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1.
Biologically active triazole Schiff bases ( L 1 L 3 ) derived from the reaction of 3‐amino‐1,2,4‐triazole with chloro‐, bromo‐ and nitro‐ substituted salicylaldehydes and their Zn(II) complexes (1–3) have been synthesized and characterized by their physical, spectral and analytical data. Triazole Schiff bases potentially act as tridentate ligands and coordinate with the Zn(II) metal atom through salicylidene‐O, azomethine‐N and triazole‐N. The complexes have the general formula [M(L‐H)2], where M = zinc(II) and L = ( L 1 – L 3 ), and observe an octahedral geometry. The Schiff bases and their Zn(II) complexes have been screened for in‐vitro antibacterial, antifungal and brine shrimp bioassay. The biological activity data show the Zn(II) complexes to be more potent antibacterial and antifungal than the parent simple Schiff bases. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
2.
Prakash Gouda Avaji Sangamesh A. Patil Prema S. Badami 《Transition Metal Chemistry》2008,33(3):275-283
A series of Co(II) complexes have been synthesized with Schiff bases derived from 3-substituted-4-amino-5-hydrazino-1,2,4-triazole
and substituted salicylaldehydes. These complexes are insoluble in water but more soluble in DMF and DMSO. The complexes have
been characterized by elemental analyses, spectral (IR, UV–Vis, 1H-NMR, FAB-mass, fluorescence), magnetic, thermal, solid-state DC electrical conductivity and molar conductance data. The
molar conductivity values indicate that they are non-electrolytes. The elemental analyses of the complexes suggest a stoichiometry
of the type Co · L1–L16 · 2H2O. The complexes have been considered as semiconductors on the basis of the solid-state DC electrical conductivity data.
Fluorescence spectra of one Schiff base and its complex were investigated in various solvents and some of the Schiff bases
and their complexes were evaluated for their antimicrobial activities. 相似文献
3.
Ravindra V. Patel Jayesh G. Panchal Shobhana K. Menon 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):63-71
The binuclear Co(II) complexes of calix[4]arene substituted 2-vanillin (R1) and 2-hydroxy naphthaldimine (R2), Schiff bases (Co2L1 and Co2L2) have been synthesized, characterized and employed as models to mimic monooxygenase in the catalytical oxidation of olefins. The kinetic mathematical model (oxygen rebound mechanism) for olefin cleavage catalyzed by the complexes has been proposed. The results show that, compared to the calix[4]arene-free analogous, the mono and multinuclear complexes of calix[4]arene Schiff bases as catalyst exhibit high activity in the olefin catalytic oxidation. 相似文献
4.
L. D. Popov S. A. Borodkin I. N. Shcherbakov Yu. N. Tkachenko V. A. Kogan 《Russian Journal of General Chemistry》2008,78(4):567-574
A series of new Schiff bases has been synthesized on the basis of (2-aminophenyl)triphenyl-phosphonium chloride and substituted salicylaldehydes. The structure of the prepared compounds has been established by means of IR, UV, and 1H NMR spectroscopy, as well as DFT B3LYP/6-31G(d,p) quantum-chemical simulation. The possible tautomerism and certain properties of the azomethines, including complex formation, have been studied. 相似文献
5.
《Journal of Saudi Chemical Society》2014,18(3):190-199
In the present study two new series of Copper(II), Nickel(II) and Cobalt(II) complexes with two newly synthesized Schiff base ligands 4,6-bis(1-(4-bromophenylimino)ethyl)benzene-1,3-diol (H2L1), 4,6-bis(1-(4-methoxyphenylimino) ethyl)benzene-1,3-diol (H2L2) and organic ligands 8-hydroxy quinoline, 1,10-phenanthroline have been prepared. The Schiff bases H2L1 and H2L2 ligands were synthesized by the condensation of 4,6-diacetyl resorcinol with 4-bromo aniline and 4-methoxy aniline. The ligands and their metal complexes have been characterized by FT-IR, Mass, 1H NMR, UV–Vis., elemental analysis, ESR and Thermal gravimetric analysis. The Schiff base and their metal complexes were tested for antimicrobial activity against gram positive bacteria Staphylococcus aureus, Streptococcus pyogenes and gram negative bacteria Escherichia coli, Pseudomonas aeruginosa and fungus Candida albicans, Aspergillus niger and Aspergillus clavatus using Broth Dilution Method. 相似文献
6.
E. İspir 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):3160-3174
Two novel Schiff base ligands, 4-((3-(trimethoxysilyl)propylimino)methyl)benzene– 1,2,3-triol (L1H) and 4-((3-(triethoxysilyl)propylimino)methyl)benzene–1,2,3-triol (L2H), have been synthesized by the reaction of 2,3,4-trihydroxybenzaldehyde with 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane, respectively. The mononuclear CoII and CuII complexes of these Schiff bases were prepared. The complexes of the Schiff bases are formed by coordination of N, O atoms of the ligands. The proposed structures were confirmed by elemental analyses, FT-IR, and UV-visible spectroscopy, magnetic susceptibility, and conductance measurements; the 1H NMR spectra of the ligands were also recorded. The analytical data show that the metal to ligand ratio in the complexes containing silicon is 1:2. The electrochemical properties of the complexes have been investigated at 100 mVs?1 scan rate in DMSO. In addition, the antimicrobial activity of L1H and L2H Schiff ligands, and their [M(L1)2] and [M(L2)2] type coordination compounds, were investigated. 相似文献
7.
Santanu Mandal Tinku Sen Uttam Mandal Dipankar Bhunia Corrado Rizzoli 《Journal of Coordination Chemistry》2019,72(22-24):3614-3624
AbstractFour new mononuclear Schiff base manganese(III) and cobalt(III) complexes viz. [Mn(L1)(NCS)] (1), [Mn(L2)(NCS)] (2), [Co(L3)(NCS)] (3), and [Co(L4)(NCS)]·0.5CH3OH·0.5H2O (4), containing thiocyanate as a common pseudohalide ion are reported. The pentadentate Schiff base ligands H2L1, H2L2, H2L3, and H2L4 were obtained by the condensation of substituted salicylaldehydes with N-(3-aminopropyl)-N-methylpropane-1,3-diamine. The syntheses of the complexes have been achieved by the reaction of manganese(II) perchlorate or cobalt(II) perchlorate with the respective Schiff bases in the presence of thiocyanate in methanol medium. Complexes 1–4 have been characterized by microanalytical, spectroscopic, single-crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1–4 adopt nearly similar structures containing the MN4O2 (M?=?Mn, Co) chromophore in which each central M(III) ion adopts a distorted octahedral geometry. Weak intermolecular H-bonding interactions are operative in these complexes to bind the molecular units. The antibacterial activity of 1–4 and their constituent Schiff bases has been tested against some common bacteria. 相似文献
8.
Summary Many new oxomolybdenum(V) and dioxomolybdenum(VI) complexes have been synthesized with tri- and tetradentate Schiff bases derived by the condensation of salicylaldehyde, thiosalicylaldehyde,o-hydroxyacetophenone, 3-carboxysalicyclaldehyde or acetylacetone with aminoalcohols, polymethylenediamines ando-phenylenediamines. Mononuclear oxothiolato Schiff base complexes of molybdenum(V) have been prepared for the first time. Quadridentate Schiff bases derived from salicylaldehyde and substituted salicylaldehydes ando-phenylenediamine have also been successfully employed to isolate dioxomolybdenum(VI) complexes in the solid state, in which two oxygen atoms of the MoO2 group arecis- to each other, similar to the situation observed for other dioxomolybdenum(VI) complexes of salicylaldehyde-polymethylenediamine Schiff base ligands.Structures have been determined with the help of elemental analyses, magnetic susceptibilities, molar conductances, i.r., electronic and1H n.m.r. spectral data.For Part IX, K. Dey, R. K. Maiti and J. K. Bhar,Indian J. Chem., in press. 相似文献
9.
2‐Ethoxy carbonylcyclopentanone (1) has been brominated to yield 2‐bromo‐2‐ethoxy carbonylcyclopentanone (2) which on further reaction with substituted thiosemicarbazones, thiocarbohydrazones, thiocarbamides and carbamides has furnished 1 ‐ thia‐3,4‐diaza‐5,7‐dioxo‐2‐[(substituted benzylidine)‐amino]spiro[4.5]dec‐2‐ene (3a–e) , 1‐thia‐3,4‐diaza‐5,7‐dioxo‐2‐[(substituted benzylidine)‐hydrazino] spiro[4.5]dec‐2‐ene (4a–e) , 1‐thia‐3‐aza‐2‐(substituted imino)‐4,6‐dioxo‐spiro[4.4]nonane (5a–f) and 1‐oxa‐3‐aza‐2‐(substituted imino)‐4,6‐dioxo‐spiro[4.4]nonane (6a–g) respectively. The structures of the compounds have been elucidated on the basis of spectral analysis. 相似文献
10.
The Schiff bases derived from 3,4-dimethyl-Δ3-tetrahydrobenzaldehyde or 4,6-dimethyl-Δ3-tetrahydrobenzaldehyde and glycine and their complexes with nickel (II) and copper (II) were synthesized and investigated.
All compounds were characterized by elemental analyses, conductivity measurements, and FT-IR spectroscopy. The Schiff base
ligands and their complexes were further characterized by 1H NMR. The results suggest that the Schiff base acts as a bidentate ligand, which bonds to the metal ions through the imino
nitrogen and carboxylate oxygen. The potassium salts of the Schiff bases are 1 : 1 electrolytes but all the complexes are
nonelectrolytes.
The article was submitted by the authors in English. 相似文献
11.
Shiwani Berry Shamsher S. Bari Pooja Yadav Ankita Garg Sadhika Khullar Sanjay K. Mandal 《合成通讯》2020,50(19):2969-2980
Abstract An efficient protocol for the stereoselective synthesis of pyrazolo[5,1-b]thiazole-3-carboxylate tethered β-lactam conjugates 8a–j from novel pyrazolo [5,1-b]thiazole-3-carboxylate substituted Schiff’s bases 6a–f is reported here. The reaction between various ketene precursors and novel Schiff’s bases 6a–f afforded exclusive formation of trans-β-lactams 8a–j. The substrate scope of this approach was investigated extensively by varying different groups (R, Z). All the novel compounds were characterized using various spectroscopic techniques, such as FT-IR, 1H NMR, 13C NMR, elemental analysis, 13C NMR (DEPT-135), and mass spectrometry in representative cases. Single crystal X-ray crystallographic study of trans-ethyl 7-(1-(4-methoxyphenyl)-4-oxo-3-phenoxyazetidin-2-yl)-6-methyl-2-(methylthio)pyrazolo[5,1-b]thiazole-3-carboxylate 8a has confirmed the molecular structure and the stereochemical outcome. To the best of our knowledge, the synthesis of such types of Schiff’s bases and β-lactam conjugates has not been reported so far. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(2):274-286
Cu(II) complexes with Schiff bases DMIIMP, DMIIMBD, DMIIMBP, DMIIMCP, DMIIMMP, and DMIIMNP (see Introduction for definitions) are derived from condensation of 3,4-dimethyl 5-amino-isoxazole with salicylaldehyde and substituted salicylaldehydes. The newly synthesized ligands were characterized by IR, UV-Vis, 1H NMR, 13C NMR, mass spectra, and elemental analysis. The Cu(II) complexes were characterized by IR, UV-Vis, ESR, elemental analysis, magnetic moments, thermogram, DTA, and single crystal analysis. The complexes have general formula [M(L)2]. The Schiff bases are bidentate coordinating through the azomethine nitrogen and phenolic oxygen of salicylaldehydes. Based on the analytical and spectral data, four-coordinate geometry is assigned for all the complexes. ESR and single crystal analysis suggests square planar geometry for all complexes. [Cu(DMIIMP)2] crystallizes in the orthorhombic system. Antimicrobial studies of Schiff bases and their metal complexes show significant activity with the metal complexes showing more activity than corresponding Schiff bases. Cytotoxicity of the copper complexes on human cervical carcinoma cells (HeLa) was measured using the Methyl Thiazole Tetrazolium assay. 相似文献
13.
Venkatesh K. Pandey Kalpana Chaturvedi Ruchi Chandra Om P. Pandey Soumitra K. Sengupta 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):1401-1408
Abstract A series of biologically active organophosphorus compounds have been synthesized by the reactions of O,O-diethylchlorophosphate with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-oxadiazole and salicylaldehyde/2-hydroxyacetophenone. The compounds have been characterized on the basis of analyses and spectral (IR, 1H, 13C NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum, and Curvularia pallescence have been evaluated. All compounds showed moderate to significant antifungal activity. 相似文献
14.
New metal based triazoles (1–12) have been synthesized by the interaction of novel Schiff base ligands (L1–L3) with the Co(II), Ni(II), Cu(II) and Zn(II) metal ions. The Schiff base ligands and their all metal(II) complexes have been thoroughly characterized using various physical, analytical and spectroscopic techniques. In vitro bacterial and fungal inhibition studies were carried out to examine the antibacterial and antifungal profile of the Schiff bases in comparison to their metal(II) complexes against two Gram‐positive, four Gram‐negative and six fungal strains. The bioactivity data showed the metal(II) complexes to have more potent antibacterial and antifungal activity than their uncomplexed parent Schiff bases against one or more bacterial and fungal species. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
15.
Two novel Schiff bases, 4,4′-methylenedianilidene-bis(3-methoxy-4-hydroxy-benzaldehyde) (L1) and 4,4′-methylenedianilidene-bis(3,4-dimethoxybenzaldehyde) (L2), have been prepared by condensing 4,4′-methylenedianiline (MDA) with vanillin and 3,4-dimethoxybenzaldehyde (DMB) respectively
in ethanolic medium. Metal complexes of the above Schiff bases are prepared from salts of Cu(II), Zn(II), Co(II) and VO(IV).
They are characterized by elemental analysis, molar conductivity, magnetic moment measurements, IR, 1H NMR, UV-Vis., FAB Mass, and EPR spectra. The elemental analysis data exhibit the formation of 1: 1 [M: L] ratio. The mode
of bonding and the geometry of the complexes have been confirmed on the basis of IR, UV-Vis. and magnetic moment measurements.
These data reveal a square-planar geometry for all the complexes except VO(IV) which has square-pyramidal geometry. The molar
conductance measurements of the Schiff base complexes reveal the existence of non-electrolytic nature. The interactions of
complexes with calf thymus DNA (CT-DNA) have been investigated by electronic absorption spectroscopy, viscosity measurements
and cyclic voltammetry. The results indicate that the complex can bind to DNA by intercalation modes. The Schiff bases and
their metal complexes have been evaluated for their antifungal and antibacterial activities against different species of pathogenic
fungi and bacteria and their results are compared with standard drugs. 相似文献
16.
《应用有机金属化学》2018,32(3)
Electrochemical transformations and antioxidant activity of some Schiff bases 1 – 5 containing ferrocenyl group and (thio‐)phenol, catechol fragments were investigated. Compounds under investigation are: 2‐(ferrocenylmethylene)amino)phenol ( 1 ), 2‐((ferrocenylmethylene)amino)‐4,6‐di‐tert‐butylphenol ( 2 ), 2‐((ferrocenylmethylene)amino)‐thiophenol ( 3 ), 3‐((ferrocenylmethylene)hydrazonomethyl)‐4,6‐di‐tert‐butylcatechol ( 4 ) and 2‐((3,5‐di‐tert‐butyl‐4‐hydroxybenzylidene)amino)thiophenol ( 5 ). In a case of compounds 1 – 3 it has shown that the sequence of electrochemical transformations leads to the products of intramolecular cyclization – 2‐ferrocenylbenzoxazole (benzothiazole). o‐Quinone formation occurs during the electrochemical oxidation of catechol‐ferrocene 4 at the first anode stage. Electrochemical oxidation of the redox‐active fragments in Schiff bases 1–4 can be achieved indirectly at a lower potential corresponding to the oxidation of ferrocenyl moiety, consequently these substances can reveal more pronounced antioxidant properties. The antioxidant activities of the compounds were evaluated using 2,2′‐diphenyl‐1‐picrylhydrazyl radical (DPPH) assay, the reaction of 2,2′‐azobis(2‐amidinopropane hydrochloride) (AAPH) induced glutathione depletion (GSH), the oxidative damage of the DNA, the process of lipid peroxidation of rat (Wistar) brain homogenates in vitro. The compounds 1–4 in the antioxidant assays show effectiveness comparable with standard antioxidants (vitamin E, Trolox) and in some parameters superior to them. In the reaction of AAPH with the glutathione compounds 2–5 have a more pronounced protective activity than Trolox. Compounds 1–5 inhibit AAPH induced oxidation damage of the DNA. The more effective inhibitors of the lipid peroxidation process in vitro are molecules containing the bulky tert‐butyl groups: 2 and 4 and Schiff base 3 . 相似文献
17.
18.
Stable ruthenium(II) complexes of Schiff bases have been prepared by reacting [RuHCl(CO)(PPh3)2(B)] (B = PPh3, pyridine or piperidine) with bis(o-vanillin)ethylenediimine (valen), bis(o-vanillin)propylene-diimine (valpn), bis(o-vanillin)tetramethylenediimine (valtn), bis(o-vanillin)o-phenylenediimine (valphn), bis(salicylaldehyde)tetramethylenediimine (saltn) and bis(salicylaldehyde)o-phenylenediimine (salphn). These complexes have been characterised by elemental analyses, i.r., electronic, 1H- and 31P{1H}-n.m.r. spectral studies. In all the above reactions, the Schiff bases replace two molecules of Ph3P, a hydride and a halide ion from the starting complexes, indicating that the Ru–N bonds present in the complexes containing heterocyclic nitrogen bases are stronger than the Ru–P bond to Ph3P. The new complexes of the general formula [Ru(CO)(B)(L)] (B = PPh3, py or pip; L = tetradentate Schiff bases) have been assigned an octahedral structure. Some of the Schiff bases and the new complexes have been tested against the pathogenic fungus Fusarium sp. 相似文献
19.
G. A. Gamov V. V. Aleksandriiskii M. N. Zavalishin A. Yu. Khokhlova V. A. Sharnin 《Russian Journal of General Chemistry》2017,87(6):1161-1166
The interaction of pyridoxal-5-phosphate with 3-methyl-1Н-pyrazole-5-carbohydrazide, 2-(3,5-dimethyl-1Н-pyrazol-4-yl)acetohydrazide, and 1Н-pyrazole-3-carbohydrazide has yielded Schiff bases; the products have been characterized by 1Н NMR and IR spectra. The binding ability of these pyrazoles with respect to pyridoxal-5-phosphate under conditions modeling the living tissues has been evaluated. Rate constants of the formation of the Schiff bases have been determined. 相似文献
20.
Singh AK Pandey OP Sengupta SK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2012,85(1):1-6
New Zn(II) complexes have been synthesized by the reactions of zinc(II) acetate with Schiff bases derived from 3-substituted phenyl-4-amino-5-hydrazino-1, 2, 4-triazole and benzaldehyde, 2-hydroxyacetophenone or indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non-electrolytes. Elemental analyses suggest that the complexes have 1:1 stoichiometry of the type [ZnL(H(2)O)(2)], [ZnL'(OAc)(2)(H(2)O)(2)] (L=dianionic Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1, 2, 4-triazole and 2-hydroxyacetophenone or indoline-2,3-dione; L'=neutral Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1, 2, 4-triazole and benzaldehyde) and they were characterized by FT-IR, (1)H NMR, (13)C NMR and FAB mass. All these Schiff bases and their complexes have also been screened for their antibacterial activities against Bacillus subtilis, Escherichia coli and antifungal activities against Colletotrichum falcatum, Aspergillus niger, Fusarium oxysporium and Carvularia pallescence by petriplates methods. 相似文献