new complexes obtained have proved their catalytic activity and 80% conversion with the viscosity-average molecular weight 230,000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst.

  1. Novel Organotin(IV) Schiff Base Complexes with Histidine Derivatives: Synthesis, Characterization, and Biological Activity

    Science.gov (United States)

    Garza-Ortiz, Ariadna; Camacho-Camacho, Carlos; Sainz-Espuñes, Teresita; Rojas-Oviedo, Irma; Gutiérrez-Lucas, Luis Raúl; Gutierrez Carrillo, Atilano; Vera Ramirez, Marco A.

    2013-01-01

    Five novel tin Schiff base complexes with histidine analogues (derived from the condensation reaction between L-histidine and 3,5-di-tert-butyl-2-hydroxybenzaldehyde) have been synthesized and characterized. Characterization has been completed by IR and high-resolution mass spectroscopy, 1D and 2D solution NMR (1H, 13C  and 119Sn), as well as solid state 119Sn NMR. The spectroscopic evidence shows two types of structures: a trigonal bipyramidal stereochemistry with the tin atom coordinated to five donating atoms (two oxygen atoms, one nitrogen atom, and two carbon atoms belonging to the alkyl moieties), where one molecule of ligand is coordinated in a three dentate fashion. The second structure is spectroscopically described as a tetrahedral tin complex with four donating atoms (one oxygen atom coordinated to the metal and three carbon atoms belonging to the alkyl or aryl substituents), with one molecule of ligand attached. The antimicrobial activity of the tin compounds has been tested against the growth of bacteria in vitro to assess their bactericidal properties. While pentacoordinated compounds 1, 2, and 3 are described as moderate effective to noneffective drugs against both Gram-positive and Gram-negative bacteria, tetracoordinated tin(IV) compounds 4 and 5 are considered as moderate effective and most effective compounds, respectively, against the methicillin-resistant Staphylococcus aureus strains (Gram-positive). PMID:23864839

  2. Novel Organotin(IV Schiff Base Complexes with Histidine Derivatives: Synthesis, Characterization, and Biological Activity

    Directory of Open Access Journals (Sweden)

    Ariadna Garza-Ortiz

    2013-01-01

    Full Text Available Five novel tin Schiff base complexes with histidine analogues (derived from the condensation reaction between L-histidine and 3,5-di-tert-butyl-2-hydroxybenzaldehyde have been synthesized and characterized. Characterization has been completed by IR and high-resolution mass spectroscopy, 1D and 2D solution NMR (1H, 13C  and 119Sn, as well as solid state 119Sn NMR. The spectroscopic evidence shows two types of structures: a trigonal bipyramidal stereochemistry with the tin atom coordinated to five donating atoms (two oxygen atoms, one nitrogen atom, and two carbon atoms belonging to the alkyl moieties, where one molecule of ligand is coordinated in a three dentate fashion. The second structure is spectroscopically described as a tetrahedral tin complex with four donating atoms (one oxygen atom coordinated to the metal and three carbon atoms belonging to the alkyl or aryl substituents, with one molecule of ligand attached. The antimicrobial activity of the tin compounds has been tested against the growth of bacteria in vitro to assess their bactericidal properties. While pentacoordinated compounds 1, 2, and 3 are described as moderate effective to noneffective drugs against both Gram-positive and Gram-negative bacteria, tetracoordinated tin(IV compounds 4 and 5 are considered as moderate effective and most effective compounds, respectively, against the methicillin-resistant Staphylococcus aureus strains (Gram-positive.

  3. PREPARATION AND CHARACTERIZATION OF SCHIFF BASE POLYMERS DERIVED FROM 4,4'-METHYLENEBIS(CINNAMALDEHYDE)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    New Schiff base polymers poly[4,4'-methylenebis(cinnamaldehyde)ethylenediimine] (PMBCen), poly[4,4'-methylenebis(cinnamaldehyde)1,2-propylenediimine] (PMBCPn), poly[4,4'-methylenebis(cinnamaldehyde)1,3-propylenediimine] (PMBCPR), poly[4,4'-methylenebis(cinnamaldehyde) 1,2-phenylenediimine] (PMBCPh), poly[4,4'-methylenebis(cinnamaldehyde)meso-stilbenediimine] (PMBCS), poly[4,4'-methylenebis(cinnamaldehyde)urea] (PMBCUR), poly[4,4'-methylenebis(cinnamaldehyde)semicarbazone] (PMBCSc), poly[4,4'-methylenebis(cinnamaldehyde)thiosemicarbazone](PMBCTSc) and poly[4,4'-methylenebis(cinnamaldehyde)hydrazone] (PMBCH) were formed by polycondensation of 4,4'-methylenebis(cinnamaldehyde) with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and 1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.

  4. Manganese–Schiff base complex immobilized silica materials for electrocatalytic oxygen reduction

    Indian Academy of Sciences (India)

    Vellaichamy Ganesan; Manas Pal; Manoj Tiwari

    2014-05-01

    Curtailment of platinum catalysts loading in fuel cell is a recent central issue. As substitutes, these days several organic metal chelate compounds having featured moieties of M–N4 or M–N2O2 (M = transition metal ion) are being used as cathode catalysts in fuel cells. Here, in this study, we report in detail the electrocatalytic activity of manganese–Schiff base complexes for oxygen reduction reaction in 0.05 M HClO4 at room temperature. Actually, [Mn(salen)]+: [N,N′-bis(salicylaldehyde) ethylenediimino manganese(III)]+ and [Mn(salophen)]+: [N,N′-bis(salicylaldehyde)-1,2-phenylenediimino manganese(III)]+ were introduced into/onto the MCM-41 type silica spheres and used for the electrocatalytic reduction of oxygen. Synthesized materials were characterized by UV–Vis, FT–IR and electrochemical techniques. Significant low overpotential for oxygen reduction in 0.05 M HClO4 on [Mn(salen)]+- and [Mn(salophen)]+-incorporated silica-modified glassy carbon electrodes was observed.

  5. Structural changes in a Schiff base molecular assembly initiated by scanning tunneling microscopy tip

    Science.gov (United States)

    Tomak, A.; Bacaksiz, C.; Mendirek, G.; Sahin, H.; Hur, D.; Görgün, K.; Senger, R. T.; Birer, Ö.; Peeters, F. M.; Zareie, H. M.

    2016-08-01

    We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines.

  6. Syntheses and molecular structures of novel Ru(II) complexes with bidentate benzimidazole based ligands and their catalytic efficiency for oxidation of benzyl alcohol

    Science.gov (United States)

    Dayan, Osman; Tercan, Melek; Özdemir, Namık

    2016-11-01

    Five bidentate ligands derived from quinoline-2-carboxylic acid, i.e. 2-(1H-benzimidazol-2-yl)quinoline (L1), 2-(1-benzyl-1H-benzimidazol-2-yl)quinoline (L2), 2-[1-(2,3,5,6-tetramethylbenzyl)-1H-benzimidazol-2-yl]quinoline (L3), 2-[1-(4-chlorobenzyl)-1H-benzimidazol-2-yl]quinoline (L4), and 2-[1-(4-methylbenzyl)-1H-benzimidazol-2-yl]quinoline (L5) were synthesized. Treatment of L1-5 with [RuCl2(p-cymene)]2 and KPF6 afforded six-coordinate piano-stool Ru(II) complexes, namely, [RuCl(L1)(p-cymene)]PF6 (C1), [RuCl(L2)(p-cymene)]PF6 (C2), [RuCl(L3)(p-cymene)]PF6 (C3), [RuCl(L4)(p-cymene)]PF6 (C4), and [RuCl(L5)(p-cymene)]PF6 (C5). Synthesized compounds were characterized with different techniques such as 1H and 13C NMR, FT-IR, and UV-vis spectroscopy. The solid state structure of L1 and C3 was confirmed by single-crystal X-ray diffraction analysis. The single crystal structure of C3 verified coordination of L3 to the Ru(II) center. The Ru(II) center has a pseudo-octahedral three legged piano stool geometry. The complexes C1-5 were tested as catalysts for the catalytic oxidation of benzyl alcohol to benzaldehyde in the presence of periodic acid (H5IO6) (Substrate/Catalyst/Oxidant = 1/0.01/0.5). The best result was obtained with C2 (3 h→90%).

  7. Synthetic Strategies and Applications of Macrocycle Molecules Based on Schiff-Base Reaction%基于Schiff-Base反应的成环策略及应用

    Institute of Scientific and Technical Information of China (English)

    张家强; 贾春阳

    2010-01-01

    基于Schiff-base反应的大环化合物是近些年来超分子领域研究的热点. 这些大环化合物不但在传感器、功能材料等领域发挥着重要的作用, 而且在自组装研究领域具有重要的意义. 从模板法和非模板法两方面分析了一些具有代表性Schiff-base大环的合成, 发现, 不但具有合适半径和构型的离子可以作为成环反应的模板, 而且强烈的分子内氢键也能有效地驱动成环反应. 同时, 对于该类大环分子合成所面临的问题及发展方向进行了评述和预测.

  8. Formation of Schiff bases of O-phosphorylethanolamine and O-phospho-D,L-serine with pyridoxal 5'-phosphate. experimental and theoretical studies.

    Science.gov (United States)

    Vilanova, Bartolomé; Gallardo, Jessica M; Caldés, Catalina; Adrover, Miquel; Ortega-Castro, Joaquín; Muñoz, Francisco; Donoso, Josefa

    2012-03-01

    Pyridoxal 5'-phosphate (PLP) is a B(6) vitamer acting as an enzyme cofactor in various reactions of aminoacid metabolism and inhibiting glycation of biomolecules. Nonenzymatic glycation of aminophospholipids alters the stability of lipid bilayers and cell function as a result. Similarly to protein glycation, aminophospholipid glycation initially involves the formation of a Schiff base. In this work, we studied the formation of Schiff bases between PLP and two compounds mimicking the polar head of natural aminophospholipids, namely: O-phosphorylethanolamine and O-phospho-D,L-serine. Based on the results, the pH-dependence of the microscopic constants of the two PLP-aminophosphate systems studied is identical with that for PLP-aminoacid systems. However, the rate and equilibrium formation constants for the Schiff bases of the aminophosphates are low relative to those for the aminoacids. A theoretical study by density functional theory of the formation mechanism for the Schiff bases of PLP with the two aminophospholipid analogues confirmed that the activation energy of formation of the Schiff bases is greater with aminophosphates; on the other hand, that of hydrolysis is essentially similar with aminoacids and aminophosphates.

  9. SYNTHESIS OF NEW HETEROCYCLIC SCHIFF BASE, THIAZOLIDINONE AND AZETIDINONE COMPOUNDS AND THEIR ANTIBACTERIAL ACTIVITY AND ANTI –HIV ACTIVITIES Synthese neuer HETEROCYCLISCHE SCHIFF BASE, Thiazolidinon UND Azetidinonverbindungen UND IHRE antibakterielle Aktivität und ANTI-HIV AKTIVITÄTEN

    Directory of Open Access Journals (Sweden)

    RAJARSHI N. PATEL, P.V.PATEL , K.R. DESAI, P.Y. PUROHIT, K.S.NIMAVAT AND K.B. VYAS

    2012-01-01

    Full Text Available Thiazolidines and azetidinopnes have been prepared by the reaction of various Schiff bases with thioglycine acid chloroacetyl chloride respectively. The intermediate Schiff bases were synthesized by the condensation of 4-amino-2,4’-dichloro diphenyl ether with various aldehydes. The structures of the compounds have been confirmed by elemental analysis and spectral analysis. The antibacterial and anti HIV activities of the compounds have been also screened.

  10. Co(II), Ni(II) and Cu(II) complexes with coumarin-8-yl Schiff-bases: spectroscopic, in vitro antimicrobial, DNA cleavage and fluorescence studies.

    Science.gov (United States)

    Patil, Sangamesh A; Unki, Shrishila N; Kulkarni, Ajaykumar D; Naik, Vinod H; Badami, Prema S

    2011-09-01

    A new series of Co(II), Ni(II) and Cu(II) complexes of the type ML·2H2O of Schiff-bases derived from m-substituted thiosemicarbazides and 8-acetyl-7-hydroxy-4-methylcoumarin have been synthesized and characterized by spectroscopic studies. Schiff-bases exhibit thiol-thione tautomerism wherein sulphur plays an important role in the coordination. The coordination possibility of the Schiff-bases towards metal ions have been proposed in the light of elemental analyses, spectral (IR, UV-vis, FAB-mass, ESR and fluorescence), magnetic and thermal studies. The low molar conductance values in DMF indicate that, the metal complexes are non-electrolytes. The cyclic voltammetric studies suggested that, the Cu(II) and Ni(II) complexes are of single electron transfer quasi-reversible nature. The Schiff-bases and its metal complexes have been evaluated for their in vitro antibacterial (Escherichia coli, Staphilococcus aureus, Bascillus subtilis and Salmonella typhi) and antifungal activities (Candida albicans, Cladosporium and Aspergillus niger) by MIC method. The Schiff-base I and its metal complexes exhibited DNA cleavage activity on isolated DNA of A. niger.

  11. SYNTHESIS OF NOVEL SCHIFF BASES OF 5-AMINOSALICYLIC ACID BY GRINDING TECHNIQUE AND ITS EVALUATION FOR ANTI-INFLAMMATORY AND ANALGESIC ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Arora Rashmi

    2012-07-01

    Full Text Available 5-Aminosalicylic acid or Mesalamine are considered as amino derivative of salicylic acid with molecular formula C7H7NO3. It is proved to a useful drug in an effective treatment of inflammatory bowel disease. It possess both anti-inflammatory and analgesic activity by targeting COX, Prostaglandins and lipoxygenase enzyme. Presence of primary amine group in the 5th position makes them an important substrate for Schiff base synthesis. Schiff base possess diverse biological activities and can be formed by various methods. In the present study grinding technique was used as a simple and effective way for synthesizing Schiff bases of 5-Aminosalicylic acid. A mixture of aromatic aldehyde and 5-Aminosalicylic acid were grinded to produce yellow coloured Schiff base and free amine group forms double bond with the carbon forming a condensation product. Further these schiff bases were evaluated for anti-inflammatory and analgesic activities. m-Chloro derivative was proved to be a potent analgesic and anti-inflammatory agent.

  12. Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2'-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents

    Institute of Scientific and Technical Information of China (English)

    AZAM Faizul; SINGH Satendra; KHOKHRA Sukhbir Lal; PRAKASH Om

    2007-01-01

    Objective:A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes.Methods:Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes.2-(2'-Hydroxy)benzylideneaminonaphthothiazole was converted to its Co(Ⅱ),Ni(Ⅱ) and Cu(Ⅱ) metal complexes upon treatment with metal salts in ethanol.All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria.The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method.Results:All the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria.In the present study among all Schiff bases 2-(2'-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(Ⅱ) metal complex was found to be most potent.Conclusion:The results obtained validate the hypothesis that Schiff bases having substitution with halogens,hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity.The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.

  13. A triazole Schiff base-based selective and sensitive fluorescent probe for Zn2 +: A combined experimental and theoretical study

    Science.gov (United States)

    Yuan, Caixia; Liu, Xinyu; Wu, Yanbo; Lu, Liping; Zhu, Miaoli

    2016-02-01

    A triazole-Schiff base, 4-(5-Chloro-2-hydroxybenzylideneamino)-1H-1,2,4-triazole-5(4H)-thione (HL), exhibits the high selectivity and sensitivity for Zn2 + in the fluorescence spectrometry over other common metal ions, especially Cd2 + in DMSO:H2O (1:9, v/v) solution. A 1:1 binding ratio of Zn2 +/L for the complex has been obtained by Uv-Vis titration experiments and Job's plot with the detection limit of 51 nmol/L. The coordination mode of the complex in solution was further confirmed by density functional theory (DFT) calculations. Time-dependent density functional theory (TD-DFT) calculations indicate that a chelation-enhanced fluorescence (CHEF) effect occurs in the process of detecting Zn ion.

  14. Investigation of the oxygen affinity of manganese(II, cobalt(II and nickel(II complexes with some tetradentate Schiff bases

    Directory of Open Access Journals (Sweden)

    Adel A.A. Emara

    2014-12-01

    Full Text Available Oxygen absorption–desorption processes for square planar Mn(II, Co(II and Mn(II complexes of tetradentate Schiff base ligands in DMF and chloroform solvents were investigated. The tetradentate Schiff base ligands were obtained by condensation reaction of ethylenediamine with salcyldehyde, o-hydroxyacetophenone or acetylacetone in the molar ratio 1:2. The square planar complexes were prepared by the reaction of the Schiff base ligands with Mn(II acetate, Co(II nitrate and Ni(II nitrate in dry ethanol under nitrogen atmosphere. The sorption processes were undertaken in the presence and absence of (pyridine axial-base in 1:1 M ratio of (pyridine:metal(II complexes. Complexes in DMF indicate significant oxygen affinity than in chloroform solvent. Cobalt(II complexes showed significant sorption processes compared to Mn(II and Ni(II complexes. The presence of pyridine axial base clearly increases oxygen affinity.

  15. Synthesis and biological evaluation of Schiff bases and azetidinones of 1-naphthol

    Directory of Open Access Journals (Sweden)

    Sushil Kumar

    2012-01-01

    Full Text Available Introduction: Schiff bases and azetidinones form an important structural class possessing wide spectrum of biological activities that include antibacterial and antifungal activity. A series of Schiff′s bases N′-(substituted benzylidene-2-(naphthalen-1-yloxy acetohydrazides (3a-f and azetidinones N-[3-chloro-2-oxo-4-(substituted phenyl-azetidin-1-yl]-2-(naphthalen-1-yloxy acetamides (4a-b were synthesized and tested for antimicrobial activity. Materials and Methods: The chemical structures of synthesized compounds were elucidated on the basis of IR and 1H NMR spectroscopy. The synthesized compounds were screened for antibacterial activity against E. coli (ESS 2231 and B. subtilis (MTCC 441. The compounds were also tested for antifungal activity against A. niger (NCIM 618 and C. albicans (NCIM 3557 by the cup diffusion method. Results and Discussion: The in vitro antimicrobial activity results showed that the N-[3-chloro-2-oxo-4-(4-substitutedphenyl-azetidin-1-yl]-2-(naphthalen-1-yloxy acetamides (4a-b exhibited better antibacterial activity than the synthesized N′-(substituted benzylidene-2-(naphthalen-1-yloxy-acetohydrazides (3a-f. Compound (4b displayed potent antibacterial activity against the B. subtilis and E. coli (MIC values of 16-64 μg/mL. The antifungal activity of the synthesized compounds (3a-f and 4a-b against the A. niger and C. albicans was relatively weak, most of the compounds showed poor activities (MIC >128μg/mL. Conclusion: The antibacterial activity of the synthesized compounds was moderate to low and antifungal activity was relatively weak. Therefore, a further study with this class of compounds is necessary to elucidate the mechanism and structure activity relationship.

  16. Synthesis, characterization and photophysical studies of a novel schiff base bearing 1, 2, 4-Triazole scaffold

    Science.gov (United States)

    Alphonse, Roshmy; Varghese, Anitha; George, Louis

    2016-06-01

    A novel Schiff base derivative containing 1, 2, 4-triazole nucleus (TMPIMP) was synthesized from 4- [1,2,4] triazol-1-ylmethyl-phenylamine and salicylaldehyde in the presence of glacial acetic acid in an ethanolic medium. The synthesized compound was characterized by 1H-NMR, IR and UV spectral analysis. The excitation and emission spectra of triazolyl methyl phenyl imino methyl phenol (abbreviated as TMPIMP) were recorded in various solvents to investigate their solvatochromic behaviour. Dipole moments of the two electronic states of TMPIMP were calculated from solvatochromic spectral shifts. These were correlated with refractive index (η) and dielectric constant (ε) of various solvents. Theoretical calculations were performed to estimate the excited state dipole moment on the basis of different solvent correlation methods, like the Bilot-Kawski, Bakhshiev, Lippert-Mataga, Kawski-Chamma-Viallet and Reichardt methods. The dipole moment in the excited state was found to be higher than that in the ground state due to a substantial redistribution of electron densities and charges. Using a multiple regression analysis, the solvent-solute interactions were determined by means of Kamlet Taft parameters (α, β, π*). Computational studies were performed by Gaussian 09 W software using a time-dependent density functional theory (TD-DFT) in order to calculate the atomic charges and frontier molecular orbital energies in the solvent phase. The calculations indicated that the dipole moment of the molecule in an excited state is much higher than that in a ground state. The chemical stability of TMPIMP was determined by means of chemical hardness (η) using HOMO-LUMO energies. The reactive centers in the molecule were also identified by molecular electrostatic potential (MESP) 3D plots as a result of TD-DFT computational analysis.

  17. Synthesis of Triazole Schiff's Base Derivatives and Their Inhibitory Kinetics on Tyrosinase Activity.

    Directory of Open Access Journals (Sweden)

    Feng Yu

    Full Text Available In the present study, new Schiff's base derivatives: (Z-4-amino-5-(2-(3- fluorobenzylidenehydrazinyl-4H-1,2,4-triazole-3-thiol (Y1, (Z-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-ylhydrazonomethylphenol (Y2, (Z-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-ylhydrazonomethylphenol (Y3 and 3-((Z-(2-(4- (((E-3-hydroxybenzylideneamino-5-mercapto-4H-1,2,4-triazol-3-ylhydrazonomethylphenol (Y4 were synthesized and their structures were characterized by LC-MS, IR and 1H NMR. The inhibitory effects of these compounds on tyrosinase activites were evaluated. Compounds Y1, Y2 and Y3 showed potent inhibitory effects with respective IC50 value of 12.5, 7.0 and 1.5 μM on the diphenolase activities. Moreover, the inhibition mechanisms were determined to be reversible and mixed types. Interactions of the compounds with tyrosinase were further analyzed by fluorescence quenching, copper interaction, and molecular simulation assays. The results together with the anti-tyrosinase activities data indicated that substitution on the second position of benzene ring showed superior ant-ityrosinase activities than that on third position, and that hydroxyl substitutes were better than fluorine substitutes. In addition, two benzene rings connecting to the triazole ring would produce larger steric hindrance, and affect the bonding between tyrosinase and inhibitors to decrease the inhibitory effects. The anti-tyrosinase effects of these compounds were in contrast to their antioxidant activities. In summary, this research will contribute to the development and design of antityrosinase agents.

  18. Syntheses, Crystal Structures and Fluorescent Properties of Two New Imidazolidino Schiff Base Compounds

    Institute of Scientific and Technical Information of China (English)

    FENG Yue; LIU Gang; TIAN Xiu-Mei; WANG Ji-De; WANG Wei

    2008-01-01

    Two new imidazolidino Schiff base compounds, (E)-N-((quinoxalin-2-yl)methylene)-2-(2-(quinoxalin-3-yl)imidazolidin-1-yl)ethanamine 1 and 2-(1-(2-(2-(quinoxalin-3-yl)imidazolidin-1-yl)ethyl)imidazolidin-2-yl)quinoxaline 2, have been synthesized and characterized by elemental analysis,1H NMR, IR, MS and single-crystal X-ray diffraction. Crystallographic data for 1: C22H21N7,Mr = 383.46, monoclinic, space group P21, a = 7.0036(14), b=6.9151(14), c=19.701(4)(A),β=96.57(3)°, Z = 2, V=947.9(3)(A)3, Dc = 1.344 g/cm3, F(000)=404, μ = 0.085 mm-1, Flack parameter =0(2), R = 0.0464 and wR = 0.1055; and those for 2: C24H26N8, Mr = 426.53, triclinic, space group P(1),a = 9.6680(19), b = 10.334(2), c = 11.389(2)(A),α= 104.12(3),β= 102.95(3),γ= 100.48(3)°, Z=2,V=1041.2(4)(A)3, Dc=1.361 g/cm3, F(000) = 452,μ = 0.086 mm-1, R = 0.0373 and wR = 0.1155. For the two compounds, the five-membered imidazolidine rings all adopt envelope conformation.Moreover, the title compounds show one-dimensional layered and three-dimensional supramolecular chainlike structures, respectively. Fluorescent properties of the two compounds have been investigated in the solid state at room temperature. Compound 1 exhibits strong fluorescence and thus may serve as excellent candidates of green fluorescent materials.

  19. A Schiff base derivative for effective treatment of diethylnitrosamine-induced liver cancer in vivo.

    Science.gov (United States)

    Demirci, Selami; Doğan, Ayşegül; Başak, Neşe; Telci, Dilek; Dede, Bülent; Orhan, Cemal; Tuzcu, Mehmet; Şahin, Kazm; Şahin, Nurhan; Özercan, İbrahim Hanifi; Şahin, Fikrettin

    2015-06-01

    Hepatocellular carcinoma is one of the most prevalent cancers, with a high morbidity rate, even in developed countries. In the present study, the curative effect of the Schiff base (SB) heterodinuclear copper(II)Mn(II) complex on diethylnitrosamine (DEN)-induced liver carcinoma was investigated. Hepatocarcinoma was initiated by an injection of DEN and promoted by phenobarbital (0.05%) in the diet. In addition, the potential nephrotoxicity of SB was evaluated in a cisplatin-induced nephrotoxicity model. Rats were administered the SB complex (1 and 2 mg/kg body weight/day) for 24 weeks, and cancer progression was investigated by macroscopic, histopathological, and western blot examinations. The administration of SB decreased the incidence and the number of hepatic nodules in a dose-dependent manner by regulating inflammation response and the apoptotic pathway. Western blot analyses from the livers of rats treated with SB after DEN induction showed significantly enhanced Bax and caspase-3 levels, with a marked decrease in the levels of Bcl-2, NF-κB p65 and cyclooxygenase (COX)-2. Results from the nephrotoxicity study showed that, whereas cisplatin increased serum urea nitrogen and creatinine levels, no increase in serum biochemical parameters was detected in SB-treated animals. Moreover, protein levels of NF-E2-related factor-2 (Nrf2) and heme oxygenase-1 were lower, whereas nuclear factor-κB (NF-κB p65) and activator protein-1 levels were higher in the kidneys of cisplatin-treated animals compared with that of the SB groups. Therefore, the SB complex could be an alternative chemotherapeutic option for liver cancer treatment once its safety in clinical applications has been examined.

  20. Syntheses and Crystal Structures of Two VO(IV) Schiff Base Complexes with Oxyammonia Ligand

    Institute of Scientific and Technical Information of China (English)

    李连之; 许涛; 王大奇; 牛梅菊; 冀海伟

    2004-01-01

    Two novel VO(IV) Schiff base complexes, VO(SALHA)2[SALHA: salicyaldehydeoxyammonia] and VO(o-VANHA)2 [o-VANHA: o-vanillin-oxyammonia], have been synthesized with salicyaldehyde or o-vanilline, hydroxylammonium chloride and vanadyl sulfate in absolute methanol, and their crystal structures were determined by single-crystal X-ray diffraction. The vanadium(IV) centers in both complexes are five-coordinate in a distorted square pyramidal geometry. VO(SALHA)2 (C14H12N2O5V, Mr = 339.20) crystallizes in the monoclinic system, space group P21/n with a = 14.716(9), b = 7.175(5), c = 14.716(9) A, β = 113.130(7), V = 1428.8(15) A3, Z = 4, Dc = 1.577 g/cm3, β = 0.71073 A, μ(MoKα) = 0.720 mm-1, F(000) = 692, the final R = 0.0466 and wR = 0.0829 for 1561 observed reflections (I > 2σ(I)). VO(o-VANHA)2 (C16H16N2O7V, Mr = 399.25) is of monoclinic, space group P21/n with a = 11.386(12), b = 10.405(10), c = 14.627(15) A, β = 93.654(19), V = 1729(3) A3, Z = 4, Dc = 1.533 g/cm3, β = 0.71073 A, μ(MoKα) = 0.615 mm-1, F(000) = 820, the final R = 0.0513 and wR = 0.1129 for 1235 observed reflections (I > 2σ(I)).