A control on hydrophobic and hydrophilic interactions between HEWL and metal Schiff-base complexes comprising of different metal ions and ligands

Energy Technology Data Exchange (ETDEWEB)

Koley Seth, Banabithi; Ray, Aurkie; Basu, Samita, E-mail: samita.basu@saha.ac.in

2015-05-15

The structural effects of different copper(II) and nickel(II) Schiff base complexes on hen egg white lysozyme (HEWL) have been investigated through steady state and time resolved absorption and fluorescence, and circular dichroism spectroscopy. The Schiff base ligands with N{sub 4} donor atoms show both hydrophobic and hydrophilic interactions, however hydrophilic interaction prevails with ligands having N{sub 2}O{sub 2} donor atoms. Variation of metal ions from Cu{sup 2+} to Ni{sup 2+} with each type of Schiff base ligand increases the probability of hydrophilic over hydrophobic interactions, which supports their significance in regulating the binding affinity between HEWL and metal complexes. On photo-excitation the complexes comprising of Cu{sup 2+} ion instead of Ni{sup 2+} ion and ligands with N{sub 4} donor system rather than N{sub 2}O{sub 2} donor system, increases the probability of intersystem crossing to populate the corresponding triplet state as observed from laser flash photolysis study. The better binding affinity of nickel complexes with different selectivities compared to copper complexes towards HEWL emphasizes the potentiality of less explored nickel complexes in drug–protein interactions. - Highlights: • Ni{sup II} and Cu{sup II} -Schiff base complexes bind hen egg white lysozyme spontaneously. • Both hydrophobic and hydrophilic interactions are effective for N{sub 4} ligands. • For N{sub 2}O{sub 2} ligands the hydrophilic is predominant over hydrophobic interaction. • Binding affinity and selectivity of Ni{sup II}-complexes are better than Cu{sup II}-complexes. • Replacement of Cu{sup 2+} by Ni{sup 2+} in a ligand enhances chance of hydrophilic interaction.

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.

Synthesis in aqueous medium and organic praseodymium complexes with ligands derived from Schiff base quinolinic. Characterization and physicochemical study; Sintesis en medio acuoso y organico de complejos de praseodimio con ligantes derivados de base de Schiff quinolicos. Caracterizacion y estudio fisicoquimico

Energy Technology Data Exchange (ETDEWEB)

Garcia G, A.

2015-07-01

It was investigated the coordination ability of the quinolinic Schiff base organic tetradentate quinolinic ligand (Q Schiff-(OH){sub 2}) towards the trivalent praseodymium by UV/Vis spectrophotometric titration (St). By St, was studied the formed species between the Q Schiff-(OH){sub 2} ligand and the praseodymium nitrate salt in equimolar concentrations (5.86 x 10{sup -4} M: 5.22 x 10{sup -4} M) in methanol. The statistical analysis of the experimental results suggested three complexed species with 1Pr:3L, 1Pr:2L y 1Pr:1L stoichiometries. The predominant stoichiometries were the second and the latter. Based on these results and data from the scientific literature, the methodology for the syntheses of the complexes Q Schiff-(OH){sub 2}-Pr in aqueous-organic and organic media was established and a molar ratio M:L= 1:2 of praseodymium nitrate and the ligand was used. The new complexes were characterized by UV/Vis, Infrared, X-ray Photoelectron Spectroscopy (XP S), Diffuse Reflectance (Dr) and Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC). Elemental analysis of C, N, O and Pr by XP S suggested 1Pr:2L:1Na (PrC{sub 32}H{sub 20}N{sub 4}O{sub 4}Na) stoichiometry of the complex synthesized by the aqueous-organic medium while for the complex synthesized by the organic medium it was 1Pr:3L (PrC{sub 48}H{sub 33}N{sub 6}O{sub 6}). In the first case, the praseodymium ion charge was neutralized by the anionic ligands whose remaining charge was compensated by the sodium ion. In the second case, the ion charge was neutralized by the ligands. The minimum formula was Pr(Q Schiff){sub 2}Na for the pure coordination compound from the aqueous-organic medium and the minimum formula Pr(Q Schiff){sub 3} for that from the organic medium. XP S also indicated that the oxidation state of praseodymium ion was maintained. Both complexes were stable in methanol, ethanol and acetonitrile at least for 5 days. The photophysical properties of the studied complexes were

Schiff Base Ligand Coated Gold Nanoparticles for the Chemical Sensing of Fe(III Ions

Directory of Open Access Journals (Sweden)

Abiola Azeez Jimoh

2015-01-01

Full Text Available New Schiff base-coated gold nanoparticles (AuNPs of type AuNP@L (where L: thiolated Schiff base ligand have been synthesized and characterized using various spectroscopic techniques. The AuNPs and AuNP@L were imaged by transmission electron microscopy (TEM and were confirmed to be well-dispersed, uniformly distributed, spherical nanoparticles with an average diameter of 8–10 nm. Their potential applications for chemosensing were investigated in UV-Vis and fluorescence spectroscopic studies. The AuNP@L exhibited selectivity for Fe3+ in an ethanol/water mixture (ratio 9 : 1 v/v. The absorption and emission spectral studies revealed a 1 : 1 binding mode for Fe3+, with binding constants of 8.5×105 and 2.9×105 M−1, respectively.

unsymmetrical Schiff base complexes

Indian Academy of Sciences (India)

the effect of the substitutional groups of the Schiff base on the oxidation and reduction potentials, we used ... Electrochemistry of these complexes showed that the presence of electron .... a solution of the ligand (1 mmol) in methanol (15 mL).

Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes

Science.gov (United States)

Bhattacharjee, Chira R.; Goswami, Pankaj; Pramanik, Harun A. R.; Paul, Pradip C.; Mondal, Paritosh

2011-05-01

Two new mixed-ligand iron(III) complexes, [Fe(L n)(acac)(C 2H 5OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac) 3] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H 2L 1) or 2-aminobenzoic acid (H 2L 2). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L n)(acac)X] ( n = 1, 2; X = Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, 1H and 13C NMR spectroscopy. Room temperature magnetic susceptibility measurements ( μeff ˜ 5.8 B.M.) are consistent with spin-free octahedral iron(III) complexes. Cyclic voltammetry of ethanol complexes revealed a quasi-reversible one electron redox response (Δ Ep > 100 mV) for the Fe(III)/Fe(II) couple. Low half wave redox potential ( E1/2) values suggested easy redox susceptibility. The ground state geometries of the ethanol and imidazole complexes have been ascertained to be distorted octahedral by density functional theory using DMol3 program at BLYP/DNP level.

Synthesis and characterization of complexes of early actinides with tridentate Schiff base ligands

International Nuclear Information System (INIS)

Mansingh, P.S.; Dash, K.C.

1995-01-01

A series of thorium(IV) and dioxouranium(VI) complexes have been synthesised with tridentate Schiff base ligands (N 2 O donor set) obtained by in-situ condensation of N, N-dimethylethylenediamine with o-hydroxy aromatic aldehydes such as salicylaldehyde (HL) or o-hydroxy naphthaldehyde (HL'). While with dioxouranium(VI), the ligands are coordinated in a neutral manner and act as tridentate donors forming complexes of the type UO 2 (HL)X 2 or UO 2 (HL')X 2 (X=Cl,I,NCS,NO 3 ,CH 3 COO) with thorium(IV) they are coordinated as deprotonated tridentate ligands yielding complexes of the type Th(L') 2 X 2 (X=I,NCS,NO 3 ). The IR spectra show that the thiocyanate group is actually N-bonded unidentate isothiocyanate and both the nitrate and the acetate groups are bonded in bidentate manner while the ligands are bonded in tridentate manner in these complexes. The PMR spectra confirm the mode of bonding of the ligands either as neutral or as deprotonated species. The thermogravimetric analyses indicate the stability of the complexes. (author). 22 refs., 1 tab

Synthesis, crystal structure, antimicrobial activity and electrochemistry study of chromium(III) and copper(II) complexes based on semicarbazone Schiff base and azide ligands

Czech Academy of Sciences Publication Activity Database

Shaabani, B.; Khandar, A.A.; Dušek, Michal; Pojarová, Michaela; Mahmoudi, F.

2013-01-01

Roč. 394, JAN (2013), s. 563-568 ISSN 0020-1693 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378271 Keywords : antimicrobial activity * azide ligand * metal complex * Schiff base ligand * X-ray structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.041, year: 2013

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and thermal decomposition kinetics of Th(IV) complex with unsymmetrical Schiff base ligand

International Nuclear Information System (INIS)

Fan Yuhua; Bi Caifeng; Liu Siquan; Yang Lirong; Liu Feng; Ai Xiaokang

2006-01-01

A new unsymmetrical Schiff base ligand (H 2 LLi) was synthesized using L-lysine, o-vanillin and salicylaladyde. Thorium(IV) complex of this ligand [Th(H 2 L)(NO 3 )](NO 3 ) 2 x 3H 2 O have been prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage was studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt = A x e -E/RT x 1/2 (1-α) x [-ln(1-α)] -1 . The kinetic parameters (E, A), activation entropy ΔS ≠ and activation free-energy ΔG ≠ were also calculated. (author)

Preparation and characterization of Schiff base Cu(II) complex and its applications on textile materials

Science.gov (United States)

Oylumluoglu, G.; Oner, J.

2017-10-01

Schiff base ligands are regarded as an important class of organic compounds on account of the fact that their complexation ability with transition metal ions. A new monomeric Schiff base Cu(II) complex, [Cu(HL)2], 1 [H2L = 2-((E)-(2-hydroxypropylimino)methyl)-4-nitrophenol] has been synthesized and characterized by elemental analysis, UV and IR spectroscopy, single crystal X-ray diffraction and photoluminescence study. While the Schiff base ligand and its Cu(II) complex are excited at λex = 349 nm in UV region, the Schiff base ligand shows a blue emission band at λmax = 480 nm whereas its Cu(II) complex shows a strong green emission band at λmax = 520 nm in the solid state at room temperature. The luminescent properties showed that the Schiff base ligand and its Cu(II) complex can be used as novel potential candidates for applications in textile such as UV-protection, antimicrobial, laundry and functional bleaching treatments.

DIPYRIDOXYL(1,8-DIAMINO-3,6-DIOXAOCTANE) SCHIFF-BASE

African Journals Online (AJOL)

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KEY WORDS: Schiff base, N,N′-dipyridoxyl(1,8-diamino-3,6-dioxaoctane), DFT, B3LYP. INTRODUCTION. Schiff bases due to structural varieties and unique characteristics are the most versatile studied ligands in coordination chemistry [1, 2] and their metal complexes play an important role in the development of inorganic ...

Screening the efficient biological prospects of triazole allied mixed ligand metal complexes

Science.gov (United States)

Utthra, Ponnukalai Ponya; Kumaravel, Ganesan; Raman, Natarajan

2017-12-01

Triazole appended mixed ligand complexes (1-8) of the general formula [ML (bpy/phen)2]Cl2, where M = Cu(II), Co(II), Ni(II) and Zn(II), L = triazole appended Schiff base (E)sbnd N-(4-nitrobenzylidene)-1H-1,2,4-triazol-3-amine and bpy/phen = 2,2‧-bipyridine/1,10-phenanthroline, have been synthesized. The design and synthesis of this elaborate ligand has been performed with the aim of increasing stability and conjugation of 1,2,4 triazole, whose Schiff base derivatives are known as biologically active compounds thereby exploring their DNA binding affinity and other biological applications. The compounds have been comprehensively characterized by elemental analysis, spectroscopic methods (IR, UV-Vis, EPR, 1H and 13C NMR spectroscopy), ESI mass spectrometry and magnetic susceptibility measurements. The complexes were found to exhibit octahedral geometry. The complexes 1-8 were subjected to DNA binding techniques evaluated using UV-Vis absorption, CV, CD, Fluorescence spectroscopy and hydrodynamic measurements. Complex 5 showed a Kb value of 3.9 × 105 M-1. The DNA damaging efficacy for the complexes was observed to be high compared to the ligand. The antimicrobial screening of the compounds against bacterial and fungal strains indicates that the complexes possess excellent antimicrobial activity than the ligand. The overall biological activity of the complexes with phen as a co-ligand possessed superior potential than the ligand.

Cr(III), Fe(III) and Co(III) complexes of tetradentate (ONNO) Schiff base ligands: Synthesis, characterization, properties and biological activity

Science.gov (United States)

Keskioğlu, Eren; Gündüzalp, Ayla Balaban; Çete, Servet; Hamurcu, Fatma; Erk, Birgül

2008-08-01

A series of metal complexes were synthesized from equimolar amounts of Schiff bases: 1,4-bis[3-(2-hydroxy-1-naphthaldimine)propyl]piperazine (bappnaf) and 1,8-bis[3-(2-hydroxy-1-naphthaldimine)- p-menthane (damnaf) with metal chlorides. All of synthesized compounds were characterized by elemental analyses, spectral (UV-vis, IR, 1H- 13C NMR, LC-MS) and thermal (TGA-DTA) methods, magnetic and conductance measurements. Schiff base complexes supposed in tetragonal geometry have the general formula [M(bappnaf or damnaf)]Cl· nH 2O, where M = Cr(III), Co(III) and n = 2, 3. But also Fe(III) complexes have octahedral geometry by the coordination of two water molecules and the formula is [Fe(bappnaf or damnaf)(H 2O) 2]Cl. The changes in the selected vibration bands in FT-IR indicate that Schiff bases behave as (ONNO) tetradentate ligands and coordinate to metal ions from two phenolic oxygen atoms and two azomethine nitrogen atoms. Conductance measurements suggest 1:1 electrolytic nature of the metal complexes. The synthesized compounds except bappnaf ligand have the antimicrobial activity against the bacteria: Escherichia coli (ATCC 11230), Yersinia enterocolitica (ATCC 1501), Bacillus magaterium (RSKK 5117), Bacillus subtilis (RSKK 244), Bacillus cereus (RSKK 863) and the fungi: Candida albicans (ATCC 10239). These results have been considerably interest in piperazine derivatives due to their significant applications in antimicrobial studies.

Schiff base transition metal complexes for Suzuki–Miyaura cross

Indian Academy of Sciences (India)

Schiff base ligand and its complex with iron (Fe), cobalt (Co), nickel (Ni) and copper (Cu) ions were synthesized using 4-aminoacetophenone and salicylaldehyde and characterized. FTIR spectrum shows that bidentate coordination of metal ions with ligand where O, N are electron donating sites of azomethine group.

Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

Science.gov (United States)

Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

2014-01-01

Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

Reactivity of nitrido complexes of ruthenium(VI), osmium(VI), and manganese(V) bearing Schiff base and simple anionic ligands.

Science.gov (United States)

Man, Wai-Lun; Lam, William W Y; Lau, Tai-Chu

2014-02-18

Nitrido complexes (M≡N) may be key intermediates in chemical and biological nitrogen fixation and serve as useful reagents for nitrogenation of organic compounds. Osmium(VI) nitrido complexes bearing 2,2':6',2″-terpyridine (terpy), 2,2'-bipyridine (bpy), or hydrotris(1-pyrazolyl)borate anion (Tp) ligands are highly electrophilic: they can react with a variety of nucleophiles to generate novel osmium(IV)/(V) complexes. This Account describes our recent results studying the reactivity of nitridocomplexes of ruthenium(VI), osmium(VI), and manganese(V) that bear Schiff bases and other simple anionic ligands. We demonstrate that these nitrido complexes exhibit rich chemical reactivity. They react with various nucleophiles, activate C-H bonds, undergo N···N coupling, catalyze the oxidation of organic compounds, and show anticancer activities. Ruthenium(VI) nitrido complexes bearing Schiff base ligands, such as [Ru(VI)(N)(salchda)(CH3OH)](+) (salchda = N,N'-bis(salicylidene)o-cyclohexyldiamine dianion), are highly electrophilic. This complex reacts readily at ambient conditions with a variety of nucleophiles at rates that are much faster than similar reactions using Os(VI)≡N. This complex also carries out unique reactions, including the direct aziridination of alkenes, C-H bond activation of alkanes and C-N bond cleavage of anilines. The addition of ligands such as pyridine can enhance the reactivity of [Ru(VI)(N)(salchda)(CH3OH)](+). Therefore researchers can tune the reactivity of Ru≡N by adding a ligand L trans to nitride: L-Ru≡N. Moreover, the addition of various nucleophiles (Nu) to Ru(VI)≡N initially generate the ruthenium(IV) imido species Ru(IV)-N(Nu), a new class of hydrogen-atom transfer (HAT) reagents. Nucleophiles also readily add to coordinated Schiff base ligands in Os(VI)≡N and Ru(VI)≡N complexes. These additions are often stereospecific, suggesting that the nitrido ligand has a directing effect on the incoming nucleophile. M≡N is also

Synthesis, characterization, single crystal X-ray determination, fluorescence and electrochemical studies of new dinuclear nickel(II) and oxovanadium(IV) complexes containing double Schiff base ligands

Science.gov (United States)

Shafaatian, Bita; Ozbakzaei, Zahra; Notash, Behrouz; Rezvani, S. Ahmad

2015-04-01

A series of new bimetallic complexes of nickel(II) and vanadium(IV) have been synthesized by the reaction of the new double bidentate Schiff base ligands with nickel acetate and vanadyl acetylacetonate in 1:1 M ratio. In nickel and also vanadyl complexes the ligands were coordinated to the metals via the imine N and enolic O atoms. The complexes have been found to possess 1:1 metals to ligands stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The nickel and vanadyl complexes exhibited distorted square planar and square pyramidal coordination geometries, respectively. The emission spectra of the ligands and their complexes were studied in methanol. Electrochemical properties of the ligands and their metal complexes were also investigated in DMSO solvent at 150 mV s-1 scan rate. The ligands and metal complexes showed both quasi-reversible and irreversible processes at this scan rate. The Schiff bases and their complexes have been characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis and conductometry. The crystal structure of the nickel complex has been determined by single crystal X-ray diffraction.

Substituent effect on redox potential of nitrido technetium complexes with Schiff base ligand. Theoretical calculations

International Nuclear Information System (INIS)

Takayama, T.; Sekine, T.; Kudo, H.

2003-01-01

Theoretical calculations based on the density functional theory (DFT) were performed to understand the effect of substituents on the molecular and electronic structures of technetium nitrido complexes with salen type Schiff base ligands. Optimized structures of these complexes are square pyramidal. The electron density on a Tc atom of the complex with electron withdrawing substituents is lower than that of the complex with electron donating substituents. The HOMO energy is lower in the complex with electron withdrawing substituents than that in the complex with electron donating substituents. The charge on Tc atoms is a good measure that reflects the redox potential of [TcN(L)] complex. (author)

Synthesis, crystal structure and biological activity of the Schiff base organotin(IV) complexes based on salicylaldehyde-o-aminophenol

Science.gov (United States)

Tan, Yu-Xing; Zhang, Zhi-Jian; Liu, Yang; Yu, Jiang-Xi; Zhu, Xiao-Ming; Kuang, Dai-Zhi; Jiang, Wu-Jiu

2017-12-01

Schiff base organotin(IV) complexes C1 ∼ C5b have been synthesized via the reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 ∼ L3) with the dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. The complexes have been characterized by IR, UV-Vis, 1H NMR, 13C NMR spectra, elemental analysis and the crystal structures have been determined by X-ray diffraction. The anticancer activity of the Schiff base ligand and complexes C1 ∼ C5b against five species of cancer cell which are Hela, MCF7, HepG2, Colo205, NCIsbnd H460 were tested respectively, the tests showed that C1 ∼ C5b exhibited significant anticancer activity for the cancer cells in comparison with the ligand, and the activity was greater than carboplatin.

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.

Synthesis, characterization, antimicrobial and cytotoxic evaluation of a bidentate schiff base ligand: (5-chloro-2-((4-nitrobenzylidene)amino)phenyl)(phenyl)methanone and its transition metal complexes

International Nuclear Information System (INIS)

Anis, I.; Noreen, Z.

2013-01-01

A Schiff base ligand (SBL): ((5-chloro-2-)(4-nitrobenzylidene) amino) phenyl)(phenyl) methanone,, was synthesized from the reaction of 4-nitrobenzaldehyde and 2-amino-5-chlorobeznzophenone followed by complexation with transition metal (II) ions (1-5). Their structures were elucidated on the basis of infrared, 1H-NMR, FAB-MS spectral, elemental analyses and molar conductance data. The octahedral geometry for complexes (1-4) and square planar geometry for complex (5) was proposed on the basis of electronic and magnetic moment data. The non-electrolytic nature of the complexes (1-5) was suggested from the conductivity data. The complexes (1-5) showed higher in vitro antimicrobial activity and in vivo lethality to shrimp larvae than the parent Schiff base ligand. (author)

Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: Synthesis, X-ray crystallography and biological activity

Science.gov (United States)

Mokhtaruddin, Nur Shuhada Mohd; Yusof, Enis Nadia Md; Ravoof, Thahira B. S. A.; Tiekink, Edward R. T.; Veerakumarasivam, Abhi; Tahir, Mohamed Ibrahim Mohamed

2017-07-01

Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines.

Synthesis, Characterization and in Vitro Antibacterial Activities of CdO Nanoparticle and Nano-sheet Mixed-ligand of Cadmium(ІІ Complex

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Zohreh Rashidi Ranjbar

2016-07-01

Full Text Available Here, we report the synthesis of a Schiff-base mixed-ligand complex of cadmium(ІІ in bulk and nano-scales via the precipitation and sonochemical methods, respectively. The complex formula is [Cd(3-bpdh(3-bpdbCl2]n (1, where the ligands are 3-bpdh = 2,5-bis(3-pyridyl-3,4-diaza-2,4-hexadiene and 3-bpdb = 1,4-bis(3-pyridyl-2,3-diaza-1,3-butadiene. The structure of mixed-ligand complex (1 was characterized by IR, 1H NMR and elemental analyses. Cadmium(ІІ oxide nanoparticles were prepared by direct thermolysis from nanosheet of complex (1. The cadmium(ІІ oxide structure was characterized by X-ray Diffraction (XRD and Energy Dispersive X-ray  analyses (EDAX. Size, morphology and structural dispersion of all obtained nanostructures were characterized by Scanning Electron Microscopy (SEM. The Schiff-base ligands, bulk and nano-scales of complex (1 and cadmium(ІІ oxide nanoparticles were analyzed for antibacterial activities against Bacillus alvei (bacteria causing the honey bee European foulbrood disease. The Minimum Inhibitory Concentrations (MIC has been shown moderate antibacterial activities compared with some other standard drugs. Known antibiotics like penicillin and SXT (Trimethoprim/sulfamethoxazole were used as positive control.

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

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Morteza Montazerozohori

2013-01-01

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

Adducts of uranium tetrachloride with neutral Schiff bases

Energy Technology Data Exchange (ETDEWEB)

Doretti, L; Madalosso, F; Sitran, S; Faleschini, S; Vigato, P A [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

1977-01-01

Studies are reported of adducts of UCl/sub 4/ with various Schiff base ligands: N-(phenyl)benzalaldimine, N-(propyl) salicylaldimine, N-(phenyl) salicylaldimine, N-(2-hydroxyphenyl)benzalaldimine, N-(4-chlorophenyl)salcylaldimine, N-(4-nitrophenyl)salicylaldimine, N,N'-o-phenylenebis(salycylideneimine). The synthesis and characterization of these ligands is reported, and the preparation and characterization of the relative adducts of UCl/sub 4/: their IR spectra are reported and discussed.

Adducts of uranium tetrachloride with neutral Schiff bases

International Nuclear Information System (INIS)

Doretti, L.; Madalosso, F.; Sitran, S.; Faleschini, S.; Vigato, P.A.

1977-01-01

Studies are reported of adducts of UCl 4 with various Schiff base ligands: N-(phenyl)benzalaldimine, N-(propyl) salicylaldimine, N-(phenyl) salicylaldimine, N-(2-hydroxyphenyl)benzalaldimine, N-(4-chlorophenyl)salcylaldimine, N-(4-nitrophenyl)salicylaldimine, N,N'-o-phenylenebis (salycylideneimine). The synthesis and characterization of these ligands is reported, and the preparation and characterization of the relative adducts of UCl 4 : their IR spectra are reported and discussed. (author)

synthesis and spectra characterization of mixed- ligand complexes

African Journals Online (AJOL)

BARTH EKWUEME

The Schiff base ligand, N-Propylidene-2-methylpyridylamine was obtained from the condensation of 2- aminomethypyridine and propanal.Also, its complexes with Cu(II),Ni(II),Zn(II),Co(II) .... determined with Thomas–Hoover capillary melting apparatus. RESULTS AND DISCUSSION. N-propylidene-2-methylpyridylamine ...

Synthesis and characterization of a Schiff base Cobalt (III) complex ...

African Journals Online (AJOL)

Schiff base molecule acts as tridentate ligand to form two five-membered chelate rings with the Co(III) ion. In the crystal structure three meridionally arranged nitrogen atoms from three azide ligands complete a distorted octahedral geometry around the metal center. The distortion from an ideal octahedron is evident from the ...

Antibacterial Co(II, Ni(II, Cu(II and Zn(II complexes with biacetyl-derived Schiff bases

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MUHAMMAD IMRAN

2010-08-01

Full Text Available The condensation reactions of biacetyl with ortho-hydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2(H2O2] where M = Co(II, Ni(II, Cu(II and Zn(II and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR, 13C-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141–160 °C. These compounds were also screened for their in vitro antibacterial activity against four bacterial species, namely: Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtilis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.

Synthesis, characterization and biological assay of Salicylaldehyde Schiff base Cu(II) complexes and their precursors

Science.gov (United States)

Iftikhar, Bushra; Javed, Kanwal; Khan, Muhammad Saif Ullah; Akhter, Zareen; Mirza, Bushra; Mckee, Vickie

2018-03-01

Three new Schiff base ligands were synthesized by the reaction of Salicylaldehyde with semi-aromatic diamines, prepared by the reduction of corresponding dinitro-compounds, and were further used for the formation of complexes with Cu(II) metal ion. The structural features of the synthesized compounds were confirmed by their physical properties and infrared, electronic and NMR spectroscopic techniques. The studies revealed that the synthesized Schiff bases existed as tetradentate ligands and bonded to the metal ion through the phenolic oxygen and azomethine nitrogen. One of the dinitro precursors was also analyzed by single crystal X-ray crystallography, which showed that it crystallizes in monoclinic system with space group P2/n. The thermal behavior of the Cu(II) complexes was determined by thermogravimetric analysis (TGA) and kinetic parameters were evaluated from the data. Schiff base ligands, their precursors and metal complexes were also screened for antibacterial, antifungal, antitumor, Brine shrimp lethality, DPPH free radical scavenging and DNA damage assays. The results of these analyses indicated the substantial potential of the synthesized Schiff bases, their precursors and Cu(II) complexes in biological field as future drugs.

Structural, spectral and biological studies of binuclear tetradentate metal complexes of N 3O Schiff base ligand synthesized from 4,6-diacetylresorcinol and diethylenetriamine

Science.gov (United States)

Emara, Adel A. A.

2010-09-01

The binuclear Schiff base, H 2L, ligand was synthesized by reaction of 4,6-diacetylresorcinol with diethylenetriamine in the molar ratio 1:2. The coordination behavior of the H 2L towards Cu(II), Ni(II), Co(II), Zn(II), Fe(III), Cr(III), VO(IV) and UO 2(VI) ions has been investigated. The elemental analyses, magnetic moments, thermal studies and IR, electronic, 1H NMR, ESR and mass spectra were used to characterize the isolated ligand and its metal complexes. The ligand acts as dibasic with two N 3O-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The bonding sites are the nitrogen atoms of the azomethine and amine groups and the oxygen atoms of the phenolic groups. The metal complexes exhibit either square planar, tetrahedral, square pyramid or octahedral structures. The Schiff base ligand and its metal complexes were tested against four pathogenic bacteria ( Staphylococcus aureus and Streptococcus pyogenes) as Gram-positive bacteria, and ( Pseudomonas fluorescens and Pseudomonas phaseolicola) as Gram-negative bacteria and two pathogenic fungi ( Fusarium oxysporum and Aspergillus fumigatus) to assess their antimicrobial properties. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

Monodentate Schiff base ligands: their structural characterization, photoluminescence, anticancer, electrochemical and sensor properties.

Science.gov (United States)

Köse, Muhammet; Ceyhan, Gökhan; Tümer, Mehmet; Demirtaş, Ibrahim; Gönül, İlyas; McKee, Vickie

2015-02-25

Two Schiff base compounds, N,N'-bis(2-methoxy phenylidene)-1,5-diamino naphthalene (L(1)) and N,N'-bis(3,4,5-trimethoxy phenylidene)-1,5-diamino naphthalene (L(2)) were synthesized and characterized by the analytical and spectroscopic methods. The electrochemical and photoluminescence properties of the Schiff bases were investigated in the different conditions. The compounds L(1) and L(2) show the reversible redox processes at some potentials. The sensor properties of the Schiff bases were examined and color changes were observed upon addition of the metal cations, such as Hg(II), Cu(II), Co(II) and Al(III). The Schiff base compounds show the bathochromic shift from 545 to 585 nm. The single crystals of the compounds (L(1)) and (L(2)) were obtained from the methanol solution and characterized structurally by the X-ray crystallography technique. The molecule L(2) is centrosymmetric whereas the L(1) has no crystallographically imposed molecular symmetry. However, the molecular structures for these compounds are quite similar, differing principally in the conformation about methoxy groups and the dihedral angle between the two aromatic rings and diamine naphthalene. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and Crystal Structure Determination of a Nickel(II Complex of an Acyclic Pentadentate (N5 Mono Schiff Base Ligand

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R. V. Parish

2001-10-01

Full Text Available The asymmetrical tripodal tetraamine ligand N[(CH23NH2]2[(CH22NH2] (ppe was condensed with 2-acetylpyridine in the presence of nickel(II ion. In ethanolwater solution the reaction stops after the first stage of condensation, and a new nickel(II complex of an acyclic pentadentate (N5 mono Schiff base ligand was obtained. X-ray structure analysis of the resulting complex, [Ni(ppe-py(H2O](ClO42, indicates that condensation with 2-acetylpyridine is at the propylene chain of ppe. The geometry around the nickel ion is distorted octahedral in which the sixth co-ordination group is a solvent molecule.

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

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ACHUT S. MUNDE

2010-03-01

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

Formation of trimetallic compounds containing redox-active nitrosyl molybdenum tris(3,5-dimethylpyrazolyl-borato groups. Schiff base complexes containing two molybdenum centres linked by meta hydroxy copper schiff base ligands

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Stanley M. Kagwanja

2000-06-01

Full Text Available The reaction of [Mo(NOTp*Cl2] [Tp* = tris(3,5-dimethyl-pyrazolylborate] with copper(II Schiff base complexes derived by condensation of two mole equivalents of 2,4-dihydroxybenzaldehyde with a diamine [1,2-C6H4(NH22, NH2(CH2nNH2, n = 2-5] affords trimetallic species containing three potential redox centres. The IR, UV-vis and EPR spectroscopic properties of these compounds are described and it is shown that, with increasing polymethylene bridges of the Schiff base ligands, the complexes distort from planarity probably towards tetrahedral structures. From cyclic and differential pulse voltammetry it is shown that the trimetallic species primarily undergo two sequential one electron reduction associated with the reduction of [Mo(NOTp*Cl]+ centres. By determination of conproportionation constants for the mono-reduced species, it is established that there is very weak interaction between the two [Mo(NOTp*Cl]+ centres in the trimetallic complexes. It is also demonstrated that the meta-substituted [Mo(NOTp*Cl]+ centres reduce at potentials more anodic than their para-substituted analogues. Reduction potentials of these complexes are also shown to be solvent dependent.

Copper(II) and palladium(II) complexes with tridentate NSO donor Schiff base ligand: Synthesis, characterization and structures

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Kumar, Sujit Baran; Solanki, Ankita; Kundu, Suman

2017-09-01

Mononuclear copper(II) complex [CuL2] and palladium(II) complexes [Pd(X)L] where X = benzoate(bz) or salicylate(sal) and HL = 2-(methylthio)phenylimino)methyl)phenol, a Schiff base ligand with NSO coordination sites have been synthesized and characterized by microanalyses, IR, UV-Visible spectra, conductivity measurement and magnetic studies. Crystal structures of all the complexes have been solved by single crystal X-ray diffraction studies and showed that there are two molecules in a unit cell in the [CuL2] complex - one molecule has square planar geometry whereas second molecule has distorted square pyramidal geometry and palladium(II) complexes have distorted square planar geometry.

Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

Science.gov (United States)

Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

2016-11-01

New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

Lanthanum(III) and praseodymium(III) complexes with bidentate and tetradentate Schiff base ligands containing indole ring

International Nuclear Information System (INIS)

Rai, Anita; Sengupta, Soumitra Kumar; Pandey, Om Prakash

2000-01-01

Complexes of lanthanum(III) and praseodymium(III) with Schiff bases, prepared from isatin with aniline, 4-chloroaniline, 2- bromoaniline, 2-nitroaniline (Hl), ethylenediamine, o- phenylenediamine and 4-methyl-o-phenylenediamine (H 2 L') have been synthesised and their physico-chemical properties investigated using elemental analysis, molar conductivities, magnetic susceptibility measurements and spectral (visible, infrared and 1 H NMR) data. The Schiff bases HL bind in a bidentate manner while schiff bases H 2 L' bind in a tetradentate manner. The probable structures of the complexes are proposed. (author)

New oxozirconium(IV) complexes with the schiff bases derived from salicylaldehyde or substituted salicylaldehydes and o-aminobenzyl alcohol

Energy Technology Data Exchange (ETDEWEB)

Syamal, A [Kurukshetra Univ. (India). Dept. of Applied Sciences and Humanities; Kumar, D [Regional Engineering Coll., Kurukshetra (India). Dept. of Chemistry

1980-10-01

Several new oxozirconium(IV) complexes with the schiff bases obtained from salicylaldehyde, 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, 5-nitrosalicylaldehyde, 4-methoxysalicylaldehyde, 5-methoxysalicylaldehyde, 3-ethoxysalicylaldehyde, 3,5-dichlorosalicylaldehyde or 2-hydroxy-1-naphthaldehyde and 0-aminobenzyl alcohol have been synthesized and characterized on the basis of elemental analysis, molecular weight, electrical conductance, infrared spectral and magnetic susceptibility measurements. The schiff bases behave as monobasic, tridentate ONO donor ligands. The complexes are of the type ZrO(LH)/sub 2/ (where LH/sub 2/ = tridentate schiff base) and are seven-coordinated. The complexes are monomers, non-electrolytes and diamagnetic. Changes in the ..nu..C=N, ..nu..C-0 (phenolic) and ..nu..C-0 (alchoholic) frequencies have been followed to find out the coordination sites of the ligands.

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.

Coordination of N,O-donor appended Schiff base ligand (H2L1) towards Zinc(II) in presence of pseudohalides: Syntheses, crystal structures, photoluminescence, antimicrobial activities and Hirshfeld surfaces

Science.gov (United States)

Majumdar, Dhrubajyoti; Biswas, Jayanta Kumar; Mondal, Monojit; Surendra Babu, M. S.; Metre, Ramesh K.; Das, Sourav; Bankura, Kalipada; Mishra, Dipankar

2018-03-01

A series of dinuclear Zn(II) complexes [Zn2 (L1) (CH3OH)2(SCN) (OAc)](1), [Zn2 (L1) (CH3OH)2(N3)2](2) and [Zn2 (L1) (Cl)2(CH3OH)]·CH3OH (3) have been synthesized by the reaction of compartmental Schiff base ligand (H2L1) [N,N‧-Bis(3-ethoxysalicylidenimino)-1,3-diaminopropane] with Zn(OAc)2·2H2O in presence of coligand like KSCN, NaN3 and NaCl respectively. X-ray diffraction analysis revealed that all the complexes are neutral and possess a 4-membered Zn2 (μ2-O)2 ring fastened by the unified coordination action of a doubly deprotonated ligand. In addition, solid state structure of the complexes display extensive intermolecular interaction which has been supported theoretically by Hirshfeld surface analysis with 2D Fingerprint plots. The synthesized Zn(II) metal complexes observed enhancement of luminescence emission compared to the parent Schiff base due to emanating ligand based intraligand (π→π∗) fluorescence. Additionally, Zn(II) metal complexes exhibited considerable antimicrobial potency against some important Gram +ve and Gram -ve bacteria.

Effect of heptadentate (N{sub 4}O{sub 3}) tripodal Schiff base ligand and its yttrium(III) complex on the luminescence and extraction of tris({beta}-diketonato)europium(III)

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Y. [Department of Chemistry, Faculty of Science, Science University of Tokyo, Tokyo 162-8601 (Japan)], E-mail: yhasegaw@rs.kagu.tus.ac.jp; Saitou, S.; Nagaoka, D.; Yajima, H. [Department of Chemistry, Faculty of Science, Science University of Tokyo, Tokyo 162-8601 (Japan); Kanesato, M. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562 (Japan)

2008-02-28

In order to learn the effect of a Schiff base and the complex of Y{sup III} on the extraction of Eu{sup III} with {beta}-diketones and on the luminescence of the extracted species, the extraction of Eu{sup III} with 2-thenoyltrifluoroacetone (Htta) and/or these Schiff bases, tris(5-t-butyl)salicylidenaminoethyl amine (H{sub 3}L{sup 1}), and its Y{sup III} complex ([YL{sup 1}]) prepared, into CHCl{sub 3} was examined. Further, the luminescence and excited spectra of CHCl{sub 3} phases extracted Eu{sup III} complexes and the solutions containing tris({beta}-diketonato)Eu{sup III} and/or the Schiff bases were measured. On the measurement of the luminescence spectra, tris(pivaloyltrifluoroacetonato)Eu{sup III} (Eu(pta){sub 3}) as well as Eu(tta){sub 3} was used. Synergistic effect with Htta and these Schiff bases was observed. However, proper effect of Y{sup III} was not observed. The luminescence intensity of Eu(tta){sub 3} at 613 nm decreased with increasing concentration of H{sub 3}L{sup 1} or [YL{sup 1}], whereas that of Eu(pta){sub 3} increased with increasing concentration of the ligands, but no difference between both Schiff bases was observed, because of picking up of Y{sup III} from [YL{sup 1}] with the interaction between [YL{sup 1}] and water.

Reaction of Non-Symmetric Schiff Base Metallo-Ligand Complexes Possessing an Oxime Function with Ln Ions

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Jean-Pierre Costes

2018-03-01

Full Text Available The preparation of non-symmetric Schiff base ligands possessing one oxime function that is associated to a second function such as pyrrole or phenol function is first described. These ligands, which possess inner N4 or N3O coordination sites, allow formation of cationic or neutral non-symmetric CuII or NiII metallo-ligand complexes under their mono- or di-deprotonated forms. In presence of Lanthanide ions the neutral complexes do not coordinate to the LnIII ions, the oxygen atom of the oxime function being only hydrogen-bonded to a water molecule that is linked to the LnIII ion. This surprising behavior allows for the isolation of LnIII ions by non-interacting metal complexes. Reaction of cationic NiII complexes possessing a protonated oxime function with LnIII ions leads to the formation of original and dianionic (Gd(NO352− entities that are well separated from each other. This work highlights the preparation of well isolated mononuclear LnIII entities into a matrix of diamagnetic metal complexes. These new complexes complete our previous work dealing with the complexing ability of the oxime function toward Lanthanide ions. It could open the way to the synthesis of new entities with interesting properties, such as single-ion magnets for example.

Synthesis and characterization of some metal complexes of a Schiff base derived from ninhydrin and α,L-alanine

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Mehabaw Getahun Derebe

2002-06-01

Full Text Available Complexes of Mn(II, Fe(III, Co(II, Ni(II and Zn(II with an intermediate Schiff base derived from ninhydrin and α,L-alanine (indane-1,3-dione-2-imine-N-2-propionate, IDIP were successfully synthesized. All complexes were distinctly colored and were characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. The ligand (Schiff base was shown to behave as a monobasic tridentate ONO donor. The Mn(II and Fe(III complexes contain only one ligand molecule plus water and chloride(s per metal ion, while all the others contain two ligand molecules per metal ion. An octahedral geometry is proposed for the metal complexes.

Ion Sensor Properties of Fluorescent Schiff Bases Carrying Dipicolylamine Groups. A Simple Spectrofluorimetric Method to Determine Cu (II) in Water Samples.

Science.gov (United States)

Vanlı, Elvan; Mısır, Miraç Nedim; Alp, Hakan; Ak, Tuğba; Özbek, Nurhayat; Ocak, Ümmühan; Ocak, Miraç

2017-09-01

Four fluorescent Schiff bases carrying dipicolylamine groups were designed and synthesized to determine their ion sensor properties in partial aqueous solution. The corresponding amine compound and the aldehyde compounds such as 1-naphthaldehyde, 9-anthraldehyde, phenanthrene-9-carboxaldehyde and 1-pyrenecarboxaldehyde were used to prepare the new Schiff bases. The influence of many metal cations and anions on the spectroscopic properties of the ligands was investigated in ethanol-water (1:1) by means of emission spectrometry. From the spectrofluorimetric titrations, the complexation stoichiometry and complex stability constants of the ligands with Cd 2+ , Zn 2+ , Cu 2+ and Hg 2+ ions were determined. The ligands did not interact with the anions. However, the Schiff base derived from phenanthrene-9-carboxaldehyde showed sensitivity for Cu 2+ among the tested metal ions. The phenanthrene-based Schiff base was used as analytical ligand for the simple and fast determination of Cu 2+ ion in water samples. A modified standard addition method was used to eliminate matrix effect. The linear range was from 0.3 mg/L to 3.8 μg/L. Detection and quantification limits were 0.14 and 0.43 mg/L, respectively. Maximum contaminant level goal (MCLG) for copper in drinking water according to EPA is 1.3 mg/L. The proposed method has high sensitivity to determine copper in drinking waters.

Synthesis, structure and catalytic activities of nickel(II) complexes bearing N4 tetradentate Schiff base ligand

Science.gov (United States)

Sarkar, Saikat; Nag, Sanat Kumar; Chattopadhyay, Asoke Prasun; Dey, Kamalendu; Islam, Sk. Manirul; Sarkar, Avijit; Sarkar, Sougata

2018-05-01

Two new nickel(II) complexes [Ni(L)Cl2] (1) and [Ni(L)(NCS)2] (2) of a neutral tetradentate mono-condensed Schiff base ligand, 3-(2-(2-aminoethylamino)ethylimino)butan-2-one oxime (L) have been synthesized and characterized using different physicochemical techniques e.g. elemental analyses, spectroscopic (IR, Electronic, NMR) methods, conductivity and molecular measurements. The crystal structure of complex (2) has been determined by using single crystal X-ray diffraction method and it suggests a distorted octahedral geometry around nickel(II) having a NiN6 coordinating atmosphere. The non-coordinated Osbnd H group on the ligand L remain engaged in H-bonding interactions with the S end of the coordinated thiocyanate moiety. These H-bonding interactions lead to Osbnd S separations of 3.132 Å and play prominent role in crystal packing. It is observed that the mononuclear units are glued together with such Osbnd H…S interactions and finally results in an 1D supramolecular sheet-like arrangement. DFT/TDDFT based theoretical calculations were also performed on the ligand and the complexes aiming at the accomplishment of idea regarding their optimized geometry, electronic transitions and the molecular energy levels. Finally the catalytic behavior of the complexes for oxidation of styrene has also been carried out. A variety of reaction conditions like the effect of solvent, effect of temperature and time as well as the effect of ratio of substrate to oxidant were thoroughly studied to judge the catalytic efficiency of the Ni(II) coordination entity.

Synthesis, Characterization, DNA Interaction, and Antitumor Activities of La (III) Complex with Schiff Base Ligand Derived from Kaempferol and Diethylenetriamine.

Science.gov (United States)

Wang, Qin; Huang, Yu; Zhang, Jin-Sheng; Yang, Xin-Bin

2014-01-01

A novel La (III) complex, [LaL(H2O)3]NO3 ·3H2O, with Schiff base ligand L derived from kaempferol and diethylenetriamine, has been synthesized and characterized by elemental analysis, IR, UV-visible, (1)H NMR, thermogravimetric analysis, and molar conductance measurements. The fluorescence spectra, circular dichroism spectra, and viscosity measurements and gel electrophoresis experiments indicated that the ligand L and La (III) complex could bind to CT-DNA presumably via intercalative mode and the La (III) complex showed a stronger ability to bind and cleave DNA than the ligand L alone. The binding constants (K b ) were evaluated from fluorescence data and the values ranged from 0.454 to 0.659 × 10(5) L mol(-1) and 1.71 to 17.3 × 10(5) L mol(-1) for the ligand L and La (III) complex, respectively, in the temperature range of 298-310 K. It was also found that the fluorescence quenching mechanism of EB-DNA by ligand L and La (III) complex was a static quenching process. In comparison to free ligand L, La (III) complex exhibited enhanced cytotoxic activities against tested tumor cell lines HL-60 and HepG-2, which may correlate with the enhanced DNA binding and cleaving abilities of the La (III) complex.

Synthesis, spectroscopic characterization and antimicrobial activity evaluation of new tridentate Schiff bases and their Co(II complexes

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Ganesh More

2017-12-01

Full Text Available A series of Schiff base tridentate ligands and their respective Co(II complexes have been synthesized and characterized by elemental analysis, magnetic susceptibility, IR, NMR and UV–Visible spectra, thermal studies. The IR spectral data suggested that all the ligands acted as monobasic tridentate towards central Co(II ion with an ONO donor atoms sequentially. Analytical data and magnetic susceptibility revealed 1:2 metal to ligand stoichiometry and octahedral geometry for all Co(II complexes. All the prepared compounds were also screened for antimicrobial activity against 5 ESBL (Extended Spectrum β-lactamase and 5 MBL (Metallo β-lactamase producing uropathogens and for antitubercular activity against Mycobacterium tuberculosis (H37Rv strain. Keywords: Schiff base, Antitubercular, Antimicrobial, ESBL, MBL, Metal complex, o-hydroxyl aldehyde, Aminothiophene

Metal chelates of some transition and non-transition metal ions with Schiff base derived from isatin with o-phenylenediamine

International Nuclear Information System (INIS)

Hassaan, A.M.A.; Khalifa, M.A.

1993-01-01

New Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II) chelates of the Schiff base derived from isatin with o-phenylenediamine have been synthesized and characterized on the basis of elemental analyses, electronic, IR and 1 H NMR spectra, and also by aid of molar conductivity and magnetic moment measurements. It has been found that the Schiff base behaves as ONNO tetradentate dibasic ligand forming chelates with 1:1 (metal:ligand) stoichiometry. Square planar environment is suggested for nickel(II) chelate. All the metal chelates show non-electrolytic behaviour

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

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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.

Preparation and properties of mononuclear and binuclear uranyl(VI), thorium(IV) and transition d ions complexes with multidentate Schiff bases

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Vidali, M; Casellato, U; Vigato, P A; Doretti, L; Madalosso, F [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

1977-01-01

The preparation, physical and chemical properties of a variety of mononuclear and binuclear complexes containing Schiff base ligands derived from 3-formylsalicylic acid and diamines are reported. The Schiff bases have six potential donor atoms and can function as tetrabasic ligands. In the mononuclear complexes the copper(II) and nickel(II) ions occupy the N/sub 2/O/sub 2/ donor set and the uranyl(VI) ion the O/sub 2/O/sub 2/ one. Both types of complexes can act as ligand toward transition metal ions to form complexes with a binuclear structure connected by two phenolic oxygens. The complexes have been characterized by magnetic measurements and by IR and visible spectral methods.

N2O2 Tipi Schiff Bazı Ligandı ile Sentezlenen Cu(II Kompleksinin X-Işını Yapısı ve Termal Özelliği

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Ahmet Karahan

2013-04-01

Full Text Available Cu(II kompleksinin X-ışınları moleküler yapısı 293 K'de tayin edildi. Cu (II kompleksi monoklinik yapıda ve uzay grubu P21/n a= 12.4007(14, b= 8.4476(9, c= 20.0286(12 Ã…, β= 97.291(7°. Termal davranışları diferansiyel termal analiz ve termogravimetrik analiz ile incelendi. Ayrıca Schiff bazı ligandının karakterizasyonunda elementel analiz, IR, UV-vis spektroskopisi, termal analiz, 1H-NMR ve 13C-NMR yöntemlerinden faydalanıldı. Anahtar kelimeler: Schiff bazı, Tek Kristal, X-ışınları analizi, Termal analiz The X-Ray Molecular Structure and Thermal Behaviour of Cu (II Complex, Synthesis With N2O2 Type Schiff Base Ligand Abstract: The X-ray molecular structure of Cu (II complex at 293 K has been determined. The Cu (II complex, has been prepared and structurally and thermal characterized. The complex crystallizes in monoclinic space group P21/n with a= 12.407(14, b= 8.4476(9, c= 20.0286(12 Ã…, β= 97.291(7°. The thermal behavior of the compound was investigated by differential thermal analysis and thermogravimetry. Additionally, Schiff base ligand also characterized by elemental analysis, IR, UV-vis spectroscopy, thermal analysis, 1H-NMR and 13C-NMR. Key words: Schiff base, Single crystal, X-ray analysis, Thermal analysis

New 3,4-diaminobenzoic acid Schiff base compounds and their complexes: synthesis, characterization and thermodynamics.

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Mohammadi, Khosro; Niad, Mahmood; Jafari, Tahereh

2014-03-25

Some new tetradentate Schiff base ligands (H3L) were prepared via condensation of 3,4-diaminobenzoic acid with 2-hydroxybenzaldehyde derivatives, such as 3,4-bis((E)-2,4-dihydroxybenzylideneamino)benzoic acid (H3L(1)), 3,4-bis((E)-2-hydroxy-3-methoxybenzylideneamino)benzoic acid (H3L(2)) and 3,4-bis((E)-5-bromo-2-hydroxybenzylideneamino)benzoic acid (H3L(4)). Additionally, a tetradentate Schiff base ligand 3,4-bis((E)-2-hydroxybenzylideneamino)benzoic acid (H3L(3)) and its complexes were synthesized. Their metal complexes of Co(II), Ni(II), Cu(II) and Zn(II) were prepared in good yields from the reaction of the ligands with the corresponding metal acetate. They were characterized based on IR, (1)H NMR, Mass spectroscopy and UV-Vis spectroscopy. Also, the formation constants of the complexes were measured by UV-Vis spectroscopic titration at constant ionic strength 0.1M (NaClO4), at 25 °C in dimethylformamide (DMF) as a solvent. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Self-assembled copper(II) metallacycles derived from asymmetric Schiff base ligands: efficient hosts for ADP/ATP in phosphate buffer.

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Kumar, Amit; Pandey, Rampal; Kumar, Ashish; Gupta, Rakesh Kumar; Dubey, Mrigendra; Mohammed, Akbar; Mobin, Shaikh M; Pandey, Daya Shankar

2015-10-21

Novel asymmetric Schiff base ligands 2-{[3-(3-hydroxy-1-methyl-but-2-enylideneamino)-2,4,6-trimethylphenylimino]-methyl}-phenol (H2L(1)) and 1-{[3-(3-hydroxy-1-methyl-but-2-enylideneamino)-2,4,6-trimethylphenylimino]-methyl}-naphthalen-2-ol (H2L(2)) possessing dissimilar N,O-chelating sites and copper(ii) metallacycles (CuL(1))4 (1) and (CuL(2))4 (2) based on these ligands have been described. The ligands and complexes have been thoroughly characterized by satisfactory elemental analyses, and spectral (IR, (1)H, (13)C NMR, ESI-MS, UV/vis) and electrochemical studies. Structures of H2L(2) and 1 have been unambiguously determined by X-ray single crystal analyses. The crystal structure of H2L(2) revealed the presence of two distinct N,O-chelating sites on dissimilar cores (naphthalene and β-ketoaminato groups) offering a diverse coordination environment. Metallacycles 1 and 2 having a cavity created by four Cu(ii) centres coordinated in a homo- and heteroleptic fashion with respective ligands act as efficient hosts for adenosine-5'-diphosphate (ADP) and adenosine-5'-triphosphate (ATP) respectively, over other nucleoside polyphosphates (NPPs). The disparate sensitivity of these metallacycles toward ADP and ATP has been attributed to the size of the ligands assuming diverse dimensions and spatial orientations. These are attuned for π-π stacking and electrostatic interactions suitable for different guest molecules under analogous conditions, metallacycle 1 offers better orientation for ADP, while 2 for ATP. The mechanism of the host-guest interaction has been investigated by spectral and electrochemical studies and supported by molecular docking studies.

Design and synthesis of binucleating macrocyclic clefts derived from Schiff-base calixpyrroles.

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Givaja, Gonzalo; Volpe, Manuel; Leeland, James W; Edwards, Michael A; Young, Thomas K; Darby, S Barnie; Reid, Stuart D; Blake, Alexander J; Wilson, Claire; Wolowska, Joanna; McInnes, Eric J L; Schröder, Martin; Love, Jason B

2007-01-01

The syntheses, characterisation and complexation reactions of a series of binucleating Schiff-base calixpyrrole macrocycles are described. The acid-templated [2+2] condensations between meso-disubstituted diformyldipyrromethanes and o-phenylenediamines generate the Schiff-base pyrrolic macrocycles H(4)L(1) to H(4)L(6) upon basic workup. The single-crystal X-ray structures of both H(4)L(3).2 EtOH and H(4)L(6).H2O confirm that [2+2] cyclisation has occurred, with either EtOH or H2O hydrogen-bonded within the macrocyclic cleft. A series of complexation reactions generate the dipalladium [Pd2(L)] (L=L(1) to L(5)), dinickel [Ni2(L(1))] and dicopper [Cu2(L)] (L=L(1) to L(3)) complexes. All of these complexes have been structurally characterised in the solid state and are found to adopt wedged structures that are enforced by the rigidity of the aryl backbone to give a cleft reminiscent of the structures of Pacman porphyrins. The binuclear nickel complexes [Ni2(mu-OMe)2Cl2(HOMe)2(H(4)L(1))] and [Ni2(mu-OH)2Cl2(HOMe)(H(4)L(5))] have also been prepared, although in these cases the solid-state structures show that the macrocyclic ligand remains protonated at the pyrrolic nitrogen atoms, and the Ni(II) cations are therefore co-ordinated by the imine nitrogen atoms only to give an open conformation for the complex. The dicopper complex [Cu2(L(3))] was crystallised in the presence of pyridine to form the adduct [Cu2(py)(L(3))], in which, in the solid state, the pyridine ligand is bound within the binuclear molecular cleft. Reaction between H(4)L(1) and [Mn(thf){N(SiMe(3))2}2] results in clean formation of the dimanganese complex [Mn2(L(1))], which, upon crystallisation, formed the mixed-valent complex [Mn2(mu-OH)(L(1))] in which the hydroxo ligand bridges the metal centres within the molecular cleft.

Preparation Characterization and Antibacterial Studies of Chelates of Schiff Base Derived from4-Aminoantipyrine, Furfural and o-phenylenediamine

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M. S. Suresh

2011-01-01

Full Text Available A new series of transition metal complexes of Mn(II, Co(II, Ni(II, Cu(II and Zn(II were synthesized from the Schiff base ligand derived from 4-aminoantipyrine, furfural and o-phenylenediamine. The structural features were derived from their elemental analyses, infrared, UV-visible spectroscopy, NMR spectroscopy, thermal gravimetric analyses, ESR spectral analyses and conductivity measurements. The data of the complexes suggested square planar geometry for the metals with primary valency two. Antimicrobial screening tests were performed against bacteria. The comparative study of the MIC values of the Schiff base and its metal complexes indicate that the metal complexes exhibit greater antibacterial activity than the free ligand.

Studies on complexation of a tridentate ONS Schiff base with lighter and heavier metals ions, and investigation into their biological properties

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Tarafder, M.T.H.; Ali, A.M.; Juan, W.D.; Crouse, K.A.; Silong, S.

1999-05-01

Several new complexes of a tridentate ONS Schiff base derived from the condensation of S-benzyldithiocarbazate with salicylaldehyde have been characterised by elemental analyses, molar conductivity measurements, infrared, and electronic spectral studies. The tridentate Schiff base (HONSH) behaves as a dinegatively charged ligand coordinating through the thiolo sulphur, the azomethine nitrogen atom and the hydroxyl oxygen atom. It forms mono-ligand complexes of the general formula, [M(ONS)X], [M = Ni(II), Cu(II), Cr(III), Sb(III), Zn(II), Zr(IV) or U(VI) and X = H 2 O, Cl]. The ligand produced bis-chelated complex with Th(IV) of composition, [Th(ONS) 2 ]. Square-planar structures were proposed for the Ni(II) and Cu(II) complexes. Antimicrobial tests indicated that the Schiff base and five of the metal complexes of Cu(II), Ni(II), U(VI), Zn(II) and Sb(III) were found to be strongly active against bacteria. Ni(II) and Sb(III) complexes were the most effective against Pseudomonas aeruginosa (gram negative) while the Cu(II) complex proved to be the best against Bacillus cereus (gram positive bacteria). Antifungal activities were also noted with the Schiff base and the U(VI) complex. These compounds have shown results against Candida albicans fungi. But none of these compounds were effective against Aspergillus ochraceous fungi. (author)

Synthesis and characterization of thorium(IV) and uranium(IV) complexes with Schiff bases

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Radoske, Thomas; Maerz, Juliane; Kaden, Peter; Patzschke, Michael; Ikeda-Ohno, Atsushi [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements

2017-06-01

We report herein the synthesis and characterization of several imine complexes of tetravalent thorium (Th(IV)) and uranium (U(IV)). The ligands investigated in this study are a Schiff base type, including the well-known salen ligand (H{sub 2}Le, Fig. 1). The complexation in solution was investigated by NMR measurements indicating paramagnetic effects of unpaired f-electrons of U(IV) on the ligand molecule. We also determined the solid-state molecular structures of the synthesized complexes by single crystal X-ray diffraction. The synthesized complexes show an eight-fold coordination geometry around the actinide center surrounded by two tetradentate ligands with 2N- and 2O-donor atoms.

Synthesis, structural, spectroscopic and biological studies of Schiff base complexes

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Diab, M. A.; El-Sonbati, A. Z.; Shoair, A. F.; Eldesoky, A. M.; El-Far, N. M.

2017-08-01

Schiff base ligand 4-((pyridin-2- yl)methyleneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (PDMP) and its complexes were prepared and characterized on the basis of elemental analysis, IR, mass spectra and thermogravimetric analysis. All results confirm that the complexes have 1:1 (M: PMDP) stoichiometric formula [M(PMDP)Cl2H2O ] (M = Cu(II), Co(II), Ni(II) and Mn(II)), [Cd(PMDP)Cl2] and the ligand behaves as a bi/tridentate forming five-membered chelating ring towards the metal ions, bonding through azomethine nitrogen/exocyclic carbonyl oxygen, azomethine pyridine nitrogen and exocyclic carbonyl oxygen. The shift in the band positions of the groups involved in coordination has been utilized to estimate the metal-nitrogen and/or oxygen bond lengths. The complexes of Co(II), Ni(II) and Cu(II) are paramagnetic and the magnetic as well as spectral data suggest octahedral geometry, whereas the Cd(II) complex is tetrahedral. The XRD studies show that both the ligand and its metal complexes (1 and 3) show polycrystalline with crystal structure. Molecular docking was used to predict the binding between PMDP ligand and the receptors. The corrosion inhibition of mild steel in 2 M HCl solution by PDMP was explored utilizing potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and (EFM) electrochemical frequency modulation method. Potentiodynamic polarization demonstrated that PDMP compound is mixed-type inhibitor. EIS spectra exhibit one capacitive loop and confirm the protective ability. The percentage of inhibition efficiency was found to increase with increasing the inhibitor concentration.

Co(II) and Cd(II) Complexes Derived from Heterocyclic Schiff-Bases: Synthesis, Structural Characterisation, and Biological Activity

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Ahmed, Riyadh M.; Yousif, Enaam I.; Al-Jeboori, Mohamad J.

2013-01-01

New monomeric cobalt and cadmium complexes with Schiff-bases, namely, N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]furan-2-carbohydrazide (L1) and N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]thiophene-2-carbohydrazide (L2) are reported. Schiff-base ligands L1 and L2 were derived from condensation of 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with furan-2-carboxylic acid hydrazide and thiophene-2-carboxylic acid hydrazide, respectively. Complexes of the general formula [M(L)2]Cl2 (where M = Co(II) or Cd(II), L = L1 or L2) have been obtained from the reaction of the corresponding metal chloride with the ligands. The ligands and their metal complexes were characterised by spectroscopic methods (FTIR, UV-Vis, 1H, and 13C NMR spectra), elemental analysis, metal content, magnetic measurement, and conductance. These studies revealed the formation of four-coordinate complexes in which the geometry about metal ion is tetrahedral. Biological activity of the ligands and their metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Pseudomonas (G−) revealed that the metal complexes become less resistive to the microbial activities as compared to the free ligands. PMID:24027449

Interaction between metals and nucleic acids. Part 3. Synthesis and structural studies of copper(II) complexes with Schiff base ligands derived from barbituric acid

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Sasaki, I.; Gaudemer, A.; Chiaroni, A.; Riche, C.

1986-02-17

Schiff bases have been prepared from 5-formylbarbituric acid and 5-formyl-1,3-dimethyl-barbituric acid and various di- or tri-amines. The structure of the corresponding copper(II) complexes have been established by elemental analysis and spectroscopic methods. The molecular structure of one of the complexes, Cu(DiMeBardpt), was determined by X-ray diffraction. Electrochemical study shows that these complexes are reduced at slightly more negative potentials than the corresponding complexes obtained from uracil, which suggests that these new ligands are better electron-donors.

Platinum(II Complexes with Tetradentate Schiff Bases as Ligands: Synthesis, Characterization and Detection of DNA Interaction by Differential Pulse Voltammetry

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Lijun Li

2012-01-01

Full Text Available Five sterically hindered platinum(II complexes with tetradentate schiff bases as ligands, [Pt(L] (L= N,N′-bisalicylidene-1,2-ethylenediamine (L1, N,N′-bisalicylidene-1,2-cyclohexanediamine (L2, N,N′-bis(5-hydroxyl-salicylidene-1,2-cyclohexanediamine (L3, N,N′-bisalicylidene-1,2-diphenyl-ethylenediamine (L4 and N,N′-bis(3-tert-butyl-5-methyl-salicylidene-1,2-diphenylethylenediamine (L5 have been synthesized and characterized by IR spectroscopy and elemental analysis. The sterical hindrance of antitumor drug candidates potentially makes them less susceptible to deactivation by sulphur containing proteins and helping to overcome resistance mechanisms. The interaction of these metal complexes with fish sperm single-stranded DNA (ssDNA was studied electrochemically based on the oxidation signals of guanine and adenine. Differential pulse voltammetry was employed to monitor the DNA interaction in solution by using renewable pencil graphite electrode. The results indicate that ligands with different groups can strongly affect the interaction between [Pt(L] complexes and ssDNA due to sterical hindrances and complex [Pt(L1] has the best interaction with DNA among the five complexes.

Synthesis, spectroscopic and biological studies of transition metal complexes of novel schiff bases derived from amoxicillin and sugars

International Nuclear Information System (INIS)

Naz, N.

2009-01-01

Fe (II), Co (II) and Ni (II) metal complexes of new Schiff bases derived from amoxicillin with sugars (D-Glucose, D-Galactose and D-Mannose) have been synthesized and characterized by elemental analysis, FTIR, electronic absorption, and atomic absorption spectroscopy, magnetic moment measurements and thermal analysis. It has been found that Schiff bases behave as bi-dentate ligands forming complexes with 1:2 (metal:ligand) stoichiometry. The complexes were neutral as confirmed by their low conductance values. The biological applications of complexes have been studied on two gram negative (Escherichia coli and Pseudomonas aeruginosa) and two gram positive (Bacillus subtilis and Staphylococcus aureus) microorganisms by Agar diffusion disc method. It has been found that all the complexes have higher biological activities than the pure amoxicillin. (author)

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

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

2013-01-01

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

Isolation and structural characterization of uranium and other f block complexes with tridentate Schiff bases

International Nuclear Information System (INIS)

Singh, Kavita; Agarwala, B.V.

1992-01-01

Two Schiff base ligands, isatin semicarbazone(ISC) and o-vanillin salicyloylhydrazone(o-VSH) have been prepared and their complexes with U, La, Ce, Pr are synthesized and characterized by IR spectra, diffuse reflectance spectra, elemental analysis and other physico-chemical techniques. (author). 4 refs

Synthesis, spectroscopy and biological investigations of manganese(III) Schiff base complexes derived from heterocyclic β-diketone with various primary amine and 2,2'-bipyridyl

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Surati, Kiran R.

2011-06-01

The mixed ligand mononuclear complex [Mn(bipy)(HPMFP)(OAc)]ClO 4 was synthesized by reaction of Mn(OAc) 3·2H 2O with HPMFP and 2,2'-bipyridyl. The corresponding Schiff base complexes were prepared by condensation of [Mn(bipy)(HPMFP)(OAc)]ClO 4 with ethylenediamine, ethanolamine and glycine (where HPMFP = 1-phenyl-3methyl-4-formyl-2-pyrazolin-5one, bipy = 2,2'-bipyridyl). All the compounds have been characterized by elemental analysis, magnetic susceptibility, conductometry measurements and 1H and 13C NMR, FT-IR, mass spectrometry. Electronic spectral and magnetic susceptibility measurements indicate square pyramidal geometry around manganese(III) ion. The thermal stabilities, activation energy E*, entropy change Δ S*, enthalpy change Δ H* and heat capacity of thermal degradation for these complexes were determined by TGA and DSC. The in vitro antibacterial and antifungal activity of four coordination compounds and ligand HPMFP were investigated. In vitro activates of Bacillus subtillis (MTCC-619), Staphylococcus aureus (MTCC-96), Escherichia coli (MTCC-722) and Klebsiella pneumonia (MTCC-109) bacteria and the fungus Candida albicans (ATCC-90028) were determined. All the compounds showed good antimicrobial activity. The antimicrobial activities increased as formation of Schiff base.

Synthesis, Characterization, Crystal Structure and Antibacterial Activities of Transition Metal(II Complexes of the Schiff Base 2-[(4-Methylphenyliminomethyl]-6-methoxyphenol

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Guo-Liang Zhao

2009-05-01

Full Text Available Five transition metal(II complexes, [ML2Cl2] 1~5, were synthesized from the reaction of MCl2·nH2O (M = Mn, Co, Ni, Cu, Cd and the Schiff base ligand 2-[(4-methylphenyliminomethyl]-6-methoxyphenol (C15H15NO2, L, obtained by condensation of o-vanillin (2-hydroxy-3-methoxybenzaldehyde with p-toluidine. They were characterized by elemental analysis, molar conductance, FT-IR spectra, thermal analysis. The structure of complex 1 was determined by single-crystal X-ray diffraction. Its crystal structure is of monoclinic system, space group P21/c with a = 9.0111(18 Å, b = 11.222(2 Å, c =28.130 (6 Å, α = 90 º, β = 92.29(3 º, γ = 90 º, V = 2867.6(10 Å3, Z = 4. The Mn atom is six-coordinate and displays distorted octahedral geometry.The Schiff base ligand and its complexes have been tested in vitro to evaluate their antibacterial activity against bacteria, viz., Escherichia coli, Staphylococcus aureus and Bacillus subtilis. It has been found that the complexes have higher activity than the corresponding free Schiff base ligand against the same bacteria.

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff base ligands: Synthesis, characterization and biocidal activities

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Shabbir, Muhammad; Akhter, Zareen; Ashraf, Ahmad Raza; Ismail, Hammad; Habib, Anum; Mirza, Bushra

2017-12-01

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff bases have been prepared and characterized by elemental analysis as well as by spectroscopic techniques (FTIR & NMR). The synthesized compounds were assessed to check their potential biocidal activity by using different biological assays (brine shrimp cytotoxicity, antimicrobial, antioxidant, antitumor and drug-DNA interaction). Results of brine shrimp cytotoxicity assay showed that ligand molecules are more bioactive than metal complexes with LD50 as low as 12.4 μg/mL. The prominent antitumor activity was shown by nickel complexes while the palladium complexes exhibited moderate activity. The synthesized compounds have shown high propensity for DNA binding either through intercalation or groove binding which represents the mechanism of antitumor effect of these compounds. Additionally, ligand molecules and nickel metal complexes showed significant antioxidant activity with IC50 values as low as 3.1 μg/mL and 18.9 μg/mL respectively while palladium complexes exhibited moderate activity. Moreover, in antimicrobial assays H2L1, Ni(L1)PPh3 and H2L3 showed dual inhibition against bacterial and fungal strains while for the rest of the compounds varying degree of activity was recorded against different strains. Overall comparison of results suggests that the synthesized compounds can be promising candidate for drug formulation and development.

Synthesis, spectroscopic and biological studies of transition metal complexes of novel schiff bases derived from cephradine and sugars

International Nuclear Information System (INIS)

Naz, N.; Iqbal, M.Z.

2011-01-01

Fe(II), Co(II) and Ni(II) metal complexes of novel schiff bases derived from Cephradine and sugars (D-Glucose, L. Arabinose and D-Galactose) were synthesized and characterized by elemental analysis, magnetic susceptibility, thermal analysis, electronic absorption and FT-IR spectral studies. It has been found that schiff bases behave as bi-dentate-ligands forming complexes with 1:2 (metal:ligand) stoichiometry. the neutral nature of the complexes was confirmed by their low conductance values. The biological activities of complexes have been evaluated against two gram negative (Escherichia coli and Pseudomonas aeruginosa) and two gram positive (Bacillus subtilis and staphylococcus aureus) bacteria by Agar diffusion disc method. It has been found that the complexes have higher activity as compared to the pure Cephradine against the same bacteria. (author)

New complex of mercury(II) with Schiff base derived from A-methylcinnamaldehyde and ethylenediamine

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Fejfarová, Karla; Dušek, Michal

2011-01-01

Roč. 37, č. 10 (2011), s. 743-747 ISSN 1070-3284 R&D Projects: GA ČR(CZ) GAP204/11/0809 Institutional research plan: CEZ:AV0Z10100521 Keywords : crystal structure * X-ray diffraction * Schiff- base ligands * Jana2006 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.547, year: 2011

A new oxidovanadium(IV) Schiff base complex containing asymmetric tetradentate ONN′O′ Schiff base ligand: synthesis, characterization, crystal structure determination, thermal study and catalytic activity

Czech Academy of Sciences Publication Activity Database

Grivani, G.; Ghavami, A.; Eigner, Václav; Dušek, Michal; Khalaji, A.D.

2015-01-01

Roč. 26, č. 6 (2015), s. 779-784 ISSN 1001-8417 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : oxidovanadium(IV) * Schiff base * crystal structure * nanoparticle * epoxidation Subject RIV: CC - Organic Chemistry Impact factor: 1.947, year: 2015

Facile synthesis of RuII Schiff base complexes: spectral characterization and antimicrobial applications

International Nuclear Information System (INIS)

Arunachalam, S.; Padma Priya, N.; Shahul Meeran, H.

2014-01-01

Diamagnetic ruthenium (II) complexes of the type (RuCl (CO) (pyridine) (L)) (where L = monobasic tridentate Schiff base ligands) were synthesized by the reactions of Schiff bases derived from the reactions of o-aminobenzoic acid and Knovenegal condensate of β - ketoesters and appropriate ruthenium metal precursor (RuHCl (CO) (PPh 3 ) 2 (py)). Elemental analyses and spectral (FT-IR, UV-Vi s and 1 H, 31 P NMR) studies of all the new synthesized complexes suggest the presence of an octahedral environment around the Ru II ion. Cyclic voltammograms of all the complexes display oxidation and reduction potentials. Superoxide dismutase activity (SOD) of these complexes has also been examined. These complexes were also subjected to study their biocidal activity against Staphylococcus epidermidis, Escherichia coli, Botrytis cinerea and Aspergillus niger. (author)

Uranyl(VI) and lanthanum(III) complexes with functionalized macrocyclic and macroacyclic Schiff bases

International Nuclear Information System (INIS)

Aguiari, A.; Brianese, N.; Tamburini, S.; Vigato, P.A.

1995-01-01

Acyclic Schiff bases have been prepared by [2 + 1] condensation of 2,6-diformyl-4-chlorophenol and H 2 NCH 2 [CH 2 XCH 2 ] n CH 2 NH 2 (n =3D 0 H 2 -I; X =3D NH, S, O n =3D 1 H 2 -II...H 2 -IV; X =3D 0 n =3D 2 H 2 -V; X =3D 0 n =3D 3 H 2 -VI). The related uranlyl(VI) and lanthanum (III) complexes have bee synthesized by reaction by reaction of the preformed ligands with the appropriate salt or by the template procedure, in the presence of base. No base was employed in the preparation of lanthanum (III) complexes, La(H 2 -II)(NO 3 ) 3 , La(H 2 -IV)(NO 3 ) 3 where the Schiff bases coordinate as neutral chelate ligands. These acyclic complexes have been used for further condensation, and symmetric and asymmetric cyclic complexes have been obtained by their reaction with the polyamines H 2 NCH 2 [CH 2 XCH 2 ]nCH 2 NH 2 or with 4,4'-diaminodibenzo -18-crown-6. By reaction with 4-aminobenzo-15-crown-5 or 2-amino-methyl-15-crown-5, the same acyclic complexes give rise to functionalized complexes bearing crown-ether moieties. Analogously, the acyclic ligand H 3 -IXX, prepared by condensation of 2,6 diformyl-4-chlorophenol and tris(aminoethyl)amine, forms mono and homodinuclear lanthanum (III) complexes, which may undergo further condensation when reacted with primary functionalized amines. (authors). 42 refs., 2 figs., 2 schemes, 1 tab

Antimicrobial, thermoanalytical and viscometric studies of metal based schiff base polymer

International Nuclear Information System (INIS)

Mughal, M.A.; Mughal, A.

2013-01-01

This study examines the synthesis, characterization, viscosity, thermal behavior and antimicrobial studies of copper(II) and nickel(II), complexes of a synthesized monomer 5,5-methylene bis(2-pyridinecarboxaldehyde) (MBPC) and a Schiff base polymer poly-5,5-methylene bis (2-pyridinecarboxaldehyde) 1,3-propylenedimine (PMBPCPR). The monomer, polymeric ligand and poly metal complexes (PMBPCPRCu) and (PMBPCPRNi) were characterized by C.H.N analysis, FT-IR, UV - Vis spectroscopy, viscometery thermogravimetric (TGA) and differential thermogravimetry (DTA). The monomer MBPC was prepared by the reaction of 2-pyridinecarboxaldehyde with 1, 3, 5-trioxane in the presence of acetic acid and sulphuric acid. The polymeric ligand was prepared by polycondensation of monomer with 1,3-propylenediamine. The biological studies of compounds revealed that they possessed significant antibacterial and antifungal properties, against Micrococcus flavus, Staphylococcus aureus, Bacillus Cirroflgellosus, Shigella flexneri, Escherichia Coli, Candida albicans, Aspergillus flavus, and A. Niger. (author)

Preparation of CuO nanoparticles by thermal decomposition of double-helical dinuclear copper(II Schiff-base complexes

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Aliakbar Dehno Khalaji

2015-12-01

Full Text Available In this paper, two double helical dinuclear copper(II complexes of bis-N,O-bidentate Schiff base ligands bis(3-methoxy-N-salicylidene-4,4'-diaminodiphenylsulfone (L1 and bis(5-bromo-N-salicylidene-4,4'-diaminodiphenylsulfone (L2 were prepared and characterized by elemental analyses (CHN, as well as thermal analysis. Elemental analyses (CHN suggested that the reaction between ligands and copper salt has been occurred in 1:1 molar ratio. In these complexes the Schiff base ligands behaves as an anionic and bis-bidentate chelate and is coordinated to the copper(II ion via two phenolic oxygen and two iminic nitrogen atoms. In these double helical dinuclear complexes, each copper(II center has a pseudo-tetrahedral coordination sphere two-wrapped ligands. Thermal analysis of ligands and their complexes were studied in the range of room temperature to 750 °C with a heating rate of 10 °C min-1. TG plots show that the ligands and their complexes are thermally decomposed via 2 and 3 thermal steps, respectively. In addition, the complexes thermally decomposed in air at 520 °C for 3 h. The obtained solids characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray powder diffraction (XRD and transmission electron microscopy (TEM. The X-ray pattern result shows that the CuO nanoparticles are pure and single phase. The TEM result shows the as prepared CuO nanoparticles were very small and similar shape with particle size about

Synthesis, density functional theory calculations and luminescence of lanthanide complexes with 2,6-bis[(3-methoxybenzylidene)hydrazinocarbonyl] pyridine Schiff base ligand.

Science.gov (United States)

Taha, Ziyad A; Ababneh, Taher S; Hijazi, Ahmed K; Abu-Salem, Qutaiba; Ajlouni, Abdulaziz M; Ebwany, Shroq

2018-02-01

A pyridine-diacylhydrazone Schiff base ligand, L = 2,6-bis[(3-methoxy benzylidene)hydrazinocarbonyl]pyridine was prepared and characterized by single crystal X-ray diffraction. Lanthanide complexes, Ln-L, {[LnL(NO 3 ) 2 ]NO 3 .xH 2 O (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Er)} were prepared and characterized by elemental analysis, molar conductance, thermal analysis (TGA/DTGA), mass spectrometry (MS), Fourier transform infra-red (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Ln-L complexes are isostructural with four binding sites provided by two nitro groups along with four coordination sites for L. Density functional theory (DFT) calculations on L and its cationic [LnL(NO 3 ) 2 ] + complexes were carried out at the B3LYP/6-31G(d) level of theory. The FT-IR vibrational wavenumbers were computed and compared with the experimentally values. The luminescence investigations of L and Ln-L indicated that Tb-L and Eu-L complexes showed the characteristic luminescence of Tb(III) and Eu(III) ions. Ln-L complexes show higher antioxidant activity than the parent L ligand. Copyright © 2017 John Wiley & Sons, Ltd.

Chiral halogenated Schiff base compounds: green synthesis, anticancer activity and DNA-binding study

Science.gov (United States)

Ariyaeifar, Mahnaz; Amiri Rudbari, Hadi; Sahihi, Mehdi; Kazemi, Zahra; Kajani, Abolghasem Abbasi; Zali-Boeini, Hassan; Kordestani, Nazanin; Bruno, Giuseppe; Gharaghani, Sajjad

2018-06-01

Eight enantiomerically pure halogenated Schiff base compounds were synthesized by reaction of halogenated salicylaldehydes with 3-Amino-1,2-propanediol (R or S) in water as green solvent at ambient temperature. All compounds were characterized by elemental analyses, NMR (1H and 13C), circular dichroism (CD) and FT-IR spectroscopy. FS-DNA binding studies of these compounds carried out by fluorescence quenching and UV-vis spectroscopy. The obtained results revealed that the ligands bind to DNA as: (Rsbnd ClBr) > (Rsbnd Cl2) > (Rsbnd Br2) > (Rsbnd I2) and (Ssbnd ClBr) > (Ssbnd Cl2) > (Ssbnd Br2) > (Ssbnd I2), indicating the effect of halogen on binding constant. In addition, DNA-binding constant of the Ssbnd and R-enantiomers are different from each other. The ligands can form halogen bonds with DNA that were confirmed by molecular docking. This method was also measured the bond distances and bond angles. The study of obtained data can have concluded that binding affinity of the ligands to DNA depends on strength of halogen bonds. The potential anticancer activity of ligands were also evaluated on MCF-7 and HeLa cancer cell lines by using MTT assay. The results showed that the anticancer activity and FS-DNA interaction is significantly dependent on the stereoisomers of Schiff base compounds as R-enantiomers displayed significantly higher activity than S-enantiomers. The molecular docking was also used to illustrate the specific DNA-binding of synthesized compounds and groove binding mode of DNA interaction was proposed for them. In addition, molecular docking results indicated that there are three types of bonds (Hsbnd and X-bond and hX-bond) between synthesized compounds and base pairs of DNA.

A Study of Complexation-ability of Neutral Schiff Bases to Some Metal Cations

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Umit Cakir

2007-09-01

Full Text Available The constants of the extraction equilibrium and the distribution fordichloromethane as an organic solvent having low dielectric constant of metal cations withchiral Schiff bases, benzaldehydene-(S-2-amino-3-phenylpropanol (I, o- benzaldehydene-(S-2-hydroxybenzaldehydene-(S-2-amino-3-phenyl-propanol (II,amino-3-methylbutanol (III with anionic dyes [4-(2-pyridylazo-resorcinol mono sodiummonohydrate (NaPar, sodium picrat (NaPic and potassium picrat (KPic] and some heavymetal chlorides were determined at 25 oC. All the ligands have given strongestcomplexation for NaPar. In contrast, similar behaviour for both alkali metal picrates is notapparent in the complexation of corresponding ligands.

Chemistry of rhenium and technetium. II. Schiff base complexes with polyfunctional amino acids

International Nuclear Information System (INIS)

Du Preez, J.G.H.; Gerber, T.I.A.; Fourie, P.J.; Van Wyk, A.J.

1984-01-01

Amino acid Schiff base technetium(V) complexes of salicylaldehyde with l-cysteine, l-serine, l-histodine, l-threonine, l-glutamic acid and l-tryptophan have been preapred by direct reaction and by constituent combination. The amino acid part of the ligands coordinates to the technetium through the carboxylate group, while the other available functional group of the amino acids plays a more minor role as blocking group or in intramolecular bonding. 3 tables

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

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K. Mohanan

2016-07-01

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

Synthesis of Two Potentially Heptadentate (N4O3 Schiff-base Ligands Derived from Condensation of Tris(3-aminopropyl-amine and Salicylaldehyde or 4-Hydroxysalicylaldehyde. Nickel(II and Copper(II Complexes of the Former Ligand

Directory of Open Access Journals (Sweden)

R. V. Parish

2002-02-01

Full Text Available Two potentially heptadentate (N4O3 tripodal Schiff-base ligands: tris(3-(salicylideneiminopropylamine (H3L1 and tris(3-(4’-hydroxysalicylideneimino-propylamine (H3L2 have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR. They are derived from the condensation reactions of tris(3-aminopropylamine (tpt, with 3 equivalents of either salicylaldehyde or the ringsubstituted salicylaldehyde, 4-hydroxysalicylaldehyde. The nickel(II and copper(II complexes of H3L1 were obtained from the its reactions Ni(II and Cu(II salts in absolute methanol. These complexes were studied by IR and FAB-Mass spectrometry.

Synthesis, Spectroscopy, Thermal Analysis, Magnetic Properties and Biological Activity Studies of Cu(II and Co(II Complexes with Schiff Base Dye Ligands

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Saeid Amani

2012-05-01

Full Text Available Three azo group-containing Schiff base ligands, namely 1-{3-[(3-hydroxy-propyliminomethyl]-4-hydroxyphenylazo}-4-nitrobenzene (2a, 1-{3-[(3-hydroxypropyl-iminomethyl]-4-hydroxyphenylazo}-2-chloro-4-nitrobenzene (2b and 1-{3-[(3-hydroxy-propyliminomethyl]-4-hydroxyphenylazo}-4-chloro-3-nitrobenzene (2c were prepared. The ligands were characterized by elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, ¹³C- and ¹H-NMR spectroscopy and thermogravimetric analysis. Next the corresponding copper(II and cobalt(II metal complexes were synthesized and characterized by the physicochemical and spectroscopic methods of elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, magnetic moment measurements, and thermogravimetric analysis (TGA and (DSC. The room temperature effective magnetic moments of complexes are 1.45, 1.56, 1.62, 2.16, 2.26 and 2.80 B.M. for complexes 3a, 3b, 3c, 4a 4b, and 4c, respectively, indicating that the complexes are paramagnetic with considerable electronic communication between the two metal centers.

synthesis, characterization an complexes with schiff base co

African Journals Online (AJOL)

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active Ru(II) complexes with coordinating Schiff base were synthesiz lemental ... synthesis and stability of Schiff bases wh ... chelates with anticancer activity have also ..... iron.Inorg. Chem,23(1), 3-10. Kostova, I.; Sasa, L.(2013). Advances in.

New ruthenium(II) carbonyl complexes bearing disulfide Schiff base ligands and their applications as catalyst for some organic transformations

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Prakash, Govindan; Viswanathamurthi, Periasamy

2014-08-01

Schiff base disulfide ligands (H2L1-6) were synthesized from the condensation of cystamine with salicylaldehyde(H2L1), 5-chlorosalicylaldehyde(H2L2), o-vanillin(H2L3), 2-hydroxyacetophenone(H2L4), 3-methyl-2-hydroxyacetophenone(H2L5), and 2-hydroxy-1-naphthaldehyde(H2L6). H2L1-6 reacts with the ruthenium precursor complex [RuHCl(CO)(PPh3)3] in benzene giving rise to six new ruthenium(II) complexes of general formula [Ru(CO)L1-6]. Characterization of the new complexes was carried out by using elemental and spectral (IR, UV-Vis, NMR (1H and 13C) and Mass) techniques. An octahedral geometry was assigned for all the complexes based on the spectral data obtained. The catalytic efficiency of the new complexes in aldehyde to amide conversion in the presence of NaHCO3, N-alkylation of aniline in the presence of t-BuOK, and transfer hydrogenation of ketones in the presence of iPrOH/KOH reactions were studied. Furthermore, the effect of solvents and catalyst/substrate ratio on the catalytic aldehyde to amide conversion were also discussed.

Synthesis of New Chiral Ligands Based on Thiophene Derivatives for Use in Catalytic Asymmetric Oxidation of Sulfides

International Nuclear Information System (INIS)

Jeong, Yong Chul; Ahn, Dae Jun; Lee, Woo Sun; Lee, Seung Han; Ahn, Kwang Hyun

2011-01-01

We discovered that the vanadium complexes of new Schiff base ligands and prepared from thiophene derivatives efficiently catalyze the asymmetric oxidation of sulfides by hydrogen peroxide to provide sulfoxides with enantioselectivities up to 79% ee and in yields up to 89%. Notably, Schiff base showed better or similar enantioselectivity than the well-studied Schiff base. These results suggest possible applications of Schiff bases derived from and in other catalytic asymmetric reactions. Chiral sulfoxides are important functional groups for various applications. For example, the biological activities of sulfoxide containing drugs such as omeprazole are strongly related to the chirality of the sulfoxide group; for this reason, esomeprazole, the enantiomerically pure form of omeprazole, was later developed. There are several chiral sulfoxide based drugs that have been introduced by the pharmaceutical industry including armodafinil, aprikalim, oxisurane, and ustiloxin. Chiral sulfoxides have also been utilized as chiral auxiliaries in asymmetric syntheses of chiral intermediates

A new copper(II) Schiff base complex containing asymmetrical tetradentate N.sub.2./sub.O.sub.2./sub. Schiff base ligand: Synthesis, characterization, crystal structure and DFT study

Czech Academy of Sciences Publication Activity Database

Grivani, G.; Baghan, S.H.; Vakili, M.; Khalaji, A.D.; Tahmasebi, V.; Eigner, Václav; Dušek, Michal

2015-01-01

Roč. 1082, Feb (2015), 91-96 ISSN 0022-2860 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : Schiff-base * copper (II) * complex * single-crystal * thermal decomposition * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.780, year: 2015

Spectroscopic studies on two mono nuclear iron (III) complexes derived from a schiff base and an azodye

International Nuclear Information System (INIS)

Mini, S.; Sadasivan, V.; Meena, S. S.; Bhatt, Pramod

2014-01-01

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 3 Ðœ‡2H 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 2 O) 2 ] and [Fe(FAHP)Cl 2 (H 2 O) 2

Synthesis and Spectral Characterization of Antifungal Sensitive Schiff Base Transition Metal Complexes

Science.gov (United States)

Sakthivel, A.; Rajasekaran, K.

2007-01-01

New N2O2 donor type Schiff base has been designed and synthesized by condensing acetoacetanilido-4-aminoantipyrine with 2-aminobenzoic acid in ethanol. Solid metal complexes of the Schiff base with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), VO(IV), Hg(II) and Cd(II) metal ions were synthesized and characterized by elemental analyses, magnetic susceptibility, molar conduction, fast atom bombardment (FAB) mass, IR, UV-Vis, and 1H NMR spectral studies. The data show that the complexes have the composition of ML type. The UV-Vis. and magnetic susceptibility data of the complexes suggest a square-planar geometry around the central metal ion except VO(IV) complex which has square-pyramidal geometry. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer, Candida albicans, Rhizoctonia bataicola and Trichoderma harizanum. All the metal complexes showed stronger antifungal activities than the free ligand. The minimum inhibitory concentrations (MIC) of the metal complexes were found in the range of 10~31 µg/ml. PMID:24015086

Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Shuranjan; Lee, Hong In [Kyungpook National University, Daegu (Korea, Republic of); Moon, Do Hyun [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Lah, Myoung Soo [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2010-11-15

New complex [Mn(II)H{sub 1.5}L]{sub 2}[Mn(II)H{sub 3}L]{sub 2}(ClO{sub 4}){sub 5}·3H{sub 2}O, where H{sub 3}L is tris{2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of [Mn(II)H{sub 1.5}L]{sup 0.5+} complex ions are extended to build a 2D puckered network with trigonal voids. [Mn(II)H{sub 3}L]{sup 2+} complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)- 6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of ABTS{sup +·} was observed by UV-vis and EPR spectroscopies, indicating that the complex 1, a fully-coordinated mononuclear Mn(II) complex with nitrogen-only ligand, has a heme-independent peroxidase activity.

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}].

Synthesis, spectroscopic and biological activities studies of acyclic and macrocyclic mono and binuclear metal complexes containing a hard-soft Schiff base.

Science.gov (United States)

Abou-Hussein, Azza A A; Linert, Wolfgang

2012-09-01

Mono- and bi-nuclear acyclic and macrocyclic complexes with hard-soft Schiff base, H(2)L, ligand derived from the reaction of 4,6-diacetylresorcinol and thiocabohydrazide, in the molar ratio 1:2 have been prepared. The H(2)L ligand reacts with Co(II), Ni(II), Cu(II), Zn(II), Mn(II) and UO(2)(VI) nitrates, VO(IV) sulfate and Ru(III) chloride to get acyclic binuclear complexes except for VO(IV) and Ru(III) which gave acyclic mono-nuclear complexes. Reaction of the acyclic mono-nuclear VO(IV) and Ru(III) complexes with 4,6-diacetylresorcinol afforded the corresponding macrocyclic mono-nuclear VO(IV) and Ru(IIII) complexes. Template reactions of the 4,6-diacetylresorcinol and thiocarbohydrazide with either VO(IV) or Ru(III) salts afforded the macrocyclic binuclear VO(IV) and Ru(III) complexes. The Schiff base, H(2)L, ligand acts as dibasic with two NSO-tridentate sites and can coordinate with two metal ions to form binuclear complexes after the deprotonation of the hydrogen atoms of the phenolic groups in all the complexes, except in the case of the acyclic mononuclear Ru(III) and VO(IV) complexes, where the Schiff base behaves as neutral tetradentate chelate with N(2)S(2) donor atoms. The ligands and the metal complexes were characterized by elemental analysis, IR, UV-vis (1)H-NMR, thermal gravimetric analysis (TGA) and ESR, as well as the measurements of conductivity and magnetic moments at room temperature. Electronic spectra and magnetic moments of the complexes indicate the geometries of the metal centers are either tetrahedral, square planar or octahedral. Kinetic and thermodynamic parameters were calculated using Coats-Redfern equation, for the different thermal decomposition steps of the complexes. The ligands and the metal complexes were screened for their antimicrobial activity against Staphylococcus aureus as Gram-positive bacteria, and Pseudomonas fluorescens as Gram-negative bacteria in addition to Fusarium oxysporum fungus. Most of the complexes exhibit

An Efficient Catalyst for the Synthesis of Schiff Bases

International Nuclear Information System (INIS)

Fareed, G.; Afza, N.; Kalhoro, M.A.

2013-01-01

An efficient high yielding synthesis of Schiff bases (1-17) is derived from condensation of 2-fluorenamine and 4-amino phenol with a variety of aldehydes catalyzed by dodecatungstosilicic acid P/sub 2/O/sub 5/ under solvent free conditions at room temperature. The catayst is found to be more efficient in terms of ease of reaction workup and high yields. This methodology contributes to an energy efficient, facile and environamental friendly synthesis for the preparation of Schiff bases. The structures of afforded Schiff bases were characterized by spectroscopic data and elemental analysis. (author)

Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-[(1H-benzimidazol-2-yl-methylene) amino] phenol

International Nuclear Information System (INIS)

Omprakash, K.L.; Chandra Pal, A.V.; Reddy, M.L.N.

1982-01-01

A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO 4 ) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (logβ 2 ) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III). (author)

Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-((1H-benzimidazol-2-yl-methylene) amino) phenol

Energy Technology Data Exchange (ETDEWEB)

Omprakash, K L; Chandra Pal, A V; Reddy, M L.N. [Osmania Univ., Hyderabad (India). Dept. of Chemistry

1982-03-01

A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO/sub 4/) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (log..beta../sub 2/) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III).

New fluorescent azo-Schiff base Cu(II) and Zn(II) metal chelates; spectral, structural, electrochemical, photoluminescence and computational studies

Science.gov (United States)

Purtas, Fatih; Sayin, Koray; Ceyhan, Gokhan; Kose, Muhammet; Kurtoglu, Mukerrem

2017-06-01

A new Schiff base containing azo chromophore group obtained by condensation of 2-hydroxy-4-[(E)-phenyldiazenyl]benzaldehyde with 3,4-dimethylaniline (HL) are used for the syntheses of new copper(II) and zinc(II) chelates, [Cu(L)2], and [Zn(L)2], and characterized by physico-chemical and spectroscopic methods such as 1H and 13C NMR, IR, UV.-Vis. and elemental analyses. The solid state structure of the ligand was characterized by single crystal X-ray diffraction study. X-ray diffraction data was then used to calculate the harmonic oscillator model of aromaticity (HOMA) indexes for the rings so as to investigate of enol-imine and keto-amine tautomeric forms in the solid state. The phenol ring C10-C15 shows a considerable deviation from the aromaticity with HOMA value of 0.837 suggesting the shift towards the keto-amine tautomeric form in the solid state. The analytical data show that the metal to ligand ratio in the chelates was found to be 1:2. Theoretical calculations of the possible isomers of the ligand and two metal complexes are performed by using B3LYP method. Electrochemical and photoluminescence properties of the synthesized azo-Schiff bases were also investigated.

Synthesis of a new ONNO donor tetradentate schiff base ligand and binuclear Cu(II) complex: Quantum chemical, spectroscopic and photoluminescence investigations

International Nuclear Information System (INIS)

Sarıoğlu, Ahmet Oral; Ceylan, Ümit; Yalçın, Şerife Pınar; Sönmez, Mehmet; Ceyhan, Gökhan; Aygün, Muhittin

2016-01-01

The Schiff base compound 3,3′-(1,4-phenylimino)-bis-[1,3-bis-(4-methoxyphenyl) propan-1-one)], formulated as C 40 H 36 N 2 O 6, and its Cu(II) complex were synthesized and characterized by analytical analysis, various spectral techniques such as FT-IR, NMR, UV–vis, magnetic measurements and molar conductivity. Thermo gravimetric analysis (TGA and DTA) carried out to obtain information about its thermal stability. The molecular structure and spectroscopic properties of the ligand were obtained with FT-IR, 1 H and 13 C NMR, UV–vis investigations as experimentally and compared with theoretical results obtained from DFT/B3LYP/6-311++G(d,p) basis set. In addition to molecular calculations of the title compound, molecular electrostatic potential (MEP), dipole moments, atomic charges, HOMO–LUMO, NLO and NBO analysis were computed. The calculated results show that the optimized geometry can well reproduce the crystal structure parameters, and the theoretical vibrational frequencies, 1 H and 13 C NMR chemical shifts show good agreement with experimental values. Photoluminescence properties of the ligand and its Cu(II) complex were examined. - Highlights: • FT-IR and 1 H– 13 C NMR spectra were recorded and compared with the theoretical results. • The photoluminescence properties were studied. • NLO, NBO analysis of the molecule were studied. • HOMO and LUMO energies, MEP distribution of the molecule were calculated.

Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

International Nuclear Information System (INIS)

Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei

2015-01-01

Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H_2ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H_2hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd_2(2,6-ndc)_2(bpp)(DMF)]·2DMF (1) and [Cd_3(hmdb)_3(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.

Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

Energy Technology Data Exchange (ETDEWEB)

Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei, E-mail: hanlei@nbu.edu.cn

2015-12-15

Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H{sub 2}ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H{sub 2}hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd{sub 2}(2,6-ndc){sub 2}(bpp)(DMF)]·2DMF (1) and [Cd{sub 3}(hmdb){sub 3}(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.

Structural investigation of oxovanadium(IV) Schiff base complexes: X-ray crystallography, electrochemistry and kinetic of thermal decomposition.

Science.gov (United States)

Asadi, Mozaffar; Asadi, Zahra; Savaripoor, Nooshin; Dusek, Michal; Eigner, Vaclav; Shorkaei, Mohammad Ranjkesh; Sedaghat, Moslem

2015-02-05

A series of new VO(IV) complexes of tetradentate N2O2 Schiff base ligands (L(1)-L(4)), were synthesized and characterized by FT-IR, UV-vis and elemental analysis. The structure of the complex VOL(1)⋅DMF was also investigated by X-ray crystallography which revealed a vanadyl center with distorted octahedral coordination where the 2-aza and 2-oxo coordinating sites of the ligand were perpendicular to the "-yl" oxygen. 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: MeO5-H>5-Br>5-Cl. Furthermore, the kinetic parameters of thermal decomposition were calculated by using the Coats-Redfern equation. According to the Coats-Redfern plots the kinetics of thermal decomposition of studied complexes is of the first-order in all stages, the free energy of activation for each following stage is larger than the previous one and the complexes have good thermal stability. The preparation of VOL(1)⋅DMF yielded also another compound, one kind of vanadium oxide [VO]X, with different habitus of crystals, (platelet instead of prisma) and without L(1) ligand, consisting of a V10O28 cage, diaminium moiety and dimethylamonium as a counter ions. Because its crystal structure was also new, we reported it along with the targeted complex. Copyright © 2014 Elsevier B.V. All rights reserved.

benzoic acid Schiff base and evaluation as corrosion

African Journals Online (AJOL)

user

acid Schiff base and evaluation as corrosion inhibitor of steel in 2.0 M H2SO4. *. 1. ECHEM .... adopted for this experiment was in accordance with .... Table 4: Kinetic data for mild steel corrosion in 2M H2SO4 containing SBDAB from weight loss measurement. inhibitor .... and anti-bacterial activity of Schiff base derived.

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

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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.

A novel approach toward the synthesis of some new tridentate Schiff bases from anil-like compounds

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Bagheri Fatemeh

2016-01-01

Full Text Available A novel method was developed for synthesizing a series of new three dentate Schiff base ligands starting from hydroxynaphthalidene pyrimidinyl amines with o-phenylenediamines or o-aminophenol or 2-amino-3-hydroxy-pyri-dine in the presence of formic acid catalyst under solvent-free conditions. In these reactions [1+1] condensation product as half-unit ligand was obtained. Moreover, the reaction of hydroxynaphthalidene pyrimidinyl amines with 3,4-diamino-pyridine and 1,8-naphthalenediamine lead to the formation of C2-naphthylated imidazopyridine and dihydropyrimidine, respectively. The attractive features of this protocol are: use of inexpensive catalyst, operationally simple, short reaction times, easy handling, and good yields.

Synthesis, characterization, spectroscopic and catalytic oxidation studies of Fe(III), Ni(II), Co(III), V(IV) and U(VI) Schiff base complexes with N, O donor ligands derived from 2,3-diaminopyridine

Energy Technology Data Exchange (ETDEWEB)

Zabardasti, Abedien; Shangaie, Sayed Asad [Lorestan Univ., Khorramabad (Iran, Islamic Republic of). Dept. of Chemistry

2016-10-15

Fifteen new complexes of transition metals were designed using three Schiff base ligands and aldol condensation of 2,3-diaminopyridine with 5-R-2-hydroxybenzaldehyde (R = F, Cl, Br) in the 1:2 molar ratio. The tetradentate ligands N,N{sup '}-bis(5-R-2-hydroxybenzaldehyde) pyridine were acquired with the common formula H{sub 2}[(5-R-sal){sub 2}py] and characterized by IR, UV-Vis spectra, {sup 1}H-NMR and elemental analysis. These ligands produce 1:1 complexes M[(5-R-sal){sub 2}py] with Fe(III), Ni(II), Co(III), V(IV) and U(VI) metal ions. The electronic property and nature of complexes were identified by IR, UV-Vis spectra, elemental analysis, X-ray crystallography and cyclic voltammetric methods. The catalytic activity of complexes for epoxidation of styrene with UHP as primary oxidant at minimal temperature (10 C) has been planned. The spectral data of the ligands and their complexes are deliberate in connection with the structural changes which happen due to complex preparation. The electrochemical outcome has good conformability with what suggested for electronic interaction among metal center and ligand by the UV-Vis and IR measurements.

New insights into the coordination chemistry of Schiff bases derived from amino acids: Planar [Ni4] complexes with tyrosine side-chains

Science.gov (United States)

Muche, Simon; Hołyńska, Małgorzata

2017-08-01

Structure and properties of a rare metal complex of the chiral Schiff base ligand derived from ortho-vanillin and L-tyrosine are presented. This study is a continuation of research on ligands containing biologically compatible moieties. The ligand is also fully characterized in form of a sodium salt, in particular in solution, for the first time. The metal complex contains a unique bowl-shaped [Ni4] core. Its structure is investigated both in solution (ESI-MS, NMR) and in solid state (X-ray diffraction studies). Under certain conditions the complex can be isolated as crystalline DMF solvate which is studied in solid state.

Mixed ligand chelates of rare earths in aqueous solution

International Nuclear Information System (INIS)

Lakhani, S.U.; Thakur, G.S.; Sangal, S.P.

1981-01-01

Mixed ligand chelates of the 1:1 trivalent lanthanoids-EDTA, HEDTA and NTA chelates-1, 2-Dihydroxybenzene (Pyrocatechol) have been investigated at 35degC and 0.2 M ionic strength maintained by NaC10 4 . The formation of mixed ligand chelates has been found in all cases. The formation of mixed ligand chelates with EDTA shows the coordination number of lanthanoids to be eight, while the mixed ligand chelates with HEDTA and NTA shows the coordination number to be seven and six respectively. The stability constants of mixed ligand chelates are smaller than the binary complexes. The order of stability constants with respect to primary ligands follows the order NTA>HEDTA>EDTA. With respect to metal ions the stability constants increases with the decrease in ionic radii such as Gd< Er< Yb. (author)

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

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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.

Bioinorganic Relevance of Some Cobalt(II Complexes with Thiophene-2-glyoxal Derived Schiff Bases

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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.

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

International Nuclear Information System (INIS)

Liu Huan; Fu Zien; Xu Kai; Cai Hualun; Liu Xin; Chen Mingcai

2012-01-01

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: ► In this work, we first proposed that specific effects of highly conjugated Schiff-base moiety on thermal properties of the Schiff-base epoxy polymer. ► As one aim of this study, the thermal and thermal-oxidative stabilities of the thermosets were studied by TGA under nitrogen and under air. ► The second aim of this study was to further understand the thermal degradation mechanism. ► 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. ► 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 epoxy polymer (DGEBA/MDA) and other mesogene-containing epoxy polymer. It is worth pointing out that the outstanding residual

Theoretical Semi-Empirical AM1 studies of Schiff Bases

International Nuclear Information System (INIS)

Arora, K.; Burman, K.

2005-01-01

The present communication reports the theoretical semi-empirical studies of schiff bases of 2-amino pyridine along with their comparison with their parent compounds. Theoretical studies reveal that it is the azomethine group, in the schiff bases under study, that acts as site for coordination to metals as it is reported by many coordination chemists. (author)

Synthesis of new nano Schiff base complexes: X-ray crystallography ...

African Journals Online (AJOL)

This study presents synthesis and characterization of new nano uranyl Schiff base complexes. Electrochemistry of these complexes showed a quasireversible redox reaction without any successive reactions. Furthermore, X-ray crystallography exhibited that beside the coordination of tetradentate Schiff base, one solvent ...

EPR interpretation, magnetism and biological study of a Cu(II) dinuclear complex assisted by a schiff base precursor.

Science.gov (United States)

Das, Kuheli; Patra, Chiranjit; Sen, Chandana; Datta, Amitabha; Massera, Chiara; Garribba, Eugenio; El Fallah, Mohamed Salah; Beyene, Belete B; Hung, Chen-Hsiung; Sinha, Chittaranjan; Askun, Tulin; Celikboyun, Pinar; Escudero, Daniel; Frontera, Antonio

2017-06-01

A new Cu(II) dinuclear complex, Cu 2 L 2 (1) was afforded employing the potentially pentatentate Schiff base precursor H 2 L, a refluxed product of o-vanillin and diethylenetriamine in methanol. Complex 1 was systematically characterized by FTIR, UV-Vis, emission and EPR spectrometry. The single crystal X-ray diffraction analysis of 1 reveals that the copper atom exhibits a distorted square planar geometry, comprising two pairs of phenolato-O and imine-N donors from two different H 2 L ligands. The temperature dependent magnetic interpretation agrees with the existence of weak antiferromagnetic interactions between the bridging dinuclear Cu(II) ions. A considerable body of experimental evidence has been accumulated to elucidate the magneto-structural relationship in this dinuclear Cu(II) complex by DFT computation. Both the ligand and complex 1 exhibit anti-mycobacterial activity and considerable efficacy on M. tuberculosis H 37 Ra (ATCC 25177) and M. tuberculosis H 37 Rv (ATCC 25618) strains. The practical applicability of the ligand and complex 1 has been examined in living cells (African Monkey Vero Cells). The MTT assay proves the non-toxicity of the probe up to 100 mg mL -1 . A new homometallic dinuclear Cu(II) complex is afforded with a tetradentate Schiff base precursor. EPR interpretation and temperature dependent magnetic studies show that complex 1 has weak antiferromagnetic coupling and DFT computation is governed to explain the magneto-structural correlation.

Synthesis and luminescence properties of novel 4-(N-carbazole methyl) benzoyl hydrazone Schiff bases

International Nuclear Information System (INIS)

Guo Dongcai; Wu Panliang; Tan Hui; Xia Long; Zhou Wenhui

2011-01-01

4-(N-carbazole methyl) benzoyl hydrazine was synthesized on the basis of carbazole, and then nine novel carbazolyl acylhydrazone Schiff bases were synthesized by the condensation reaction between 4-(N-carbazole methyl) benzoyl hydrazine and the substituted benzaldehydes. The relationships between the substituted group types and the UV fluorescence spectral properties, as well as the fluorescence quantum yields of the title Schiff bases were also investigated. The results show that the introduction of both the donating and accepting electron groups causes various grade redshifts of the fluorescence characteristic emission peak of the title Schiff bases to occur.The fluorescence quantum yields of the title Schiff bases with the donating group are increased, and the highest fluorescence quantum yield is up to 0.703. - Highlights: → Nine novel Schiff bases have been designed and synthesized. → Introduction of the donating electron groups causes various grade red shifts of the fluorescence characteristic emission peak and the UV characteristic absorption peak of the synthesized Schiff bases. → Introduction of the donating electron groups causes the fluorescence quantum yields to be increased considerably. →Introduction of the accepting electron groups causes the fluorescence intensity and quantum yield of the synthesized Schiff bases to be reduced. → Fluorescence quantum yield of o-hydroxyl-substituted Schiff base is up to 0.703; this Schiff base is expected to be used as hole transport optical material.

Synthesis, spectroscopy and antimicrobial activity of vanadium(III) and vanadium(IV) complexes involving Schiff bases derived from tranexamic acid and X-ray structure of Zwitter ion of tranexamic acid

International Nuclear Information System (INIS)

Shahzadi, S.; Ali, S.; Badshah, A.; Parvez, M.; Ahmed, E.; Malik, A.

2007-01-01

The synthesis of six new vanadium complexes of Schiff base derived from Tranexamic acid is reported. All the complexes were characterized by elemental analysis, infrared, electronic spectra, and mass spectrometry. FTIR data reveals that the Schiff base acts as a bidentate and the complexes exhibit the hexa-coordinated geometry in solid state. These complexes were screened for their biological activity against various bacterial and fungal strains. All the ligands show higher activity after complexation. The crystal structure of the Zwitter ion of the Tranexamic acid has been determined by X-ray single crystal diffraction [ru

Lanthanide(III) Complexes with Tridentate Schiff Base Ligand ...

African Journals Online (AJOL)

Lanthanide complexes, hydrazino, antioxidant activity, X-ray structure. 1. Introduction ... measured using a Johnson Matthey scientific magnetic suscepti- bility balance. 2.1. .... of the ligand and that the nitrogen atom supporting this proton is not involved in the ... 4f-electrons are not involved in the coordination. These facts.

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.

2009-07-01

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 1H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, 1H 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*, ΔH*, ΔS* and ΔG* 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.

Synthesis, spectroscopic and DNA binding ability of Co{sup II}, Ni{sup II}, Cu{sup II} and Zn{sup II} complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex

Energy Technology Data Exchange (ETDEWEB)

Yarkandi, Naeema H. [Chemistry Department, Faculty of Applied Science, Umm Al–Qura University, Makkah (Saudi Arabia); El-Ghamry, Hoda A., E-mail: helghamrymo@yahoo.com [Chemistry Department, Faculty of Applied Science, Umm Al–Qura University, Makkah (Saudi Arabia); Chemistry Department, Faculty of Science, Tanta University, Tanta (Egypt); Gaber, Mohamed [Chemistry Department, Faculty of Science, Tanta University, Tanta (Egypt)

2017-06-01

A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L){sub 2}]·l2H{sub 2}O, [Ni(L)Cl·(H{sub 2}O){sub 2}].5H{sub 2}O, [Cu(L)Cl] and [Zn(L)(CH{sub 3}COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, {sup 1}H &{sup 13}C NMR, mass spectral analysis, molar conductivity measurement, UV–Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV–Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (K{sub b}). - Highlights: • Synthesis of Co{sup II}, Ni{sup II}, Cu{sup II} and Zn{sup II} complexes of the Schiff base ligand based on 2-(aminomethyl)benzimidazole moiety. • The constitutions and structures of the ligand and complexes were elucidated. • Molecular structure of Co{sup II} complex was confirmed by single crystal X-ray diffraction method. • The ligand and its complexes interact with SS-DNA via intercalation mods.

Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

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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.

Tetradentate-arm Schiff base derived from the condensation reaction of 3,3′-dihydroxybenzidine, glyoxal/diacetyl and 2-aminophenol: Designing, structural elucidation and properties of their binuclear metal(II complexes

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E. Akila

2017-05-01

Full Text Available The novel binuclear Schiff base complexes were prepared by the reaction of 3,3′-dihydroxybenzidine, glyoxal/diacetyl and 2-aminophenol in 1:2:2 M ratio. The binucleating Schiff base ligand and its complexes of Cu(II, Ni(II and VO(II ions were characterized by elemental analysis, molar conductance, 1H NMR, infrared, electronic spectra, cyclic voltammetry, thermal, magnetic and EPR studies. The low molar conductance values of the complexes support the non-electrolytic in nature. In IR spectra, the comparison of shift in frequency of the complexes with the ligand reveals the coordination of donor atom to the metal atom. The binuclear nature of the complexes is assessed from their magnetic susceptibility values. The electronic and EPR spectra of the metal complexes provide information about the geometry of the complexes and are in good agreement with the proposed square planar geometry for Cu(II, Ni(II and square pyramidal for VO(II complexes. Molecular modeling has been used to suggest the structure of the complexes. The DNA cleavage ability of the complexes was monitored by gel electrophoresis using supercoiled pUC18 DNA. The metal complexes were screened for their antibacterial activities against pathogenic bacteria like Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Bacillus subtilis. The activity data show that the metal complexes are more potent activity than the parent Schiff base ligand against microorganisms.

Synthesis of new Schiff bases as materials for the design of ...

African Journals Online (AJOL)

Synthesis of new Schiff bases as materials for the design of photovoltaics cells. ... We describe the synthesis of new organic Schiff bases chromophores 5 containing a rhodanine-3- acetic as electron accepteur moiety. Imines 3 were obtained by a condensation reaction from a lead molecule, the aminothiazolinethione 1 with ...

Nickel Oxide (NiO nanoparticles prepared by solid-state thermal decomposition of Nickel (II schiff base precursor

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Aliakbar Dehno Khalaji

2015-06-01

Full Text Available In this paper, plate-like NiO nanoparticles were prepared by one-pot solid-state thermal decomposition of nickel (II Schiff base complex as new precursor. First, the nickel (II Schiff base precursor was prepared by solid-state grinding using nickel (II nitrate hexahydrate, Ni(NO32∙6H2O, and the Schiff base ligand N,N′-bis-(salicylidene benzene-1,4-diamine for 30 min without using any solvent, catalyst, template or surfactant. It was characterized by Fourier Transform Infrared spectroscopy (FT-IR and elemental analysis (CHN. The resultant solid was subsequently annealed in the electrical furnace at 450 °C for 3 h in air atmosphere. Nanoparticles of NiO were produced and characterized by X-ray powder diffraction (XRD at 2θ degree 0-140°, FT-IR spectroscopy, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The XRD and FT-IR results showed that the product is pure and has good crystallinity with cubic structure because no characteristic peaks of impurity were observed, while the SEM and TEM results showed that the obtained product is tiny, aggregated with plate-like shape, narrow size distribution with an average size between 10-40 nm. Results show that the solid state thermal decomposition method is simple, environmentally friendly, safe and suitable for preparation of NiO nanoparticles. This method can also be used to synthesize nanoparticles of other metal oxides.

Synthesis and characterization of mixed ligand chiral nanoclusters

KAUST Repository

Guven, Zekiye P.; Ustbas, Burcin; Harkness, Kellen M.; Coskun, Hikmet; Joshi, Chakra Prasad; Besong, Tabot M.D.; Stellacci, Francesco; Bakr, Osman; Akbulut, Ozge

2016-01-01

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

Synthesis and characterization of mixed ligand chiral nanoclusters

KAUST Repository

Guven, Zekiye P.

2016-06-22

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

Synthesis, characterization and biological activity of some transition metals with Schiff base derived from 2-thiophene carboxaldehyde and aminobenzoic acid

Science.gov (United States)

Mohamed, Gehad G.; Omar, M. M.; Hindy, Ahmed M. M.

2005-12-01

Metal complexes of Schiff base derived from 2-thiophene carboxaldehyde and 2-aminobenzoic acid (HL) are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analysis (TGA). The ligand dissociation as well as the metal-ligand stability constants were calculated pH metrically at 25 °C and ionic strength μ = 0.1 (1 M NaCl). The complexes are found to have the formulae [M(HL) 2](X) n· yH 2O (where M = Fe(III) (X = Cl, n = 3, y = 3), Co(II) (X = Cl, n = 2, y = 1.5), Ni(II) (X = Cl, n = 2, y = 1) and UO 2(II) (X = NO 3, n = 2, y = 0)) and [M(L) 2] (where M = Cu(II) (X = Cl) and Zn(II) (X = AcO)). The molar conductance data reveal that Fe(III) and Co(II), Ni(II) and UO 2(II) chelates are ionic in nature and are of the type 3:1 and 2:1 electrolytes, respectively, while Cu(II) and Zn(II) complexes are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a terdentate manner with ONS donor sites of the carboxylate O, azomethine N and thiophene S. From the magnetic and solid reflectance spectra, it is found that the geometrical structure 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*, Δ H*, Δ S* and Δ G* 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 Schiff base ligand against one or more bacterial species.

Synthesis, characterization, density functional study and antimicrobial evaluation of a series of bischelated complexes with a dithiocarbazate Schiff base ligand

Directory of Open Access Journals (Sweden)

E. Zangrando

2017-02-01

Full Text Available A nitrogen-sulfur Schiff base HL (1 derived from S-hexyldithiocarbazate and 4-methylbenzaldehyde has been reacted with different divalent metal ions in 2:1 molar ratio, producing neutral complexes (2–7 of general formula MIIL2 (where M = Ni, Cu, Zn, Cd, Pd and Pb. All compounds were characterized using established physico-chemical and spectroscopic methods. The single crystal structures of CuII and ZnII complexes are compared and discussed with those of NiII and PdII already reported by us, underlining the geometrical variations occurring in the HL ligand upon coordination. The metal complexes, as revealed by the X-ray diffraction analyses, show a square planar or tetrahedral coordination geometry, and in the former case either a cisoid or transoid configuration of chelating ligands. Density functional theory (DFT and time-dependent density functional theory (TD-DFT calculations have been performed on the isolated cis/trans complexes of Ni and Pd complexes in order to evaluate the stability of the isomer isolated in solid state. The thermodynamic parameters for trans to cis isomerization of NiL2 complex [ΔH = −29.12 kJ/mol and ΔG = −43.97 kJ/mol] indicated that the trans isomer (observed in solid state is more stable than the cis one. On the other hand, relative enthalpy [ΔH = −4.37 kJ/mol] and Gibbs free energy [ΔG = −5.50 kJ/mol] of PdL2 complex disclosed a small difference between the energies of the two isomers. Experimental UV–vis and TD-DFT calculation confirmed that these complexes have distinctive LMCT bands with a broad shoulder at 400–550 nm. With the purpose of providing insight into the properties and behavior of the complexes in solution, photoluminescence and electrochemical experiments have been also performed. Finally, the anti-bacterial activity of these compounds was evaluated against three pathogenic Gram-negative organisms such as Escherichia coli, Salmonella typhi and Shigella flexneri, but

Synthetic structural and biochemical studies of coordination compounds of Bismuth (III) with Schiff bases of sulpha drugs

International Nuclear Information System (INIS)

Khan, Shahina; Gupta, M.K.; Varshney, S; Varshney, A.K.

2006-01-01

The reactions of Bismuth trichloride with Schiff's bases derived from sulpha drugs in 1:1 molar ratio leads to the formation of a new series of coordination compound of Bismuth (III). Their structures have been confirmed on the basis of elemental analysis, ultraviolet, infrared and multinuclear magnetic resonance (1H 13C) spectral studies. The antimicrobial activities of the ligands and their coordination compound have been screened in vitro against the organism Escherichia coli, Stuplhylococus crureus, Prouteus mirabilis, Bacillus thuren giensis, penicilliurn cf.vsogenum, Aspergillns raiger and Fusarium Oxysporum. (author)

Synthesis and characterization of the polyaniline dopant Schiff base

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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

Mixed ligand chelate therapy for plutonium and cadmium poisoning

Energy Technology Data Exchange (ETDEWEB)

Schubert, J; Derr, S K [Hope Coll., Holland, MI (USA)

1978-09-28

Some experiments with mice are described in which complete removal of tissue deposits of /sup 239/Pu and prevention of mortality in animals given lethal doses of Cd were achieved using a mixed ligand chelate treatment (MLC). The mixed ligand consisted of diethylenetriaminepentaacetic acid and salicylic acid.

Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure–activity relationship

Science.gov (United States)

Hui Wang; Mingyue Jiang; Shujun Li; Chung-Yun Hse; Chunde Jin; Fangli Sun; Zhuo Li

2017-01-01

Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure–activity relationships (QSARs) for CAAS compounds against Aspergillus niger (A. niger) and...

Synthesis and characterization of nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) complexes of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide

International Nuclear Information System (INIS)

Syamal, A.; Maurya, M.R.

1986-01-01

Synthesis of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide, and its coordination compounds with nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) are described. The ligand and the complexes have been characterized on the basis of analytical, conductance, molecular weight, i.r., electronic and n.m.r. spectra and magnetic susceptibility measurements. The stoichiometries of the complexes are represented as NiL . 3H 2 O, CoL . 2H 2 O, CuL, MnL . 2H 2 O, ZnL . H 2 O, Zr(OH) 2 (LH) 2 , Zr(OH) 2 L . 2MeOH, UO 2 L . MeOH and MoO 2 L . MeOH (where LH 2 =Schiff base). The copper(II) complex shows a subnormal magnetic moment due to antiferromagnetic exchange interaction while the nickel(II), cobalt(II) and manganese(II) complexes show normal magnetic moments at room temperature. The i.r. and n.m.r. spectral studies show that the Schiff base behaves as a dibasic and tridentate ligand coordinating through the deprotonated phenolic oxygen, enolic oxygen and azomethine nitrogen. (orig.)

Physico-chemical characterization of mixed-ligand complexes of Mn(III based on the acetylacetonate and maleic acid and its hydroxylamine derivative

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Cakić Suzana M.

2005-01-01

Full Text Available Two new Mn(III mixed-ligand complexes with two acetylacetonate (acac ligands and one maleate ligand and its hydroxylamine derivative of the general formula [Mn(C5H7O22L] were prepared. Their structure was established by using elemental analysis, FTIR and UV/VIS spectroscopic methods, as well as magnetic measurement. Replacement of the acetylacetonate ligand by the corresponding acid ligand has been confirmed in Mn(III acetylacetonate. Based on the obtained experimental data and literature indications, structural formulae to these compounds were assigned.

Coordination chemistry of oxovanadium(V) complexes with active Schiff bases: synthetic, spectral, and antimicrobial approach

International Nuclear Information System (INIS)

Garg, R; Fahmi, N.; Singh, R.V.

2007-01-01

The Schiff bases, 3-(indolin-2-one)hydrazinecarbothioamide, 3-(indolin-2-one)hydrazinecarboxamide, 5,6-dimethyl-3-(indolin-2-one)hydrazinecarbothioamide, and 5,6-dimethyl-3-(indolin-2-one)hydrazinecarboxamide, have been synthesized by the condensation of 1H-indol-2,3-dione and 5,6-dimethyl-1H-indol-2,3-dione with the corresponding hydrazinecarbothioamide and hydrazinecarboxamide, respectively. The complexes of oxovanadium and ligands have been characterized by elemental analyses, melting points, conductance measurements, molecular weight determinations, and IR, 1 H NMR and UV spectral studies. These studies showed that the ligands coordinated to the oxovanadium in a monobasic bidentate fashion through oxygen or sulfur and the nitrogen donor system. Thus, penta- and hexa coordinated environment around the vanadium atom has been proposed. All the complexes and their parent organic moieties have been screened for their biological activity on several pathogenic fungi and bacteria and were found to possess appreciable fungicidal and bactericidal properties [ru

Synthesis of schiff bases of pyridine-4-carbaldehyde and their antioxidant and DNA binding studies

International Nuclear Information System (INIS)

Shamim, S.; Murtaza, S.; Nazar, M.F.

2016-01-01

A series of Schiff bases of pyridine-4-carbaldehyde with 3-aminobenzoic acid, 2-aminobenzoic acid, 4-aminobenzoic acid, 1,3-phenylenediamine, 1,2-phenylenediamine, 2-aminothiophenol, 4-aminoantipyrene, 2-aminophenol and naphthalene-1-amine was synthesized and compounds were characterized by FTIR, NMR and mass spectrometry. The synthesized compounds were evaluated for their antioxidant and DNA binding interaction studies. DPPH scavenging method was used to evaluate the antioxidant activities of synthesized Schiff bases at six gradually increasing concentrations of 0.5-5mg/ml. 2-((pyridin-4-ylmethylidene)amino)phenol came out to be the most efficient antioxidant at a concentration of 4mg/ml with 74% inhibition of free radicals generated by DPPH. The DNA binding interaction of the synthesized Schiff bases was determined using UV-Vis absorption titration method. Both the hypochromic and hyperchromic effects were observed along the series. The values for the binding constant (K) and free energy change (G) were calculated and most of the Schiff bases have high positive K values which indicate the efficient binding of Schiff bases with DNA. Molecular docking studies as carried out using PatchDock molecular algorithm software also indicated the high values for geometrical shape complementarity score suggesting the stabilities of Schiff bases/DNA complex. Docking studies also suggested the minor groove binding of the Schiff bases with DNA. Drug-likeness of the synthesized compounds was also tested in silico and the results are accordingly discussed. (author)

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

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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.

Studies on new complexes of dioxo uranium(VI) and thorium(IV) with some schiff bases derived from trimethoprime salicyldehyde and o-vanillin (Paper No. AL-50)

International Nuclear Information System (INIS)

Pujar, M.A.; Pirgonde, B.R.

1990-02-01

Dioxouranium(VI) and thorium(IV) form 1:1(Metal:Ligands) complexes with some schiff bases. The complexes have been characterized through elemental analyses, electronic and IR spectral, conductance and magnetic susceptibility measurements. They are considered dimeric or polymeric hexa or octa-coordinated arrangement around metal ion moiety. Force constants and U-O bond lengths have been calculated. (author). 1 tab

Polymerization of MMA catalyzed by different novel mixed ligand lanthanocene ｛ ( Cp ) ( Cl ) LnSchiff-base (THF) ｝, ( COT ) Ln(methoxyethylindenyl) (THF)/Al (i-Bu) 3 systems

Institute of Scientific and Technical Information of China (English)

YOUSAF, Muhammad; QIAN, Yan-Long; FENG, Zuo-Feng; HUANG, Ji-Ling; SUN, Jun-Quan; PAN, Zhi-Da

2000-01-01

This article deals that the rare earth metal complexes along with Al (i-Bu)3 can catalyze the polymerization of methyl methacrylate (MMA) into high molecular weight poly(MMA) along with narrow molecular weight distributions (MWD). A typical example wan mentioned in the case of ｛Cp(Cl)Sm Schiff-base(THF)｝ which expresses maximum (conv.%= 55.46 and Mn=354×103) efficiency along with narrow MWD(Mw/Mn＜2) at 60°C. The resulting polymer was partially syndiotactic (＞60%). The effect of the catalyst, temperature, catalyst/MMA molar ratio, catalyst/Al(i-Bu)3 molar ratio on the polymerization of MMA at 60°C were also investigated.

Electrocatalytic oxidation of organic substrates with molecular oxygen using tetradentate ruthenium(III)-Schiff base complexes as catalysts

International Nuclear Information System (INIS)

Ourari, Ali; Khelafi, Mostefa; Aggoun, Djouhra; Jutand, Anny; Amatore, Christian

2012-01-01

Three complexes Ru(III)ClL n involving different tetradentate Schiff base ligands L n (see L 1 , L 2 and L 3 in ) were used as catalysts in the oxidation of cyclooctene and tetraline in the presence of molecular dioxygen associated with benzoic anhydride. The efficiency of this oxidation reaction was tested in the presence of two apical bases: 1- or 2-methylimidazole. All complexes exhibit a quasi-reversible redox system. The electrolysis experiments were carried out at controlled potential for each complex, using different substrates such as cyclooctene and tetraline. The oxidized products are cyclooctene oxide (turnover 6.7), a mixture of 1-tetralol and 1-tetralone (turnover 7.6) respectively.

The electric and thermoelectric properties of Cu(II)-Schiff base nano-complexes

Science.gov (United States)

Ibrahim, E. M. M.; Abdel-Rahman, Laila H.; Abu-Dief, Ahmed M.; Elshafaie, A.; Hamdan, Samar Kamel; Ahmed, A. M.

2018-05-01

The physical properties, such as electric and optical properties, of metal-Schiff base complexes have been widely investigated. However, their thermoelectric (TE) properties remain unreported. This work presents Cu(II)-Schiff base complexes as promising materials for TE power generation. Therefore, three Cu(II)-Schiff base complexes (namely, [Cu(C32H22N4O2)].3/2H2O, [Cu(C23H17N4O7Br)], and [Cu(C27H22N4O8)].H2O) have been synthesized in nanosized scale. The electric and TE properties have been studied and comprehensive discussions have been presented to promote the nano-complexes (NCs) practical applications in the field of TE power generation. The electrical measurements confirm that the NCs are semiconductors and the electrical conduction process is governed by intermolecular and intramolecular transfer of the charge carriers. The TE measurements reveal that the Cu(II)-Schiff base NCs are nondegenerate P-type semiconductors. The measured Seebeck coefficient values were higher compared to the values reported in previous works for other organic materials indicating that the complexes under study are promising candidates for theremoelectric applications if the electrical conductivity could be enhanced.

An experimental and theoretical study on the interaction of DNA and BSA with novel Ni2 +, Cu2 + and VO2 + complexes derived from vanillin bidentate Schiff base ligand

Science.gov (United States)

Dostani, Morteza; Kianfar, Ali Hossein; Mahmood, Wan Ahmad Kamil; Dinari, Mohammad; Farrokhpour, Hossein; Sabzalian, Mohammad R.; Abyar, Fatemeh; Azarian, Mohammad Hossein

2017-06-01

In this investigation, the structure of bidentate N,N-Schiff base ligand of vanillin, (E)-4-(((2-amino-5-nitrophenyl)imino)methyl)-2-methoxyphenol (HL) was determined by single crystal X-ray diffraction. The interaction of new [CuL2], [NiL2] and [VOL2] complexes with DNA and BSA was explored through UV-Vis and fluorescence spectroscopy. The electronic spectra changes displayed an isosbestic point for the complexes upon titration with DNA. The Kb values for the complexes [CuL2], [NiL2] and [VOL2] were 2.4 × 105, 1.9 × 105 and 4.2 × 104, respectively. [CuL2] complex was bound more toughly than [NiL2] and [VOL2] complexes. These complexes had a significant interaction with Bovine Serum Albumin (BSA) and the results demonstrated that the quenching mechanism was a static procedure. Also, the complexes interacted with BSA by more than one binding site (n > 1). Finally, the theoretical studies were performed using the docking method to calculate the binding constants and recognize the binding site of the DNA and BSA with the complexes. The ligand and complexes including Ni2 +, Cu2 + and VO2 + ions were colonized by fungal growth.

DNA incision evaluation, binding investigation and biocidal screening of Cu(II), Ni(II) and Co(II) complexes with isoxazole Schiff bases.

Science.gov (United States)

Ganji, Nirmala; Chityala, Vijay Kumar; Marri, Pradeep Kumar; Aveli, Rambabu; Narendrula, Vamsikrishna; Daravath, Sreenu; Shivaraj

2017-10-01

Two new series of binary metal complexes [M(L 1 ) 2 ] and [M(L 2 ) 2 ] where, M=Cu(II), Ni(II) & Co(II) and L 1 =4-((3,4-dimethylisoxazol-5-ylimino)methyl)benzene-1,3-diol; L 2 =2-((3,4-dimethylisoxazol-5-ylimino)methyl)-5-methoxyphenol were synthesized and characterized by elemental analysis, 1 H NMR, 13 C NMR, FT-IR, ESI mass, UV-Visible, magnetic moment, ESR, SEM and powder XRD studies. Based on these results, a square planar geometry is assigned for all the metal complexes where the Schiff base acts as uninegatively charged bidentate chelating agent via the hydroxyl oxygen and azomethine nitrogen atoms. DNA binding studies of all the complexes with calf thymus DNA have been comprehensively investigated using electronic absorption spectroscopy, fluorescence quenching and viscosity studies. The oxidative and photo cleavage affinity of metal complexes towards supercoiled pBR322 DNA has been ascertained by agarose gel electrophoresis assay. From the results, it is observed that all the metal complexes bind effectively to CT-DNA via an intercalative mode of binding and also cleave pBR322 DNA in a promising manner. Further the Cu(II) complexes have shown better binding and cleavage properties towards DNA. The antimicrobial activities of the Schiff bases and their metal complexes were studied on bacterial and fungal strains and the results denoted that the complexes are more potent than their Schiff base ligands. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, structure, DNA/BSA binding and antibacterial studies of NNO tridentate Schiff base metal complexes

Science.gov (United States)

Sakthi, Marimuthu; Ramu, Andy

2017-12-01

A new salicylaldehyde derived 2,4-diiodo-6-((2-phenylaminoethylimino)methyl)phenol Schiff base(L) and its transition metal complexes of the type MLCl where, M = Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been synthesized. The coordination mode of Schiff base holding NNO donor atoms with metal ions was well investigated by elemental analysis, ESI-mass as well as IR, UV-vis, CV and NMR spectral studies. The binding efficiency and mode of these complexes with biological macromolecules viz., herring sperm DNA (HS- DNA) and bovine serum albumin (BSA) have been explored through various spectroscopic techniques. The characteristic changes in absorption, emission and, circular dichroism spectra of the complexes with DNA indicate the noticeable interaction between them. From the all spectral information complexes could interact with DNA via non-intercalation mode of binding. The hyperchromisim in absorption band and hypochromisim in emission intensity of BSA with different complex concentrations shown significant information, and the binding affinity value has been predicted from Stern-Volmer plots. Further, all the complexes could cleave the circular plasmid pUC19 DNA efficiently by using an activator H2O2. The ligand and all metal(II) complexes showed good antibacterial activities. The molecular docking studies of the complexes with DNA were performed in order to make a comparison and conclusion with spectral technic results.

Ligand and Metal Based Multielectron Redox Chemistry of Cobalt Supported by Tetradentate Schiff Bases.

Science.gov (United States)

Andrez, Julie; Guidal, Valentin; Scopelliti, Rosario; Pécaut, Jacques; Gambarelli, Serge; Mazzanti, Marinella

2017-06-28

We have investigated the influence of bound cations on the reduction of cobalt complexes of redox active ligands and explored the reactivity of reduced species with CO 2 . The one electron reduction of [Co II ( R salophen)] with alkali metals (M = Li, Na, K) leads to either ligand-centered or metal-centered reduction depending on the alkali ion. It affords either the [Co I ( R salophen)K] complexes or the [Co II 2 (bis-salophen)M 2 ] (M = Li, Na) dimers that are present in solution in equilibrium with the respective [Co I (salophen)M] complexes. The two electron reduction of [Co II ( OMe salophen)] results in both ligand centered and metal centered reduction affording the Co(I)-Co(II)-Co(I) [Co 3 (tris- OMe salophen)Na 6 (THF) 6 ], 6 complex supported by a bridging deca-anionic tris- OMe salophen 10- ligand where three OMe salophen units are connected by two C-C bonds. Removal of the Na ion from 6 leads to a redistribution of the electrons affording the complex [(Co( OMe salophen)) 2 Na][Na(cryptand)] 3 , 7. The EPR spectrum of 7 suggests the presence of a Co(I) bound to a radical anionic ligand. Dissolution of 7 in pyridine leads to the isolation of [Co I 2 (bis- OMe salophen)Na 2 Py 4 ][Na(cryptand)] 2 , 8. Complex 6 reacts with ambient CO 2 leading to multiple CO 2 reduction products. The product of CO 2 addition to the OMe salophen ligand, [Co( OMe salophen-CO 2 )Na] 2 [Na(cryptand)] 2 , 9, was isolated but CO 3 2- formation in 53% yield was also detected. Thus, the electrons stored in the reversible C-C bonds may be used for the transformation of carbon dioxide.

Synthesis of mononuclear copper(II) complexes of N3O2 and N4O2 donors containing Schiff base ligands: Theoretical and biological observations

Science.gov (United States)

Mancha Madha, K.; Gurumoorthy, P.; Arul Antony, S.; Ramalakshmi, N.

2017-09-01

A new series of six mononuclear copper(II) complexes were synthesized from N3O2 and N4O2 donors containing Schiff base ligands, and characterized by various spectral methods. The geometry of the complexes was determined using UV-Vis, EPR and DFT calculations. The complexes of N3O2 donors (1-3) adopted square pyramidal geometry and the remaining complexes of N4O2 donors (4-6) show distorted octahedral geometry around copper(II) nuclei. Redox properties of the complexes show a one-electron irreversible reduction process in the cathodic potential (Epc) region from -0.74 to -0.98 V. The complexes show potent antioxidant activity against DPPH radicals. Molecular docking studies of complexes showed σ-π interaction, hydrogen bonding, electrostatic and van der Waals interactions with VEGFR2 kinase receptor. In vitro cytotoxicity of the complexes was tested against human breast cancer (MDA-MB-231) cell lines and one normal human dermal fibroblasts (NHDF) cell line through MTT assay. The morphological assessment data obtained by Hoechst 33258 and AO/EB staining revealed that the complexes induce apoptosis pathway of cell death.

Self-Assembly, Interfacial Nanostructure, and Supramolecular Chirality of the Langmuir-Blodgett Films of Some Schiff Base Derivatives without Alkyl Chain

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Tifeng Jiao

2013-01-01

Full Text Available A special naphthyl-containing Schiff base derivative, N,N′-bis(2-hydroxy-1-naphthylidene-1,2-phenylenediamine, was synthesized, and its coordination with various metal ions in situ at the air/water interface has been investigated. Although the ligand contains no alkyl chain, it can be spread on water surface. When metal ions existed in the subphase, an interfacial coordination between the ligand and different metal ions occurred in the spreading film, while different Nanostructures were fabricated in the monolayers. Interestingly to note that among various metal ions, only the in situ coordination-induced Cu(II-complex film showed supramolecular chirality, although the multilayer films from the ligand or preformed complex are achiral. The chirality of the in situ Cu(II-coordinated Langmuir film was developed due to the special distorted coordination reaction and the spatial limitation at the air/water interface. A possible organization mechanism at the air/water interface was suggested.

Studies on mixed ligand complexes of lanthanide (III) ions

International Nuclear Information System (INIS)

Rajendran, G.; Usha Devi, K.G.

2002-01-01

As part of our research programme, we have prepared and characterized a few nitrato, thiocyanato and perchlorato complexes of lanthanide(III) ions with ligands, viz., a Schiff base derived from p-anisidine and vanillin and diphenyl sulphoxide. The complexes were characterized by the measurement of electrical conductances and magnetic susceptibilities, molecular mass and metal percentage and spectral analysis. The thermal decompositions were studied by TG and DTG techniques. The thiocyanato complexes were prepared by substitution method from nitrato complexes. p-Anisidine-vanillin (HDDA) and diphenyl sulphoxide (DPSO) are coordinated to the metal ion in unidentate fashion. All the anions were involved in coordination in these complexes. Thus they were found to have non- electrolytic behaviour with composition [Ln(HDDA) 2 (DPSO)X 3 ] where X = NO 3 ) or SCN perchlorato complexes were prepared from metal perchlorate as done in the case of nitrato complexes. They were found to have electrical conductance which corresponds to 1 : 1 electrolyte. Hence one of the perchlorate ions is outside the coordination sphere. The composition of this complex is found to be [Ln(HDDA) 3 (DPSO)(ClO 4 ) 2 ]ClO 4 . (author)

Syntheses and Characterization of Some Tetradentate Schiff-Base Complexes and Their Heteroleptic Analogues

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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.

Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

International Nuclear Information System (INIS)

Wang, Chao; Zhao, Jun; Xia, Liang; Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan

2016-01-01

Three new coordination polymers, namely, {[Ni(H 2 L)(bix)(H 2 O) 2 ]·2h 2 O} n (1), {[Ni(HL)(Hdpa)(H 2 O) 2 ]·H 2 O} n (2), {[Ni(L) 0.5 (bpp)(H 2 O)]·H 2 O} n (3) (H 4 L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H 4 L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6 6 -dia-type framework with H 4 L ligand adopts a μ 2 -bridging mode with two symmetry-related carboxylate groups in μ 1 -η 1 :η 0 monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, in which the H 4 L ligand adopts a μ 2 -bridging mode with two carboxylate groups in μ 1 -η 1 :η 1 and μ 1 -η 1 :η 0 monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H 4 L ligand displays a μ 4 -bridging coordination mode. The H 4 L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6 6 -dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled” strategy is significant potential for network design.

Spectrophotometric and spectrofluorimetric investigation of different equilibria of a recently synthesized Schiff base with the aid of chemometric methods

Energy Technology Data Exchange (ETDEWEB)

Afkhami, Abbas, E-mail: afkhami@basu.ac.i [Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174 (Iran, Islamic Republic of); Keypour, Hasan; Khajavi, Farzad [Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174 (Iran, Islamic Republic of); Rezaeivala, Majid [Department of Chemical Engineering, Hamedan University of Technology, Hamedan 65155 (Iran, Islamic Republic of)

2011-07-15

In this study ground and excited states acidic dissociation constants of a recently synthesized Schiff base was obtained in a DMF:water mixture of 30:70 (v/v) using absorption and fluorescent spectra of the Schiff base in different pH values with the aid of chemometric methods. In addition, the fluorescent of the two kinds of tautomers of this Schiff base was investigated and the rate of tautomerization was obtained using rank annihilation factor analysis (RAFA). The effect of different kinds of surfactants such as sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and Triton X-100 on fluorescence spectrum of the Schiff base in a DMF:water mixture of 2:98 (v/v) was investigated. CTAB increased the fluorescence intensity of the Schiff base while SDS and Triton X-100 had no significant effect on it. {beta}-Cyclodextrin increased the fluorescence intensity of the Schiff base. Also the sensing behavior of this Schiff base toward metal ions was studied in DMF and ethanol by fluorescence spectroscopy. The Schiff base showed prominent fluorescent signal in the presence of Zn{sup 2+}, whereas other metal ions failed to induce response and ground-state dissociation constant of the complex was determined by direct fluorimetric titration as a function of Zn{sup 2+} concentration. - Highlights: {yields} Acidity and rate of the tautomerization of a recently synthesized Schiff base were studied. {yields} Ground and excited states acidity constants and tautomerization rate constant were obtained. {yields} These parameters were obtained with the aid of hard model and Rank annihilation factor analysis. {yields} The effect of some factors on the fluorescence intensity of the Schiff base was studied.

Spectrophotometric and spectrofluorimetric investigation of different equilibria of a recently synthesized Schiff base with the aid of chemometric methods

International Nuclear Information System (INIS)

Afkhami, Abbas; Keypour, Hasan; Khajavi, Farzad; Rezaeivala, Majid

2011-01-01

In this study ground and excited states acidic dissociation constants of a recently synthesized Schiff base was obtained in a DMF:water mixture of 30:70 (v/v) using absorption and fluorescent spectra of the Schiff base in different pH values with the aid of chemometric methods. In addition, the fluorescent of the two kinds of tautomers of this Schiff base was investigated and the rate of tautomerization was obtained using rank annihilation factor analysis (RAFA). The effect of different kinds of surfactants such as sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and Triton X-100 on fluorescence spectrum of the Schiff base in a DMF:water mixture of 2:98 (v/v) was investigated. CTAB increased the fluorescence intensity of the Schiff base while SDS and Triton X-100 had no significant effect on it. β-Cyclodextrin increased the fluorescence intensity of the Schiff base. Also the sensing behavior of this Schiff base toward metal ions was studied in DMF and ethanol by fluorescence spectroscopy. The Schiff base showed prominent fluorescent signal in the presence of Zn 2+ , whereas other metal ions failed to induce response and ground-state dissociation constant of the complex was determined by direct fluorimetric titration as a function of Zn 2+ concentration. - Highlights: → Acidity and rate of the tautomerization of a recently synthesized Schiff base were studied. → Ground and excited states acidity constants and tautomerization rate constant were obtained. → These parameters were obtained with the aid of hard model and Rank annihilation factor analysis. → The effect of some factors on the fluorescence intensity of the Schiff base was studied.

A Langmuir study of novel Schiff Base ligand for ion sensor application

African Journals Online (AJOL)

The analysis made from extrapolating the П-A graphs led to the result of the estimated area and the radius of the ligand molecules oriented on the air-water subphase. The UV-Visible spectrometer was used to study the optical properties of the ligands. This study was made in order to recognize the fundamental properties of ...

Chitosan-based Schiff base-metal complexes (Mn, Cu, Co) as ...

Indian Academy of Sciences (India)

and A C PISE. Chemistry Research ... Data obtained by thermal analysis revealed that these complexes showed good thermal ... vents along with its inherent chirality makes chitosan .... resulting Schiff base IC was cooled, filtered and washed with ethanol ..... experiments with homogeneous Mn-salen catalyst at different ...

Synthesis and structure elucidation of a copper(II) Schiff-base complex: in vitro DNA binding, pBR322 plasmid cleavage and HSA binding studies.

Science.gov (United States)

Tabassum, Sartaj; Ahmad, Musheer; Afzal, Mohd; Zaki, Mehvash; Bharadwaj, Parimal K

2014-11-01

New copper(II) complex with Schiff base ligand 4-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-benzoic acid (H₂L) was synthesized and characterized by spectroscopic and analytical and single crystal X-ray diffraction studies which revealed that the complex 1 exist in a distorted octahedral environment. In vitro CT-DNA binding studies were performed by employing different biophysical technique which indicated that the 1 strongly binds to DNA in comparison to ligand via electrostatic binding mode. Complex 1 cleaves pBR322 DNA via hydrolytic pathway and recognizes minor groove of DNA double helix. The HSA binding results showed that ligand and complex 1 has ability to quench the fluorescence emission intensity of Trp 214 residue available in the subdomain IIA of HSA. Copyright © 2014 Elsevier B.V. All rights reserved.

Designer Ligands. Part 13. Synthesis and Catalytic Activity of ...

African Journals Online (AJOL)

Copper(I), copper(II), cobalt(II) and zinc(II) complexes of a macrocyclic, multidentate Schiff-base ligand have been prepared and, with the exception of the zinc(II) complex, have been shown to exhibit biomimetic catecholase activity. Keywords: Copper(II);Cobalt(II); Zinc(II); Biomimetic complexes; Catecholase activity

Evaluation of calix[4]arene tethered Schiff bases for anion recognition

International Nuclear Information System (INIS)

Chawla, H.M.; Munjal, Priyanka

2016-01-01

Two calix[4]arene tethered Schiff base derivatives (L1 and L2) have been synthesized and their ion recognition capability has been evaluated through NMR, UV–vis and fluorescence spectroscopy. L1 interacts with cyanide ions very selectively to usher a significant change in color and fluorescence intensity. On the other hand L2 does not show selectivity for anion sensing despite having the same functional groups as those present in L1. The differential observations may be attributed to plausible stereo control of anion recognition and tautomerization in the synthesized Schiff base derivatives.

Evaluation of calix[4]arene tethered Schiff bases for anion recognition

Energy Technology Data Exchange (ETDEWEB)

Chawla, H.M., E-mail: hmchawla@chemistry.iitd.ac.in; Munjal, Priyanka

2016-11-15

Two calix[4]arene tethered Schiff base derivatives (L1 and L2) have been synthesized and their ion recognition capability has been evaluated through NMR, UV–vis and fluorescence spectroscopy. L1 interacts with cyanide ions very selectively to usher a significant change in color and fluorescence intensity. On the other hand L2 does not show selectivity for anion sensing despite having the same functional groups as those present in L1. The differential observations may be attributed to plausible stereo control of anion recognition and tautomerization in the synthesized Schiff base derivatives.

Study of diamagnetism in uranyl complexes of some Schiff bases

International Nuclear Information System (INIS)

Dodwad, S.S.; Sawant, A.S.

1992-01-01

Uranyl complexes of Schiff bases obtained by condensing salicylaldehyde with aromatic amines have been isolated and characterised. The complexes have the formula M (LH) 2 (NO 3 ) 2 where M = UO 2 and LH = Schiff base. The magnetic susceptibilities of these complexes have been measured on a Gouy balance. These values have been compared with the computed ones. The percentage deviation between the observed and computed values of molar magnetic susceptibilities clearly show that they are outside experimental error and therefore significant. These deviations have been discussed in the light of VanVleck's, equation for molar susceptibility of polyatomic molecule. (author). 3 refs., 1 tab

Synthesis, characterization and biological activity of C6-Schiff bases derivatives of chitosan.

Science.gov (United States)

Xu, Ruibo; Aotegen, Bayaer; Zhong, Zhimei

2017-12-01

C 6 -Schiff bases derivatives of chitosan were synthesized for the first time. C 2 -amino groups and C 3 -hydroxy groups were firstly protected by CuSO 4 ·5H 2 O, and the C 6 -hydroxy was then transformed into aldehyde, which then reacted with anilines through nucleophilic addition to introduce the CN group at C 6 -position in chitosan chain. Finally, C 6 -Schiff bases derivatives of chitosan were got by the deprotection of C 2 -NH 2 with cation exchange resin. The structures and properties of the new synthesized products were characterized by Fourier transform infrared spectroscopy, 13 C NMR, SEM image, and elemental analysis. The antibacterial activities of derivatives were tested in the experiment, and the results showed that the prepared chitosan derivatives had significantly improved antibacterial activity toward Staphylococcus aureus and Escherichia coli. The Cytotoxicity test showed that the prepared chitosan derivatives had low Cytotoxicity, compared with chitosan and C 2 -benzaldehyde Schiff bases of chitosan. This paper allowed a new method for the synthesis of Schiff bases of chitosan, which was enlightening. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Studies on coordination chemistry and bioactivity of metal complexes of a bidentate NN schiff base, (2-pyridyl-methylene)(phenyl) hydrazine, produced from the condensation of pyridine-2-carboxaldehyde with phenylhydrazine

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Zakaria, C.M.; Idrus, Razmi Mohd; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

2003-07-01

A bidentate Schiff base, (2-pyridyl-methylene)(phenyl) hydrazine, with NN donor sequence, was isolated from the condensation of pyridine-2-carboxaldehyde with phenylhydrazine in ethanol. Metal complexes of this ligand with Ni(II), Zn(It), and Cu(n) ions were synthesized and characterized by a variety of physico-chemical techniques. The structure of the Schiff base was solved by X-ray diffraction studies, which indicated that it was monoclinic with a space group of C2/c. The complexes were all four coordinated. The compounds were tested against four pathogenic bacteria and fungi. The nickel complex, [Ni(NN) 2 Cl 2 ], in particular, was found to be active against all the fungi tested. The complexes were however inactive against leukemic cell lines (CEM-SS). (author)

Gas adsorption and gas mixture separations using mixed-ligand MOF material

Science.gov (United States)

Hupp, Joseph T [Northfield, IL; Mulfort, Karen L [Chicago, IL; Snurr, Randall Q [Evanston, IL; Bae, Youn-Sang [Evanston, IL

2011-01-04

A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

New donor-acceptor-donor molecules based on quinoline acceptor unit with Schiff base bridge: synthesis and characterization

Energy Technology Data Exchange (ETDEWEB)

Kotowicz, Sonia [Institute of Chemistry, University of Silesia, 9 Szkolna Street, 40-006 Katowice (Poland); Siwy, Mariola [Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 34 M. Curie-Sklodowska Str., 41-819 Zabrze (Poland); Filapek, Michal; Malecki, Jan G. [Institute of Chemistry, University of Silesia, 9 Szkolna Street, 40-006 Katowice (Poland); Smolarek, Karolina; Grzelak, Justyna; Mackowski, Sebastian [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, 5 Grudziadzka Str., 87-100 Torun (Poland); Slodek, Aneta, E-mail: aneta.slodek@us.edu.pl [Institute of Chemistry, University of Silesia, 9 Szkolna Street, 40-006 Katowice (Poland); Schab-Balcerzak, Ewa, E-mail: ewa.schab-balcerzak@us.edu.pl [Institute of Chemistry, University of Silesia, 9 Szkolna Street, 40-006 Katowice (Poland); Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 34 M. Curie-Sklodowska Str., 41-819 Zabrze (Poland)

2017-03-15

Three solution-processable small organic molecules bearing quinoline as electron-accepting moiety were synthesized via condensation reaction of novel 6-amino-2-(2,2’-bithiophen-5-yl)-4-phenylquinoline with 2,2’-bithiophene-5-carboxaldehyde, 9-ethyl-9H-carbazole-3-carbaldehyde and 9-phenanthrenecarboxaldehyde. The presence of alternating electron-donating and accepting units results in a donor-acceptor-donor architecture of these molecular systems. Thermal, photophysical, and electrochemical properties of these small molecules were examined and the experimental results were supported by the density functional theory calculations. The obtained molecular systems exhibited high thermal stability with decomposition temperatures (5% weight loss) exceeding 330 °C in nitrogen atmosphere. It was found, based on DSC measurements, that investigated Schiff bases form amorphous material with glass transition temperatures between 88 and 190 °C. They also showed a UV–vis absorption in the range of 250–500 nm both in solution and in solid state as film and blend with PMMA and PVK. Photoluminescence measurements revealed moderately strong blue-light emission of the imines in solution as well as in PMMA blend with quantum yields in the range of 2–26%. In the case of imines dispersed in PVK matrix the emission of green light was mainly observed. In addition, when mixed with plasmonically active silver nanowires, the compounds exhibit relatively strong electroluminescence signal, associated with plasmonics enhancement, as evidenced by high-resolution photoluminescence imaging. The energy band gap estimated based on cyclic voltammetry was between 2.38 and 2.61 eV. - Highlights: • New Schiff bases possess donor-acceptor-imine-bridge-donor architecture were synthesized and examined. • Thorough characterization of optical and electrochemical properties of novel Schiff bases has been carried out. • Optical and electrochemical measurements were compared with DFT

New μ-OAC bridged dinuclear copper(II) complex with tridentate Schiff base ligand: synthesis, characterization, crystal structure, and CuO nano-particles formation

Czech Academy of Sciences Publication Activity Database

Grivani, G.; Eigner, Václav; Dušek, Michal; Sadeghi, B.; Khalaji, A.D.

2015-01-01

Roč. 41, č. 7 (2015), s. 456-461 ISSN 1070-3284 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : Schiff base * complex structure * x-ray crystallography * Jana2006 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.516, year: 2015

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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

International Nuclear Information System (INIS)

Sallam, S.A.; Abbas, A.M.

2013-01-01

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 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

Mixed-Ligand Complexes Of Nickel (II) With 2-Acetylpyridine ...

African Journals Online (AJOL)

The preparation and spectral properties of five nickel (II) mixed-ligands complexes (Ni [2-Actsc.Y]CI2), derived from 2-acetylpyridinethiosermicarbazones and some nitrogen/sulphur monodentate ligands such as thiophene, ammonia, picoline, pyridine and aniline are described. The complexes have been characterized on ...

Synthesis of mixed ligand europium complexes: Verification of predicted luminescence intensification

International Nuclear Information System (INIS)

Lima, Nathalia B.D.; Silva, Anderson I.S.; Gonçalves, Simone M.C.; Simas, Alfredo M.

2016-01-01

Mixed ligand europium complexes are predicted to be more luminescent than what would be expected from their corresponding repeating ligand compounds according to a conjecture recently advanced by our research group; a conjecture that has already been validated for strongly luminescent europium complexes. In this article, we seek to further verify the validity of this conjecture for complexes which are much more symmetric, and which thus display lower levels of luminescence. Accordingly, we synthesized complexes Eu(DBM) 3 (L) 2 , and all novel mixed ligand combinations Eu(DBM) 3 (L,L') with L and L' equal to DBSO, PTSO, and TPPO. The syntheses were carried out via displacement reactions from the starting complex Eu(DBM) 3 (H 2 O) 2 , passing through the intermediates Eu(DBM) 3 (L) 2 and finally, by displacement of L by L', arriving at Eu(DBM) 3 (L,L'). The ligands L obey the following order of displacement TPPO>PTSO>DBSO>H 2 O, which had been previously described by our group. In the present article, we further show that this displacement order could have been predicted by Sparkle/RM1 thermochemical calculations. Subsequently, we determined the radiative decay rates, A rad , for all six compounds by photophysical measurements. As expected, results show that the measured A rad values for all novel mixed ligand complexes are larger than the average of the A rad values for the corresponding repeating ligand coordination compounds. In conclusion, the present article does broaden the scope of our conjecture, which enunciates that an increase in the diversity of ligands around the europium ion tends to intensify the luminescence. - Highlights: • Mixed ligand europium complexes are predicted to be more luminescent than repeating ligand ones. • Radiative decay rates increase with structural coordination asymmetry. • The non-ionic ligands displacement order in substitution reactions is TPPO>PTSO>DBSO>H 2 O. • Sparkle/RM1 correctly predicts the

Influence of Ferrocene and Transition Metals on the Biological Activities of Schiff Bases

International Nuclear Information System (INIS)

Sadeq, A.; Fatesh, S.A.; Ibrahim, A.A.

2016-01-01

A series of organic and organometallic Schiff bases bearing phenylferrocene and their six transition metal complexes have been prepared and tested for their potential biological applications by using antifungal, antibacterial, antitumor activities, toxicity testing against the brine shrimp and DNA damage analysis. The copper and cobalt complexes of organic Schiff base showed significant antibacterial activity. The antifungal activities tested against six fungal strains revealed that N-(4-hydroxybenzylidene) aniline (A5) had the highest antifungal activity. Most of these compounds showed cytotoxic activity against the brine shrimp. The results of showed that these compounds had significant antitumor activity, up to 97% in the case of N-(4-chlorobenzylidene) aniline (A3). Only two compounds N-(2-hydroxy benzylidene) 4-ferrocenylaniline (F2) and Nickel (II) complex of organic Schiff base (CO/sub 2/) had DNA damaging activity at 20mg/ml concentration. (author)

Heterocyclic Schiff bases as non toxic antioxidants: Solvent effect, structure activity relationship and mechanism of action

Science.gov (United States)

Shanty, Angamaly Antony; Mohanan, Puzhavoorparambil Velayudhan

2018-03-01

Phenolic heterocyclic imine based Schiff bases from Thiophene-2-carboxaldehyde and Pyrrole-2-carboxaldehyde were synthesized and characterized as novel antioxidants. The solvent effects of these Schiff bases were determined and compared with standard antioxidants, BHA employing DPPH assay and ABTS assay. Fixed reaction time and Steady state measurement were used for study. IC50 and EC50 were calculated. Structure-activity relationship revealed that the electron donating group in the phenolic ring increases the activity where as the electron withdrawing moiety decreases the activity. The Schiff base derivatives showed antioxidant property by two different pathways namely SPLET and HAT mechanisms in DPPH assay. While in ABTS method, the reaction between ABTS radical and Schiff bases involves electron transfer followed by proton transfer (ET-PT) mechanism. The cytotoxicity of these compounds has been evaluated by MTT assay. The results showed that all these compounds are non toxic in nature.

Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

Energy Technology Data Exchange (ETDEWEB)

Wang, Chao [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); Zhao, Jun, E-mail: junzhao08@126.com [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Xia, Liang [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China)

2016-06-15

Three new coordination polymers, namely, {[Ni(H_2L)(bix)(H_2O)_2]·2h_2O}{sub n} (1), {[Ni(HL)(Hdpa)(H_2O)_2]·H_2O}{sub n} (2), {[Ni(L)_0_._5(bpp)(H_2O)]·H_2O}{sub n} (3) (H{sub 4}L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H{sub 4}L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6{sup 6}-dia-type framework with H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two symmetry-related carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 0} monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, in which the H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 1} and μ{sub 1}-η{sup 1}:η{sup 0} monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H{sub 4}L ligand displays a μ{sub 4}-bridging coordination mode. The H{sub 4}L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6{sup 6}-dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled�

Studies on coordination chemistry and bioactivity of some nitrogen-sulfur donor ligands with some heavy metal ions

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Zakaria, C.M.; Wan bin Abdullah; Grouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

2003-08-01

A bidentate NS ligand, hydraziniumdithiocarbazate (HzDTC), was prepared. The reaction of HzDTC with benzoin (HzDTCl) yielded a new Schiff base. Some complexes of cadmium(II), tin(II) and antimony(III) containing HzDTC and S-picolyldithiocarbazate (SPDTC) were prepared and characterized by a variety of physico-chemical techniques. The structure of the Schiff base, bis(methylphenyl)methylene (N-phenylmethylene-N'-phenylmethine)hydrazine, was solved by X-ray crystallography. The HzDTC and SPDTC behaved as uninegatively charged bidentate ligands. The antibacterial and anti-fungal properties of ligands and their metal complexes were evaluated against four pathogenic bacteria and fungi. HzDTC was very effective against all the microbes while the complexes of HzDTC were antibacterial. The complexes of SPDTC were effective against fungi. [Cd(HzDTC)Br. H 2 O], in particular, was moderately active against CEM-SS (human cell T-lymphoblastic leukemia) cells. (author)

Intramolecular hydrogen bonding and tautomerism in Schiff bases ...

Indian Academy of Sciences (India)

Administrator

C NMR, DEPT and aided by 2D HETCOR and HMBC heteronuclear correlation techniques. The UV-vis spectra of the Schiff bases have been systematically studied in organic solvents of different polarity, acidic and basic media and found useful in understanding of tautomeric equilibria (phenol-imine, O–H...N and ...

Manganese–Schiff base complex immobilized silica materials for ...

Indian Academy of Sciences (India)

Administrator

Curtailment of platinum catalysts loading in fuel cell is a recent central issue. As substitutes ... catalytic activity of manganese–Schiff base complexes for oxygen reduction reaction in 0⋅05 M HClO4 at room ... producing industries (Adzic et al 1998; Subhramannia et ..... Chronoamperometry is carried out to calculate the.

Mixed-ligand Al complex—a new approach for more high efficient OLEDs

International Nuclear Information System (INIS)

Petrova, Petia K.; Tomova, Reni L.; Stoycheva-Topalova, Rumiana T.; Kaloyanova, Stefka S.; Deligeorgiev, Todor G.

2012-01-01

The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq 2 Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq 3 . Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq 3 The better performance of the devices make the novel Al complex a very promising material for OLEDs. - Highlights: ► A novel electroluminescent Alq 2 Acac complex is presented as material for OLED. ► Electroluminescent emission of Alq 2 Acac is very similar to that of commercial Alq 3 . ► Devices with Alq 2 Acac show better characteristics compared to those with Alq 3 .

Ionophoretic method in the study of mixed ligand ternary chelates of UO2(II), Ni(II) and Zn(II) involving nitrilotriacetate and cytosine as ligands

International Nuclear Information System (INIS)

Mishra, A.P.; Mishra, S.K.; Yadava, K.L.

1987-01-01

A novel electrophoretic technique is described for the assessment of the equilibria in mixed-ligand complex system in solution. It is based on the movement of spot of the metal ion under an electric field with the complexants added in the background electrolyte at fixed pH. The concentration of primary ligand nitrilotriacetate was constant while that of secondary ligand (cytosine) was varied. The plot of log (cytosine) against mobility was used to obtain information on the formation of the mixed complexes and to calculate its stability constants. Experimentally obtained logK values are as 5.62, 4.55 and 4.42 for mixed complexes of UO 2 (II), Ni(II) and Zn(II) respectively at μ=0.1 and temp.=35 +- 01.degC. (author). 10 refs

Mixed-ligand complexes of ruthenium(II) incorporating a diazo ...

Indian Academy of Sciences (India)

Unknown

Dedicated to the memory of the late Professor Bhaskar G Maiya. *For correspondence. Mixed-ligand complexes of ruthenium(II) incorporating a diazo ligand: Synthesis .... water (1 : 1) for 5 h to give a dark red solution. The solution was cooled to room temperature. After eva- poration of the solvent, the solid was collected,.

Synthesis and Spectroscopic Analysis of Schiff Bases of Imesatin ...

African Journals Online (AJOL)

ADOWIE PERE

of other applications such as, identification, detection and determination of ... In the light of different applications of Schiff bases derived from ..... cm-1 and weak bands in the region 1709 – 1743 cm‐1 assignable to ... Signals due to the N–H ...

Characterization of Schiff base derived from 2-hydroxo-1 ...

African Journals Online (AJOL)

Molar conductance measurements showed that the complex is non electrolyte with very high stability constant value. Gibb's free energy determination showed that the complex is very stable as shown in the high decomposition temperature measurements. Keywords: Potentiometry, Schiff base, Spectrophotometry, Stability ...

Charge transfer processes on electrodes modified by polymer films of metal complexes with Schiff bases

International Nuclear Information System (INIS)

Levin, O.V.; Karushev, M.P.; Timonov, A.M.; Alekseeva, E.V.; Zhang, Shuanghua; Malev, V.V.

2013-01-01

Electrochemical properties of glassy carbon electrodes modified by two polymer films of different nickel complexes with Schiff base ligands containing methoxy substituents in their aromatic parts were studied in acetonitrile solutions with cyclic voltammetry, quartz crystal microbalance, atomic force microscopy, and impedance spectroscopy. It was observed that introduction of such substituents leads to a noticeable splitting of cycling voltammetric curves into at least two ox/red transitions. In addition, solvent flows accompanying the counter-ions ones during charging/discharge processes within the films appeared significantly greater than those observed in the case of non-substituted ligands. The obtained impedance results as a whole were satisfactorily treated in scope of the so-called model of homogeneous films with two kinds of charge carriers. However, determinations of the Warburg constant as a function of the electrode potential require additional verifications, at least in the ranges of overlapping ox/red transitions. In particular, it was established that in this region the impedance frequency dependence was some superposition of the diffusion (Warburg) and the pseudo-capacitive constituents. This, most likely, resulted from the presence of three kinds of charge carriers in the film interior

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

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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.

EXAFS Studies of Some Copper(II) Mixed-Ligand Complexes

International Nuclear Information System (INIS)

Joshi, S. K.; Katare, R. K.; Shrivastava, B. D.

2007-01-01

X-ray K-absorption spectroscopic studies have been carried out on copper (II) mixed-ligand complexes with glutamic acid and aspartic acid as the primary ligands, where as water, pyridine, imidazole and benz-imidazole have been used as secondary ligands. Chemical shifts obtained from the X-ray absorption data have indicated that the glutamic acid complexes are more ionic as compared to their corresponding aspartic acid complexes having similar secondary ligands. Further, we have estimated the average metal-ligand bond distances from the from structure data. For the different complexes studied under the present investigation, the studies reveal that the bonding parameter α1 decreases with the increase in the percentage covalency of the metal-ligand bond. Thus, the bonding parameter α1 may be used for the estimation of percentage covalency of the metal-ligand bond in other similar complexes

Mixed complex combinations with a new schiff base used as membranes ion-selective for copper and nickel ions, analytical applications)

International Nuclear Information System (INIS)

Mitu, L.; Tigae, C.

2009-01-01

Four electrodes with liquid membrane, Cu/sup 2+/ -selective and Ni/sup 2+/ -selective, not previously described in the literature, were prepared and characterized. Electrodes 1 and 2 are based on mixed complexes of Cu(II) and Ni(II) with isonicotinoylhydrazone-2-aldehyde pyrrole (INH2AP= HL/sup 1/) as ligand and electrodes 3 and 4 are based on the mixed complexes with isonicotinoyl- hydrazone-2-hydroxy-l-naphthaldehyde (INH2HNA = H/sub 2/L/sup 2/ ) Cu/sup 2+/. selective and Ni/sup 2+/ -selective electrodes have been used to determine the copper and nickel ions in aqueous solutions, by both direct potentiometric and potentiometric titration with EDTA. They have also been used for determining the Cu/sup 2+/ and Ni/sup 2+/ ions in industrial waters by direct potentiometry. The analytical results obtained have been checked by the standard addition method and by comparison with determinations through atomic absorption spectrometry. (author)

Selective fluorescent probe based on Schiff base derived from hydroxymethyl coumarin and aminated Sudan I dye for Mg2+ detection

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Jiafa Xu

2017-05-01

Full Text Available A “turn-on” fluorescent sensor, SU-CM is synthesized for Mg2+ detection. The design of SU-CM is based on Schiff base ligand which is derived from the reaction between hydroxymethyl coumarin and aminated Sudan I dye. The low concentration of SU-CM (1 × 10−6 M exhibits a good sensitivity to Mg2+ in isopropyl alcohol solution at room temperature when excited at 372 nm. The titration of Mg2+ into SU-CM undergoes a linear enhancement with increasing concentrations of Mg2+ up to a final mole ratio of 1:1. In addition, SU-CM also shows an excellent specificity from the results that fluorescent intensity emitted at 474 nm is not influenced by adding other 12 ions. Our research suggests that SU-CM may become a favorable candidate for establishment of an efficient Mg2+ response.

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

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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.

Schiff base metal derivatives enhance the expression of HSP70 and suppress BAX proteins in prevention of acute gastric lesion.

Science.gov (United States)

Golbabapour, Shahram; Gwaram, Nura Suleiman; Al-Obaidi, Mazen M Jamil; Soleimani, A F; Ali, Hapipah Mohd; Abdul Majid, Nazia

2013-01-01

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.

Studies on some VO(IV, Ni(II and Cu(II complexes of non-symmetrical tetradentate Schiff-bases

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Aderoju A. Osowole

2008-08-01

Full Text Available The coordination chemistry of VO(IV, Ni(II and Cu(II with unsymmetrical Schiff base ligands, [HO(OCH3C6H3C(CH3:N(CH2CH2N:C(CH3CH:C(C6H5OH], H2L and [HO(OCH3C6H3C(CH3:N(CH2CH2N:C(CH3CH:C(CH3OH], H2L1 (derived from condensation of 1-phenyl-1,3-butanedione/2,4-pentanedione, ethylenediamine and 5-methoxy-2-hydroxy acetophenone is discussed. The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral measurements. They are magnetically dilute, non-electrolytes in nitromethane. The ligands are tetradentately coordinating via the imine N and enolic O atoms, resulting in 5-coordinate square-pyramidal geometry for the VO(IV complexes and 4-coordinate square-planar geometry for the Ni(II and Cu(II complexes. The assignment of geometry is supported by magnetic and spectral measurements.

Analytical applications of some macro-schiff's bases for spectrophotometric determination of some metal ions

International Nuclear Information System (INIS)

Ahmed, N. A. M.

2005-06-01

In this research three schiff's bases PAD, N, NBPAD and N, NBHPAD were synthesized by condensation of o-phenylenediamine with p-aminoacetophenone, to give an intermediate which then further condensed with benzil, and 2,5 hexanedione, respectively, in ethanol to give macro schiff's bases. These schiff's bases were identified using I.R spectra, UV/VIS spectrophotometer, elemental analyzer, and melting point. Their applications as analytical reagents were studied using UV/VIS spectrophotometer with Pb(II), Cr(VI), Cu(II), Cd(II), V(V), Ni(II), Hg(II), Zn(II), Co(II), Fe(II) and Fe(III). Various parameters were investigated in order to find their optimum conditions for the analytical application of these schiff's bases. These include the effect of solvent, the effect of micelle as well as the presence of foreign metal ions. Good results were obtained for determination of Cr(VI), and V(V) with N, NBPAD in terms of linearity detection limit, and interference, and for the determination of Fe(II) with N, NBHPAD. The stoichiometry of some these complexes was determined. The study also showed a good results for the determination of Hg(II), and Pb(II) (two serious environmental pollutants) if interference is removed.(Author)

Equilibrium studies on mixed ligand complexes of some tripositive rare earth ions

International Nuclear Information System (INIS)

Vimal, Rashmi; Singh, Mamta; Ram Nayan

1996-01-01

Interaction of the rare earth ions, La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ and Eu 3+ with the pair of ligands 1-amino-2-naphthol-4-sulphonic acid (an, H 2 A) and o-aminophenol (ap, HB) have been studied in aqueous solution at 25 degC (μ=0.1 M KNO 3 /NaCl). Equilibrium constants of the reactions involving the formations of the mixed ligand species MAB, MA 2 B 2- , MB 2 A - (M = metal ion) and the binary complexes containing up to three ligand molecules have been evaluated from the pH-metric data, and coordinating behaviour of the ligands in the formation of the mixed ligand complexes has been discussed. (author). 10 refs., 1 tab., 1 fig

Binuclear new complexes of dioxouranium (VI) and thorium (IV) with some Schiff bases derived from 4,4'-diamino stilbene-2,2'-disulphonic acid-vanillin and O-vanillin

International Nuclear Information System (INIS)

Pujar, M.A.; Siddappa, K.

1992-01-01

Dioxouranium (VI) and thorium (IV) form 1:1 (metal:ligand) complexes with some Schiff bases. The complexes have been characterized through elemental analyses, conductance, UV-Visible, IR, NMR, TG data and magnetic susceptibility measurements. They are found to be dimeric with hexa or octa-coordinated arrangement around metal ion moiety. The Fsub(U-O) (mdyn A o ) and the length R UO (A o ) of U-O bond are calculated from the IR data. (author). 8 refs., 1 tab

Mixed-ligand Al complex-a new approach for more high efficient OLEDs

Energy Technology Data Exchange (ETDEWEB)

Petrova, Petia K., E-mail: petia@clf.bas.bg [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Tomova, Reni L.; Stoycheva-Topalova, Rumiana T. [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Kaloyanova, Stefka S.; Deligeorgiev, Todor G. [Applied Organic Chemistry, Faculty of Chemistry, University of Sofia, Sofia 1164 (Bulgaria)

2012-02-15

The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq{sub 2}Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq{sub 3}. Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq{sub 3} The better performance of the devices make the novel Al complex a very promising material for OLEDs. - Highlights: Black-Right-Pointing-Pointer A novel electroluminescent Alq{sub 2}Acac complex is presented as material for OLED. Black-Right-Pointing-Pointer Electroluminescent emission of Alq{sub 2}Acac is very similar to that of commercial Alq{sub 3}. Black-Right-Pointing-Pointer Devices with Alq{sub 2}Acac show better characteristics compared to those with Alq{sub 3}.

A soft tissue adhesive based on aldehyde-sodium alginate and amino-carboxymethyl chitosan preparation through the Schiff reaction

Science.gov (United States)

Wu, Yu; Yuan, Liu; Sheng, Nai-an; Gu, Zi-qi; Feng, Wen-hao; Yin, Hai-yue; Morsi, Yosry; Mo, Xiu-mei

2017-09-01

Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginate with sodium periodate to convert 1,2-hydroxyl groups into aldehyde groups to get aldehyde-sodium alginate (ASA). Carboxymethyl chitosan was modified with ethylenediamine (ED) in the presence of water-soluble N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) to introduce additional amino groups to get amino-carboxymethyl chitosan (A-CS). Upon mixing the A-SA and A-CS aqueous solutions together, a gel rapidly formed based on the Schiff's base reaction between aldehyde groups in A-SA and amino groups in A-CS. FTIR analysis confirmed the characteristic peak of Schiff's base group in the hydrogel. It was confirmed that the gelation time be dependent on the aldehyde group content in A-SA and amino group content in A-CS. The fasted hydrogel formation takes place within 10 min. The data of bonding strength and cytotoxicity measurement also showed that the hydrogel had good adhesion and biocompatibility. All these results support that this gel has the potential as soft tissue adhesive.

The concept of mixed organic ligands in metal-organic frameworks: design, tuning and functions.

Science.gov (United States)

Yin, Zheng; Zhou, Yan-Ling; Zeng, Ming-Hua; Kurmoo, Mohamedally

2015-03-28

The research on metal-organic frameworks (MOFs) has been developing at an extraordinary pace in its two decades of existence, as judged by the exponential growth of novel structures and the constant expansion of its applicability and research scope. A major part of the research and its success are due to the vital role of the concept of mixed organic ligands in the design, tuning and functions. This perspective, therefore, reviews the recent advances in MOFs based on this concept, which is generally based on employing a small polydentate ligand (here labelled as "nodal ligand") to form either clusters, rods or layers, which are then connected by a second ditopic linker ligand to form the framework. The structures of the materials can be grouped into the following three categories: layer-spacer (usually known as pillared-layer), rod-spacer, and cluster-spacer based MOFs. Depending on the size and geometry of the spacer ligands, interpenetrations of frameworks are occasionally found. These MOFs show a wide range of properties such as (a) crystal-to-crystal transformations upon solvent modifications, post-synthetic metal exchange or ligand reactions, (b) gas sorption, solvent selectivity and purification, (c) specific catalysis, (d) optical properties including colour change, luminescence, non-linear optic, (e) short- and long range magnetic ordering, metamagnetism and reversible ground-state modifications and (f) drug and iodine carriers with controlled release. In the following, we will highlight the importance of the above concept in the design, tuning, and functions of a selection of existing MOFs having mixed organic ligands and their associated structures and properties. The results obtained so far using this concept look very promising for fine-tuning the pore size and shape for selective adsorption and specificity in catalytic reactions, which appears to be one way to propel the advances in the application and commercialization of MOFs.

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.

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

A theoretical investigation on the neutral Cu(I) phosphorescent complexes with azole-based and phosphine mixed ligand

Science.gov (United States)

Ding, Xiao-Li; Shen, Lu; Zou, Lu-Yi; Ma, Ming-Shuo; Ren, Ai-Min

2018-04-01

A theoretical study on a series of neutral heteroleptic Cu(I) complexes with different azole-pyridine-based N^N ligands has been presented to get insight into the effect of various nitrogen atoms in the azole ring on photophysical properties. The results reveal that the highest occupied molecular orbital (HOMO) levels and the emission wavelengths of these complexes are mainly governed by the nitrogen atom number in azole ring. With the increasing number of nitrogen atom , the electron density distribution of HOMO gradually extend from the N^N ligand to the whole molecule, meanwhile, the improved contribution from Cu(d) orbits in HOMO results in an effective mixing of various charge transfermodes, and hence, the fast radiative decay(kr) and the slow non-radiative decay rate(knr) are achieved. The photoluminescence quantum yield (PLQY) show an apparent dependence on the nitrogen atom number in the five-membered nitrogen heterocycles. However, the increasing number of nitrogen atoms is not necessary for increasing PLQY. The complex 3 with 1,2,4-triazole-pyridine-based N^N ligands is considered to be a potential emitter with high phosphorescence efficiency. Finally, we hope that our investigations will contribute to systematical understanding and guiding for material molecular engineering.

New complexes of Co(II, Ni(II, Cu(II with Schiff base N,N’-bis-(3-methoxy-saliciliden-3,3’-dimethylbenzidine

Directory of Open Access Journals (Sweden)

Alan Ionela

2013-01-01

Full Text Available The new N,N’-bis-(3-methoxy-saliciliden-3,3’-dimetilbenzidine (H2L Schiff base and complexes with Co(II, Ni(II and Cu(II of type [M(HLCl(H2O] (M=Co(II, Cu(II [M2L(H2O4]X2 (M=Co(II, X=ClO4 and M=Cu(II, X=NO3 and [M2L(CH3COO2] (M=Co(II, Ni(II, Cu(II were synthesised. The ligand and complexes were characterized by elemental analysis, conductibility measurements, magnetic moments at room temperature, IR, NMR, UV-VIS-NIR, EPR spectra and thermogravimetric analysis. A molar ratio of 1:1 or 1:2 between ligand and metal was determined from the elemental analysis. Except for perchlorate complex that behave as electrolyte, the rest of complexes are non-electrolytes. The spectral data suggest a tetrahedral, pseudo-tetrahedral or square-planar stereochemistry respectively, data confirmed by magnetic behaviour of complexes. The antimicrobial tests indicate a fungicide effect both for ligand and complexes.

Coordination polymers of some lanthanide(III) nitrate with schiff bases

International Nuclear Information System (INIS)

Dwivedi, D.K.; Shukla, B.K.; Shukla, R.K.

1991-01-01

The Schiff bases derived from 2-hydroxy-1-naphthaldehyde and salicylaldehyde with o-dianisidine, p-phenylene diamine and benzidine and their lanthanide(III) complexes have been synthesized and characterized by elemental, I.R., thermal, magnetic and D.R.S. studies. (author). 7 refs

Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

International Nuclear Information System (INIS)

Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V.

2012-01-01

A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V. The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity

Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

Energy Technology Data Exchange (ETDEWEB)

Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V. [Univ. of Madras, Madras (India)

2012-11-15

A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V. The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

Schiff base-Poloxamer P85 combination demonstrates chemotherapeutic effect on prostate cancer cells in vitro.

Science.gov (United States)

Demirci, Selami; Doğan, Ayşegül; Türkmen, Neşe Başak; Telci, Dilek; Rizvanov, Albert A; Şahin, Fikrettin

2017-02-01

Prostate cancer is a multistep and complicated cancer type that is regulated by androgens at the cellular level and remains the second commonest cause of death among men. Discovery and development of novel chemotherapeutic agents enabling rapid tumor cell death with minimal toxic effects to healthy tissues might greatly improve the safety of chemotherapy. The present study evaluates the anti-cancer activity of a novel heterodinuclear copper(II)Mn(II) complex (Schiff base) in combination with poly(ethylene oxide) and poly(propylene oxide) block copolymer (Pluronic) P85. We used assays for cell proliferation, apoptosis, cell migration and invasion, DNA binding and cleavage to elucidate the molecular mechanisms of action, in addition to the anti-inflammatory potency of the new combination. The combined treatment of Schiff base and P85 lead to a remarkable anti-cancer effect on prostate cancer cell lines. Cell proliferation was inhibited in Schiff base-P85 treatment. The activity of this formulation is on DNA binding and cleavage and prevents inflammation in in vitro conditions. This is the first study presenting the anti-cancer activity of the present Schiff base derivative and its combination with P85 to treat prostate cancer in vitro. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Preparation and Characterization of a Molybdenum(VI Schiff Base Complex as Magnetic Nanocatalyst for Synthesis of 2-Amino-4H-benzo[h]chromenes

Directory of Open Access Journals (Sweden)

Naghmeh Divsalar

2016-10-01

Full Text Available A new recoverable molybdenum nanocatalyst was prepared by immobilization  of a Schiff base ligand on the surface of silica coated magnetite nanoparticles (Fe3O4@SiO2 through condensation reaction between 3-aminopropyl triethoxysilane and 2-hydroxy1-naphthaldehyde and succeeding reaction with dioxomolybdenum(VI acetylacetonate (MoO2(acac2. The synthesized catalyst was characterized by inductively coupled plasma, thermogravimetric analysis, scanning electron microscopy, vibrating sample magnetometry, Energy-dispersive X-ray, Fourier transform infrared and X-raydiffraction spectroscopy. Catalytic performance of the synthesized nanocatalyst was investigated for the preparation of 2-amino-4H-benzo[h]chromenes. The compounds were prepared high yield through one-pot, three-component reaction of 1-naphthol, various of aldehydes and malonitrile in the presence of nanocatalyst, Fe3O4@SiO2@Mo-Schiff base, under solvent-free conditions. The benefits of this protocol are short reaction time, simple work-up procedure, high yields and use of the concept of green chemistry. The magnetic nanocatalyst could be separated easily from the reaction media using an external magnetic field and reused in subsequent catalytic runs without significant deterioration of its activity.

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 decarboxyl......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...

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

Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic β-diketone with aromatic and aliphatic diamine

Science.gov (United States)

Surati, Kiran R.; Thaker, B. T.

2010-01-01

The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H 2L 1), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H 2L 2), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H 2L 3) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H 2L 4) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, 1H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn 3(μ 3-O)(OAc) 6(H 2O) 3]·3H 2O with ligands H 2L 1, H 2L 2, H 2L 3 and H 2L 4. All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion.

Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic beta-diketone with aromatic and aliphatic diamine.

Science.gov (United States)

Surati, Kiran R; Thaker, B T

2010-01-01

The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(1)), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(2)), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(3)) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(4)) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, (1)H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn(3)(mu(3)-O)(OAc)(6)(H(2)O)(3)].3H(2)O with ligands H(2)L(1), H(2)L(2), H(2)L(3) and H(2)L(4). All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion. Copyright 2009. Published by Elsevier B.V.

Effect of Schiff's Bases as Corrosion Inhibitors on Mild Steel in Sulphuric Acid

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R. K. Upadhyay

2007-01-01

Full Text Available Mass loss and thermometric methods have been used to study the corrosion inhibitory effect of synthesised Schiff's bases viz. N-(furfurilidine – 4- methoxy aniline (SB1, N-(furfurilidine – 4- methylaniline (SB2, N-(salicylidine – 4- methoxy aniline (SB3, N-(cinnamalidine – 4 –methoxy aniline (SB4 and N-(cinnamalidine - 2-methylaniline (SB5 on mild steel in sulphuric acid solutions. Results show that both methods have good agreement with each other and inhibition efficiency depends upon the concentration of inhibitor as well as that of acid. Maximum inhibition efficiency is shown at highest concentration of Schiff's bases at the highest strength of acid.

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...

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

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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.

Crystal structures and catalytic performance of three new methoxy substituted salen type nickel(II) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine

Science.gov (United States)

Ghaffari, Abolfazl; Behzad, Mahdi; Pooyan, Mahsa; Amiri Rudbari, Hadi; Bruno, Giuseppe

2014-04-01

Three new nickel(II) complexes of a series of methoxy substituted salen type Schiff base ligands were synthesized and characterized by IR, UV-Vis and 1H NMR spectroscopy and elemental analysis. The ligands were synthesized from the condensation of meso-1,2-diphenyl-1,2-ethylenediamine with n-methoxysalicylaldehyde (n = 3, 4 and 5). Crystal structures of these complexes were determined. Electrochemical behavior of the complexes was studied by means of cyclic voltammetry in DMSO solutions. Catalytic performance of the complexes was studied in the epoxidation of cyclooctene using tert-butylhydroperoxide (TBHP) as oxidant under various conditions to find the optimum operating parameters. Low catalytic activity with moderate epoxide selectivity was observed in in-solvent conditions but in the solvent-free conditions, enhanced catalytic activity with high epoxide selectivity was achieved.

Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity

Science.gov (United States)

Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin

2018-02-01

Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (LG, LP) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by 1H NMR, 13C NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of LG and LP. The LG, LP and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi.

Characterization and crystal structures of new Schiff base macrocyclic compounds

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Ghoran, S.H.; Pojarová, Michaela; Dušek, Michal

2015-01-01

Roč. 56, č. 7 (2015), s. 1410-1414 ISSN 0022-4766 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : synthesis * macrocyclic Schiff base * single crystal structure analysis * spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.536, year: 2015

Synthesis, characterization and biological behavior of some Schiff's and Mannich base derivatives of Lamotrigine

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A.A. Kulkarni

2017-02-01

Full Text Available A series of various Schiff's and Mannich base derivatives (N1–2 & ND1–6 of Lamotrigine with isatin and substituted isatin were synthesized to get more potent anticonvulsant agents. The starting material for the synthesis of various new Schiff's and Mannich base derivatives was isatin (1H-indole- 2, 3-dione which in turn was prepared from substituted isonitrosoacetanilide using aniline. Lamotrigine reacts with isatin & substituted isatin gave Schiff's bases (N1–2 which on reaction with various secondary amines (dimethylamine, diethylamine, morpholine produced Mannich bases (ND1–6. The structures of newly synthesized compounds were characterized by using TLC, UV, FT-IR, 1HNMR and studied for their anticonvulsant activity. Anticonvulsant activity of all the derivatives was evaluated by MES method using phenobarbitone sodium & Lamotrigine as standard drugs and % reduction of time spent by animals in extension, flexion, clonus, and stupor phase were noted. Compounds ND-4 and ND-6 showed significant anticonvulsant activity when compared with that of standard drugs. The remaining all compounds show moderate activity. Biological activity data of the synthesized derivatives revealed that, the synthesized derivatives are good anticonvulsant agents as compared to Lamotrigine.

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

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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%.

An efficient synthesis and spectroscopic characterization of Schiff bases containing 9,10-anthracenedione moiety

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Fareed Ghulam

2013-01-01

Full Text Available A new method has been developed for the synthesis of novel Schiff bases containg anthraquinone moiety using dodeca-Tungstosilicic acid/P2O5 under solvent free conditions at room temperature. The reaction was completed in 1-3 minutes with excellent yields. This method was found to be more efficient, easy and hazardous free for the synthesis of azomethines. The development of these type of methadologies in synthetic chemistry may contribute to green chemistry. The structures of synthesized novel Schiff bases was elucidated using 1H-NMR, 13C-NMR, LCMS, FTIR and CHN analysis.

and Zn(II) Complexes with the Schiff base N-salicylidene-4-chlor

African Journals Online (AJOL)

2017-12-13

Dec 13, 2017 ... 2010) Schiff bases are used as intermediate for the ... Infrared spectral analysis .... Table 6: Percentage Composition of the Metal in the complexes using Gravimetric Method .... Internal journal of pharmacy & Technology.

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

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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.

Synthesis, characterization and antimicrobial activities of a Schiff ...

African Journals Online (AJOL)

Complexes of Cu(II), Ni(II) and Mn(II) with a Schiff base derived from condensation reaction of phenylalanine and acetylacetone have been synthesized and characterized analytically and spectroscopically. Melting point of the Schiff base was 188oC and the complexes decompose within a temperature range of 210-242oC.

Small-molecule azomethines: Organic photovoltaics via Schiff base condensation chemistry

OpenAIRE

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 preparing a photovoltaic device directly from the reaction mixture without any form of workup.

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

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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.

A coumarin based Schiff base probe for selective fluorescence detection of Al3 + and its application in live cell imaging

Science.gov (United States)

Sen, Bhaskar; Sheet, Sanjoy Kumar; Thounaojam, Romita; Jamatia, Ramen; Pal, Amarta Kumar; Aguan, Kripamoy; Khatua, Snehadrinarayan

2017-02-01

A new coumarin based Schiff base compound, CSB-1 has been synthesized to detect metal ion based on the chelation enhanced fluorescence (CHEF). The cation binding properties of CSB-1 was thoroughly examined in UV-vis and fluorescence spectroscopy. In fluorescence spectroscopy the compound showed high selectivity toward Al3 + ion and the Al3 + can be quantified in mixed aqueous buffer solution (MeOH: 0.01 M HEPES Buffer; 9:1; v/v) at pH 7.4 as well as in BSA media. The fluorescence intensity of CSB-1 was enhanced by 24 fold after addition of only five equivalents of Al3 +. The fluorescence titration of CSB-1 with Al3 + in mixed aqueous buffer afforded a binding constant, Ka = (1.06 ± 0.2) × 104 M- 1. The colour change from light yellow to colourless and the appearance of blue fluorescence, which can be observed by the naked eye, provides a real-time method for Al3 + sensing. Further the live cell imaging study indicated that the detection of intracellular Al3 + ions are also readily possible in living cell.

Synthesis, characterization and in vitro biological activities of new water-soluble copper(II), zinc(II), and nickel(II) complexes with sulfonato-substituted Schiff base ligand

Czech Academy of Sciences Publication Activity Database

Hosseini-Yazdi, S.A.; Mirzaahmadi, A.; Khandar, A.A.; Eigner, Václav; Dušek, Michal; Lotfipour, F.; Mahdavi, M.; Soltani, S.; Dehghan, G.

2017-01-01

Roč. 458, Mar (2017), s. 171-180 ISSN 0020-1693 R&D Projects: GA ČR(CZ) GA15-12653S; GA MŠk(CZ) LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : water-soluble Schiff base * thiosemicarbazone * antimicrobial * antioxidant * cytotoxicity * crystal structure Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 2.002, year: 2016

Silica functionalized Cu(II) acetylacetonate Schiff base complex: An efficient catalyst for the oxidative condensation reaction of benzyl alcohol with amines

Science.gov (United States)

Anbarasu, G.; Malathy, M.; Karthikeyan, P.; Rajavel, R.

2017-09-01

Silica functionalized Cu(II) acetylacetonate Schiff base complex via the one pot reaction of silica functionalized 3-aminopropyltriethoxysilane with acetyl acetone and copper acetate has been reported. The synthesized material was well characterized by analytical techniques such as FT-IR, UV-DRS, XRD, SEM-EDX, HR-TEM, EPR, ICP-AES and BET analysis. The characterization results confirmed the grafting of Cu(II) Schiff base complex on the silica surface. The catalytic activity of synthesized silica functionalized Cu(II) acetylacetonate Schiff base complex was evaluated through the oxidative condensation reaction of benzyl alcohol to imine.

Ruthenium(III) Complexes of Heterocyclic Tridentate (ONN) Schiff Base: Synthesis, Characterization and its Biological Properties as an Antiradical and Antiproliferative Agent

Science.gov (United States)

Ejidike, Ikechukwu P.; Ajibade, Peter A.

2016-01-01

The current work reports the synthesis, spectroscopic studies, antiradical and antiproliferative properties of four ruthenium(III) complexes of heterocyclic tridentate Schiff base bearing a simple 2′,4′-dihydroxyacetophenone functionality and ethylenediamine as the bridging ligand with RCHO moiety. The reaction of the tridentate ligands with RuCl3·3H2O lead to the formation of neutral complexes of the type [Ru(L)Cl2(H2O)] (where L = tridentate NNO ligands). The compounds were characterized by elemental analysis, UV-vis, conductivity measurements, FTIR spectroscopy and confirmed the proposed octahedral geometry around the Ru ion. The Ru(III) compounds showed antiradical potentials against 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, with DPPH scavenging capability in the order: [(PAEBOD)RuCl2] > [(BZEBOD)RuCl2] > [(MOABOD)RuCl2] > [Vit. C] > [rutin] > [(METBOD)RuCl2], and ABTS radical in the order: [(PAEBOD)RuCl2] < [(MOABOD)RuCl2] < [(BZEBOD)RuCl2] < [(METBOD)RuCl2]. Furthermore, in vitro anti-proliferative activity was investigated against three human cancer cell lines: renal cancer cell (TK-10), melanoma cancer cell (UACC-62) and breast cancer cell (MCF-7) by SRB assay. PMID:26742030

Ruthenium(III Complexes of Heterocyclic Tridentate (ONN Schiff Base: Synthesis, Characterization and its Biological Properties as an Antiradical and Antiproliferative Agent

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Ikechukwu P. Ejidike

2016-01-01

Full Text Available The current work reports the synthesis, spectroscopic studies, antiradical and antiproliferative properties of four ruthenium(III complexes of heterocyclic tridentate Schiff base bearing a simple 2′,4′-dihydroxyacetophenone functionality and ethylenediamine as the bridging ligand with RCHO moiety. The reaction of the tridentate ligands with RuCl3·3H2O lead to the formation of neutral complexes of the type [Ru(LCl2(H2O] (where L = tridentate NNO ligands. The compounds were characterized by elemental analysis, UV-vis, conductivity measurements, FTIR spectroscopy and confirmed the proposed octahedral geometry around the Ru ion. The Ru(III compounds showed antiradical potentials against 2,2-Diphenyl-1-Picrylhydrazyl (DPPH and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS radicals, with DPPH scavenging capability in the order: [(PAEBODRuCl2] > [(BZEBODRuCl2] > [(MOABODRuCl2] > [Vit. C] > [rutin] > [(METBODRuCl2], and ABTS radical in the order: [(PAEBODRuCl2] < [(MOABODRuCl2] < [(BZEBODRuCl2] < [(METBODRuCl2]. Furthermore, in vitro anti-proliferative activity was investigated against three human cancer cell lines: renal cancer cell (TK-10, melanoma cancer cell (UACC-62 and breast cancer cell (MCF-7 by SRB assay.

Mixed-ligand complexes of dioxouranium(VI)

International Nuclear Information System (INIS)

Ahuja, Renu; Dwivedi, K.

1995-01-01

A number of mixed ligand complexes of UO 2 2+ ion have been studied with aminopolycarboxylic acids, such as ethylenediaminetetraacetic acid with coordination number (CN) = 6, nitrilotriacetic acid with CN = 4 and iminodiacetic acid with CN = 3. Ethyleneglycol-bis-2-aminoethylether tetraacetic acid (EGTA) is an octadentate aminopolycarboxylic acid and forms stable binary complexes with many metal ions at low pH. In this paper the results obtained for the study of 1:1:1 UO 2 VI -EGTA-aspartic acid/glutamic acid systems are studied. (author). 7 refs., 1 fig., 1 tab

and Ni (II) complexes with Schiff base derived from 2-amino benzoic

African Journals Online (AJOL)

CLEMENT O BEWAJI

The molar conductance of the complexes measured are low, indicating their ... ethanolic solution (1.22g, 0.01mol) to the same volume of ethanolic solution of 2- ... prepared by neutralizing a known quantity of the Schiff base with calculated ...

Synthesis of novel '4+1' Tc(III)/Re(III) mixed-ligand complexes with dendritically modified ligands

International Nuclear Information System (INIS)

Gniazdowska, E.; Kuenstler, J.U.; Stephan, H.; Pietzsch, H.J.

2006-01-01

Coordination chemistry of technetium and rhenium attracts a considerable interest due to the nuclear medicine applications of their radionuclides. Inert, so-called '3+1' or '4+1' technetium/rhenium mixed-ligand complexes open a new way to application of 99 mTc/ 188 Re labeled compounds in tumor diagnosis and therapy. In the presented paper, authors describe the synthesis and study of novel 99 mTc/ 188 Re complexes with dendritically functionalized tetradentate (tripodal chelator 2,2',2''-nitrilotris(ethanethiol), NS 3 and carboxyl group-bearing ligand, NS 3 (COOH) 3 ) and monodentate (dendritically modified isocyanide, CN-R(COOMe) 3 and isocyanide-modified peptide, CN-GGY) ligands. To verify the identity of the prepared n.c.a. complexes, non-radioactive analogous '4+1' Re compounds were synthesized. The experimental data show that a dendritic modification of the tetradentate/monodentate ligands changes the complex lipophilicity and does not influence its stability

N,N′-Dipyridoxyl(1,8-diamino-3,6-dioxaoctane) Schiff-base

African Journals Online (AJOL)

The N,N′-dipyridoxyl(1,8-diamino-3,6-dioxaoctane) (=H2L) Schiff-base has been synthesized and characterized by IR, 1H NMR, mass spectrometry and elemental analysis. Its optimized geometry and theoretical vibrational frequencies have been computed using density functional theory (DFT) method via the B3LYP ...

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).

Dihydroxycoumarin Schiff base synthesis and structure determination from powder diffraction data

Czech Academy of Sciences Publication Activity Database

Rohlíček, Jan; Ketata, I.; Ben Ayed, T.; Ben Hassen, R.

2013-01-01

Roč. 1051, NOV (2013), s. 280-284 ISSN 0022-2860 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378271 Keywords : powder diffraction * structure solution * Schiff base * dihydroxycoumarine Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.599, year: 2013

Synthesis, Photophysical and Electrochemical Properties of a Mixed Bipyridyl-Phenanthrolyl Ligand Ru(II Heteroleptic Complex Having trans-2-Methyl-2-butenoic Acid Functionalities

Directory of Open Access Journals (Sweden)

Adewale O. Adeloye

2011-09-01

Full Text Available In this work, two ligands: 4-(trans-2-Methyl-2-butenoic acid-2,2'-bipyridine (L1 and 5-(trans-2-methyl-2-butenoic acid-1,10-phenanthroline (L2, with the corresponding mixed-ligand heteroleptic Ru(II complex were synthesized and characterized by FT-IR, 1H-, 13C-NMR spectroscopy and elemental analysis. The influence of the mixed functionalized polypyridyl ruthenium(II complex on the photophysical and electrochemical properties were investigated and compared to individual single-ligand homoleptic complexes. Interestingly, the mixed-ligand complex formulated as [RuL1L2(NCS2] exhibits broad and intense metal-to-ligand charge transfer (MLCT absorption with a high molar extinction coefficient (λmax = 514 nm, ε = 69,700 M−1 cm−1, better than those of individual single-ligand complexes, [Ru(L12(NCS2] and [Ru(L22(NCS2], and a strong photoluminescence intensity ratio in the red region at λem = 686 nm. The electrochemical properties of the complex indicated that the redox processes are ligand-based.

Synthesis, Characterization and Antimicrobial Activity of Cu(II, Co(II and Ni(II Complexes with O, N, and S Donor Ligands

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Vidyavati Reddy

2008-01-01

Full Text Available The complexes of the type ML2 [where M = Cu(II, Co(II, and Ni(II] L = 1-phenyl-1-ene-3-(2-hydroxyphenyl-prop-2-ene with 3- substituted-5-mercapto-4-amino-1,2,4-triazoles. Schiff base ligands have been prepared by reacting 3-(2-hydroxyphenyl-1-phenylprop-2-en-1-one and 3-phenyl/pyridyl-4-amino-5-mercapto-1,2,4-triazoles in an alcoholic medium. The complexes are non-electrolytes in DMF. The resulting complexes were characterized by elemental analysis, magnetic measurements, conductivity measurements and spectral studies. The Schiff base acts as a tridentate dibasic and coordinating through the deprotonated oxygen, thioenolic sulphur and azomethine nitrogen atoms. It is found that Cu(II, Co(II, and Ni(II complexes exhibited octahedral geometry. The antimicrobial activities of ligands and its complexes were screened by cup plate method.

Synthesis, Characterization and Biological Activities of Creatinine Amides and Creatinine Schiff Bases.

Science.gov (United States)

Mumtaz, Amara; Zahoor, Fareeha; Zaib, Sumera; Nawaz, Muhammad Azhar H; Saeed, Aamer; Waseem, Amir; Khan, Afsar; Hussain, Izhar; Iqbal, Jamshed

2017-01-30

In spite of substantial progress in scientific cognizance and medical technology, still infectious diseases are among the leading cause of morbidity and mortality. Creatinine and Schiff bases are well known for their diverse range of biological activities and thought to be emerging and useful therapeutic target for the treatment of several diseases. The present work was aimed to illustrate the influence of substitution of amides and Schiff bases on creatinine and their antimicrobial, antioxidant and anti-urease effectiveness was determined. Creatinine substituted amides (1-2) and creatinine Schiff bases (3-7) were synthesized and characterized by NMR and IR spectral data in combination with elemental analysis. All the compounds (1-7) were investigated on Jack bean urease for their urease inhibitory potential. Investigation of antimicrobial activity of the compounds was made by the agar dilution method. Moreover, 1,1-diphenyl-2- picrylhydrazyl (DPPH) method was used to determine their antioxidant potential. Molecular docking studies were also carried out to elucidate their relationship with the binding pockets of the enzyme. The compounds were found to be potent inhibitors of urease. The synthesized derivatives exhibited significant inhibition against Gram-positive and Gram-negative bacterial strains, as compared to standard, ciprofloxacin. Creatinine based derivatives exhibited potential antifungal activity when tested on infectious and pathogenic fungal strains. Similarly, most of the compounds exhibited good antioxidant activity. These derivatives may serve as a source of potential antioxidants and also help to retard microbial growth in food industry. Similarly, the studies provide a basis for further research to develop more potent urease inhibitory compounds of medicinal /agricultural interest. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Synthesis, spectroscopic and DNA binding ability of CoII, NiII, CuII and ZnII complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex.

Science.gov (United States)

Yarkandi, Naeema H; El-Ghamry, Hoda A; Gaber, Mohamed

2017-06-01

A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L) 2 ]·l2H 2 O, [Ni(L)Cl·(H 2 O) 2 ].5H 2 O, [Cu(L)Cl] and [Zn(L)(CH 3 COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, 1 H & 13 C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (K b ). Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, characterization, X-ray crystallography, acetyl cholinesterase inhibition and antioxidant activities of some novel ketone derivatives of gallic hydrazide-derived Schiff bases.

Science.gov (United States)

Gwaram, Nura Suleiman; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen; Buckle, Michael J C; Sukumaran, Sri Devi; Chung, Lip Yong; Othman, Rozana; Alhadi, Abeer A; Yehye, Wageeh A; Hadi, A Hamid A; Hassandarvish, Pouya; Khaledi, Hamid; Abdelwahab, Siddig Ibrahim

2012-02-28

Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.

Polarographic study of Cd(II)-Schiff base complexes and d.m.e. menthanol-water medium

International Nuclear Information System (INIS)

Patel, M.S.; Trivedi, T.; Vyas, D.N.

1978-01-01

Three Schiff base complexes of Cd 2+ have been investigated polarographically in 60% menthanol-water medium at 26 0 C. The Schiff bases used are salicyladehyde tris buffer (ST), benzaldehydetris buffer (BT) and vanillin tris buffer (VT). Cd-ST and Cd-VT complexes produce reversible reduction wave at dme, while Cd-BT gives a quasi reversible wave. Stability constants of the complexes have been determined and the standard overall electrode reaction rate constant (ksub(e)sup(o)) B of the Cd-BT complex is determined by three different methods. The log β values of complexes are : Cd-ST, 2.72; Cd-VT, 4.90; and Cd-BT, 4.41. (author)

Morphology-controlled hydrothermal synthesis of MnCO3 hierarchical superstructures with Schiff base as stabilizer

International Nuclear Information System (INIS)

Hu, He; Xu, Jie-yan; Yang, Hong; Liang, Jie; Yang, Shiping; Wu, Huixia

2011-01-01

Graphical abstract: MnCO3 microcrystals with hierarchical superstructures were synthesized by using the CO2 in atmosphere as carbonate ions source and Schiff base as shape guiding-agent in water/ethanol system under hydrothermal condition. Highlights: → The most interesting in this work is the use of the greenhouse gases CO 2 in atmosphere as carbonate ions source to precipitate with Mn 2+ for producing MnCO 3 crystals. → This work is the first report related to the small organic molecule Schiff base as shape guiding-agent to produce different MnCO 3 hierarchical superstructures. → We are controllable synthesis of the MnCO 3 hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like microcrystals. → The as-prepared MnCO 3 could be used precursor to fabricate the Mn 2 O 3 hierarchical superstructures after thermal decomposition at high temperature. -- Abstract: MnCO 3 with hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like were synthesized in water/ethanol system under environment-friendly hydrothermal condition. In the synthesis process, the CO 2 in atmosphere was used as the source of carbonate ions and Schiff base was used as shape guiding-agent. The different superstructures of MnCO 3 could be obtained by controlling the hydrothermal temperature, the molar ratio of manganous ions to the Schiff base, or the volume ratio of water to ethanol. A tentative growth mechanism for the generation of MnCO 3 superstructures was proposed based on the rod-dumbbell-sphere model. Furthermore, the MnCO 3 as precursor could be further successfully transferred to Mn 2 O 3 microstructure after heating in the atmosphere at 500 o C, and the morphology of the Mn 2 O 3 was directly determined by that of the MnCO 3 precursor.

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.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemopreventive evaluation of a Schiff base derived copper (II) complex against azoxymethane-induced colorectal cancer in rats.

Science.gov (United States)

Hajrezaie, Maryam; Hassandarvish, Pouya; Moghadamtousi, Soheil Zorofchian; Gwaram, Nura Suleiman; Golbabapour, Shahram; Najihussien, Abdrabuh; Almagrami, Amel Abdullah; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Fani, Somaye; Kamalidehghan, Behnam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

2014-01-01

Based on the potential of Schiff base compounds to act as sources for the development of cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic Schiff base compound Cu(BrHAP)2 on colonic aberrant crypt foci (ACF). This study involved five groups of male rats. The negative control group was injected with normal saline once a week for 2 weeks and fed 10% Tween 20 for 10 weeks, the cancer control group was subcutaneously injected with 15 mg/kg azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and 35 mg/kg 5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the Schiff base compound once a day for 10 weeks. Application of the Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (P<0.05) when compared with the cancer control group. Analysis of colorectal specimens revealed that treatments with the Schiff base compound decreased the mean crypt scores in azoxymethane-treated rats. Significant elevations of superoxide dismutase, glutathione peroxidase and catalase activities and a reduction in the level of malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group. The current study demonstrated that the Cu(BrHAP)2 compound has promising chemoprotective activities that are evidenced by significant decreases in the numbers of ACFs in azoxymethane-induced colon cancer.

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

International Nuclear Information System (INIS)

Dowlati, Bahram; Othman, Mohamed Rozali

2013-01-01

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, 1 H NMR, 13 C NMR and ESI-MS 2

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.

Potentiometric studies on mixed-ligand chelates of uranyl ion with carboxylic acid phenolic acids

International Nuclear Information System (INIS)

Bandiwadekar, S.P.; Chavar, A.M.

1988-01-01

Mixed ligand complexes of UO 2 2+ with bidentate carboxylic and phenolic acids have been studied potentiometrically at 30 ± 0.1degC and μ=0.2M (NaClO 4 ). 1:1 and 1:2 complexes of UO 2 2+ with phthalic acid (PTHA), maleic acid (MAE), malonic acid (MAL), quinolinic acid (QA), 5-sulphosalicylic acid (5-SSA), salicylic acid (SA), and only 1:1 complexes in the case of mandelic acid (MAD) have been detected. The formation of 1:1:1 mixed ligand complexes has been inferred from simultaneous equilibria in the present study. The values of ΔlogK, Ksub(DAL), Ksub(2LA) or Ksub(2AL) for the ternary complexes have been calculated. The stabilities of mixed ligand complexes depend on the size of the chelate ring and the stabilities of the binary complexes. (author). 15 refs

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

OpenAIRE

Madasamy Kumar; Tamilenthi Padmini; Kandasamy Ponnuvel

2017-01-01

A series of new cholesterol based Schiff base derivatives, namely cholesteryl-n-(4-((E)-(4′-cyanobiphenyl-4-ylimino)methyl)phenoxy)alkanoate (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 exhib...

Bibenzimidazole containing mixed ligand cobalt(III) complex as a selective receptor for iodide

Digital Repository Service at National Institute of Oceanography (India)

Indumathy, R.; Parameswarana, P.S.; Aiswarya, C.V.; Nair, B.U.

Two new mixed ligand cobalt(III) complexes containing bibenzimidazole (bbenzimH₂) ligand with composition [Co(phen)₂bbenzimH₂](ClO₄)₃ (1) and [Co(bpy)₂bbenzimH₂](ClO_4...

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. Copyright © 2012 Elsevier B.V. All rights reserved.

Facile synthesis of conjugated polymeric Schiff base as negative electrodes for lithium ion batteries

International Nuclear Information System (INIS)

Ye, Haijun; Jiang, Fangqing; Li, Hongqin; Xu, Zheng; Yin, Jiao; Zhu, Hui

2017-01-01

Graphical abstract: Polymeric Schiff base (PSB) exhibits a stable cyclability as an organic Li-ion battery anode Display Omitted -- Highlights: •A conjugated Schiff base polymer has been synthesized by a solid-phase reaction. •The polymer suppresses the dissolution of organic monomer into the organic electrolyte. •The polymer demonstrates high reversible capacity and excellent cyclic performance. -- Abstract: The redox-active organic compounds show great potentials as anodes for high energy density Li-ion batteries (LIBs), comparing with the traditional transition metal-based inorganic compounds. However, the inevitable dissolution behaviors of these organics in organic electrolyte will arouse the recession in their cycling stabilities. To circumvent this problem, we successfully applied an electrochemically active imine group to connect the carbonyl compound to form conjugated polymer, where the occurrence of multi-electron reactions suppressed the dissolution of anthraquinone in the organic electrolyte with improved cycling stability and high capacity for LIBs. In detail, by virtue of a facile solid-phase reaction between 1, 4-diaminoanthraquinone (14DAAQ) and p-phthalaldehyde (PPD), a highly conjugated polymeric Schiff base (PSB) was synthesized. The obtained PSB exhibited a reversible specific capacity of 175 mAh g −1 at a current density of 10 mA g −1 . In addition, after 100 cycles, a cycling stability with 90% capacity retention can be maintained, manifesting a promising application of the organic material in high performance anodes for LIBs.

Effect of the substitutional groups on the electrochemistry, kinetic of thermal decomposition and kinetic of substitution of some uranyl Schiff base complexes

Energy Technology Data Exchange (ETDEWEB)

Asadi, Zahra; Nasrollahi, Rahele; Ranjkeshshorkaei, Mohammad; Firuzabadi, Fahimeh Dehghani [Shiraz Univ. (Iran, Islamic Republic of). Chemistry Dept.; Dusek, Michal; Fejfarova, Karla [ASCR, Prague (Czech Republic). Inst. of Physics

2016-05-15

Uranyl(VI) complexes, [UO{sub 2}(X-saloph)(solvent)], where saloph denotes N,N{sup '}-bis(salicylidene)-1,2-phenylenediamine and X = NO{sub 2}, Cl, Me, H; were synthesized and characterized by 61H NMR, IR, UV-Vis spectroscopy, thermal gravimetry (TG), cyclic voltammetry, elemental analysis (C.H.N) and X-ray crystallography. X-ray crystallography of [UO{sub 2}(4-nitro-saloph)(DMF)] revealed coordination of the uranyl by the tetradentate Schiff base ligand and one solvent molecule, resulting in seven-coordinated uranium. The complex of [UO{sub 2}(4-nitro-saloph)(DMF)] was also synthesized in nano form. Transmission electron microscopy image showed nano-particles with sizes between 30 and 35 nm. The TG method and analysis of Coats-Redfern plots revealed that the kinetics of thermal decomposition of the complexes is of the first-order in all stages. The kinetics and mechanism of the exchange reaction of the coordinated solvent with tributylphosphine was investigated by spectrophotometric method. The second-order rate constants at four temperatures and the activation parameters showed an associative mechanism for all corresponding complexes with the following trend: 4-Nitro > 4-Cl > H > 4-Me. It was concluded that the steric and electronic properties of the complexes were important for the reaction rate. For analysis of anticancer properties of uranyl Schiff base complexes, cell culture and MTT assay was carried out. These results showed a reduction of jurkat cell line concentration across the complexes.

A novel extended architecture with 4 6·6 4 topology based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units

Science.gov (United States)

Tong, Ruizhan; Ren, Xiaoyu; Li, Zuoxi; Liu, Bin; Hu, Huaiming; Xue, Ganglin; Fu, Feng; Wang, Jiwu

2010-09-01

A novel inorganic-organic hybrid compound based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units, Cu 8I(imi) 4(bpy) 6(H 2O)[As 2VW 2VW 16VlO 62]·2H 2O ( 1) (bpy=4,4'-bipydine; imi=imidazole), has been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, luminescent spectrum and single crystal X-ray diffraction. Single-crystal X-ray diffraction revealed that four terminal and three bridging oxygen atoms of the Wells-Dawson cluster are coordinated to Cu(I) ions and form an unprecedented hepta-supporting polyoxometalate. The functionalized arsenotungstates are further connected by two kinds of tridentate linkers, Imi-Cu-(bpy)-Cu-(bpy)-Cu-(bpy)-Cu-Imi and Imi-Cu-(bpy)-Cu-(bpy)-Cu-H 2O, to construct a 3D framework with 4 6·6 4 topology. The hybrid material has an intense emission at about 397 nm.

Water soluble chromone Schiff base derivatives as fluorescence receptor for aluminium(III)

Czech Academy of Sciences Publication Activity Database

Jakubek, M.; Kejík, Z.; Parchaňský, Václav; Kaplánek, R.; Vasina, L.; Martásek, P.; Král, V.

2017-01-01

Roč. 29, č. 1 (2017), s. 1-7 ISSN 1061-0278 R&D Projects: GA TA ČR(CZ) TE01020028 Institutional support: RVO:61388963 Keywords : aluminium sensing * chelator * chromone * fluorescence * Schiff base Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.264, year: 2016

Schiff Bases of Benzothiazol-2-ylamine and Thiazolo[5,4-b] pyridin-2-ylamine as Anticonvulsants: Synthesis, Characterization and Toxicity Profiling.

Science.gov (United States)

Shukla, Rashmi; Singh, Ajeet P; Sonar, Pankaj K; Mishra, Mudita; Saraf, Shailendra K

2016-01-01

Schiff bases have a broad spectrum of biological activities like antiinflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic and so forth. Thus, after a thorough perusal of literature, it was decided to conjugate benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine with aromatic and heteroaromatic aldehydes to get a series of Schiff bases. Synthesis, characterization, in-silico toxicity profiling and anticonvulsant activity of the Schiff bases of Benzothiazol-2-ylamine and Thiazolo [5, 4-b] pyridin-2-ylamine. Aniline/4-aminopyridine was converted to the corresponding thiourea derivatives, which were cyclized to obtain benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine. Finally, these were condensed with various aromatic and heteroaromatic aldehydes to obtain Schiff bases of benzothiazol-2-ylamine and thiazolo [5, 4-b] pyridin-2-ylamine. The synthesized compounds were characterized and screened for their anticonvulsant activity using maximal electroshock (MES) test and isoniazid (INH) induced convulsions test. In-silico toxicity profiling of all the synthesized compounds was done through "Lazar" and "Osiris" properties explorer. Majority of the compounds were more potent against MES induced convulsions than INH induced convulsions. Schiff bases of benzothiazol-2-ylamine were more effective than thiazolo [5, 4-b] pyridin-2-ylamine against MES induced convulsions. The compound benzothiazol-2-yl-(1H-indol-2-ylmethylene)-amine (VI) was the most potent member of the series against both types of convulsions. Compound VI exhibited the most significant activity profile in both the models. The compounds did not exhibit any carcinogenicity or acute toxicity in the in-silico studies. Thus, it may be concluded that the Schiff bases of benzothiazol-2-ylamine exhibit the potential to be promising and non-toxic anticonvulsant agents.

Functionalization of mesoporous silica membrane with a Schiff base fluorophore for Cu(II) ion sensing

Energy Technology Data Exchange (ETDEWEB)

Chen Xiaotong [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Department of Chemistry, Tsinghua University, Beijing 100084 (China); Yamaguchi, Akira [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Tokai, Ibaraki 319-1106 (Japan); Namekawa, Manato [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Kamijo, Toshio [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Tsuruoka National College of Technology, Aza-Sawada, Tsuruoka 997-8511 (Japan); Teramae, Norio, E-mail: teramae@m.tohoku.ac.jp [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Tong, Aijun, E-mail: tongaj@mail.tsinghua.edu.cn [Department of Chemistry, Tsinghua University, Beijing 100084 (China)

2011-06-24

Graphical abstract: Highlights: > A hybrid mesoporous membrane (SB-HMM) functionalized by Schiff base fluorophores was fabricated. > SB-HMM showed strong fluorescence with aggregation-induced emission enhancement properties. > SB-HMM was applicable for the detection of Cu(II) in an aqueous solution with good reversibility and reproducibility. - Abstract: A Schiff base (SB) immobilized hybrid mesoporous silica membrane (SB-HMM) was prepared by immobilizing a Schiff base onto the pore surface of mesoporous silica (pore size = 3.1 nm) embedded in the pores of a porous anodic alumina membrane. In contrast to the non-fluorescent analogous SB molecule in homogeneous solutions, SB-HMM exhibited intense fluorescence due to emission enhancement caused by aggregation of SB groups on the pore surface. The high quantum efficiency of the surface SB groups allows SB-HMM to function as a fluorescent sensor for Cu(II) ions in an aqueous solution with good sensitivity, selectivity and reproducibility. Under the optimal conditions described, the linear ranges of fluorescence intensity for Cu(II) are 1.2-13.8 (M (R{sup 2} = 0.993) and 19.4-60 (R{sup 2} = 0.992) (M. The limit of detection for Cu(II) is 0.8 {mu}M on basis of the definition by IUPAC (C{sub LOD} = 3.3S{sub b}/m).

Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems ...

African Journals Online (AJOL)

Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems. ... method has been used to study heavy metal interaction in model lake water in KNO3 ... is of no consequential effect because in its normal state, the [OH-] of the lake water is ...

Synthesis, crystal structure and bioactivity of manganese complexes with asymmetric chiral Schiff base

Science.gov (United States)

Zhang, Enfeng; Wei, Yi; Huang, Fuping; Yu, Qing; Bian, Hedong; Liang, Hong; Lei, Fuhou

2018-03-01

A couple of chiral unsymmtrical Schiff base ligands, (1R,2R) (-)chxn (salH) (naftalH) and (1S,2S) (-)chxn (salH) (naftalH) had been synthesized by the condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with two isomers of (1R,2R)-trans-1,2-cyclohexanediamin and (1S,2S)-trans-1,2-cyclohexanediamin, respectively. At the same time, two manganese complexes have been synthesized and fully characterized by FT-IR spectrum, elemental analyses, single crystal X-ray diffraction. The interaction of the two Mn (III) complexes with bovine serum albumin (BSA) was investigated by spectroscopic techniques. The result reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. The binding constant and binding mode has been determined. The secondary structure and the amino acid residues microenvironment of BSA change in the presence of these complexes. SOD-like activity and ABTS free radical scavenging ability were also studied. The antioxidant capacity of the compounds showed that the complexes and their corresponding BSA adducts showed some SOD activity. The results of ABTS free radical scavenging showed that the activity of the BSA adduct was more obvious than that of the complex.

Evaluation of Adsorption Capacity of Chitosan-Citral Schiff Base for Wastewater Pre-Treatment in Dairy Industries

Directory of Open Access Journals (Sweden)

Desislava K. Tsaneva

2017-06-01

Full Text Available In this study, we aimed to evaluate the adsorption capacity of the Schiff base chitosan-citral for its application in dairy wastewater pre-treatment. Chemical oxygen demand (COD reduction was the factor used to evaluate the adsorption efficiency. The maximum COD percentage reduction of 35.3% was obtained at 40.0 °C, pH 9.0, adsorbent dose 15 g L-1, contact time 180 min and agitation speed 100 rpm. It was found that the Langmuir isotherm fitted well the equilibrium data of COD uptake (R2 = 0.968, whereas the kinetic data were best fitted by the pseudo-second order model (R2=0.999. Enhancement of the adsorption efficiency up to 29.8% in dependence of the initial COD concentration of the dairy wastewater was observed by adsorption with the Schiff base chitosan-citral adsorbent compared to the non-modified chitosan at the same experimental conditions. The results indicated that the Schiff base chitosan-citral can be used for dairy wastewater physicochemical pretreatment by adsorption, which might be applied before the biological unit in the wastewater treatment plant to reduce the load.

A Quantum Chemical and Statistical Study of Phenolic Schiff Bases with Antioxidant Activity against DPPH Free Radical

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El Hassane Anouar

2014-04-01

Full Text Available 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.

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

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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.

Two novel mixed-ligand complexes containing organosulfonate ligands.

Science.gov (United States)

Li, Mingtian; Huang, Jun; Zhou, Xuan; Fang, Hua; Ding, Liyun

2008-07-01

The structures reported herein, viz. bis(4-aminonaphthalene-1-sulfonato-kappaO)bis(4,5-diazafluoren-9-one-kappa(2)N,N')copper(II), [Cu(C(10)H(8)NO(3)S)(2)(C(11)H(6)N(2)O)(2)], (I), and poly[[[diaquacadmium(II)]-bis(mu-4-aminonaphthalene-1-sulfonato)-kappa(2)O:N;kappa(2)N:O] dihydrate], {[Cd(C(10)H(8)NO(3)S)(2)(H(2)O)(2)].2H(2)O}(n), (II), are rare examples of sulfonate-containing complexes where the anion does not fulfill a passive charge-balancing role, but takes an active part in coordination as a monodentate and/or bridging ligand. Monomeric complex (I) possesses a crystallographic inversion center at the Cu(II) atom, and the asymmetric unit contains one-half of a Cu atom, one complete 4-aminonaphthalene-1-sulfonate (ans) ligand and one 4,5-diazafluoren-9-one (DAFO) ligand. The Cu(II) atom has an elongated distorted octahedral coordination geometry formed by two O atoms from two monodentate ans ligands and by four N atoms from two DAFO molecules. Complex (II) is polymeric and its crystal structure is built up by one-dimensional chains and solvent water molecules. Here also the cation (a Cd(II) atom) lies on a crystallographic inversion center and adopts a slightly distorted octahedral geometry. Each ans anion serves as a bridging ligand linking two Cd(II) atoms into one-dimensional infinite chains along the [010] direction, with each Cd(II) center coordinated by four ans ligands via O and N atoms and by two aqua ligands. In both structures, there are significant pi-pi stacking interactions between adjacent ligands and hydrogen bonds contribute to the formation of two- and three-dimensional networks.

Polymer complexes.. XXXX. Supramolecular assembly on coordination models of mixed-valence-ligand poly[1-acrylamido-2-(2-pyridyl)ethane] complexes

Science.gov (United States)

El-Sonbati, A. Z.; El-Bindary, A. A.; Diab, M. A.

2003-02-01

The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [( 11)+( 12)] in the paper and in mononuclear polymer complexes ( 1)-( 5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX 2 and KPtCl 4 in the presence of N-heterocyclic base consisting of polymer complexes ( 9)+( 10), and in monouclear compounds ( 6)-( 8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds ( 13)+( 14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.

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

OpenAIRE

Mishra, A. P.; Sharma, Neha; Jain, Rajendra K.

2012-01-01

Se sintetizaron bases de Schiff bidentadas y tridentadas (NO), (ONO) a través de la reacción de condensación entre la metil-isobutilcetona y el 2-amino-4clorofonol y 2-hidroxiacetofenona con la hidracina del ácido isonicotínico. Los complejos metálicos 1:1 o 1:2 han sido preparados mediante la interacción de estas bases de Schiff y los iones Ni(II) y Cu(II). La síntesis fue realizada empleando el método convencional y el de microondas, y los productos fueron caracterizados por análisis elemen...

Synthesis, characterization, antimicrobial and anthelmentic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

International Nuclear Information System (INIS)

Reddy, K. R. K; Mahendra, K.N.

2008-01-01

The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th(IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) were synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 1 H NMR, TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO 2 (VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmintic activity of the ligand and its complexes against earthworms was also investigated [ru

Synthesis, crystal structure and excellent photoluminescence properties of copper (II and cobalt (II complexes with Bis(1[(4-butylphenylimino]methyl naphthalen-2-ol Schiff base

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V.B. Nagaveni

2018-03-01

Full Text Available Copper (II and Cobalt (II metal complexes (4a- and 4b-complexes using Schiff base ligand 1-[(4-butylphenylimino]methyl naphthalen-2-ol (3 have been synthesized. The single crystals of Copper (II and Cobalt (II complex phosphors were grown and characterized by Fourier-Transform Infrared (FT-IR, single crystal X-ray diffraction (XRD, SEM (Scanning Electron Microscope and EDS (Energy Dispersive X-ray spectroscopy. Photoluminescence study of the phosphors revealed the presence of excitation peaks at 333 nm and 360 nm for 4a-complex (λemi = 495 nm and excitation peaks at 300 nm and 360 nm for 4b-complex (λemi = 496 nm. The calculated CCT values of the complexes pointed out that these materials can be used to obtain cold white light from the light emitting devices. Diffuse reflectance spectra (DRS showed the measured band gap energies of 1.78 eV and 1.44 eV for Cu (II and Co (II complexes, respectively. It is concluded that the 4a- and 4b-complexes become white and blue green light emitting diodes respectively and will be useful in the development of strong electroluminescent materials. Keywords: 1[(4-butylphenylimino]methylnaphthalen-2-ol, Schiff base, Cu (II and Co (IIcomplex, Photoluminescence, Single crystal XRD, OLED

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

2015-02-01

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, 1H NMR, 13C 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+, Al3+, Ni2+, Co2+, Fe3+, Zn2+, Pb2+) 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 Cu2+ ions were also investigated using quantum chemical computations.

Formation of Mixed-Ligand Complexes of Pd2+ with Nucleoside 5'-Monophosphates and Some Metal-Ion-Binding Nucleoside Surrogates

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Oleg Golubev

2014-10-01

Full Text Available Formation of mixed-ligand Pd2+ complexes between canonical nucleoside 5'-monophosphates and five metal-ion-binding nucleoside analogs has been studied by 1H-NMR spectroscopy to test the ability of these nucleoside surrogates to discriminate between unmodified nucleobases by Pd2+-mediated base pairing. The nucleoside analogs studied included 2,6-bis(3,5-dimethylpyrazol-1-yl-, 2,6-bis(1-methylhydrazinyl- and 6-(3,5-dimethylpyrazol-1-yl-substituted 9-(β-d-ribofuranosylpurines 1–3, and 2,4-bis(3,5-dimethylpyrazol-1-yl- and 2,4-bis(1-methylhydrazinyl-substituted 5-(β-d-ribofuranosyl-pyrimidines 4–5. Among these, the purine derivatives 1-3 bound Pd2+ much more tightly than the pyrimidine derivatives 4, 5 despite apparently similar structures of the potential coordination sites. Compounds 1 and 2 formed markedly stable mixed-ligand Pd2+ complexes with UMP and GMP, UMP binding favored by 1 and GMP by 2. With 3, formation of mixed-ligand complexes was retarded by binding of two molecules of 3 to Pd2+.

Studies on coordination chemistry and bioactivity of complexes of a tridentate ONS Schiff base with some heavier transition metal ions

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Tan Mei Lin; Ali, A.M.

2003-09-01

A tridentate Schiff base, S-benzyl-β-N-(2-hydroxyphenyl)methylenedithiocarbazate, (HONSH), with a donor sequence of ONS, was synthesized from the condensation of S-benzyldithiocarbazate (SBDTC) with an equimolar amount of 2-hydroxybenzaldehyde in absolute ethanol. The reactions of HONSH with metal ions [La(III), Ce(IV) and Th(IV)] yielded complexes of compositions, [La(ONS)NO 3 .2H 2 O], [Ce(ONS)(NO 3 ) 2 ] and [Th(ONS) 2 ]. The ligands and the complexes were characterized from elemental analyses and spectroscopic measurements. The metal complexes were found to be active against colon cancer cell lines with the CD 50 values of 27.5, 28.4 and 19.3 μg/ml for the La(III), Ce(FV) and Th(IV) complexes, respectively. The La(IH) complex was found to be very active against leukemic cell lines with the CD 50 value of 6.8 μg/ml. (author)

Syntheses of polystyrene supported chelating resin containing the Schiff base derived from salicylaldehyde and triethylene tetramine and its copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI), zirconium(IV) and uranium(VI) complexes

International Nuclear Information System (INIS)

Syamal, A.; Singh, M.M.

1998-01-01

A new polymer-anchored chelating ligand has been synthesized by the reaction of chloromethylated polystyrene (containing 0.94 mmol of Cl per gram of resin and 1% cross-linked with divinylbenzene) and the Schiff base derived from salicylaldehyde and triethylenetetramine. A new series of polystyrene supported, Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), Zr(IV), dioxomolybdenum (VI) and dioxouranium (VI) complexes of the formulae PS-LCu, PS-LNi, PS-LCo, PS-LFeCl.DMF, PS-LZn, PS-LCd, PS-LZr(OH) 2 . DMF, PS L MoO 2 and PS-LUO 2 (where PS-LH 2 = polymer-anchored Schiff base and DMF dimethyl-formamide) have been synthesized and characterised by elemental analysis, infrared, electronic spectra and magnetic susceptibility measurements. The complexes PS-LCu, PS-LNi and PS-LCo have square planar structure, PS-LFeCl.DMF, PS-LMoO 2 and PS-LUO 2 have octahedral structure, PS L Zn and PS-LCd are tetrahedral and PS-LZr(OH) 2 .DMF is pentagonal bipyramidal. The polymer-anchored Cu(II), Co(II) and Fe(III) complexes are paramagnetic while Ni(II), Zn(II), Cd(II), Zr(IV), dioxomolybdenum(VI) and dioxouranium(VI) complexes are diamagnetic. The negative shift of the v (C=N) (azomethine) and the positive shift of v (C--O)(phenolic) are indicative of ONNO donor behaviour of the polymer-anchored Schiff base. (author)

Near infrared organic light-emitting diodes based on acceptor-donor-acceptor (ADA) using novel conjugated isatin Schiff bases

International Nuclear Information System (INIS)

Taghi Sharbati, Mohammad; Soltani Rad, Mohammad Navid; Behrouz, Somayeh; Gharavi, Alireza; Emami, Farzin

2011-01-01

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.

Synthesis and Characterization of New Amino Acid-Schiff Bases and Studies their Effects on the Activity of ACP, PAP and NPA Enzymes (In Vitro

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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.

One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

KAUST Repository

Wang, Xiaofang; Wang, Runwei; Liu, Xiaofang; Zhu, Pinwen; Qiu, Shilun

2017-01-01

The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H2pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd2Cl3(2-pzc)(bbbi)2] (2)) under hydrothermal conditions

Thermodynamics of mixed-ligand complex formation of mercury (II) ethylenediaminetetraacetate with amino acids in solution

Energy Technology Data Exchange (ETDEWEB)

Pyreu, Dmitrii, E-mail: pyreu@mail.ru [Department of Inorganic and Analytic Chemistry, Ivanovo State University, Ermak 39, Ivanovo 153025 (Russian Federation); Kozlovskii, Eugenii [Department of Inorganic and Analytic Chemistry, Ivanovo State University, Ermak 39, Ivanovo 153025 (Russian Federation); Gruzdev, Matvei; Kumeev, Roman [Institute of Solution Chemistry, Ivanovo (Russian Federation)

2012-11-20

Highlights: Black-Right-Pointing-Pointer Stable mixed ligand complexes of HgEdta with amino acids at physiological pH value. Black-Right-Pointing-Pointer The thermodynamic and NMR data evident the ambidentate coordination mode of arginine. Black-Right-Pointing-Pointer Participation of the guanidinic group of Arg in coordination process. Black-Right-Pointing-Pointer Binuclear complexes (HgEdta){sub 2}L with the bridging function of amino acid. - Abstract: The mixed-ligand complex formation in the systems Hg{sup 2+} - Edta{sup 4-} - L{sup -}(L = Arg, Orn, Ser) has been studied by means of calorimetry, pH-potentiometry and NMR spectroscopy in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO{sub 3}). The thermodynamic parameters of formation of the HgEdtaL, HgEdtaHL and (HgEdta){sub 2}L complexes have been determined. The most probable coordination mode for the complexone and the amino acid in the mixed-ligand complexes was discussed.

Mixed-ligand complexes of zirconium (IV) and uranium with salicylaldehyde and some heterocyclic azopyrazolones

International Nuclear Information System (INIS)

Amrallahi, A.H.

1994-01-01

Mixed-ligand complexes of Zr(IV) and U(IV) with salicylaldehyde (SA) and some heterocyclic azopyrazolenes have been studied spectrophotometrically. All formed chelates have ratio 1:1:1. The stoichiometry and stability of the binary mixed chelates been evaluated. Elemental analysis, molar conductance and IR spectra have been used for identification of solid mixed complexes. (author)

Electronic structure and spectroscopic properties of mononuclear manganese(III) Schiff base complexes: a systematic study on [Mn(acen)X] complexes by EPR, UV/vis, and MCD spectroscopy (X = Hal, NCS).

Science.gov (United States)

Westphal, Anne; Klinkebiel, Arne; Berends, Hans-Martin; Broda, Henning; Kurz, Philipp; Tuczek, Felix

2013-03-04

The manganese(III) Schiff base complexes [Mn(acen)X] (H2acen: N,N'-ethylenebis(acetylacetone)imine, X: I(-), Br(-), Cl(-), NCS(-)) are considered as model systems for a combined study of the electronic structure using vibrational, UV/vis absorption, parallel-mode electron paramagnetic resonance (EPR) and low-temperature magnetic circular dichroism (MCD) spectroscopy. By variation of the co-ligand X, the influence of the axial ligand field within a given square-pyramidal coordination geometry on the UV/vis, EPR, and MCD spectra of the title compounds is investigated. Between 25000 and 35000 cm(-1), the low-temperature MCD spectra are dominated by two very intense, oppositely signed pseudo-A terms, referred to as "double pseudo-A terms", which change their signs within the [Mn(acen)X] series dependent on the axial ligand X. Based on molecular orbital (MO) and symmetry considerations, these features are assigned to π(n.b.)(s, a) → yz, z(2) ligand-to-metal charge transfer transitions. The individual MCD signs are directly determined from the calculated MOs of the [Mn(acen)X] complexes. The observed sign change is explained by an inversion of symmetry among the π(n.b.)(s, a) donor orbitals which leads to an interchange of the positive and negative pseudo-A terms constituting the "double pseudo-A term".

Mixed-ligand Pt(II) dithione-dithiolato complexes: influence of the dicyanobenzodithiolato ligand on the second-order NLO properties.

Science.gov (United States)

Espa, Davide; Pilia, Luca; Marchiò, Luciano; Artizzu, Flavia; Serpe, Angela; Mercuri, Maria Laura; Simão, Dulce; Almeida, Manuel; Pizzotti, Maddalena; Tessore, Francesca; Deplano, Paola

2012-03-28

The mixed-ligand dithiolene complex [Pt(Bz(2)pipdt)(dcbdt)] (1) bearing the two ligands Bz(2)pipdt = 1,4-dibenzyl-piperazine-3,2-dithione and dcbdt = dicyanobenzodithiolato, has been synthesized, characterized and studied to evaluate its second-order optical nonlinearity. The dithione/dithiolato character of the two ligands gives rise to an asymmetric distribution of the charge in the molecule. This is reflected by structural data showing that in the C(2)S(2)PtS(2)C(2) dithiolene core the four sulfur atoms define a square-planar coordination environment of the metal where the Pt-S bond distances involving the two ligands are similar, while the C-S bond distances in the C(2)S(2) units exhibit a significant difference in Bz(2)pipdt (dithione) and dcbdt (dithiolato). 1 shows a moderately strong absorption peak in the visible region, which can be related to a HOMO-LUMO transition, where the dcbdt ligand (dithiolato) contributes mostly to the HOMO, and the Bz(2)pipdt one (dithione) mostly to the LUMO. Thus this transition has ligand-to-ligand charge transfer (CT) character with some contribution of the metal and undergoes negative solvatochromism and molecular quadratic optical nonlinearity (μβ(0) = -1296 × 10(-48) esu), which was determined by the EFISH (electric-field-induced second-harmonic generation) technique and compared with the values of similar complexes on varying the dithiolato ligand (mnt = maleonitriledithiolato, dmit = 2-thioxo-1,3-dithiole-4,5-dithiolato). Theoretical calculations help to elucidate the role of the dithiolato ligands in affecting the molecular quadratic optical nonlinearity of these complexes.

Spectroscopic analyses on interaction of Amantadine-Salicylaldehyde, Amantadine-5-Chloro-Salicylaldehyde and Amantadine-o-Vanillin Schiff-Bases with bovine serum albumin (BSA)

Science.gov (United States)

Wang, Zhiqiu; Gao, Jingqun; Wang, Jun; Jin, Xudong; Zou, Mingming; Li, Kai; Kang, Pingli

2011-12-01

In this work, three Tricyclo [3.3.1.1(3,7)] decane-1-amine (Amantadine) Schiff-Bases, Amantadine-Salicylaldehyde (AS), Amantadine-5-Chloro-Salicylaldehyde (AS-5-C) and Amantadine-o-Vanillin (AS-o-V), were synthesized by direct heating reflux method in ethanol solution and characterized by infrared spectrum and elementary analysis. Fluorescence quenching was used to study the interaction of these Amantadine Schiff-Bases (AS, AS-5-C and AS-o-V) with bovine serum albumin (BSA). According to fluorescence quenching calculations the bimolecular quenching constant ( Kq), apparent quenching constant ( KSV), effective binding constant ( KA) and corresponding dissociation constant ( KD), binding site number ( n) and binding distance ( r) were obtained. The results show that these Amantadine Schiff-Bases can obviously bind to BSA molecules and the binding strength order is AS < AS-5-C = AS-o-V. Synchronous fluorescence spectroscopy reveals that these Amantadine Schiff-Bases adopt different way to bind with BSA molecules. That is, the AS and AS-5-C are accessibility to tryptophan (Trp) residues more than the tyrosine (Tyr) residues, while the AS-o-V is equally close to the Tyr and Trp residues.

Synthesis, characterization, DNA interaction and antimicrobial screening of isatin-based polypyridyl mixed-ligand Cu(II and Zn(II complexes

Directory of Open Access Journals (Sweden)

NATARAJAN RAMAN

2010-06-01

Full Text Available Several mixed ligand Cu(II/Zn(II complexes using 3-(phenyl-imino-1,3-dihydro-2H-indol-2-one (obtained by the condensation of isatin and aniline as the primary ligand and 1,10-phenanthroline (phen/2,2’-bipyridine (bpy as an additional ligand were synthesized and characterized analytically and spectroscopically by elemental analyses, magnetic susceptibility and molar conductance measurements, as well as by UV–Vis, IR, NMR and FAB mass spectroscopy. The interaction of the complexes with calf thymus (CT DNA was studied using absorption spectra, cyclic voltammetric and viscosity measurements. They exhibit absorption hypochromicity, and the specific viscosity increased during the binding of the complexes to calf thymus DNA. The shifts in the oxidation–reduction potential and changes in peak current on addition of DNA were shown by CV measurements. The Cu(II/Zn(II complexes were found to promote cleavage of pUC19 DNA from the supercoiled form I to the open circular form II and linear form III. The complexes show enhanced antifungal and antibacterial activities compared with the free ligand.

An efficient ab initio DFT and PCM assessment of the potentiometric selectivity of a salophen type Schiff base.

Science.gov (United States)

Demir, Serkan; Yilmaz, Hakan; Dilimulati, Maowulidan; Andaç, Müberra

2014-06-01

As a neutral carrier component for the preparation of a potentiometric membrane sensor, the affinity and selectivity of the salophen type Schiff base ligand obtained by 1:2 condensation of 2.3-diaminopyridine with salicylaldehyde toward a series of common cations has been fully examined by DFT/B3LYP and integral equation formalism polarizable continum model (IEF-PCM or only given with PCM as default input in the computations) in combination with the experimental data. Both the potentiometric measurements and DFT calculations have exhibited that the ionophore shows appreciable selectivity for Cu(2+) ion over other cations. Four different approaches where the last three are the modified version of each other have been evaluated and compared with potentiometric data. Based upon the results of comparison among the approaches suggested to verify the selective behavior of ionophore toward Cu(2+), PCM implemented approach having a whole computational groundwork has given well-matched results with the observed data and with the method augmented with experimental hydration energies. The foremost interferences were detected by determining potentiometric selectivity coefficients for each metal ion relative to Cu(2+) and compared to the results obtained by the DFT calculations.

A voltammetric method for Fe(iii) in blood serum using a screen-printed electrode modified with a Schiff base ionophore.

Science.gov (United States)

Mittal, Susheel K; Rana, Sonia; Kaur, Navneet; Banks, Craig E

2018-05-23

Herein, a potent electrochemical ionophore (SMS-2) based on a Schiff base has been used for the modification of a screen-printed electrode (SPE). The modified disposable electrode can selectively detect ferric ions in an aqueous medium. Redox behavior of the proposed strip was characterized using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Incorporation of the ligand in the ink of the SPE enhanced the analytical performance of the electrode, and its surface modification was confirmed by SEM and EDX analysis. Shifting/quenching of the cathodic peak potential of the ionophore after binding with Fe(iii) ions was used to detect and measure the ferric ion concentration. This sensor can identify Fe(iii) in the detection range from 0.625 μM to 7.5 μM. The modified SPE can selectively detect ferric ions in the presence of many other interfering ions and has been successfully used to determine the Fe(iii) content in blood serum samples. The metal-ionophore complex structure was optimized using DFT calculations to study the energetics of the metal-ionophore interactions.

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

Czech Academy of Sciences Publication Activity Database

Asadi, Z.; Asadi, M.; Zeinali, A.; Ranjkeshshorkaei, M.; Fejfarová, Karla; Eigner, Václav; Dušek, Michal; Dehnokhalaji, A.

2014-01-01

Roč. 126, č. 6 (2014), s. 1673-1683 ISSN 0974-3626 R&D Projects: GA ČR(CZ) GAP204/11/0809 Institutional support: RVO:68378271 Keywords : uranyl schiff base complexes * kinetic study * kinetics of thermal decomposition * X-ray crystallography * cyclic voltammetry Subject RIV: CA - Inorganic Chemistry Impact factor: 1.191, year: 2014

Sub-20 nm Stable Micelles Based on a Mixture of Coiled-Coils: A Platform for Controlled Ligand Presentation.

Science.gov (United States)

Ang, JooChuan; Ma, Dan; Jung, Benson T; Keten, Sinan; Xu, Ting

2017-11-13

Ligand-functionalized, multivalent nanoparticles have been extensively studied for biomedical applications from imaging agents to drug delivery vehicles. However, the ligand cluster size is usually heterogeneous and the local valency is ill-defined. Here, we present a mixed micelle platform hierarchically self-assembled from a mixture of two amphiphilic 3-helix and 4-helix peptide-polyethylene glycol (PEG)-lipid hybrid conjugates. We demonstrate that the local multivalent ligand cluster size on the micelle surface can be controlled based on the coiled-coil oligomeric state. The oligomeric states of mixed peptide bundles were found to be in their individual native states. Similarly, mixed micelles indicate the orthogonal self-association of coiled-coil amphiphiles. Using differential scanning calorimetry, fluorescence recovery spectroscopy, and coarse-grained molecular dynamics simulation, we studied the distribution of coiled-coil bundles within the mixed micelles and observed migration of coiled-coils into nanodomains within the sub-20 nm mixed micelle. This report provides important insights into the assembly and formation of nanophase-separated micelles with precise control over the local multivalent state of ligands on the micelle surface.

Theoretical investigation of tautomeric equilibrium in ortho-hydroxy phenyl Schiff bases

Science.gov (United States)

Kluba, M.; Lipkowski, P.; Filarowski, A.

2008-10-01

This Letter presents a study of the tautomeric equilibrium in ortho-hydroxy phenyl Schiff bases. The influence of substitution and solvent (simulated by the self-consistent reaction field model, SCRF) on the energy barrier of the transition state and on proton transfer is investigated. Dependencies of the HOMA and HOSE aromaticity indices on the molecular, transition state, and proton transfer forms were obtained. The state of chelate chain and phenyl ring aromaticity depending on the tautomeric equilibrium is studied.

Some mixed ligand hydridocarbonyl and hydridophosphine complexes of ruthenium(II) and iridium(III)

International Nuclear Information System (INIS)

Pandey, R.N.; Kumar, Sunil; Kumar, Arun; Kumar, S.K.

1993-01-01

Mixed-ligand hydridocarbonyl and hydridophosphine complexes of Ru II and Ir III have been isolated from the displacement reaction of [RuH(CO)(Pφ 3 ) 3 Cl] with ligand isonicotinic acid hydrazide (INAH) in benzene medium. Most probable structures are assigned on the basis of elemental analysis, electronic, infrared and far-infrared spectral studies. In all cases bonding of INAH occurs through amino nitrogen of hydrazine residue. (author). 15 refs., 1 tab

Synthesis, characterization and biodistribution of new [sup 99m]Tc Oxo and nitrido complexes of unsaturated tetradentate (N[sub 2]S[sub 2]) ligands

Energy Technology Data Exchange (ETDEWEB)

Coulais, Y.; Gantet, P.; Tafani, J.A.M.; Vende, D.; Guiraud, R. (Faculte de Medecine Toulouse-Purpan, Toulouse (France). Lab. de Biophysique et de Medecine Nucleaire); Cros, G.; Darbieu, M.H. (Centre National de la Recherche Scientifique (CNRS), Toulouse (France). Lab. de Chimie de Coordination); Pasqualini, R. (Cis-Bio International, Gif-sur-Yvette (France))

1993-04-01

Three unsaturated Schiff base tetradentate (N[sub 2]S[sub 2] or N[sub 2]SO) ligands were synthesized and characterized. Oxo and nitrido 99m-technetium complexes were obtained with these ligands. The nitrido complexes were formed using a new easy method available as a kit. When injected into rats and mice, these lipophilic complexes were able to cross blood-brain barrier but brain perfusion imaging could not be performed due to the insufficient uptake and retention time. (author).

Synthesis, electrochemistry, and spectroscopic properties of six-coordinate monooxomolybdenum(VI) complexes containing tridentate Schiff base and bidentate catecholate ligands. Crystal and molecular structure of (N-salicylidene-2-aminophenolato)(naphthalene-2,3-diolato)oxomolybdenum(VI)

International Nuclear Information System (INIS)

Mondal, J.U.; Schultz, F.A.; Brennan, T.D.; Scheidt, W.R.

1988-01-01

Six-coordinate monooxomolybdenum(VI) complexes, MoO(cat)(Sap), where Sap 2- = the Schiff base dianion N-salicylidene-2-aminophenolate and cat 2- = catecholate Cat 2- , naphthalene-2,3-diolate (Naphcat 2- ), or 3,5-di-tert-butylcatecholate (DTBcat 2- ), are prepared by reacting the Mo(VI) dimer. [MoO 2 (Sap)] 2 , with the appropriate catechol. The products are characterized by cyclic voltammetry, mass spectrometry, and uv/vis, ir, and 95 Mo NMR spectroscopy. The MoO(cat)(Sap) complexes represent the first examples of a mononuclear MoO 4+ center with a coordination number of six. The crystal structure of the MoO-(Naphcat)(Sap) derivative is reported, confirming the six-coordinate, distorted octahedrla environment about Mo(VI). Bond angles in the coordination group deviate from the ideal value of 90/degrees/ as a consequence of the ligand bite constraints and because all four O-Mo-O angles involving the terminal oxo ligand are larger than the ideal 90/degrees/ value. MoO(cat)(Sap) complexes undergo reversible one-electronic reduction at -0.5 to -0.7 V versus Fc /sup +/0/ followed by irreversible one-electron reduction at -1.6 to -1.9 V. Reversible MoO 4+ /MoO 3+ electrochemistry is attributed to the fact that the Mo d/sub xy/orbital of MoO(cat)(Sap) can be singly occupied upon reduction to Mo(V) without unfavorable interaction with the four bonds in its equatorial plane. This contrasts with the irreversible electrochemical behavior of seven-coordinate MoO 4+ complexes, which contain five such bonds. The 95 Mo NMR chemical shift of MoO(Naphcat)(Sap) is +385 ppM versus external molybdate; this value is highly deshielded with respect to seven-coordinate MoO 4+ and six-coordinate MoO 2 2+ complexes with O and N donors. 35 references, 4 figures, 5 tables

Schiff bases derived from L-Tyrosine L-Tryptophan and their Cu(II) chelates as effective means for preventive-treatment of radiation injuries

International Nuclear Information System (INIS)

Malakyan, M.H.; Bajinyan, S.A.; Matosyan, V.H.; Tonoyan, V.J.; Babayan, K.N.; Boyajyan, A.S.; Yeghiazaryan, D.E.; Vardevanyan, L.A.; Sorenson, J.R.J.

2008-01-01

Full text: Study on essential metallo element chelates as radioprotectors presents a promising direction in a search for and development of novel anti-radiation agents and offers a new approach to overcome the pathological effects of ionizing radiation. The key idea elucidating the radioprotective effects of metallo element-containing chelates of amino acid derivatives is their role in stimulation of de novo synthesis of metallo element-dependent enzymes required for recovery of hemopoietic activity and immuno competency lost as a consequence of radiation damage. Aimed to develop novel anti-radiation remedies of less toxicity and high efficacy, Schiff bases derived from L-Tyrosine and L-Tryptophan and their Cu(II) chelates were synthesized. In experiments in vitro and in vivo biological and pharmacological properties of the mentioned Schiff Bases and their copper complexes are under study. According to the results obtained, L-Tyrosinate and L-Tryptophanate Schiff bases are low toxic compounds with a weak antioxidant activity and exert radioprotective effects in case of animal X-ray irradiation at a dose level equal or less than LD 50/30 . Unlike Schiff Bases, their appropriate Cu(II) chelates possess high anti radical/antioxidant activity and manifest expressed radio-protective action at LD 100/30 dose of ionizing radiation. Anti-radiation effects of amino acid Schiff bases and their metallo chelates are manifested in case of both subcutaneous and oral single administration to the animal organism at 10, 20, or 40 mg/kg 1, 3, 6, or 24 hours prior to radiation exposure. Conclusions are drawn basing on determinations of survival and average life-span indices of irradiated animals, as well as on studies for their hematological, biochemical, immunological, biophysical indices. It is revealed that on the background of preliminary administration of the compounds studied to the animal organism the characteristics of DNA are significantly improved, the immune status

INTERACTION OF IRON(II MIXED-LIGAND COMPLEXES WITH DNA: BASE-PAIR SPECIFICITY AND THERMAL DENATURATION STUDIES

Directory of Open Access Journals (Sweden)

Mudasir Mudasir

2010-06-01

Full Text Available A research about base-pair specificity of the DNA binding of [Fe(phen3]2+, [Fe(phen2(dip]2+ and [Fe(phen(dip2]2+ complexes and the effect of calf-thymus DNA (ct-DNA binding of these metal complexes on thermal denaturation of ct-DNA has been carried out. This research is intended to evaluate the preferential binding of the complexes to the sequence of DNA (A-T or G-C sequence and to investigate the binding strength and mode upon their interaction with DNA. Base-pair specificity of the DNA binding of the complexes was determined by comparing the equilibrium binding constant (Kb of each complex to polysynthetic DNA that contain only A-T or G-C sequence. The Kb value of the interaction was determined by spectrophotometric titration and thermal denaturation temperature (Tm was determined by monitoring the absorbance of the mixture solution of each complex and ct-DNA at λ =260 nm as temperature was elevated in the range of 25 - 100 oC. Results of the study show that in general all iron(II complexes studied exhibit a base-pair specificity in their DNA binding to prefer the relatively facile A-T sequence as compared to the G-C one. The thermal denaturation experiments have demonstrated that Fe(phen3]2+ and [Fe(phen2(dip]2+ interact weakly with double helical DNA via electrostatic interaction as indicated by insignificant changes in melting temperature, whereas [Fe(phen2(dip]2+  most probably binds to DNA in mixed modes of interaction, i.e.: intercalation and electrostatic interaction. This conclusion is based on the fact that the binding of [Fe(phen2(dip]2+ to ct-DNA moderately increase the Tm value of ct- DNA   Keywords: DNA Binding, mixed-ligand complexes

Polarographic study of mixed-ligand complexes of cadmium(II) with L-amino acid and vitamin B5

International Nuclear Information System (INIS)

Jain, Alok K.; Khan, Farid

1998-01-01

A survey of literature shows that ternary complexes of Cd II with L-amino acids and vitamin B 5 have not been studied so far. The present communication reports the formation of mixed-ligand complexes of Cd II with L-amino acids as primary ligands and vitamin B 5 as secondary ligand, studied by polarographic technique. (author)

Synthesis and DNA interaction of a Sm(III) complex of a Schiff base ...

African Journals Online (AJOL)

The interaction between the Sm(III) complex of an ionic Schiff base [HL]-, derived from vanillin and L-tryptophan, and herring sperm DNA at physiological pH (7.40) has been studied by UV-Vis absorption, fluorescence and viscosity methods. The binding ratios nSm(III) : nK[HL] = 1:1 and nSm(III)L: nDNA =5:1 were confirmed ...

Reactions of copper(II), nickel(II), and zinc(II) acetates with a new water-soluble 4-phenylthiosemicarbazone Schiff base ligand: synthesis, characterization, unexpected cyclization, antimicrobial, antioxidant, and anticancer activities

Czech Academy of Sciences Publication Activity Database

Hosseini-Yazdi, S.A.; Mirzaahmadi, A.; Khandar, A.A.; Eigner, Václav; Dušek, Michal; Mahdavi, M.; Soltani, S.; Lotfipour, F.; White, J.

2017-01-01

Roč. 124, Mar (2017), s. 156-165 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA15-12653S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : antimicrobial * antioxidant * cytotoxicity * thiosemicarbazone * water-soluble Schiff base Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.926, year: 2016

Highly sensitive simultaneous electrochemical determination of trace amounts of Pb(II) and Cd(II) using a carbon paste electrode modified with multi-walled carbon nanotubes and a newly synthesized Schiff base

International Nuclear Information System (INIS)

Afkhami, Abbas; Ghaedi, Hamed; Madrakian, Tayyebeh; Rezaeivala, Majid

2013-01-01

Highlights: ► A new chemically modified carbon paste electrode was constructed and used. ► A new Schiff base and multi-walled carbon nanotube was used as modifiers. ► The electrochemical properties of the modified electrode were studied. ► The electrode was used to the simultaneous determination of Pb 2+ and Cd 2+ . -- Abstract: A new chemically modified electrode was constructed for rapid, simple, accurate, selective and highly sensitive simultaneous determination of lead and cadmium using square wave anodic stripping voltammetry (SWASV). The electrode was prepared by incorporation of new synthesized Schiff base and multi-walled carbon nanotubes (MWCNT) in carbon paste electrode. The limit of detection was found to be 0.25 ng mL −1 and 0.74 ng mL −1 for Pb 2+ and Cd 2+ , respectively. The stability constants of the complexes of the ligand with several metal cations in ethanol medium were determined. The effects of different cations and anions on the simultaneous determination of metal ions were studied and it was found that the electrode is highly selective. The proposed chemically modified electrode was used for the determination of lead and cadmium in several foodstuffs and water samples

Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

Science.gov (United States)

Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

2016-10-01

Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

Thermodynamics of mixed-ligand complex formation of zinc nitrilotriacetate with amino acids and dipeptides in solution

International Nuclear Information System (INIS)

Pyreu, Dmitrii; Gruzdev, Matvey; Kumeev, Roman; Gridchin, Sergei

2014-01-01

Highlights: • Stable mixed ligand complexes of ZnNta with amino acids and dipeptides. • Histamine-like coordination mode of His in the complex ZnNtaHis. • Glycine-like coordination of Lys and Orn in the complexes ZnNtaL and ZnNtaHL • NH 2 , CO-coordination mode of GlyGly in the complex ZnNtaGG. • NH 2 , N − or NH2, N − , COO-coordination modes of GlyGly in the complex ZnNtaGGH −1 . - Abstract: The isothermal calorimetry, pH-potentiometric titration and 1 H and 13 C NMR methods has been used to study the mixed-ligand complex formation in the systems Zn 2+ –Nta 3– –L − (L = His, Orn, Lys, GlyGly, AlaAla) in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO 3 ). The thermodynamic parameters of formation of the mixed complexes have been determined. The relationship between the probable coordination modes of the complexone and amino acid or dipeptide molecules in the mixed-ligand complex and the thermodynamic parameters has been discussed

Thermodynamics of mixed-ligand complex formation of zinc nitrilotriacetate with amino acids and dipeptides in solution

Energy Technology Data Exchange (ETDEWEB)

Pyreu, Dmitrii, E-mail: pyreu@mail.ru [Department of Inorganic and Analytic Chemistry, Ivanovo State UniversityErmak 39, Ivanovo 153025 (Russian Federation); Gruzdev, Matvey; Kumeev, Roman [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Gridchin, Sergei [Ivanovo State University of Chemistry and Technology, Ivanovo (Russian Federation)

2014-10-20

Highlights: • Stable mixed ligand complexes of ZnNta with amino acids and dipeptides. • Histamine-like coordination mode of His in the complex ZnNtaHis. • Glycine-like coordination of Lys and Orn in the complexes ZnNtaL and ZnNtaHL • NH{sub 2}, CO-coordination mode of GlyGly in the complex ZnNtaGG. • NH{sub 2}, N{sup −} or NH2, N{sup −}, COO-coordination modes of GlyGly in the complex ZnNtaGGH{sub −1}. - Abstract: The isothermal calorimetry, pH-potentiometric titration and {sup 1}H and {sup 13}C NMR methods has been used to study the mixed-ligand complex formation in the systems Zn{sup 2+}–Nta{sup 3–}–L{sup −} (L = His, Orn, Lys, GlyGly, AlaAla) in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO{sub 3}). The thermodynamic parameters of formation of the mixed complexes have been determined. The relationship between the probable coordination modes of the complexone and amino acid or dipeptide molecules in the mixed-ligand complex and the thermodynamic parameters has been discussed.

Synthesis, spectroscopic characterization, electrochemistry and biological evaluation of some metal (II) complexes with ONO donor ligand containing benzo[b]thiophene and coumarin moieties

Science.gov (United States)

Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

2014-09-01

Schiff base ligand 3-chloro-N‧-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzo[b]thiophene-2-carbohydrazide and its Cu(II), Co(II), Ni(II) and Zn(II) complexes were synthesized, characterized by elemental analysis and various physico-chemical techniques like, IR, 1H NMR, ESI-mass, UV-Visible, thermogravimetry - differential thermal analysis, magnetic measurements and molar conductance. Spectral analysis indicates octahedral geometry for all the complexes. Cu(II) complex have 1:1 stoichiometry of the type [M(L)(Cl)(H2O)2], whereas Co(II), Ni(II) and Zn(II) complexes have 1:2 stoichiometric ratio of the type [M(L)2]. The bonding sites are the oxygen atom of amide carbonyl, nitrogen of azomethine function and phenolic oxygen of the Schiff base ligand via deprotonation. The thermogravimetry - differential thermal analysis studies gave evidence for the presence of coordinated water molecules in the composition of Cu(II) complex which was further supported by IR measurements. All the complexes were investigated for their electrochemical activity, but only the Cu(II) complex showed the redox property. In order to evaluate the effect of antimicrobial potency of metal ions upon chelation, ligand and its metal complexes along with their respective metal chlorides were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The results showed that the metal complexes were found to be more active than free ligand. Ligand and its complexes were screened for free radical scavenging activity by DPPH method and DNA cleavage activity using Calf-thymus DNA (Cat. No-105850).

Synthesis, spectral characterization and in vitro antifungal activity of Lanthanum(III) and Praseodymium(III) complexes with Schiff bases derived from 5-substituted-4-amino-5-hydrazino-1,2,4-triazoles and isatin

International Nuclear Information System (INIS)

Singh, Shweta; Tripathi, Priti; Pandey, Om P.; Sengupta, Soumitra K.

2013-01-01

The new lanthanum(III) and praseodymium(III) complexes of the general formula (LnCl(L)(H 2 O) 2 ) (Ln = La III or Pr III ; H 2 L = Schiff bases derived from 3-substituted-4-amino-5-hydrazino-1,2,4-triazoles and isatin) have been prepared. The complexes have been characterized by elemental analyses, molecular weight by FAB-mass, thermogravimetry, electrical conductance, magnetic moment and spectral (electronic, infrared, far-infrared, 1 H NMR and 13 C NMR) data. The ligands and all prepared complexes were assayed for antifungal (Aspergillus niger and Helminthosporium oryzae) activities. The activities have been correlated with the structures of the complexes. (author)

Sodium dodecyl sulfate coated alumina modified with a new Schiff's base as a uranyl ion selective adsorbent

Energy Technology Data Exchange (ETDEWEB)

Tashkhourian, J., E-mail: tashkhourian@susc.ac.ir [Department of Chemistry, College of Science, Shiraz University, 71454 Shiraz (Iran, Islamic Republic of); Moradi Abdoluosofi, L.; Pakniat, M. [Department of Chemistry, Faculty of Science, Persian Gulf University, Bushehr 75169 (Iran, Islamic Republic of); Montazerozohori, M. [Department of Chemistry, Faculty of Science, Yasouj University, Yasouj (Iran, Islamic Republic of)

2011-03-15

A simple and selective method was used for the preconcentration and determination of uranium(VI) by solid-phase extraction (SPE). In this method, a column of alumina modified with sodium dodecyl sulfate (SDS) and a new Schiff's base ligand was prepared for the preconcentration of trace uranyl(VI) from water samples. The uranium(VI) was completely eluted with HCl 2 M and determined by a spectrophotometeric method with Arsenazo(III). The preconcentration steps were studied with regard to experimental parameters such as amount of extractant, type, volume and concentration of eluent, pH, flow rate of sample source and tolerance limit of diverse ions on the recovery of uranyl ion. A preconcentration factor more than 200 was achieved and the average recovery of uranyl(VI) was 99.5%. The relative standard deviation was 1.1% for 10 replicate determinations of uranyl(VI) ion in a solution with a concentration of 5 {mu}g mL{sup -1}. This method was successfully used for the determination of spiked uranium in natural water samples.

Kinetics of thermal decomposition and kinetics of substitution reaction of nano uranyl Schiff base complexes

Czech Academy of Sciences Publication Activity Database

Asadi, Z.; Zeinali, A.; Dušek, Michal; Eigner, Václav

2014-01-01

Roč. 46, č. 12 (2014), s. 718-729 ISSN 0538-8066 R&D Projects: GA ČR(CZ) GAP204/11/0809 Institutional support: RVO:68378271 Keywords : uranyl * Schiff base * kinetics * anticancer activity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.517, year: 2014

Design, Green Synthesis, and Anti-Inflammatory Activity of Schiff Base of 1,3,4-oxadiazole Analogues

Czech Academy of Sciences Publication Activity Database

Sahoo, B. M.; Dinda, S. C.; Kumar, B. V. V. R.; Panda, J.; Brahmkshatriya, Pathik

2014-01-01

Roč. 11, č. 1 (2014), s. 82-89 ISSN 1570-1808 Institutional support: RVO:61388963 Keywords : anti-inflammatory activity * design * green synthesis * oxadiazole * schiff base * spectroscopic studies Subject RIV: CC - Organic Chemistry Impact factor: 0.770, year: 2014

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.

Can mixed ligand therapy completely remove plutonium from the body

Energy Technology Data Exchange (ETDEWEB)

Volf, V [Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Genetik und Toxikologie von Spaltstoffen

1980-08-01

Results of experiments to determine the effects of mixed ligand chelate treatment on tissue levels of /sup 238/Pu in rats after injection of /sup 238/Pu citrate are presented and discussed. It is concluded that when attempting to remove Pu from the body there seems to be no reason for combining Ca-DTPA, the present chelate of choice, with catechol or Tiron, or with salicylate and its derivatives.

Synthesis, characterization and biological evaluation of [{sup 188}Re(N)(cys{approx})(PNP)]{sup +/0} mixed-ligand complexes as prototypes for the development of {sup 188}Re(N)-based target-specific radiopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Thieme, Stefan [Institute of Radiopharmacy, Forschungszentrum Dresden Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Agostini, Stefania [Department of Pharmaceutical Sciences, University of Padua, Via Marzolo 5, 35131 Padova (Italy); Bergmann, Ralf; Pietzsch, Jens; Pietzsch, Hans-Juergen [Institute of Radiopharmacy, Forschungszentrum Dresden Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Carta, Davide; Salvarese, Nicola [Department of Pharmaceutical Sciences, University of Padua, Via Marzolo 5, 35131 Padova (Italy); Refosco, Fiorenzo [ICIS-CNR, Corso Stati Uniti 4, 35127 Padova (Italy); Bolzati, Cristina, E-mail: bolzati@icis.cnr.i [Department of Pharmaceutical Sciences, University of Padua, Via Marzolo 5, 35131 Padova (Italy); ICIS-CNR, Corso Stati Uniti 4, 35127 Padova (Italy)

2011-04-15

We report on an efficient procedure for the preparation of [{sup 188}Re(N)(PNP)]-based complexes (where PNP is diphosphinoamine) useful in the development of target-specific radiopharmaceuticals. The radiochemical yield of the compounds was optimized considering such reaction parameters as nature of the nitrido nitrogen donor, reaction times and pH level. The chemical identity of the {sup 188}Re agents was determined by high-performance liquid chromatography comparison with the corresponding well-characterized cold Re compounds. {sup 188}Re(N) mixed compounds have been evaluated with regard to stability toward transchelation with GSH and degradation by serum enzymes. The clearance of selected radiocompounds from normal tissues and their in vivo stability were evaluated in rats by biodistribution and imaging studies. [{sup 188}Re(N)(cys{approx})(PNP)]{sup +/0} mixed-ligand compounds were efficiently prepared in aqueous solution from perrhenate using a multistep procedure based on the preliminary formation of the labile {sup 188}Re{sup III}-EDTA species, which easily undergo oxidation/ligand exchange reaction to afford the [{sup 188}Re{sup V{identical_to}}N]{sup 2+} core in the presence of dithiocarbazate. The final mixed-ligand compounds were obtained, at 100{sup o}C, by adding the two bidentate ligands to the buffered [{sup 188}Re{sup V{identical_to}}N]{sup 2+} solution (pH 3.2-3.6). However, a relatively high amount of cys{approx} ligand was required to obtain a quantitative radiochemical yield. The complexes were stable toward reoxidation to perrhenate and ligand exchange reactions. In vivo studies showed rapid distribution and elimination of the complexes from the body. No specific uptakes in sensitive tissues/organs were detected. A positive correlation of the distribution of the complexes estimated with biodistribution studies (%ID) and with micro-SPECT semiquantification imaging analysis (standard uptake values) was observed. These results support the

C-13 NMR spectra of all-trans-N-retinylidene-n-butylamine as an analogue of the Schiff base linkage compound in visual pigment

Energy Technology Data Exchange (ETDEWEB)

Tokito, Y; Inoue, Y; Chujo, R [Tokyo Inst. of Tech. (Japan). Faculty of Science; Miyoshi, Y

1975-01-01

In the process of visual excitation, a visual pigment, rhodopsin, plays a role of a photoreceptor, and it has been known that the first step in the process is the photoisomerization of the rhodopsin visual chromophore. The bathochromic shift has been regarded as the result of the formation of Schiff base linkage of retinal with opsin. In this study, C-13 NMR spectra were obtained for the analogue of the compound with Schiff base linkage in the visual pigment, and the chemical shift change for going from all trans-retinal to all trans-N-retinylidene-n-butylamine (NRB) was discussed. Further, the effect of N protonation in NRB was examined as the reflection of the function of visual pigment. The compound with Schiff base linkage of all trans-retinal with n-butylamine, namely NRB, was used. The nuclear magnetic resonance (NMR) spectra of carbon-13 Fourier transformation were obtained for this sample at natural abundance with a JNM PS-100 spectrometer. In the C-13 FT NMR spectrum of NRB, besides eight peaks in the C-13 NMR of all trans-retinal, four peaks were observed in higher field region. They originated from the portion of n-butylamine in the compound with Schiff base linkage. The peaks in lower field region were assigned to eleven conjugated polyene carbons by the measurement of spin-lattice relaxation time and shift. The chemical shift change for going from retinal to NRB is shown. It is concluded that the ..pi..-electrons in polyene chains are considerably delocalized by the collapse of bond alteration in the retinal forming Schiff base linkage.

Synthesis and characterization of dioxouranium (VI) complexes of Schiff bases derived from isatin, isovanillin and o-vanillin

International Nuclear Information System (INIS)

Singh, Kavita; Agarwala, B.V.; Naganagowda, G.A.

1996-01-01

Three Schiff bases viz. isatin semicarbazone, isovanillin thiosemicarbazone, o-vanillin para-anisidine and their dioxouranium (VI) complexes have been synthesised and characterized by elemental analysis, IR and NMR spectral studies. (author). 19 refs., 1 tab

Mixed ligand lanthanide complexes with dipivaloylmethane and acetic acid

International Nuclear Information System (INIS)

Lyu Fehnkhua; Kuz'mina, N.P.; Mazo, G.N.; Martynenko, L.I.

1995-01-01

Methods of elemental, X-ray phase, thermal analyses and infrared spectroscopy were used to characterize solid products, formed in MDpm 3 -HAcet-H-hexane systems (M = Pr, Nd, Eu, Gd, Ho, Er, Yb, HDpm -dipivaloylmethane, HAcet - acetic acid). It was established that prepared mixed ligand complexes (MLC) had MDpm 2 Acet composition for all studied rare earths. Differenced in properties of cerium and yttrium rare earths are manifested in processes of MLC thermal dissociation, proceeding at low pressure and 170 deg C. 6 refs., 4 tabs

Synthesis, characterization, X-ray crystal structure and conductometry studying of a number of new Schiff base complexes; a new example of binuclear square pyramidal geometry of Cu(II) complex bridged with an oxo group

Science.gov (United States)

Golbedaghi, Reza; Alavipour, Ehsan

2015-11-01

Three new binuclear Cu(II), Mn(II), Co(II) complexes [Cu2(L) (ClO4)](ClO4)2 (1), [Mn2(L) (ClO4)](ClO4)2 (2), and [Co2(L) (ClO4)](ClO4)2 (3), {L = 1,3-bis(2-((Z)-(2-aminopropylimino)methyl)phenoxy)propan-2-ol} have been synthesized. Single crystal X-ray structure analysis of complex 1 showed that the complex is binuclear and all nitrogen and oxygen atoms of ligand (N4O3) are coordinated to two Cu(II) center ions. In addition, the crystal structure studying shows, a perchlorate ion has been bridged to the Cu(II) metal centers. However, two distorted square pyramidal Cu(II) ions are bridged asymmetrically by a perchlorate ion and oxygen of hydroxyl group of Schiff base ligand. In addition, the conductometry behaviors of all complexes were studied in acetonitrile solution.

Studies on some mixed ligand complexes of UO2(VI) in solution

International Nuclear Information System (INIS)

Katkar, V.S.; Munshi, K.N.

1987-01-01

Potentiometric studies on some mixed ligand complexes of UO 2 (VI) with ethylenediamine N,N' diacetic acid as primary ligand and succinic acid, malic acid, maleic acid, fumaric acid, malonic acid, adipic acid, itaconic acid, phthalic acid and mandelic acid as secondary ligands have been carried out employing modified form of Irving-Rossotti's pH titration technique. The study was carried out at three different temperatures, viz. 5deg, 25deg and 45degC and at fixed ionic strength of 0.2M KNO 3 . Thermodynamic parameters, e.g. ΔG, ΔH and ΔS have been evaluated and further ΔG and ΔH values have been separated into their electrostatic components, ΔGe and ΔHe and cratic components, ΔGsub(c) and ΔHsub(c). The effect of change in dielectric constant and change in ionic strength of the medium have also been investigated. The sequence of stability constants has been correlated with the properties of secondary ligands. (author). 21 refs., 5 tabs

Preparations and crystal structures of 8 coordinate uranyl(VI) complexes having macrocyclic ligands derived from pyrroledicarboxialdehydes and diamines

International Nuclear Information System (INIS)

Komagine, J.; Takeda, M.; Takahashi, M.

2006-01-01

Six 8-coordinate uranyl(VI) complexes with macrocyclic Schiff base ligands derived from 2,6-pyrroledicarboxialdehyde and diamines are prepared and the crystal structures for two of them are determined focusing on the relation between the size of the ligands and U-N bond distances. No difference in average uranyl bond distances and bond angles are observed between [UO 2 (bipytn)](a) and [UO 2 (bipydmtn)](b). U-N bonds of these complexes are, however, not equal; the U-N(pyrrole) bonds [2.45(a), 2.44(b) A] are much shorter than the U-N(imine) bonds [2.67(a), 2.67(b) A]. (author)

The optical behavior of amorphous microribbons for hydroxy-naphthol based Schiff bases

Energy Technology Data Exchange (ETDEWEB)

Shen, Ping; Liu, Chunlin; Yang, Wei; Liu, Xuan; Du, Jinya [College of Biological and Pharmaceutical Science, China Three Gorges University, Yichang 443002 (China); Liu, Yi [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Yang, Changying, E-mail: changying.yang@ctgu.edu.cn [College of Biological and Pharmaceutical Science, China Three Gorges University, Yichang 443002 (China)

2017-05-15

The optical behaviors of three hydroxy-naphthol based Schiff bases, L1, L2 and L3, in aggregated states in 1,4-dioxane (Diox) – H{sub 2}O mixture, were investigated. The intermolecular hydrogen bond between luminogen and water resulted in the twisting of benzothiazole group, which is favorable for the assembly of organic molecules into J-aggregates. And also a bathochromic shift in absorption and enhancement of the fluorescence emission (aggregation-induced enhanced emission, AIEE) can be observed. L1 and L2 in Diox-H{sub 2}O mixture with water volume fractions (f{sub w}) 95% assembled into microribbons with 40–50 nm thickness, twisted together to make amorphous supramolecular organogels. Whereas L3 assembled into needle-like nanorods with the thickness up to ~200 nm, consistence with its lower emission intensity compared to L1, L2 aggregates. Moreover, a drastic blue-shift and an enhancement of emission efficiency of L1-L3 were also observed in solid states with the morphology change from the crystalline to the amorphous state by grinding. It was found that L1 aggregates showed fluorescence switch-off sensing towards Cu{sup 2+}, with higher selectivity and sensitivity compared to L1 in Diox solution. - Graphical abstract: Three Schiff bases derivatives, L1, L2 and L3, consisting of hydroxy-naphthol and thiazole group, exhibited AIEE effect in Diox-H{sub 2}O mixture with f{sub w} 95% (for L1 and L2) or 99% (for L3). The formation of amorphous nanoparticles is advantageous for emission enhancement. The drastic blue-shift and an enhancement of emission efficiency were also observed in L1-L3 with the morphology change from the crystalline to the amorphous state in solid by grinding. It was found that L1 AIEE system could be constructed as a chemoprobe towards Cu{sup 2+} fluorescence recognition, with higher selectivity and sensitivity compared to L1 in Diox solution.

Two coordination polymers based on semicarbazone Schiff base and azide: synthesis, crystal structure, electrochemistry, magnetic properties and biological activity

Czech Academy of Sciences Publication Activity Database

Shaabani, B.; Khandar, A.A.; Dušek, Michal; Pojarová, Michaela; Mahmoudi, F.; Feher, A.; Kajňaková, M.

2013-01-01

Roč. 66, č. 5 (2013), s. 748-762 ISSN 0095-8972 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378271 Keywords : Schiff bases * semicarbazone * coordination polymer * structure analyses Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.224, year: 2013

Cadmium (II) macrocyclic Schiff-base complexes containing piperazine moiety: Synthesis, spectroscopic, X-ray structure, theoretical and antibacterial studies

Science.gov (United States)

Keypour, Hassan; Mahmoudabadi, Masoumeh; Shooshtari, Amir; Bayat, Mehdi; Mohsenzadeh, Fariba; Gable, Robert William

2018-03-01

The new Cd(II) macrocyclic Schiff-base complexes were prepared via the metal templated [1 + 1] cyclocondensation of 2,2'-(piperazine-1,4-diylbis (methylene))dianiline (A) and 2,6-pyridinedicarbaldehyde or 2,6-diacetylpyridine. The products were characterized by elemental analysis, mass spectrometry and spectroscopic methods such as: FT-IR, 1H and 13C-NMR, the crystal structure of [CdL1(ClO4)2](CH3CN) (1) complex was also obtained by single-crystal X-ray crystallography. The complexes were tested for in vitro antibacterial properties against some bacteria. The complexes had antibacterial properties and in some cases were active even more than standards. The geometries of the [CdLn (ClO4)2], (n = 1,2) complexes have been optimized at the BP86/def2-SVP level of theory. Also the nature of Cd←Ln (n = 1, 2) bonds in [CdLn (ClO4)2], (n = 1,2) complexes are studied with the help of NBO and Energy decomposition analysis (EDA). Results showed that the nature of metal-ligand bond in the complexes is slightly more electrostatic with a contribution of about 52% in total interaction energy.

One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

KAUST Repository

Wang, Xiaofang

2017-12-24

The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H2pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd2Cl3(2-pzc)(bbbi)2] (2)) under hydrothermal conditions. Complex 1 was obtained in the absence of in situ reaction and 2 was synthesized with 2,3-H2pzdc in situ generating 2-pyrazinecarboxylate (2-pzc−). The structural details reveal that 1 has a 3D framework with dia topology, and 2 is a 2D layer structure and develops a 3D supramolecular structure via strong π⋯π stacking interactions. The ligand effects were compared for the two frameworks. In addition, fluorescence properties and thermal stabilities of 1 and 2 in the solid were studied.

Multi-wavelength spectrophotometric determination of acidity constant of some newly synthesized Schiff bases and their QSPR study

Science.gov (United States)

Hemmateenejad, Bahram; Emami, Leila; Sharghi, Hashem

2010-01-01

The acidity constants of some newly synthesized Schiff base derivatives were determined by hard-model based multivariate data analysis of the spectrophotometric data in the course of pH-metric titration in 50% (v/v) methanol-water binary solvent. The employed data analysis method was also able to extract the pure spectra and pH-dependent concentration profiles of the acid-base species. The molecules that possess different substituents (both electron donating and withdrawing) on the ortho-, meta- and para-positions of one of the phenyl ring showed variable acidity constants ranging from 8.77 to 11.07 whereas the parent molecule had an acidity constant of 10.25. To investigate the quantitative effects of changing of substitution pattern on the acidity constant, a quantitative structure-property relation analysis was conducted using substituent constants and molecular descriptor. Some models with high statistical quality (measured by cross-validation Q2) were obtained. It was found that the acidity constant of the studied molecules in the methanol-water mixed solvent not only is affected by electronic features of the solutes but also by the lipophilic interaction between methanol part of solvent and the deprotonated solutes.

A Study of Complexation-ability of Neutral Schiff Bases to Some Metal Cations

OpenAIRE

Topal, Giray; Tümerdem, Recep; Basaran, Ismet; Gümüş, Arzu; Cakir, Umit

2007-01-01

The constants of the extraction equilibrium and the distribution for dichloromethane as an organic solvent having low dielectric constant of metal cations with chiral Schiff bases, benzaldehydene-(S)-2-amino-3-phenylpropanol (I), ohydroxybenzaldehydene-( S)-2-amino-3-phenyl-propanol (II), benzaldehydene-(S)-2- amino-3-methylbutanol (III) with anionic dyes [4-(2-pyridylazo)-resorcinol mono sodium monohydrate (NaPar), sodium picrat (NaPic) and potassium picrat (KPic)] and some heavy metal chlor...

Synthesis and properties of mixed-ligand ruthenium(II) complexes containing 2-(2-pyridyl)-benzimidazole and related ligands

International Nuclear Information System (INIS)

Haga, Masaaki; Tanaka, Toshio.

1979-01-01

Mixed-ligand ruthenium(II) complexes of the [Ru(bpy) 2 L]sup(n+) (ClO 4 )sub(n) type, where bpy= 2,2'-bipyridine; L= 2-(2-pyridyl)-benzimidazole (PBImH) when n= 2, and L= 2-(2-pyridyl)-benzimidazolate (PBIm) and 2-(o-hydroxyphenyl)-benzimidazole (OBImH) when n= 1, were prepared. Anodic peak potentials and ruthenium-to-bipyridine charge transfer bands of these complexes are rationalized in terms of the donor ability of L. (author)

Synthesis and properties of mixed-ligand ruthenium(II) complexes containing 2-(2-pyridyl)-benzimidazole and related ligands

Energy Technology Data Exchange (ETDEWEB)

Haga, M [Mie Univ., Tsu (Japan); Tanaka, T

1979-07-01

Mixed-ligand ruthenium(II) complexes of the (Ru(bpy)/sub 2/L)sup(n+) (ClO/sub 4/)sub(n) type, where bpy= 2,2'-bipyridine; L= 2-(2-pyridyl)-benzimidazole (PBImH) when n= 2, and L= 2-(2-pyridyl)-benzimidazolate (PBIm) and 2-(o-hydroxyphenyl)-benzimidazole (OBImH) when n= 1, were prepared. Anodic peak potentials and ruthenium-to-bipyridine charge transfer bands of these complexes are rationalized in terms of the donor ability of L.

Studies on coordination chemistry and bioactivity of metal complexes of some nitrogen-sulfur donor ligands: Section A: hydraziniumdithiocarbazate and its complexes. Section B: complexes of Ni2+ and Cu2+ ions with s-picolyldithiocarbazate

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Liza bt Abdullah; Crouse, Karen A.; Ali, A.M.

2003-08-01

Two new nitrogen - sulphur donor ligands, hydraziniumdithiocarbazate(HzDTC) and S-picolyldithiocarbazate(SPDTC), along with three novel Schiff bases were prepared. Complexes of some of HzDTC with nickel(II), zinc(II), and those of SPDTC with nickel(II) and copper(II) were prepared and characterized by a variety of physico- chemical techniques. The ligand, HzDTC, was a potential bidentate and uninegatively charged providing terminal amino and thiolate bindings with the metal ions, while SPDTC coordinates via the pyridine nitrogen and the thiolate anion. All of the compounds were tested against four pathogenic bacteria and fungi. HzDTC was found to be very effective antimicrobial than its complexes. The complexes of SPDTC and the Schiff bases of HzDTC were more antifungal. None of the compounds were effective anti- cancer agents except for [Ni(HzDTCA)Cl.H 2 O], which was moderately active against CEM- SS (Human cell T- lymphoblastic) leukemic cells. (author)

Synthesis, X-ray crystallography, spectroscopy, electrochemistry, thermal and kinetic study of uranyl Schiff base complexes

Czech Academy of Sciences Publication Activity Database

Asadi, Z.; Golzard, F.; Eigner, Václav; Dušek, Michal

2013-01-01

Roč. 66, č. 20 (2013), s. 3629-3646 ISSN 0095-8972 R&D Projects: GA ČR(CZ) GAP204/11/0809 Institutional support: RVO:68378271 Keywords : X-ray crystallography * uranyl Schiff base complex * kinetics of thermal decomposition * cyclic voltammetry * kinetics and mechanism Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.224, year: 2013

Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base

Science.gov (United States)

Dixit, Ritu B.; Uplana, Rahul A.; Patel, Vishnu A.; Dixit, Bharat C.; Patel, Tarosh S.

2010-01-01

Cefadroxil drug loaded biopolymeric films of chitosan-furfural schiff base were prepared by reacting chitosan with furfural in presence of acetic acid and perchloric acid respectively for the external use. Prepared films were evaluated for their strength, swelling index, thickness, drug content, uniformity, tensile strength, percent elongation, FTIR spectral analysis and SEM. The results of in vitro diffusion studies revealed that the films exhibited enhanced drug diffusion as compared to the films prepared using untreated chitosan. The films also demonstrated good to moderate antibacterial activities against selective gram positive and gram negative bacteria. PMID:21179325

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.

Mixed ligand complexes of uranyl lactate with some simple and heterocyclic amines

International Nuclear Information System (INIS)

Jaiswal, S.R.; Rupainwar, D.C.

1984-01-01

Mixed ligand complexes of uranyl lactate with simple and heterocyclic amines having a general formula UO 2 (C 3 H 5 O 3 ).nL.xH 2 O, were prepared, where n=1 and x=1 for L=ethylenediamine (En), dimethyl aniline (DMAn), diethyl amine (DEA), orthophenylenediamine (OPDA), pyridine (Py), 2-picoline(2-Pic), 3-picoline(3-Pic), 4-Picoline(4-Pic), piperidine (Pipy), 2,4-lutidine (2,4 Lut), 2-Aminopyridine (2 APy), quinoline (Quin), isoquinoline (Isoquin) but x=0 for the ligands 2,2'-bipyrldyl (Bipy) and 1,10-phenenthroline (Phen). All the compounds are bright yellow coloured with high decomposition temp. (>200deg) and were characterized by electronic and infrared spectral data. (author)

Characterization and crystal structure of a 17-membered macrocyclic Schiff base compound MeO-sal-pn-bn

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Ghoran, S.H.; Rohlíček, Jan; Dušek, Michal

2015-01-01

Roč. 56, č. 2 (2015), s. 259-265 ISSN 0022-4766 Grant - others:AV ČR(CZ) Praemium Academiae Institutional support: RVO:68378271 Keywords : macrocyclic * Schiff base * spectroscopy * powder diffraction * orthorhombic Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.536, year: 2015

New transition metal complexes of 2,4-dihydroxybenzaldehyde benzoylhydrazone Schiff base (H2dhbh): Synthesis, spectroscopic characterization, DNA binding/cleavage and antioxidant activity

Science.gov (United States)

Aboafia, Seyada A.; Elsayed, Shadia A.; El-Sayed, Ahmed K. A.; El-Hendawy, Ahmed M.

2018-04-01

New complexes [VO2(Hdhbh)] (1), [VO(phen)(dhbh)].1.5H2O (2), [Zn(Hdhbh)2] (3), [MoO2(dhbh)(D)] (D = H2O (4) or MeOH (5)), [Ru(PPh3)(dhbh)Cl(H2O)] (6), and [Pd(Hdhbh)Cl]·H2O (7) (H2dhbh = Schiff base derived from 2,4-dihydroxybenzaldehyde and benzoylhydrazone) have been isolated and characterized by IR, 1H NMR, Mass, UV-Visible and ESR spectroscopy. They were also investigated by cyclic voltammetry, thermal and magnetic measurements and the structure of complex cis-[MoO2(dhbh)(H2O)] (4) was solved by X-ray crystallography. Analytical data showed that H2dhbh behaves as monobasic/or dibasic tridentate ligand via phenolate O, azomethine N and amide O/or deprotonated amide O atoms. Antioxidant activity of the complexes has been evaluated against DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and it has been found that oxovandium (IV) complex (2) displays the highest radical scavenging potency comparable to ascorbic acid as a standard antioxidant. The DNA binding properties of the ligand and its complexes have been investigated by electronic spectroscopy together with DNA cleavage by gel electrophoresis whose results showed also that vanadium (IV) complex (2) has a significant oxidative cleavage among other complexes.

Synthesis, characterization and computational studies of zinc(ii)-halide complexes with a bidentate Schiff base ligand (2,5-MeO-ba).sub.2./sub.En: the crystal structure of (2,5-MeO-ba).sub.2./sub.En

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Mighani, H.; Gholinejad, M.; Grivani, G.; Jalali Akerdi, S.; Fejfarová, Karla; Dušek, Michal

2013-01-01

Roč. 54, č. 4 (2013), s. 766-773 ISSN 0022-4766 Institutional research plan: CEZ:AV0Z10100521 Keywords : zinc(II) halides * Schiff base * crystal structure * density functional theory Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.501, year: 2013

Antibacterial evaluation of some Schiff bases derived from 2-acetylpyridine and their metal complexes.

Science.gov (United States)

Gwaram, Nura Suleiman; Ali, Hapipah Mohd; Khaledi, Hamid; Abdulla, Mahmood Ameen; Hadi, A Hamid A; Lin, Thong Kwai; Ching, Chai Lay; Ooi, Cher Lin

2012-05-18

A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

Complexation of nitrogen and sulphur donor Schiff's base ligand to Cr(III) and Ni(II) metal ions: Synthesis, spectroscopic and antipathogenic studies

Science.gov (United States)

Sharma, Amit Kumar; Chandra, Sulekh

2011-01-01

2,6-Diacetyl pyridine based ligand was synthesized by the reaction of 2,6-diacetyl pyridine with thiocarbohydrazide in presence of acetic acid. The coordination compounds with Cr(III) and Ni(II) metal ions having [Cr(L)X]X 2 and [Ni(L)X]X compositions (where L = ligand and X = NO 3-, Cl - and CH 3COO -) were synthesized and characterized by physicochemical and spectral studies. The studies like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV-Vis, NMR, mass and EPR reveal that the complexes are octahedral. The compounds were examined against the pathogenic fungal and bacterial strains like Alternaria brassicae, Aspergillus niger, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa. A. niger causes the diseases Apergillosis and Otomycosis in humans.

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.

Crystal structure, DNA binding, cleavage, antioxidant and antibacterial studies of Cu(II), Ni(II) and Co(III) complexes with 2-((furan-2-yl)methylimino)methyl)-6-ethoxyphenol Schiff base

Science.gov (United States)

Venkateswarlu, Kadtala; Kumar, Marri Pradeep; Rambabu, Aveli; Vamsikrishna, Narendrula; Daravath, Sreenu; Rangan, Krishnan; Shivaraj

2018-05-01

Three novel binary metal complexes; 1 [Cu(L)2], 2 [Ni(L)2] and 3 [Co(L)3] where, L (2-(((furan-2-yl) methylimino)methyl)-6-ethoxyphenol, C14H15NO3), were synthesized and characterized by various spectral techniques. Based on spectral studies square planar geometry is assigned for Cu(II) and Ni(II) complexes, whereas Co(III) owned octahedral geometry. Ligand, [Cu(L)2] and [Ni(L)2] are crystallized and found to be monoclinic crystal systems. CT-DNA absorption binding studies revealed that the complexes show good binding propensity (Kb = 5.02 × 103 M-1, 2.77 × 103 M-1, 1.63 × 104 M-1 for 1, 2 and 3 respectively). The role of these complexes in the oxidative and photolytic cleavage of supercoiled pBR322 DNA was studied and found that the complexes cleave the pBR322 DNA effectively. The catalytic ability of 1, 2 and 3 follows the order: 3 > 1 >2. Antioxidant studies of the new complexes revealed that they exhibit significant antioxidant activity against DPPH radical. The Schiff base and its metal complexes have been screened for antibacterial studies by Minimum Inhibitory Concentration method. It is observed that all metal complexes showed more activity than free ligand.

Synthesis and characterization of some metal complexes of a Schiff ...

African Journals Online (AJOL)

KEY WORDS: Metal complexes, Schiff base, Ninhydrin, α,L-Alanine, .... Buck Scientific Infrared Spectrophotometer Model 500 in the range of 4000 .... Assignments based on Nakamoto [35], ν - stretching vibration, δ - bending or deformation.

Complexation study of cadmium with a schiff base vanillin trisbuffer

International Nuclear Information System (INIS)

Trivedi, T.; Patel, M.S.; Vyas, D.N.

1978-01-01

Polarographic study of complexation of cadmium with a Schiff base derived from vanillin and trisbuffer was carried out in DMF-water media of three different compositions (viz. 0%, 30% and 50% v/v of DMF). 1:1, 1:2 and 1:3 complex species are present in the solution. Overall stability constants were calculated using DeFord and Hume treatment at three different temperatures (viz. 30 0 , 40 0 and 50 0 ). Free energy change ΔG, enthalpy change ΔH and entropy change ΔS were also calculated for all the three media. A new, methamatical model, recently developed by Mihailov, to calculate stability constants from nbar values was used to check the data obtained from DeFord and Hume method. (author)

Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

KAUST Repository

Huang, Lin; Xue, Ming; Song, Qingshan; Chen, Siru; Pan, Ying; Qiu, Shilun

2014-01-01

A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, b

A novel highly sensitive and selective optical sensor based on a symmetric tetradentate Schiff-base embedded in PVC polymeric film for determination of Zn{sup 2+} ion in real samples

Energy Technology Data Exchange (ETDEWEB)

Abdel Aziz, Ayman A., E-mail: aymanaziz31@gmail.com [Chemistry Department, Faculty of Science, Ain Shams University, 11566 Cairo (Egypt); Chemistry Department, Faculty of Science, University of Tabuk, 71421, Tabuk (Saudi Arabia)

2013-11-15

A novel prepared Zn{sup 2+} ion PVC membrane sensor based on a novel Schiff base; N,N′bis(salicylaldehyde)2,3-diaminonaphthalene (SDN) for the determination of Zn{sup 2+} ion was described. The chemosensor was synthesized under microwave irradiation via condensation of 2,3-diaminonaphthalene and salicylaldehyde. Photoluminescence characteristics of the novel Schiff base ligand were investigated in different solvents including dicholoromethane (DCM), tetrahydrofuran (THF) and ethanol (EtOH). SDN was found to have higher emission intensity and Stoke’s shift value (Δλ{sub ST}) in EtOH solution. The sensor exhibited a specific fluorescent on response to Zn{sup 2+}. The response of the sensor is based on the fluorescence enhancement of SDN (LH{sub 2}) by Zn{sup 2+} ion as a result of formation the rigid structure L-Zn complex. The experiment results also show that the response behavior of SDN to Zn{sup 2+} is pH independent in the range of pH 6.0–8.0. At pH 7.0, the proposed sensor displays a calibration response for Zn{sup 2+} over a wide concentration range of 1.0×10{sup −9}–2.0×10{sup −3} mol L{sup −1} with a limit of detection (LOD) 8.1×10{sup −10} mol L{sup −1} (0.0529659 μg L{sup −1}). The sensor shows excellent selectivity toward Zn{sup 2+} with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to detect Zn{sup 2+} in human hair samples, different brands of powdered milk and some pharmaceuticals. -- Highlights: • A novel Zn(II) chemosensor has been developed. • Wide linear concentration range of 1.0×10{sup −9}–2.0×10{sup −3} mol L{sup −1}. • Application for determination of Zn(II) in real samples.

Structural investigation of oxovanadium(IV) Schiff base complexes: X-ray crystallography, electrochemistry and kinetic of thermal decomposition

Czech Academy of Sciences Publication Activity Database

Asadi, M.; Asadi, Z.; Savaripoor, N.; Dušek, Michal; Eigner, Václav; Shorkaei, M.R.; Sedaghat, M.

2015-01-01

Roč. 136, Feb (2015), 625-634 ISSN 1386-1425 R&D Projects: GA ČR(CZ) GAP204/11/0809 Institutional support: RVO:68378271 Keywords : Oxovanadium(IV) complexes * Schiff base * Kinetic s of thermal decomposition * Electrochemistry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.653, year: 2015

Characterization of a meso-chiral isomer of a hexanuclear Cu(II) cage from racemization of the L-alanine Schiff base.

Science.gov (United States)

Rajesh, Chinnaiyan Mahalingam; Ray, Manabendra

2014-09-14

We are reporting structural characterization of two new hexanuclear cages (H3O)2[Cu3(μ3-OH)(μ3-NH3)(0.5)(L)3]2·8H2O (1) and (H3O)2[Cu3(μ3-OH)(μ3-H2O)(0.5)(L)3]2·8H2O (1a) where L(2-) is the dianionic form of the Schiff base of L-alanine and salicylaldehyde. The complex 1 has two C3 symmetric hydroxo bridged trinuclear halves joined by an ammonia or water molecule at the center through H-bonding. Each of the trinuclear halves is enantiopure but of opposite chirality to the other half, making the hexanuclear unit a meso isomer. Temperature dependent magnetic measurements showed the presence of ferromagnetic interactions among trinuclear Cu(II) units, a rare occurrence among trinuclear Cu(II) complexes. Characterization of the LiHL showed it to be enantiopure. Addition of a base, monitored using optical rotation, showed that racemization occurs as a result of base addition. The racemization depends on the base as well as the temperature. Base or Cu(II) induced racemization of amino acid derivatives has been indicated in a number of cases in the past but structural characterization of the products or formation of this type of chiral hexanuclear architecture was never reported. Structures of the complex and the ligand have a number of interesting H-bonding situations.

Stability constants of mixed ligand complexes of dioxouranium(II) and thorium(IV) with complexones and isomeric alanines

International Nuclear Information System (INIS)

Singh, R.K.; Saxena, M.C.

1992-01-01

The present work reports on the stability sequence between UO 2 II and Th IV ions for their mixed ligands complexes with the two isomeric alanines, α-alanine (α-ala) and β-alanine (β-ala) containing a complexone as primary ligand. The complexones used are iminodiacetate (IMDA), nitrilotricetate (NTA), 2-hydroxyethylenediaminetriacetate (HEDTA), ethylenediaminetetraacetate (EDTA), 1,2-diaminocyclohexanetraacetate (CDTA) and diethylenetriminepentaacetate (DTPA). (author). 9 refs., 1 tab

Synthesis, structure and stability of a chiral imine-based Schiff-based ligand derived from L-glutamic acid and its [Cu4] complex

Science.gov (United States)

Muche, Simon; Levacheva, Irina; Samsonova, Olga; Biernasiuk, Anna; Malm, Anna; Lonsdale, Richard; Popiołek, Łukasz; Bakowsky, Udo; Hołyńska, Małgorzata

2017-01-01

Studies of the stability of a ligand derived from L-glutamic acid and ortho-vanillin and its new [Cu4] complex are presented. The [Cu4] complex contains a heterocubane [CuII4O4] core and pendant carboxylic groups increasing its solubility in water, also under basic conditions. The stability of the complex in different solvents is confirmed with ESI-MS studies and such experiments as successful recrystallization. The complex is stable also under physiological conditions whereas the ligand is partly decomposed to L-glutamic acid and ortho-vanillin.

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.

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

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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.

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

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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.

Complexes of trivalent lanthanide ions with schiff base derived from vanillin and triethylenetetraamine

International Nuclear Information System (INIS)

Shahma, A.; Athar, M.; Ahmad, N.

1982-01-01

Complexes of lanthanide(III) ions with the schiff base derived from vanillin and triethylenetetraamine have been synthesised and characterised on the basis of elemental analyses, molar conductance, magnetic moment, IR and thermal analysis data. The thermograms show the elimination (OH)(OCH 3 )C 6 H 3 CH-group at low temperatures before the elimination of triethylenetetraamine part corroborating the observation made on the basis of IR spectral data. This is a clear indication of the non-coordination of the phenolic hydroxyl groups. The lanthanide ions in the complexes exhibit eight coordination numbers. (author)

Mixed-ligand complexes of copper (II with ditiolfenols and heterocyclic diamines

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K. A. Kuliev

2017-01-01

Full Text Available By the methods spectrophotometric methods was investigated complex formation of copper with 2,6-ditiolphenol and its derivatives (2,6-ditiol-4-methylphenol, 2,6-ditiol-4-ethylphenol and 2,6-ditiol-4-tert-buthylphenol in the presence of heterocyclic diamines. As heterocyclic diamines phenantroline (Fen, batophenantroline and dipyridile were used. It was established, that mixedligand complex were formed in weak acidic medium (pHop=6,0-8,5. Maximum of light absorption observed at (=522–550 nm. Molar coefficient of light absorption was ( = (3.08–4.92?104. The stoichiometry of complexes had been discovered using shift the equilibrium and relative yield methods. During the extraction of copper(II complexes with ditiol-phenols with the presence of heterocyclic diamines there was discovered that there is no chlorophorm molecules in the composition of the extracted complexes. IR spectra shows that hydroxyl group is involved to the formation of a bond with the metal and that phenantroline is included in the composition of the copper complex. In the organic phase mixed-ligand complexes have the monomeric form and can’t polymerize; that fact can be proved by calculations. By dint of spectrophotometric, IR-spectroscopic, thermogravimetric experiments and some published data we were able to determine the structural formula of complexes. Also had been determined main spectrophotometric characteristics of copper(II mixed-ligand complexes: pH of the beginning of the deposition, optimal pH, detection limit and sensivity. For separation and finding copper, we studied the effect of interfering foreign ions: alkali, alkaline earth and rare earth elements, as well as acid anions selected masking reagents. On the base of the results was offered photometric method for determination of copper in steel different trade-marks and in food. This method characterized by good reproduction (relatively standard deviation no more 0.05 and low limit of discovery.

Antibacterial Evaluation of Some Schiff Bases Derived from 2-Acetylpyridine and Their Metal Complexes

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Thong Kwai Lin

2012-05-01

Full Text Available A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA, Acinetobacter baumanni (AC, Klebsiella pneumonie (KB and Pseudomonas aeruginosa (PA using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

Schiff Base modified on CPE electrode and PCB gold electrode for selective determination of silver ion

Science.gov (United States)

Leepheng, Piyawan; Suramitr, Songwut; Phromyothin, Darinee

2017-09-01

The schiff base was synthesized by 2,5-thiophenedicarboxaldehyde and 1,2,4-thiadiazole-3,5-diamine with condensation method. There was modified on carbon paste electrode (CPE) and Printed circuit board (PCB) gold electrode for determination silver ion. The schiff base modified electrodes was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. The electrochemical study was reported by cyclic voltammetry method and impedance spectroscopy using modified electrode as working electrode, platinum wire and Ag/AgCl as counter electrode and reference electrode, respectively. The modified electrodes have suitable detection for Ag+. The determination of silver ions using the modified electrodes depended linearly on Ag+ concentration in the range 1×10-10 M to 1×10-7 M, with cyclic voltammetry sensitivity were 2.51×108 μAM-1 and 1.88×108 μAM-1 for PCB gold electrode and CPE electrode, respectively, limits of detection were 5.33×10-9 M and 1.99×10-8 M for PCB gold electrode and CPE electrode, respectively. The modified electrodes have high accuracy, inexpensive and can applied to detection Ag+ in real samples.

Development of a fluorescent chelating ligand for scandium ion having a Schiff base moiety

Science.gov (United States)

Yamada, Hiroshi; Kojo, Masahito; Nakahara, Tomomi; Murakami, Kumi; Kakima, Takashi; Ichiba, Hideaki; Yajima, Takehiko; Fukushima, Takeshi

2012-05-01

A fluorescent ligand, 1-(2-hydroxy-3-methoxybenzaldehyde)-4-aminosalicylhydrazone (HMB-ASH), was newly designed and synthesized, and its fluorescence characteristics for metal ions were investigated in the pH range 3.0-10.5 (at a difference of 0.5 for each metal). After testing 31 different metal ions, it was found that HMB-ASH was able to emit fluorescence intensely at 512 nm with an excitation wavelength of 353 nm in the presence of Sc3+, one of the rare earth metals, at pH values around 3.5 and 8.0. The other metal ions hardly showed fluorescence with HMB-ASH. The fluorescence was more intense at pH 8.0, and the detection limit of Sc3+ in a buffer solution (pH 8.0) was approximately 18.8 nmol L-1 (0.85 ppb).

Aggregation induced emission enhancement of pyrene-appended Schiff base luminophore and its photovoltaic effect

Energy Technology Data Exchange (ETDEWEB)

Panda, Uttam; Roy, Suman; Mallick, Debashis [Department of Chemistry, Jadavpur University, Kolkata 700032 (India); Dalapati, Pradip [Condensed Matter Physics Research Center, Department of Physics, Jadavpur University, Kolkata 700032 (India); Biswas, Subir [Immunology Lab, Department of Zoology, University of Calcutta, Kolkata 700019 (India); Manik, Nabin Baran [Condensed Matter Physics Research Center, Department of Physics, Jadavpur University, Kolkata 700032 (India); Bhattacharyya, Arindam [Immunology Lab, Department of Zoology, University of Calcutta, Kolkata 700019 (India); Sinha, Chittaranjan, E-mail: c_r_sinha@yahoo.com [Department of Chemistry, Jadavpur University, Kolkata 700032 (India)

2016-07-15

Pyrene appended Schiff base, 1,3-bis-((E)-pyrene-1-ylmethyleneamino)propan-2-ol (HL), a fluorophore, shows aggregation induced emission enhancement upon addition of water in DMF (4:1, v/v) solution; the quantum yield (Φ) is increased by 0.034–0.450. Under illumination of solar radiation HL (10{sup −3} M) impregnated photovoltaic cell generates 4.4 mA/6.29 V electricity. DFT and TD-DFT computation of optimized geometry of HL has explained the photophysical properties.

Synthesis and Spectroscopic Studies of Mixed Ligand Complexes of Pt(II and Pd(II with Ethyl-α-Isonitrosoacetoacetate and Dienes

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Anita Krishankant Taksande

2015-12-01

Full Text Available The mixed ligand complexes of the kind [M(L1 (L2] where M= Pt(II, Pd(II.L1 = primary ligand ethyl-α-isonitrosoacetoacetate derived from reaction between ethyl acetoacetate, acetic acid and sodium nitrite and L2=secondary ligand para-phenyldiamine (PPD are synthesized. All the prepared complexes were identified and confirmed by elemental analysis, molar conductance measurements, and infrared electronic absorption. Their complexes has been made based on elemental analysis, molar conductivity, UV-Vis, FT-IR and 1HNMR spectroscopy and magnetic moment measurements as well as thermal analysis (TGA and DTA. The elemental analysis information recommends that the stoichiometry of the complexes to be 1:2:1. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral information showed the coordination sites of the free ligand with the central metal particle. The electronic absorption spectral information disclosed the existence of an octahedral geometry for Pt(II and Pd(II complexes. DOI: http://dx.doi.org/10.17807/orbital.v7i4.633 

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.

Synthesis and evaluation of ligands with mixed amide and phosphonate, phosphinoxide, and phosphonothioate sites for An(III)/Ln(III) extraction

NARCIS (Netherlands)

Iqbal, M.; Struijk, R.G.; Huskens, Jurriaan; Sypula, M.; Wilden, A.; Modolo, G.; Verboom, Willem

2012-01-01

Various organophosphorus ligands with a combination of different donor sites were synthesized and evaluated by solvent extraction studies for the complexation of Am(III)/Eu(III). Among the ligands with a glycolamide backbone, those with mixed amide and PO donor sites and a central oxygen or nitrogen

Pd-isatin Schiff base complex immobilized onγ-Fe2O3 as a magnetically recyclable catalyst for the Heck and Suzuki cross-coupling reactions

Institute of Scientific and Technical Information of China (English)

Sara Sobhani; Farzaneh Zarifi

2015-01-01

A Pd‐isatin Schiff base complex immobilized onγ‐Fe2O3 (Pd‐isatin Schiff base‐γ‐Fe2O3) was synthe‐sized and characterized by Fourier transform infrared, scanning electron microscopy, high resolu‐tion transmission electron microscopy, X‐ray diffraction, thermogravimetric gravimetric analysis, inductively‐coupled plasma, X‐ray photoelectron spectroscopy, and elemental analysis. It was used as a magnetically reusable Pd catalyst for the Heck and Suzuki cross‐coupling reactions.

Structure-Activity Relationships for Some Diamine, Triamine and Schiff Base Derivatives and Their Copper(II) Complexes

OpenAIRE

Bolos, C. A.; Nikolov, G. St.; Ekateriniadou, L.; Kortsaris, A.; Kyriakidis, D. A.

1998-01-01

Ethylenediamine (en), putrescine (pu), diethylenetriamine (dien), dipropylenetriamine (dpta), spermidine (spmd) and their CuII compounds as well as the Schiff bases with 2-furaldehyde (dienOO), 2- thiophenecarboxaldehyde (dienSS) and pyrrole-2-carboxaldehyde (dienNN) of dien and that of dpta with 2- thiophenecarboxaldehyde (dptaSS), were prepared and characterised. They were tested against Bacillus substilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Xanth...

Dioxouranium (VI) nitrate complexes of some schiff bases derived from furfural and 2-acetylfuran with certain amino compounds

International Nuclear Information System (INIS)

Sobhanadevi, G.; Indrasenan, P.

1989-01-01

Dioxouranium(VI) nitrate complexes with 10 schiff bases obtained by the condensation of furfural and 2-acetylfuran with isonicotinoylhydrazine, benzoylhydrazine, salicyloylhydrazine, anthranilic acid, and 4-aminoantipyrine have been synthesized and characterized on the basis of IR spectra, conductance, magnetic, elemental analyses and molecular weight data. (author). 1 tab., 10 refs

Synthesis and characterization of Th(IV) complex of bis-schiff base from o-vanillin and o-phenylene diamine

International Nuclear Information System (INIS)

Fan Yuhua; Bi Caifeng; Bao Meng

1997-01-01

The new solid complex of thorium nitrate with bis-schiff base (L) derived from o-vanillie and o-phenylene diamine has been synthesized and characterized by elemental analysis, DTA-TG, IR, UV and molar conductance analysis. The composition of the complex is confirmed to be ThL(NO 3 ) 4

Copper(II Complexes with Ligands Derived from 4-Amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one: Synthesis and Biological Activity

Directory of Open Access Journals (Sweden)

Raluca Cernat

2006-11-01

Full Text Available The synthesis of Cu(II complexes derived from Schiff base ligands obtainedby the condensation of 2-hydroxybenzaldehyde or terephtalic aldehyde with 4-amino-antipyrine (4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one is presented. The newlyprepared compounds were characterized by 1H-NMR, UV-VIS, IR and ESRspectroscopy. The determination of the antimicrobial activity of the ligands and of thecomplexes was carried out on samples of Escherichia coli, Klebsiella pneumoniae,Acinetobacter boumanii, Pseudomonas aeruginosa, Staphylococcus aureus and Candidasp. The qualitative and quantitative antimicrobial activity test results proved that all theprepared complexes are very active, especially against samples of Ps. aeruginosa, A.Boumanii, E. coli and S. aureus.

Synthesis of an S T = 7 [Mn 3 ] Mixed-Valence Complex Based on 1,3-Propanediol Ligand Derivatives and Its One-Dimensional Assemblies

KAUST Repository

Huang, Jian; Wu, Gang; Bai, Jiaquan; Jiang, Yuan; Li, Guanghua; Qiu, Shilun; Clé rac, Rodolphe

2013-01-01

. In this work, a new ST = 7 trinuclear mixed-valence Mn complex, [MnIIIMnII 2(LA) 2(Br)4(CH3OH)6] ·Br· (CH3OH)1.5·(H2O)0.5 (1), is reported using a pyridinium-functionalized 1,3-propanediol ligand (H 2LABr = 1-(3-bromo-2,2-bis

Secondary Interactions Arrest the Hemiaminal Intermediate To Invert the Modus Operandi of Schiff Base Reaction: A Route to Benzoxazinones.

Science.gov (United States)

Patel, Ketan; Deshmukh, Satej S; Bodkhe, Dnyaneshwar; Mane, Manoj; Vanka, Kumar; Shinde, Dinesh; Rajamohanan, Pattuparambil R; Nandi, Shyamapada; Vaidhyanathan, Ramanathan; Chikkali, Samir H

2017-04-21

Discovered by Hugo Schiff, condensation between amine and aldehyde represents one of the most ubiquitous reactions in chemistry. This classical reaction is widely used to manufacture pharmaceuticals and fine chemicals. However, the rapid and reversible formation of Schiff base prohibits formation of alternative products, of which benzoxazinones are an important class. Therefore, manipulating the reactivity of two partners to invert the course of this reaction is an elusive target. Presented here is a synthetic strategy that regulates the sequence of Schiff base reaction via weak secondary interactions. Guided by the computational models, reaction between 2,3,4,5,6-pentafluoro-benzaldehyde with 2-amino-6-methylbenzoic acid revealed quantitative (99%) formation of 5-methyl-2-(perfluorophenyl)-1,2-dihydro-4H-benzo[d][1,3]oxazin-4-one (15). Electron donating and electron withdrawing ortho-substituents on 2-aminobenzoic acid resulted in the production of benzoxazinones 9-36. The mode of action was tracked using low temperature NMR, UV-vis spectroscopy, and isotopic ( 18 O) labeling experiments. These spectroscopic mechanistic investigations revealed that the hemiaminal intermediate is arrested by the hydrogen-bonding motif to yield benzoxazinone. Thus, the mechanistic investigations and DFT calculations categorically rule out the possibility of in situ imine formation followed by ring-closing, but support instead hydrogen-bond assisted ring-closing to prodrugs. This unprecedented reaction represents an interesting and competitive alternative to metal catalyzed and classical methods of preparing benzoxazinone.

Coordination chemistry of actinide elements: preparation of new uranium complexes with schiff bases and their characterization (Preprint No. CT-31)

International Nuclear Information System (INIS)

Hingorani, S.; Reddy, P.S.N.; Agarwala, B.V.

1988-02-01

The Schiff bases, o-vanillin semicarbazone (oVSC) and 2-pyridine carboxaldehyde isonicotinoyl hydrazone (PCINH) have been prepared and their novel complexes with dioxouranium(VI) have been synthesized and characterized by IR spectra, elemental analysis and other physico-chemical techniques. (author)

Selective extraction of trivalent actinides with hard-soft mixed donor ligands: role of intra-ligand synergism

International Nuclear Information System (INIS)

Ghanty, Tapan K.

2016-01-01

In recent years, considerable attention has been given to understand the coordination chemistry of trivalent lanthanide (Ln) and actinide (An) with various ligands because of its close link with the nuclear waste management processes. It is well known that lanthanide-actinide separation is a challenging and difficult task because of very similar chemical properties of these two series of ions, which are associated with similar ionic radii and coordination numbers. Recently, we have introduced a new concept, 'intra-ligand synergism', where hard donor atom, such as, oxygen preferentially binds to trivalent actinides (An(III)) as compared to the valence iso-electronic trivalent lanthanides (Ln(III)) in presence of another soft donor centre. In the present work, the conventional concept of selective complexation of actinides with soft donor ligands (either S or N donor) has been modified through exploiting this concept, and thereby the higher selectivity of 1,10-phenanthroline-2,9-dicarboxylamide (PDAM) based ligands, namely PDAM and its isobutyl and decyl derivatives towards Am(III) ion has been predicted theoretically through density functional calculations. Subsequently, several such amide derivatives have been synthesized to optimize the solubility of the ligands in organic phase. Finally, solvent extraction experiments have been carried out to validate the theoretical prediction on the selectivity of oxygen donor ligands towards Am(III) as compared to Eu(III), and a maximum separation factor of about 51 has been achieved experimentally using 2,9-bis(N-decylaminocarbonyl)-1,10-phenanthroline ligand. The separation factor is increased with the decrease in pH, which is very interesting since extraction of the Am 3+ ion is considered to be important under highly acidic conditions from the nuclear waste management point of view. (author)

A ligand channel through the G protein coupled receptor opsin.

Directory of Open Access Journals (Sweden)

Peter W Hildebrand

Full Text Available The G protein coupled receptor rhodopsin contains a pocket within its seven-transmembrane helix (TM structure, which bears the inactivating 11-cis-retinal bound by a protonated Schiff-base to Lys296 in TM7. Light-induced 11-cis-/all-trans-isomerization leads to the Schiff-base deprotonated active Meta II intermediate. With Meta II decay, the Schiff-base bond is hydrolyzed, all-trans-retinal is released from the pocket, and the apoprotein opsin reloaded with new 11-cis-retinal. The crystal structure of opsin in its active Ops* conformation provides the basis for computational modeling of retinal release and uptake. The ligand-free 7TM bundle of opsin opens into the hydrophobic membrane layer through openings A (between TM1 and 7, and B (between TM5 and 6, respectively. Using skeleton search and molecular docking, we find a continuous channel through the protein that connects these two openings and comprises in its central part the retinal binding pocket. The channel traverses the receptor over a distance of ca. 70 A and is between 11.6 and 3.2 A wide. Both openings are lined with aromatic residues, while the central part is highly polar. Four constrictions within the channel are so narrow that they must stretch to allow passage of the retinal beta-ionone-ring. Constrictions are at openings A and B, respectively, and at Trp265 and Lys296 within the retinal pocket. The lysine enforces a 90 degrees elbow-like kink in the channel which limits retinal passage. With a favorable Lys side chain conformation, 11-cis-retinal can take the turn, whereas passage of the all-trans isomer would require more global conformational changes. We discuss possible scenarios for the uptake of 11-cis- and release of all-trans-retinal. If the uptake gate of 11-cis-retinal is assigned to opening B, all-trans is likely to leave through the same gate. The unidirectional passage proposed previously requires uptake of 11-cis-retinal through A and release of photolyzed all

Synthesis, characterization, crystal structure and theoretical studies of new chiral Schiff base (E)-4-hydroxy[(1-phenylethyl)iminomethyl]benzyne

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Gholinejad, M.; Rad, S.M.; Grivani, G.; Fejfarová, Karla; Dušek, Michal

2015-01-01

Roč. 41, č. 3 (2015), 1635-1645 ISSN 0922-6168 R&D Projects: GA ČR(CZ) GC202/07/J007 Institutional support: RVO:68378271 Keywords : Schiff base * crystal structure * DFT calculation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.833, year: 2015

Prolinimines: N-Amino-l-Pro-methyl Ester (Hydrazine) Schiff Bases from a Fish Gastrointestinal Tract-Derived Fungus, Trichoderma sp. CMB-F563.

Science.gov (United States)

Mohamed, Osama G; Khalil, Zeinab G; Capon, Robert J

2018-01-19

A rice cultivation of a fish gastrointestinal tract-derived fungus, Trichoderma sp. CMB-F563, yielded natural products incorporating a rare hydrazine moiety, embedded within a Schiff base. Structures inclusive of absolute configurations were assigned to prolinimines A-D (1-4) on the basis of detailed spectroscopic and C 3 Marfey's analysis, as well as biosynthetic considerations, biomimetic total synthesis, and chemical transformations. Of note, monomeric 1 proved to be acid labile and, during isolation, underwent quantitative transformation to dimeric 3 and trimeric 4. Prolinimines are only the second reported natural products incorporating an N-amino-Pro residue, the first to include l-Pro, the first to occur as Schiff bases, and the first to be isolated from a microorganism.

Crystal structures and luminescence of two cadmium-carboxylate cluster-based compounds with mixed ligands

Energy Technology Data Exchange (ETDEWEB)

Ma, Hui-Fang; Lei, Qian; Wang, Yu-Ling; Yin, Shun-Gao; Liu, Qing-Yan [College of Chemistry and Chemical Engineering and Key Lab. of Functional Small Organic Molecule of Ministry of Education, Jiangxi Normal Univ., Nanchang (China)

2017-04-04

Reactions of Cd(NO{sub 3}){sub 2}.4H{sub 2}O with 2-quinolinecarboxylic acid (H-QLC) in the presence of 1,4-benzenedicarboxylic acid (H{sub 2}-BDC) or 1,3,5-benzenetricarboxylic acid (H-BTC) in DMF/H{sub 2}O solvent afforded two compounds, namely, [Cd(QLC)(BDC){sub 1/2}(H{sub 2}O)]{sub n} (1) and [Cd(QLC)(BTC){sub 1/3}]{sub n} (2). Both compounds are two-dimensional (2D) frameworks but feature different cadmium-carboxylate clusters as a result of the presence of the polycarboxylate ligands with different geometries and coordination preference. The dinuclear Cd{sub 2}(QLC){sub 2} units in 1 are bridged by the pairs of bridging water ligands to give a one-dimensional (1D) chain, which is further linked by the second ligand of BDC{sup 2-} to form a 2D structure. Compound 2 is constructed from unique hexanuclear macrometallacyclic Cd{sub 6}(QLC){sub 6} clusters, which are linked by the surrounding BTC{sup 3-} ligands to generate a 2D structure. Photoluminescence studies showed both compounds exhibit ligand-centered luminescent emissions with emission maxima at 405 and 401 nm, respectively. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Synthesis, solvatochromaticity and bioactivities of some transition metal complexes with 2-(R-benzylideneamino)-pyridin-3-ol Schiff base derivatives

Science.gov (United States)

Ahmed, I. S.; Kassem, M. A.

2010-10-01

New four Schiff bases are prepared by condensation of 2-amino-pyridin-3-ol with 3, 4-dihydroxy-benzaldehyde (I), 2-hydroxybenzaldehyde (II), 5-bromo-2-hydroxybenzaldehyde (III), and 4-dimethylaminobenzaldehyde (IV). The structures of these compounds are characterized based on elemental analyses (C. H. N), IR and 1H NMR. Also, the electronic absorption spectra are recorded in organic solvents of different polarity. The solvents are selected to be covered a wide range of parameters (refractive index, dielectric constant and hydrogen bonding capacity). The UV-vis absorption spectra of Schiff base compounds are investigated in aqueous buffer solutions of varying pH and utilized for the determination of ionization constant, p Ka and activation free energy, Δ G* of the ionization process. The biological activity against bacterial species and fungi as microorganisms representing different microbial categories such as (two Gram-negative bacteria, Eschericha coli and Agrobacterium sp.),three Gram-positive bacteria ( Staphylococcus aureus, Bacillus subtlus and Bacillus megatherium), yeast ( Candida albicans), and fungi ( Aspergillus niger) were studied.

Trithiocyanurate Complexes of Iron, Manganese and Nickel and Their Anticholinesterase Activity

Directory of Open Access Journals (Sweden)

Pavel Kopel

2014-04-01

Full Text Available The complexes of Fe(II, Mn(II and Ni(II with a combination of a Schiff base, nitrogen-donor ligand or macrocyclic ligand and trithiocyanuric acid (ttcH3 were prepared and characterized by elemental analysis and spectroscopies. Crystal and molecular structures of the iron complex of composition [Fe(L1](ttcH2(ClO4·EtOH·H2O (1, where L1 is Schiff base derived from tris(2-aminoethylamine and 2-pyridinecarboxaldehyde, were solved. It was found that the Schiff base is coordinated to the central iron atom by six nitrogens forming deformed octahedral arrangement, whereas trithiocyanurate(1- anion, perchlorate and solvent molecules are not coordinated. The X-ray structure of the Schiff base sodium salt is also presented and compared with the iron complex. The anticholinesterase activity of the complexes was also studied.

Mn(II), Zn(II) and VO(II) Schiff

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 3. Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) Schiff base complexes derived from o-phenylenediamine and acetoacetanilide. N Raman Y Pitchaikani Raja A Kulandaisamy. Inorganic Volume 113 Issue 3 June 2001 pp 183-189 ...

and hetero-dinuclear complexes with a new septadentate Schiff

Indian Academy of Sciences (India)

Unknown

disulphide yields a septadentate Schiff base with N2SO4 donor frame of which ..... bond has been calculated according to the published method 25 and the .... complexes exhibit CuII → CuIII oxidation and CuII → CuI reduction reaction at cyclic.

Two Zinc(II) metal-organic frameworks with mixed ligands of 5-amino-tetrazolate and l,2,4,5-benzenetetracarboxylate: Synthesis, structural diversity and photoluminescent properties

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiao-Bing [Department of Chemistry, Shaoguan University, Shaoguan, Guangdong 512005 (China); Lu, Wen-Guan, E-mail: lwg@sgu.edu.cn [Department of Chemistry, Shaoguan University, Shaoguan, Guangdong 512005 (China); Zhong, Di-Chang [School of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou 341000 (China)

2017-06-15

The reactions of Zn(NO{sub 3}){sub 2}·6H{sub 2}O with mixed ligands of 5-amino-tetrazole (Hatz) and l,2,4,5-benzenetetracarboxylic acid (H{sub 4}btec) under hydro(solvo)thermal conditions, gave two three-dimensional (3D) porous metal-organic frameworks (MOFs) of ([Zn{sub 3}(atz){sub 2}(btec)(DMF){sub 2}]·DMF·2H{sub 2}O){sub n} (1) and [Zn{sub 2}(Hprz)(atz)(btec)(H{sub 2}O)]{sub n} (2) in the absence and presence of piperazine (prz), respectively. 1 and 2 were characterized by infrared spectra (IR), elemental analyses (EA) and single-crystal/powder X-ray diffraction. In 1, the adjacent 1D [Zn{sub 3}(btec)]{sub n}{sup 2n+} chains are linked together by atz{sup −} ligands to form a 3D porous MOF with 1D tetragonal channels filled with coordinated and guest DMF, and lattice water molecules. In 2, the adjacent 2D [Zn{sub 2}(btec)]{sub n} wavelike sheets are pillared through atz{sup −} ligands to generate a 3D layered-pillared porous MOF with 1D open channels, which are occupied by coordinated Hprz{sup +} cations and coordinated water molecules. Additionally, thermal stabilities and photoluminescent properties of both compounds in the solid-state at room temperature have been investigated and discussed in detail. - Graphical abstract: Two new MOFs constructed from Zn(II) salts with mixed ligands of 5-amino-tetrazole and l,2,4,5-benzenetetracarboxylic acid were synthesized under different reaction conditions. Structural diversities indicate that the reaction solvent system or the presence of organic base play crucial roles in modulating structures of these compounds. And more, their thermal stability and luminescence are also discussed. - Highlights: • Two new Zn(II) MOFs based on mixed ligands were synthesized. • The two Zn(II) MOFs exhibit different structural motifs. • The two Zn(II) MOFs are photoluminscent in the solid state at room temperature.

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.

X-ray crystallography, electrochemistry, spectral and thermal analysis of some tetradentate schiff base complexes and formation constant measurements

Czech Academy of Sciences Publication Activity Database

Asadi, Z.; Savarypour, N.; Dušek, Michal; Eigner, Václav

2017-01-01

Roč. 47, č. 11 (2017), s. 1501-1508 ISSN 2470-1556 R&D Projects: GA ČR(CZ) GA15-12653S Institutional support: RVO:68378271 Keywords : X-ray crystallography * transition metal Schiff base complexes * thermogravimetry * electrochemistry * formation constant measurements Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.)

A Mixed-Ligand Chiral Rhodium(II) Catalyst Enables the Enantioselective Total Synthesis of Piperarborenine B.

Science.gov (United States)

Panish, Robert A; Chintala, Srinivasa R; Fox, Joseph M

2016-04-11

A novel, mixed-ligand chiral rhodium(II) catalyst, Rh2(S-NTTL)3(dCPA), has enabled the first enantioselective total synthesis of the natural product piperarborenine B. A crystal structure of Rh2(S-NTTL)3(dCPA) reveals a "chiral crown" conformation with a bulky dicyclohexylphenyl acetate ligand and three N-naphthalimido groups oriented on the same face of the catalyst. The natural product was prepared on large scale using rhodium-catalyzed bicyclobutanation/ copper-catalyzed homoconjugate addition chemistry in the key step. The route proceeds in ten steps with an 8% overall yield and 92% ee. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

{μ2-6,6′-Dimethoxy-2,2′-[butane-1,4-diylbis(nitrilomethylidyne]diphenolato}trinitratocopper(IIneodymium(III

Directory of Open Access Journals (Sweden)

Jing-Chun Xing

2010-11-01

Full Text Available In the title complex, [CuNd(C20H22N2O4(NO33], the CuII ion is coordinated in a distorted square-planar environment by two O atoms and two N atoms of a tetradentate Schiff base ligand. The NdIII ion is ten-coordinated by three bis-chelating nitrate groups and four O atoms of the Schiff base ligand. The atoms of one of the nitrato ligands are disordered over two sets of sites, with refined occupancies of 0.567 (13 and 0.433 (17.

Experimental study of the energetics of tetradentate N2O2 Schiff bases derived from salicylaldehyde

International Nuclear Information System (INIS)

Ribeiro da Silva, Maria D.M.C.; Goncalves, Jorge M.; Silva, Ana L.R.; Silva, Adelina M.R.O.A.; Oliveira, Paula C.F.C.; Ribeiro da Silva, Manuel A.V.

2004-01-01

The standard (p 0 = 0.1 MPa) molar enthalpies of formation, at T = 298.15 K, in the gaseous phase of two Schiff bases, N,N'-bis(salicylaldehydo)ethylenediimine and N,N'-bis(salicylaldehydo)tetramethylenediimine, were determined from their enthalpies of combustion and sublimation, obtained by static bomb calorimetry in oxygen and by the Knudsen effusion technique, respectively. The enthalpies of fusion of both compounds have been determined by differential scanning calorimetry

Studies on mixed ligand complexes of adenine and xanthine with some rare earth ions

International Nuclear Information System (INIS)

Rastogi, P.R.; Singh, Mamta; Nayan, Ram

1993-01-01

Interactions of 6-aminopurine (adenine, HA) and 2,6-dihydroxypurine (xanthine, HB) with trivalent rare earth ions Y, Tb, Dy, Ho, Er and Tm, have been studied by pH-titration methods in aqueous solution at 20 o (μ = 0.1 M KNO 3 ). The ligands in their mixtures with tripositive rare earth ions (M 3+ ) form a number of mixed ligand complexes, M 3+ -adenine-xanthine, M 3+ -(adenine) 2 -xanthine, M 3+ -adenine-(xanthine) 2 in addition to the binary complexes, M 3+ -(adenine), M 3+ -(adenine) 2 , M 3+ -(adenine) 3 , M 3+ -(xanthine), M 3+ -(xanthine) 2 and M 3+ -(xanthine) 3 . The stability constants of these complexes have been evaluated and the results discussed. (author). 13 refs., 1 fig., 1 tab

Chemical modification of silica gel with synthesized Schiff base hydrazone derivative and application for preconcentration and separation of U(VI) ions from aqueous solutions

International Nuclear Information System (INIS)

Gamze Karayel Incili; Gul Asiye Aycik

2014-01-01

Schiff base hydrazone derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of U(VI) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, Schiff base hydrazone derivative (HL) was chemically bonded to silica gel surface immobilized 3-aminopropyl trimethoxysilane, then analyzed by Fourier transform infrared, Brunauer-Emmett-Teller, scanning electron microscopy and elemental analysis. The influence of the solution pH, amount of sorbent, contact time, temperature, foreign ion effect and initial U(VI) concentration was investigated. The maximum U(VI) uptake capacity was found to be 8.46 mg/g. (author)

Synthesis, characterization and electrochemical investigations of mixed-ligand copper(II)-organic supramolecular frameworks

Science.gov (United States)

Singh, Sandeep K.; Srivastava, Ashish Kumar; Srivastava, Krishna; Banerjee, Rahul; Prasad, Jagdish

2017-11-01

Two mixed-ligand copper(II)-organic coordination compounds with 5,5‧-dimethyl-2,2‧-bipyridine (5,5‧-Me2bpy) as a primary ligand while aliphatic malonate (Hmal) and aromatic 2-hydroxynicotinate (2-OHNA) as secondary ligands, were synthesized. These complexes are formulated as: [Cu(Hmal)(5,5‧-Me2bpy)(H2O)](ClO4) 1 and [Cu2(2-OHNA)2(5,5‧-Me2bpy)2(NO3)](NO3) 2. These two complexes were structurally characterized by single crystal X-ray diffraction analysis. Characterization was further supported by powder X-ray diffraction analysis, elemental analyses, FT-IR, FAB-MASS and TGA, DSC studies. Cyclic voltammetric and UV-visible spectral studies of these two complexes have also been done. The electrochemical studies of complex 1 in DMSO and DMF have shown that this complex undergoes quasi-reversible diffusion-controlled one-electron transfer reaction without any chemical complication while complex 2 in DMSO undergoes quasi-reversible diffusion-controlled one electron transfer reaction, following EC mechanism. The electrochemical behaviour of complex 2 in DMF is complicated probably due to presence of more than one species in solution phase.

Synthesis, spectral characterization, theoretical, antimicrobial, DNA interaction and in vitro anticancer studies of Cu(II and Zn(II complexes with pyrimidine-morpholine based Schiff base ligand

Directory of Open Access Journals (Sweden)

M. Sankarganesh

2018-05-01

Full Text Available Novel Cu(II (1 and Zn(II (2 complexes with 4-(1-(4-morpholinophenylethylideneaminopyrimidine-5-carbonitrile (L have been synthesized and characterized by various spectroscopic and analytical techniques. DFT (density functional theory studies result confirms that, LMCT mechanism have been done between L and M(II ions. The antimicrobial studies indicate that the ligand L and complexes 1 & 2 exhibit higher activity against the E. coli bacteria and C. albicans fungi. The groove binding mode of ligand L and complexes 1 & 2 with CT-DNA have been confirmed by electronic absorption, competitive binding, viscometric and cyclic voltammetric studies. The electronic absorption titration of ligand L and complexes 1 & 2 with DNA have been carried out in different buffer solutions (pH 4.0, 7.0 & 10.0. The Kb values of ligand L and complexes 1 & 2 are higher in acidic buffer at pH 4.0 (Kb = 2.42 × 105, L; 2.8 × 105, 1; 2.65 × 105, 2 and the results revealed that, the interaction of synthesized compounds with DNA were higher in the acidic medium than basic and neutral medium. Furthermore, CT-DNA cleavage studies of ligand L and complexes 1 & 2 have been studied. The in vitro anticancer activities results show that complexes 1 & 2 have moderate cytotoxicity against cancer cell lines and low toxicity on normal cell line than ligand L. Keywords: Pyrimidine, Morpholine, DFT, Antimicrobial, DNA binding, Anticancer studies

Schiff-Sherrington syndrome in a horse - Case report

Directory of Open Access Journals (Sweden)

Cibele Lima Lhamas

2015-06-01

Full Text Available ABSTRACT. Lhamas C.L., Anjos B.L., Pfingstag K.G., Quevedo L.S. & Duarte C.A. [Schiff-Sherrington syndrome in a horse - Case report.] Síndrome de Schiff-Sherrington em equino - Relato de caso. Revista Brasileira de Medicina Veterinária, 37(2:163-166, 2015. Curso de Pós-Graduação em Ciência Animal, Universidade Federal do Pampa, Campus Uruguaiana, BR 472, Km 585, Uruguaiana, RS 97500-970, Brasil. E-mail: claudiaduarte@unipampa.edu.br Schiff-Sherrington syndrome clinically corresponds to a manifestation of rigidity extensor or hypertonia of the forelimb and hypotonic paralysis of the hind limbs. It is a common condition in dogs, however, rarely described in large animals. It can be caused by trauma and spinal cord compression conditions. The aim of this study was to describe the case of a two-year-old male horse with Schiff-Sherrington syndrome. The animal was sent with signs of paresis and ataxia of the hind limbs, and during the necropsy, multiple fractures were observed in the 1st and 2nd lumbar vertebrae and spinal cord compression.

A chiroptical switch based on supramolecular chirality transfer through alkyl chain entanglement and dynamic covalent bonding.

Science.gov (United States)

Lv, Kai; Qin, Long; Wang, Xiufeng; Zhang, Li; Liu, Minghua

2013-12-14

Chirality transfer is an interesting phenomenon in Nature, which represents an important step to understand the evolution of chiral bias and the amplification of the chirality. In this paper, we report the chirality transfer via the entanglement of the alkyl chains between chiral gelator molecules and achiral amphiphilic Schiff base. We have found that although an achiral Schiff base amphiphile could not form organogels in any kind of organic solvents, it formed co-organogels when mixed with a chiral gelator molecule. Interestingly, the chirality of the gelator molecules was transferred to the Schiff base chromophore in the mixed co-gels and there was a maximum mixing ratio for the chirality transfer. Furthermore, the supramolecular chirality was also produced based on a dynamic covalent chemistry of an imine formed by the reaction between an aldehyde and an amine. Such a covalent bond of imine was formed reversibly depending on the pH variation. When the covalent bond was formed the chirality transfer occurred, when it was destroyed, the transfer stopped. Thus, a supramolecular chiroptical switch is obtained based on supramolecular chirality transfer and dynamic covalent chemistry.

Synthesis of an S T = 7 [Mn 3 ] Mixed-Valence Complex Based on 1,3-Propanediol Ligand Derivatives and Its One-Dimensional Assemblies

KAUST Repository

Huang, Jian

2013-10-07

Controlled organization of high-spin complexes and single-molecule magnets is a great challenge in molecular magnetism in order to study the effect of the intercomplex magnetic interactions on the intrinsic properties of a given magnetic object. In this work, a new ST = 7 trinuclear mixed-valence Mn complex, [MnIIIMnII 2(LA) 2(Br)4(CH3OH)6] ·Br· (CH3OH)1.5·(H2O)0.5 (1), is reported using a pyridinium-functionalized 1,3-propanediol ligand (H 2LABr = 1-(3-bromo-2,2-bis(hydroxymethyl)propyl)pyridinium bromide). Using azido anions as bridging ligands and different pyridinium-functionalized 1,3-propanediol ligands (H2LBBr = 1-(3-bromo-2,2-bis(hydroxymethyl)propyl)-4-picolinium bromide; H 2LCBr = 1-(3-bromo-2,2-bis(hydroxymethyl)propyl)-3,5- lutidinium bromide), the linear [MnIIIMnII 2L2X4]+ building block has been assembled into one-dimensional coordination networks: [MnIIIMn II 2(LA)2(Br)4(CH 3OH)4(N3)]·((C2H 5)2O)1.25 (2∞), [MnIIIMn II 2(LB)2(Br)4(C 2H5OH)(CH3OH)(H2O) 2(N3)]·(H2O)0.25 (3∞), and [MnIIIMnII 2(LC) 2(Cl)3.8(Br)0.2(C2H 5OH)3(CH3OH)(N3)] (4∞). The syntheses, characterization, crystal structures, and magnetic properties of these new [Mn3]-based materials are reported. © 2013 American Chemical Society.

Synthesis, Characterization and Antimicrobial Activities of Transition Metal Complexes of methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate

International Nuclear Information System (INIS)

Ikram, M.; Rehman, S.

2016-01-01

New metal complexes with Schiff base ligand methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate, were synthesized and characterized. Elemental analyses, EI-MS, 1H and 13C(1H)-NMR were used for ligand characterization whereas elemental analyses, EI-MS, IR and UV-Visible spectroscopic techniques were used for the transition metal compounds. All these analyses reveal the bis arrangement of the ligand around the metal centres. The compounds were studied for their antimicrobial activities against different pathogenic microbial species. It was found that the Schiff base ligand was completely inactive in comparison to the transition metal compounds. It was also observed that nickel based metal complex shown good results against Candida albican (25 mm) and zinc based metal complex against Agrobacterium tumefaciens (16 mm). (author)

Synthesis and luminescent properties of two Schiff-base boron complexes

Energy Technology Data Exchange (ETDEWEB)

Hou Qiufei [Key Lab for Supramolecular Structure and Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Liyan [Key Lab for Supramolecular Structure and Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhang Hongyu [Key Lab for Supramolecular Structure and Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Wang Yue [Key Lab for Supramolecular Structure and Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Jiang Shimei [Key Lab for Supramolecular Structure and Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)]. E-mail: smjiang@jlu.edu.cn

2007-10-15

Schiff bases N,N'-o-phenylenebis (salicylideneimine) (H{sub 2} L{sup 1} ), N,N'-p-phenylenebis (salicylideneimine) (H{sub 2} L{sup 2} ) and their corresponding boron complexes (BF{sub 2}){sub 2} L{sup 1} (BF{sub 2}){sub 2} L{sup 2} were synthesized, respectively. The two boron complexes have been characterized by {sup 1}H NMR, mass spectrometry and elemental analysis, while the luminescent properties of them were investigated with UV-VIS spectroscopy and photoluminescence spectroscopy. Then the three-layer devices [ITO/NPB (60 nm)/(BF{sub 2}){sub 2} L{sup 1} (50 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm)] (device I) and [ITO/NPB (60 nm)/(BF{sub 2}){sub 2} L{sup 2} (50 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm)] (device II) were fabricated by vacuum deposition. These two devices both exhibited blue green emission at 500 nm, but showed different luminances and efficiencies.

Dynamic ligand-based pharmacophore modeling and virtual ...

Indian Academy of Sciences (India)

Five ligand-based pharmacophore models were generated from 40 different .... the Phase module of the Schrodinger program.35 Each model consisted of six types of ... ligand preparation included the OPLS_2005 force field and to retain the ...

Solid state and solution photoluminescence properties of a novel meso–meso-linked porphyrin dimer Schiff base ligand and its metal complexes

Energy Technology Data Exchange (ETDEWEB)

Tümer, Mehmet, E-mail: mtumer@ksu.edu.tr; Ali Güngör, S.; Raşit Çiftaslan, A.

2016-02-15

We prepared novel meso-meso linked 4-bromo-2,6-bis[5-(4-iminophenyl)-10,15,20-triphenylporphyrin]phenol (HL) and its Cu(II), Fe(III), Mn(III), Pt(II) and Zn(II) transition metal complexes. Structural characterizations of the ligand (HL) and its metal complexes were done by the spectroscopic and analytical methods. The electronic absorption and photoluminescence spectra of the ligand, its metal complexes and the metal salts used for preparing of the complexes were investigated in the solid and solution state. The emission and excitation data of the CuCl{sub 2}·2H{sub 2}O in both solid and the solution state were obsrved in the longest wavelenght. On the other hand, the emission value of the ZnCl{sub 2} salt was shown at the shortest wavelenght. The emission values of the [LCu{sub 4}Cl{sub 3}(H{sub 2}O){sub 2}]H{sub 2}O and LPt{sub 4}Cl{sub 3} complexes in the solid state are bigger than the other metal salts. The ligand and its metal complexes show the very interesting absorption spectral properties in the solid state. Metal complexes have less number Q bands in the solid state. The electrochemical properties of the ligand and its metal complexes were investigated and found that they show the reversible or irreversible redox processes at the different scan rates. Thermal properties of the compopunds were investigated in the 20–900 °C temperature range.

Acoustical Studies of Some Schiff Bases in 1,4-Dioxane and Dimethylformamide at 318.15 K

Institute of Scientific and Technical Information of China (English)

BALUJA Shipra

2006-01-01

From experimental data of density, viscosity and ultrasonic velocity, the various acoustical properties, such as specific impedance (Z), isentropic compressibility (κs), Rao's molar sound function (Rm), the van der Waals constant (b), molar compressibility (W), intermolecular free length (Lf), relaxation strength (r), internal pressure (π),free volume (Vf), solvation number (Sn) etc., were calculated for three Schiff bases in 1,4-dioxane and dimethylformamide (DMF) at 318.15 K. The results are interpreted in terms of molecular interactions occurring in the solutions.

Synthesis and characterization of zinc(II), cadmium(II) and mercury(II) complexes with bis(bidentate) Schiff bases

International Nuclear Information System (INIS)

Das, Mrinal Kanti; Ghosh, Shyamali

1998-01-01

A few Zn(II), Cd(II) and Hg(II) complexes of the bis(bidentate) Schiff bases derived from p-phenylenediamine and salicylaldehyde (H 2 Salpphen), and o-phenylenediamine and o-vanillin (H 2 Vanophen), of the type MCl 2 .H 2 L(H 2 L = H 2 Salpphen or H 2 Vanophen) have been synthesised. The complexes have been characterized by elemental analysis, infrared, 1 H and 13 C NMR and mass spectra. (author)

cis-dioxomolybdenum(VI)-(ONO)

Indian Academy of Sciences (India)

Various ONO type Schiff base ligands L(H)2 used for the preparation of ... and derivatives.6–33 Depending on the method of prepa- ration .... HCl. Scheme 6. Synthesis of a Mo(VI) Schiff base complexe by selective inversion at C–1 carbon of a ...

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.

Solution stabilities of some mixed ligand complexes of UO22+ and Th4+ with complexones and salicylic acids

International Nuclear Information System (INIS)

Singh, R.K.; Saxena, M.C.

1991-01-01

Formation constants (log Ksub(MAL)sup(MA)) of mixed ligands complexes (MAL), where M = UO 2 2+ or Th 4+ , A = IMDA, NTA, HEDTA, EDTA, CDTA or DTPA, L = salicylic acid (SA) or 5-sulphosalicylic acid (SSA), have been determined by pH titrations using Irving-Rossotti approach at 25 o C and at I =0.2 (mol dm -3 , KNO 3 ). The solution stabilities exhibit the sequence (i) Th 4+ >UO 2 2+ , (ii) IMDA>NTA>HEDTA>EDTA>CDTA>DTPA, and (iii) SA>SSA with respect to metal ions, primary ligands and secondary ligands, respectively. The formation constants log Ksub(ML)sup(M) and log Ksub(ML 2 )sup(ML) have also been determined. The Δlog K values have been found to be negative-increasing numerically with the negative charge on the deprotonated primary ligand (A n- ). (author). 17 refs., 1 tab

Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

International Nuclear Information System (INIS)

Kolhe, Vishnu; Dwivedi, K.

1996-01-01

Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

Synthesis of α-Amino Acids via Asymmetric Phase Transfer-Catalyzed Alkylation of Achiral Nickel(II) Complexes of Glycine-Derived Schiff Bases

NARCIS (Netherlands)

Belokon, Yuri N.; Bespalova, Natalia B.; Churkina, Tatiana D.; Císařová, Ivana; Ezernitskaya, Marina G.; Harutyunyan, Syuzanna R.; Hrdina, Radim; Kagan, Henri B.; Kočovský, Pavel; Kochetkov, Konstantin A.; Larionov, Oleg V.; Lyssenko, Konstantin A.; North, Michael; Polášek, Miroslav; Peregudov, Alexander S.; Prisyazhnyuk, Vladimir V.; Vyskočil, Štěpán

2003-01-01

Achiral, diamagnetic Ni(II) complexes 1 and 3 have been synthesized from Ni(II) salts and the Schiff bases, generated from glycine and PBP and PBA, respectively, in MeONa/MeOH solutions. The requisite carbonyl-derivatizing agents pyridine-2-carboxylic acid(2-benzoyl-phenyl)-amide (PBP) and

A novel trinuclear copper(II) complex containing a symmetric tetradentate N.sub.2./sub.O.sub.2./sub. Schiff base ligand: synthesis, characterization, crystal structure and its usage as a new precursor for the preparation of CuO particles

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Ghorbani, M.; Feizi, N.; Akbari, A.; Eigner, Václav; Dušek, Michal

2017-01-01

Roč. 121, Jan (2017), s. 9-12 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA15-12653S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : trinuclear complex * copper(II) complex * Schiff base * crystal structure * thermal decomposition Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 1.926, year: 2016

Solute-solvent interactions in chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane at 308.15 K according to ultrasonic and viscosity data

Science.gov (United States)

Gangani, B. J.; Patel, J. P.; Parsania, P. H.

2015-12-01

The density, viscosity and ultrasonic speed (2 MHz) of chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane were investigated at 308.15 K. Various acoustical parameters such as specific acoustical impedance ( Z), adiabatic compressibility ( Ka), Rao's molar sound function ( R m), van der Waals constant ( b), internal pressure (π), free volume ( V f), intermolecular free path length ( L f), classical absorption coefficient (α/ f 2)Cl) and viscous relaxation time (τ) were determine using ultrasonic speed ( U), viscosity (η) and density (ρ) data of Schiff bases solutions and correlated with concentration. Linear increase of Z, b, R, τ, and (α/ f 2)Cl except π (nonlinear) and linear decrease of Ka and L f except V f (nonlinear) with increasing concentration of Schiff bases suggested presence of strong molecular interactions in the solutions. The positive values of solvation number further supported strong molecular interactions in the solutions. The nature and position of halogen substituent also affected the strength of molecular interactions.

Lorentz-violating contributions to the nuclear Schiff moment and nuclear EDM

Science.gov (United States)

Araujo, Jonas B.; Casana, Rodolfo; Ferreira, Manoel M.

2018-03-01

In the context of an atom endowed with nuclear electric dipole moments (EDM), we consider the effects on the Schiff moment of C P T -even Lorentz-violating (LV) terms that modify the Coulomb potential. First, we study the modifications on the Schiff moment when the nucleus interacts with the electronic cloud by means of a Coulomb potential altered only by the P -even LV components. Next, by supposing the existence of an additional intrinsic LV EDM generated by other LV sources, we assess the corrections to the Schiff moment when the interaction nucleus-electrons runs mediated by a Coulomb potential modified by both the P -odd and P -even LV components. We then use known estimates and EDM measurements to discuss upper bounds on the new Schiff moment components and the possibility of a nuclear EDM component ascribed to LV effects.

Four Mixed-Ligand Zn(II Three-Dimensional Metal-Organic Frameworks: Synthesis, Structural Diversity, and Photoluminescent Property

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Chih-Chieh Wang

2017-11-01

Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.

Tetradentate Schiff base platinum(II) complexes as new class of phosphorescent materials for high-efficiency and white-light electroluminescent devices.

Science.gov (United States)

Che, Chi-Ming; Chan, Siu-Chung; Xiang, Hai-Feng; Chan, Michael C W; Liu, Yu; Wang, Yue

2004-07-07

The capabilities of readily prepared and sublimable Pt(II) Schiff base triplet emitters as OLED dopants have been examined; maximum luminous and power efficiencies and luminance of 31 cd A(-1), 14 lm W(-1), and 23,000 cd m(-2), respectively, and white EL (CIE: 0.33, 0.35) by simultaneous host/dopant emission, have been achieved.

Synthesis, Characterization, and Antibacterial Studies of Mixed Ligand Dioxouranium Complexes with 8-Hydroxyquinoline and Some Amino Acids

Science.gov (United States)

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

2011-01-01

Mixed ligand complexes of dioxouranium (VI) of the type [UO2(Q)(L)·2H2O] have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and amino acids (HL) such as L-threonine, L-tryptophan, and L-isoleucine as secondary ligands. The metal complexes have been characterized by elemental analysis, electrical conductance, magnetic susceptibility measurements, and spectral and thermal studies. The electrical conductance studies of the complexes indicate their nonelectrolytic nature. Magnetic susceptibility measurements revealed diamagnetic nature of the complexes. Electronic absorption spectra of the complexes show intraligand and charge transfer transitions, respectively. Bonding of the metal ion through N- and O-donor atoms of the ligands is revealed by IR studies, and the chemical environment of the protons is confirmed by NMR studies. The thermal analysis data of the complexes indicate the presence of coordinated water molecules. The agar cup and tube dilution methods have been used to study the antibacterial activity of the complexes against the pathogenic bacteria S. aureus, C. diphtheriae, S. typhi, and E. coli. PMID:22389843

Synthesis characterization and biological evaluation of a novel mixed ligand 99mTc complex as potential brain imaging agent

International Nuclear Information System (INIS)

Rey, A.; Manta, E.; Leon, A.; Papadopoulos, M.; Pirmettis, Y.; Raptopoulou, C.; Chiotellis, E.; Leon, E.; Mallo, L.

1998-01-01

One approach in the design of neutral oxotechnetium complexes is based on the simultaneous substitution of a tridentate dianionic ligand and a monodentate monoanionic coligand on a [Tc(V)O] +3 precursor. Following this ''mixed ligand'' concept, a novel 99m Tc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethylethylenediamine as ligand and 1-octanethiol as coligand is prepared and evaluated as potential brain radiopharmaceutical. Preparation of the complex at tracer level was accomplished by using 99m Tc-glucoheptonate as precursor. The substitution was optimized and a coligand/ligand ratio of 5 was selected. Under this conditions the labeling yield was over 80% and a major product (with radiochemical purity > 80%) was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium complex as structural model. The Re complex was also prepared by substitution method and isolated as a crystalline product. The crystals were characterized by UV-vis and IR spectra and elemental analysis. Results were consistent with the expected ReOLC structure. X ray crystallographic study demonstrated that the complex adopts a distorted trigonal bipyramidal geometry. The basal plane is defined by the SS atoms of the ligand and the oxo group, while the N of the ligand and the S of the colligand occupy the two apical positions. All sulphur atoms underwent ionization leading to the formation of a neutral compound. 99 Tc complex was also prepared. Although it was not isolated due to the small amount of reagents employed, the HPLC profile was identical to the one observed for the rhenium complex suggesting the same chemical structure. Biodistribution in mice demonstrated early brain uptake, fast blood clearance, excretion through hepatobiliary system and a brain/blood ratio that increased significantly with time. (author)

Formation of Mixed-Ligand Complexes of Metals(II) with Monoamine Complexones and Amino Acids in Solution

Science.gov (United States)

Pyreu, D. F.; Gridchin, S. N.

2018-05-01

The formation of mixed-ligand complexes in the M(II)-Nta, Ida-L (M = Cu(II), Ni, Zn, Co(II), L = Ser, Thr, Asp, Arg, Asn) systems, where Ida and Nta are the residues of iminodiacetic and nitrilotriacetic acids, respectively, is studied using pH measurements, calorimetry and spectrophotometry. The thermodynamic parameters (log K, Δr G 0, Δr H, Δr S) of their formation at 298.15 K and ionic strength I = 0.5 (KNO3) are determined. The most likely scenario of amino acid residue coordination in the composition of mixed complexes is discussed.

Thermophysical properties of ionic liquid, 1-hexyl-3-methylimidazolum bromide + N-N′bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base + N,N-dimethylformamide solutions

International Nuclear Information System (INIS)

Shekaari, Hemayat; Bezaatpour, Abolfazl; Khoshalhan, Maryam

2012-01-01

Highlights: ► Thermodynamic properties of ionic liquids + BPIE Schiff base + DMF were studied. ► There are preferential interactions between ionic liquid and BPIE molecules. ► The nonpolar–nonpolar interactions are dominant interactions between BPIE and ionic liquid. - Abstract: Effect of N-N′bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base on thermodynamic properties of ionic liquid, 1-hexyl-3-methylimidazolium bromide ([HMIm]Br) in N,N-dimethylformamide (DMF) solutions were determined at T = 298.15–313.15 K. The standard partial molar volumes, V φ 0 , partial molar volumes of transfer, Δ tr V φ 0 have been calculated using the measured density data. The cosphere overlap model was used to interpretate the partial molar volumes of transfer, Δ tr V φ 0 . The calculated Hepler's constants, ∂ 2 V φ 0 /∂ 2 T, indicate that the BPIE and ionic liquid have structure-breaking (chaotropic) tendency. Ion association constants, K a , and limiting molar conductivities, Λ 0 , viscosity B-coefficients and molar refractions, R D , have been used to confirm the conclusions obtained from the volumetric properties. The results were interpreted in terms of various solute–solvent interactions occuring in the investigated solutions and indicating an enhancement in the nonpolar–nonpolar interactions between the BPIE Schiff base and the ionic liquid with increasing BPIE concentration.

Effect of lanthanide contraction on the mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien): Syntheses and characterizations of lanthanide complexes with a tetraelenidoantimonate ligand

International Nuclear Information System (INIS)

Zhao Jing; Liang Jingjing; Pan Yingli; Zhang Yong; Jia Dingxian

2011-01-01

Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en) 2 (dien)(η 2 -SbSe 4 )] (Ln=Ce(1a), Nd(1b)), [Ln(en) 2 (dien)(SbSe 4 )] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)(μ-η 1 ,η 2 -SbSe 4 )] ∞ (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)(η 2 -SbSe 4 )] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe 4 ] 3- acts as a monodentate ligand mono-SbSe 4 , a bidentate chelating ligand η 2 -SbSe 4 or a tridentate bridging ligand μ-η 1 ,η 2 -SbSe 4 to the lanthanide(III) center depending on the Ln 3+ ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with E g between 2.08 and 2.51 eV. - Graphical Abstract: Two structural types of lanthanide(III) selenidoantimonates are formed in both en-dien and en-trien mixed polyamines across lanthanide series, indicating the lanthanide contraction effect on the structures of the lanthanide(III) selenidoantimonates. Highlights: → Two structural types of lanthanide selenidoantimonates are prepared across the lanthanide series in both Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) systems. → The [SbSe 4 ] 3- anion acts as a mono-SbSe 4 , a η 2 -SbSe 4 or a μ-η 1 ,η 2 -SbSe 4 ligand to the Ln 3+ ions. → The soft base ligand [SbSe 4 ] 3- can be controlled to coordinate to the Ln 3+ ions with en+dien and en+trien as co-ligands.

Synthesis of .alpha.-Amino Acids via Asymmetric Phase Transfer-Catalyzed Alkylation of Achiral Niclkel(II) Complexes of Glycine-Derived Schiff bases

Czech Academy of Sciences Publication Activity Database

Belokon, Y. N.; Bespalova, N. B.; Churkina, T. D.; Císařová, I.; Ezernitskaya, M. G.; Harutyunyan, S. R.; Hrdina, R.; Kagan, H. B.; Kočovský, P.; Kochetkov, K. A.; Larionov, O. G.; Lysenko, K. A.; North, M.; Polášek, Miroslav; Peregudov, A. S.; Prisyazhnyuk, V. V.; Vyskočil, Š.

2003-01-01

Roč. 125, - (2003), s. 12860-12870 ISSN 0002-7863 R&D Projects: GA ČR GP203/01/D051 Institutional research plan: CEZ:AV0Z4040901 Keywords : .alpha.amino acids * achiral nickel(II) * glycine-derived schiff bases Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.516, year: 2003

Synthesis and Biological Evaluation of New (−-Gossypol-Derived Schiff Bases and Hydrazones

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Vu Van Vu

2017-01-01

Full Text Available A series of 14 new (--gossypol Schiff bases and hydrazones have been synthesized via an in situ procedure in high yields. Structural data showed that all target compounds exist as the enamine tautomer. Bioassays showed that several compounds exhibited cytotoxic effects against three human cancer cell lines. Compound 8a showed the greatest cytotoxic effect against hepatocellular carcinoma (HepG2, lung carcinoma (LU-1, and breast cancer (MCF-7 cell lines with IC50 values of 20.93, 13.58, and 9.40 μM, respectively. However, in an antibacterial test, compounds 8a and 8b inhibited Staphylococcus aureus and Bacillus cereus and compound 8e inhibited only Staphylococcus aureus at the same MIC values of 1024 μg/ml.

A new tridentate Schiff base Cu(II) complex: synthesis, experimental and theoretical studies on its crystal structure, FT-IR and UV-Visible spectra.

Science.gov (United States)

Saheb, Vahid; Sheikhshoaie, Iran; Setoodeh, Nasim; Rudbari, Hadi Amiri; Bruno, Giuseppe

2013-06-01

A new Cu(II) complex [Cu(L)(NCS)] has been synthesized, using 1-(N-salicylideneimino)-2-(N,N-methyl)-aminoethane as tridentate ONN donor Schiff base ligand (HL). The dark green crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FT-IR) and UV-Visible spectra. Electronic structure calculations at the B3LYP and MP2 levels of theory are performed to optimize the molecular geometry and to calculate the UV-Visible and FT-IR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TD-DFT) method is used to calculate the electronic transitions of the complex. A scaling factor of 1.015 is obtained for vibrational frequencies computed at the B3LYP level using basis sets 6-311G(d,p). It is found that solvent has a profound effect on the electronic absorption spectrum. The UV-Visible spectrum of the complex recorded in DMSO and DMF solution can be correctly predicted by a model in which DMSO and DMF molecules are coordinated to the central Cu atom via their oxygen atoms. Copyright © 2013 Elsevier B.V. All rights reserved.

Crystal structures, DFT calculations, and Hirshfeld surface analyses of two new copper(II) and nickel(II) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine

Science.gov (United States)

Seifikar Ghomi, Leila; Behzad, Mahdi; Tarahhomi, Atekeh; Arab, Ali

2017-12-01

Two new Ni(II) and Cu(II) complexes of a tetradentate Schiff base ligand (1 and 2, respectively), derived from the condensation of meso-1,2-diphenyl-1,2-ethylenediamine with 2-hydroxy-6-methoxy benzaldehyde, were synthesized and characterized by IR, UV-Vis, 1H NMR spectroscopy, and X-Ray crystallography. The central metal ions in both complexes are coordinated via the N2O2 coordination sphere of the ligand with square-planar geometry. DFT results revealed that the Msbnd N and Msbnd O interactions (M = Ni, Cu) are weaker than the typical covalent single bond indicating that ionic and electrostatic interactions are dominated in Msbnd N and Msbnd O bonds. Hirshfeld surface (HS) analyses of the studied structures 1 and 2 have been performed. The study using 3D HSs and 2D fingerprint plots (FPs) highlighted the dominant contacts H⋯H, C⋯H/H⋯C and O⋯H/H⋯O in both structures, and H⋯Cl in 2. The molecular assemblies held by C⋯O/O⋯C (in 1) and C⋯C (in 1 and 2) type dipole-dipole interactions are also found in the crystal packing contributing towards stability. The significant contributions arising from the mentioned interactions in crystal packing are also revealed from the Hirshfeld surface FPs showing a major contribution to total HS area for the H⋯H contacts for both structures.

Bis[2-(cyclopentyliminomethyl-5-methoxyphenolato]copper(II

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Xiao-Hui Ji

2010-08-01

Full Text Available The title compound, [Cu(C13H16NO22], is a mononuclear copper(II complex derived from the Schiff base ligand 2-(cyclopentyliminomethyl-5-methoxyphenol and copper acetate. The CuII atom is four-coordinated by the phenolate O atoms and imine N atoms from two Schiff base ligands, in a highly distorted square-planar geometry. The O- and N-donor atoms are mutually trans and the dihedral angle between the two benzene rings is 55.8 (3°.

The hydrophobic substituent in aminophospholipids affects the formation kinetics of their Schiff bases.

Science.gov (United States)

Caldés, Catalina; Vilanova, Bartolomé; Adrover, Miquel; Donoso, Josefa; Muñoz, Francisco

2013-04-01

Schiff bases (SBs) are the initial products of non-enzymatic glycation reactions, which are associated to some diabetes-related diseases. In this work, we used physiological pH and temperature conditions to study the formation kinetics of the SBs of 1,2-dihexanoyl-sn-glycero-3-phosphoethanolamine (DPHE) and 1,2-dihexanoyl-sn-glycero-3-phospho-l-serine (DHPS) with various glycating compounds and with pyridoxal 5'-phosphate (an effective glycation inhibitor). Based on the obtained results, the hydrophobic environment simultaneously decreases the nucleophilic character of the amino group (k1) and increases its pKa, thereby increasing the formation rate of SB (kobs). Therefore, the presence of hydrophobic chains in aminophospholipids facilitates the formation and stabilization of SBs, and also, in a biological environment, their glycation. Additionally, the results confirm the inhibitory action of B6 vitamers on aminophospholipid glycation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of the substitutional groups on the electrochemistry, kinetic of thermal decomposition and kinetic of substitution of some uranyl Schiff base complexes

Czech Academy of Sciences Publication Activity Database

Asadi, Z.; Nasrollahi, R.; Dušek, Michal; Fejfarová, Karla; Ranjkeshshorkaei, M.; Firuzabadi, F.D.

2016-01-01

Roč. 13, č. 5 (2016), 913-924 ISSN 1735-207X R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : Schiff base complex * kinetic study * anticancer activity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.407, year: 2016

New Homologues Series of Heterocyclic Schiff Base Ester: Synthesis and Characterization

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Yee-Ting Chong

2016-01-01

Full Text Available A homologous series of liquid crystal bearing with heterocyclic thiophene Schiff base ester with alkanoyloxy chain (CH3(CH2nCOO–, where n=4, 6, 8, 10, 12, 14, 16 was successfully synthesized through the modification of some reported methods. The structural information of these compounds was isolated and characterized through some spectroscopic techniques, such as FTIR, 1H, and 13C NMR and elemental analysis. Textural observation was carried out using a polarizing optical microscope (POM over heating and cooling cycles. It was found that all synthesized compounds (3a–g exhibited an enantiotropic nematic phase upon the heating and cooling cycle with high thermal stability. Moreover, a characteristic bar transition texture was observed for compounds 3f and 3g which have shown transition of nematic-to-smectic C phase. This has been further confirmed by obtaining relative phase transition temperature using the differential scanning calorimetry (DSC.

Cocomplexation of urea and UO22+ in a Schiff base macrocycle: a mimic of an enzyme binding site

International Nuclear Information System (INIS)

van Staveren, C.J.; Fenton, D.E.; Reinhoudt, D.N.; van Eerden, J.; Harkema, S.

1987-01-01

As part of the authors work on the complexation of neutral molecules by macrocyclic ligands, they are particularly interested in the complexation of urea. They have shown that urea can form complexes with (aza-)18-crown but the association constants of these complexes in water are very small (18-crown-6-urea, log K/sub s/ = 0.1). Protonation of urea effects stronger binding especially when the crown ether is sufficiently large to form an encapsulated complex (e.g., the complex benzo-27-crown-9-urea-HClO 4 ). Protonation of the weakly basic urea (pK/sub a/ = 0.1, water, 25 0 C) requires strongly acidic conditions and to avoid this they have introduced a covalently linked carboxylic group in the cavity of the macrocycle. A strong hydrogen bond of urea with 2-carboxyl-1,3-xylyl-30-crown-9 results in an encapsulated complex. The concept of using an electrophilic center to bind urea in the cavity of a crown ether proved to be a more general concept. A metal cation can serve as the electrophile as was shown by the isolation and single-crystal X-ray analysis of the 2,6-pyrido-27-crown-9-urea-LiClO 4 (1:2:1) complex in which one of the urea molecules is encapsulated. In an effort to bind an electrophilic metal ion in the crown ethers irreversibly they have concentrated their work on macrocycles of type 1, since the strong binding of quadridentate (salen type) Schiff bases with soft metal ions is well-known

A schiff-base receptor based naphthalimide derivative: Highly selective and colorimetric fluorescent turn-on sensor for Al{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Kang, Lei; Liu, Ya-Tong; Li, Na-Na; Dang, Qian-Xi [Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030 (China); Xing, Zhi-Yong, E-mail: zyxing@neau.edu.cn [Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030 (China); Li, Jin-Long; Zhang, Yu [College of Heilongjiang Province Key Laboratory of Fine Chemicals, Qiqihar University, Qiqihar 161006 (China)

2017-06-15