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1.
《Journal of Coordination Chemistry》2012,65(11):1696-1709
Four heterocyclic Schiff-base ligands derived from condensation of 4-amino-1,3 dimethyl-2,6 pyrimidine-dione with 2-hydroxybenzaldehyde, 2-methoxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde and 4-(dimethylamino) benzaldehyde, (HL1, L2, HL3and L4), respectively, and their Co(II) and Ni(II) complexes have been prepared and characterized via elemental analysis, molar conductance, magnetic moment, thermal and XRPD analysis as well as spectral data (IR, 1H-NMR, mass and solid reflectance). IR data reveal that the ligands are bidentate neutral ligands except HL1, which is monobasic tridentate with coordination sites azomethine (N), carbonyl (O) and phenolic (O). Conductance data suggest that all complexes are non-electrolytes, except cobalt(II) complexes of L2and HL3are 1 : 1 electrolytes. The mass spectra confirm the proposed structure of the ligands and their complexes. The solid reflectance spectral data and magnetic moment measurements suggest octahedral, tetrahedral and square planar geometrical structures for the metal complexes. The spectral data were utilized to compute the important ligand field parameters B, β and Dq; LFSE also was calculated. The thermal behavior is also studied. Antibacterial and antifungal properties of the ligands and their complexes show broad-spectrum activities and the metal complexes show higher activity than the free ligands. 相似文献
2.
Gabrijela Brađan Andrej Pevec Iztok Turel Igor N. Shcherbakov Milica Milenković Marina Milenković 《Journal of Coordination Chemistry》2016,69(18):2754-2765
Isothiocyanate complexes of Zn(II) and Cd(II) with the condensation product of 2,6-diacetylpyridine and trimethylammoniumacetohydrazide (Girard’s T reagent) were synthesized, characterized, and their antimicrobial activities were evaluated. The structures of the complexes were determined by elemental analysis, IR, and NMR spectroscopy. The crystal structure of the Zn(II) complex was also determined. Quantum-chemical calculations of the geometry and total energy of isomers of 2,6-diacetylpyridine-bis(trimethylammoniumacetohydrazone) were performed in vacuum and methanol solution, with the aim to explain conformational behavior and E/Z isomerism of this compound. DFT calculations of the molecular structures and the relative stabilities of linkage isomers of the Cd(II) complex showed that the isomer with N–Cd–N coordination of SCN? is the most stable. Complexes of Zn(II) and Cd(II) exhibited low to moderate activity against the tested microbial strains. 相似文献
3.
《Journal of Coordination Chemistry》2012,65(24):4411-4420
The 12- and 14-membered diazadioxo macrocyclic ligands, 1,2?:?7,8-diphenyl-6,9-diaza-3,12-dioxocyclododecane (L1) and 1,2?:?8,9-diphenyl-7,10-diaza-3,14-dioxocyclotetradecane (L2), were synthesized by condensation between o-phenylenediamine, 1,2-dibromoethane/1,3-dibromopropane, and catechol. Metal complexes [ML1Cl2] and [ML2Cl2] [M?=?Co(II), Ni(II), Cu(II), and Zn(II)] were prepared by interaction of L1 or L2 with metal(II) chlorides. The ligands and their complexes were characterized by elemental analyses, IR, 1H, and 13C NMR, EPR, UV-Vis spectroscopy, magnetic susceptibility, conductivity measurements, and Electrospray ionization-mass spectral (ESI-MS) studies. The results of elemental analyses, ESI-MS, Job's method, and conductivity measurements confirmed the stoichiometry of ligands and their complexes while absorption bands and resonance peaks in IR and NMR spectra confirmed the formation of ligand framework around the metal ions. Stereochemistry was inferred from the UV-Vis, EPR, and magnetic moment studies. 相似文献
4.
Satish M. Annigeri M. P. Sathisha Vidyanand K. Revankar 《Transition Metal Chemistry》2007,32(1):81-87
Binuclear cobalt(II), nickel(II), copper(II) and zinc(II) complexes of general composition [M2L1-2(μ-Cl)Cl2] · nH2O with the Schiff-base ligands (where L1H and L2H are the potential pentadentate ligands derived by condensing 2,6-diformyl-4-methylphenol with 4-amino-3-antipyrine and 2-hydroxy-3-hydrazinoquinoxiline,
respectively) have been synthesized and characterized. Analytical and spectral studies support the above formulation. 1H-NMR and IR spectra of the complexes suggest they have an endogenous phenoxide bridge, with chloride as the exogenous bridge
atom. The electronic spectra of all the complexes are well characterized by broad d–d and a high intensity charge-transfer
transitions. The complexes are chloro-bridged as evidenced by two intense far-IR bands centered around 270–280 cm−1. Magnetic susceptibility measurements show that complexes are antiferromagnetic in nature. The compounds show significant
growth inhibitory activity against fungi Aspergillus niger and Candida albicans and moderate activity against bacteria Bacillus cirroflagellosus and Pseudomonas auresenosa. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(12):1917-1926
Tridentate Schiff-base ligands derived from condensation of 3-formyl-4-hydroxybenzyl-triphenylphosphonium chloride with glycine, L-alanine, L-valine, L-leucine and L-phenylalanine in the presence of Zn(OAc)2 · 2H2O form five new water-soluble Zn(II) complexes, which were characterized by elemental analyses, IR, electronic absorption and 1H, 13C NMR spectroscopies. In the IR spectra of the complexes, the difference between the asymmetric and the symmetric carboxylate stretching frequencies is larger than ~210 cm?1, which implies that the carboxylate groups are monodentate. UV-Vis electronic absorption studies show that Zn(II) functions as a trap for the Schiff-base intermediate. Schiff-base complexes formation were confirmed by the appearance of new signals in the 1H NMR for the azomethine hydrogen at ~8 ppm and condensed L-amino acids at 3.4–3.8 ppm (C(3)–H). These complexes are formed through coordination of the ONO from the carboxyl, imino and phenoxy groups of the ligands to Zn(II). 相似文献
6.
Co(II), Ni(II), Cu(II) and Zn(II) complexes of isatinyl‐2‐aminobenzoylhydrazone: synthesis,characterization and anticancer activity
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Rekha S. Hunoor Basavaraj R. Patil Dayananda S. Badiger Chandrashekhar V. M. I. S. Muchchandi Kalagouda B. Gudasi 《应用有机金属化学》2015,29(2):101-108
This article describes the synthesis, structural aspects and biological studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of a new hydrazone derived from the condensation of isatin and 2‐aminobenzoylhydrazide. The ligand is well characterized using 1H NMR, 13C NMR, 2D HETCOR, mass and IR spectral studies. The chelating tendency of the ligand towards transition metal ions is established using analytical and spectral studies, which reveal the monobasic tridentate nature of the ligand. Octahedral geometry for Co(II), Cu(II) and Zn(II) and tetrahedral geometry for Ni(II) are tentatively proposed. All the synthesized compounds were screened for in vitro anticancer activity against Ehrlich ascites carcinoma and human cancer cell lines (adenocarcinoma HT29, kidney cancer cell line K293 and breast cancer cell line MDA231) using tryphan blue exclusion method and MTT assay. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
7.
Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) have been synthesised using a Schiff base formed by the condensation
of o-phenylenediamine with acetoacetanilide in alcohol medium. All the complexes were characterised on the basis of their
microanalytical data, molar conductance, magnetic susceptibility, IR, UV-Vis1H NMR and ESR spectra. IR and UV-Vis spectral data suggest that all the complexes are square-planar except the Mn(II) and
VO(II) chelates, which are of octahedral and square pyramidal geometry respectively. The monomeric and neutral nature of the
complexes was confirmed by their magnetic susceptibility data and low conductance values. The ESR spectra of copper and vanadyl
complexes in DMSO solution at 300 K and 77 K were recorded and their salient features are reported. 相似文献
8.
In this study, two novel Schiff base ligands (L1 and L2) derived from condensation of methyl 2-amino-6-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate and methyl 2-amino-6-phenyl-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate, both starting matter with 5-bromo-salicylaldehyde, and their Zn(II) and Ni(II) metal complexes have been prepared using a molar ratio of ligand:metal as 1:1 except the Ru(II) complexes 1:0.5. The structures of the obtained ligands and their metal complexes were characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, UV–vis, thermal analysis methods, mass spectrometry, and magnetic susceptibility measurements. Antioxidant and antiradical activity of Schiff base ligands and their metal complexes were been evaluated in vitro tests. Antioxidant activities of metal complexes generally were more effectives than free Schiff bases. 1c and 2c were used as catalysts for the transfer hydrogenation (TH) of ketones. 1c, 2c complexes were found to be efficient catalyst for transfer hydrogenation reactions. 相似文献
9.
《Journal of Coordination Chemistry》2012,65(11):1730-1743
1-S-Methylcarbodithioate-4-substituted thiosemicarbazides (L1-L3) have been prepared and confirmed by spectral data and elemental analysis. Co(II), Ni(II), Cu(II), Cd(II) and Zn(II) complexes with L1-L3 have been prepared and characterized by elemental and thermal analyses, molar conductance, magnetic moment, as well as spectral data (IR, 1H NMR, mass and electronic spectra). The molar conductance data reveal that the chelates are non-electrolytes. The IR and 1H NMR spectra showed that L1-L3 are deprotonated in the complexes and act as binegative SNNS donors. The electronic spectra of the complexes as well as their magnetic moments provide information about geometries. Thermogravimetric analysis of some complexes suggests different decomposition steps and ending with metal sulfide as final product. The redox properties of the complexes are explored by cyclic voltammetry. 相似文献
10.
New complexes of Co(II), Ni(II), Cu(II), and Zn(II) with new Schiff bases derived by the condensation of p-aminoacetophenoneoxime with 5-methoxysalicylaldehyde are synthesized. The compounds are characterized by elemental analyses, magnetic susceptibility measurements, IR, 1H and 13C NMR spectra, electronic spectral data, and molar conductivity. The thermal stabilities of the compounds are also reported. The Schiff base acts as bidentate O,N-donor atoms, and their metal complexes are supposed to possess a tetrahedral geometry with respect to the central metal ion. The general formula of the 5-methoxysalicyliden-p-aminoacetophenoneoxime Co(II), Ni(II), Cu(II), and Zn(II) complexes is Co(L)2, Ni(L)2, Cu(L)2, and Zn(L)2. 相似文献
11.
Mishra L Bindu K Bhattacharya S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(5):807-813
2,6-Diacetylpyridine and 1,2-diaminoethane in the presence of copper(II) and zinc(II) chlorides containing a few drops of acetic acid were condensed into compositions [CuLH2]2.2HCl.H2O (1), [Cu2LPyz]2.2HCl.4CH3COCH3 (2) [CuZnLPyz]2.2HCl.2CH3COCH3.10H2O (3) and [ZnL'Cl]3.3HCl.3H2O (4) substantiated by elemental analyses, IR, UV-vis, 1H NMR and FAB mass spectral data. Demetallation of a Ni(II) complex (isolated as above) afforded macrocyclic skeleton LH4, whereas L' symbolizes a skeleton of the ligand containing only ethylenediamine and 2,6-diacetylpyridine. Molecular structure optimization using MM2 force field calculations for the complexes revealed distorted square pyramidal geometry around Cu(II) centers in complexes 1 and 2 and tetrahedral geometry around Cu(II) and Zn(II) centers with different degrees of distortion in complex 3 whereas three Zn(II) atoms (each in distorted square pyramidal geometry) attached via Cl bridges form a cyclic structure in complex 4. In complexes 1 and 2,Cu-Cu = 2.63-2.66 angstroms indicated the possibility of coupling between the two Cu(II) centers which has been supported by lower magnetic moment as well as ESR spectra showing half-field signal. 相似文献
12.
Małgorzata T. Kaczmarek Izabela Pospieszna-Markiewicz Wanda Radecka-Paryzek 《Journal of inclusion phenomena and macrocyclic chemistry》2004,49(1-2):115-119
The template reaction of 2,6-diacetylpyridine with biogenic diamine–putrescine in the presence of cadmium(II), mercury(II) or lead(II) ions produces the complexes of 22-membered macrocyclic ligand L1 with an N6 set of donor atoms as a result of [2 + 2] Schiff base cyclocondensation. The lead(II) complex containing Schiff base acyclic ligand L2 terminated by one carbonyl and one amine group as product of the partial [2 + 2] condensation has been also isolated and might be regarded as possible intermediate in the formation of the macrocyclic L1 complex. Analogous reaction involving the uranyl nitrate generates the complex containing the same Schiff base acyclic ligand L2 as a final product of template reaction. The complexes were characterized by spectral data (IR, 1H NMR, FAB-MS), thermogravimetric and elemental analyses. A notable feature of the FAB mass spectrum of the uranyl complex is the appearance of the clusters of the form [(UO2) n O]+(n= 1–7) along with the peak corresponding to molecular ion. 相似文献
13.
Synthesis,spectroscopic, thermal analyses,biological activity and molecular docking studies on mixed ligand complexes derived from Schiff base ligands and 2,6‐pyridine dicarboxylic acid
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Two novel Schiff base ligands (La and Lb) were prepared from the condensation of quinoline 2‐aldehyde with 2‐aminopyridine (ligand La) and from the condensation of oxamide with furfural (ligand Lb). Mixed ligand complexes of the type M+2La/b Lc were prepared, where (La and Lb) the primary ligands and Lc was 2,6‐pyridinedicarboxylic acid as secondary ligand. Metal ions used were Fe(II), Co(II), Ni(II) and Zn(II) for mixed ligands La Lc and Fe(II), Co(II), Ni(II), Cu(II), Hg(II) and Zn(II) for LbLc mixed ligands. La and Lb Schiff base ligands were both characterized using elemental analyses, molar conductance, IR, 1H and 13C NMR. Mass spectra for Lb, [Zn(La)LcCl]Cl and [Cu(Lb)LcCl]Cl were also studied. ESR spectrum of the [Cu(Lb) LcCl]Cl complex was also recorded The metal complexes were synthesized and characterized using elemental analyses, spectroscopic (IR, 1H NMR, UV‐visible, diffused reflectance), molar conductance, magnetic moment and thermal studies. The IR and 1H NMR spectral data revealed that 2,6‐pyridinedicarboxalic acid ligand coordinated to the metal ions via pyridyl N and carboxylate O without proton displacement. In addition, the IR data showed that La and Lb ligands behaved as neutral bidentate ligands with N2 donation sites (quinoline N and azomethine N for La and two azomethine N for Lb). Based on spectroscopic studies, an octahedral geometry was proposed for the complexes. The thermal stability and degradation of the metal complexes were investigated by thermogravimetric analysis. The binding modes and affinities of La, Lb and Zn(II) complexes towards receptors of crystal structure of E. coli (PDB ID: 3 t88) and mutant oxidoreductase of breast cancer (PDB ID: 3 hb5) receptors were also studied. The antimicrobial activity against two species of Gram positive, Gram negative bacteria and fungi were tested for the Schiff base ligands, 2,6‐pyridinedicarboxylic acid and the mixed ligand complexes and revealed that the synthesized mixed ligand complexes exhibited higher antimicrobial activity than their free Schiff base ligands. 相似文献
14.
《Journal of Coordination Chemistry》2012,65(16):2736-2744
New Mannich bases bis(thiosemicarbazide methyl) phosphinic acid H3L1 and bis(1-phenylsemicarbazide methyl) phosphinic acid H3L2 were synthesized from condensation of phosphinic acid and formaldehyde with thiosemicarbazide and 1-phenylsemicarbazide, respectively. Monomeric complexes of these ligands, of general formula K2[CrIII(L n )Cl2], K3[FeII(L1)Cl2], K3[MnII(L2)Cl2], and K[M(L n )] (M = Co(II), Ni(II), Cu(II), Zn(II) or Cd(II); n = 1, 2) are reported. The mode of bonding and overall geometry of the complexes were determined through IR, UV-Vis, NMR, and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, and conductance. These studies revealed octahedral geometries for the Cr(III), Mn(II), and Fe(II) complexes, square planar for Co(II), Ni(II), and Cu(II) complexes and tetrahedral for the Zn(II) and Cd(II) complexes. Complex formation via molar ratio in DMF solution has been investigated and results were consistent to those found in the solid complexes with a ratio of (M : L) as (1 : 1). 相似文献
15.
H. Keypour H. Khanmohammadi K. P. Wainwright M. R. Taylor 《Journal of the Iranian Chemical Society》2004,1(1):53-64
Three new pendant arm Schiff-base macrocyclic complexes, [CdLn]2+ (n = 5, 6, 7), have been prepared via cyclocondensation of 2,6-diacetylpyridine with three different branched hexaamines in the presence of Cd(II). The ligands are 15-, 16- and 17-membered pentaaza macrocycles having two 2-aminoethyl pendant arms [L5 = 2,13-dimethyl-6,9-bis(aminoethyl)-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene, L6 = 2,14-dimethyl-6,10-bis(aminoethyl)-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca-1(19),2,13,15,17-pentaene and L7 = 2,15-dimethyl-6,11-bis(aminoethyl)-3,6,11,14,20-pentaazabicyclo[14.3.1]eicosa-1(20),2,14,16,18-pentaene]. All complexes were investigated by IR, 1H and 13C NMR, COSY(H,H) and HETCOR(H,C) spectroscopy and X-ray diffraction. In the solid state structure of each complex the Cd(II) ion is situated centrally within an approximately planar pentaaza macrocyclic ring, binding to the five nitrogen atoms, and also to the two pendant amines which are located on opposite sides of the macrocyclic plane. ab initio HF-MO calculations using a standard 3-21G* basis set have been used to verify that these similar basic structures correspond to energy minima in the gas phase. 相似文献
16.
Some metal complexes of Schiff bases have been prepared by the interactions of palladium(II) and platinum(II) chloride with 5-chloro-1,3-dihydro-3-[2-(phenyl)-ethylidene]-2H-indol-2-one-hydrazinecarbothioamide(L1H) and 5-chloro-1,3-dihydro-3-[2-(phenyl)-ethylidene]-2H-indol-2-one-hydrazinecarboxamide(L2H), in bimolar ratios. All the new compounds have been characterized by elemental analyses, conductance measurements, molecular weight determinations, IR and 1H NMR spectral studies. The spectral data are consistent with a square planar geometry around Pd(II) and Pt(II) in which the ligands act as neutral bidentate and monobasic bidentate ligands, coordinating through the nitrogen and sulfur/oxygen atoms. Free ligands and their metal complexes were screened for their antimicrobial activity on different species of pathogenic fungi and bacteria and their biopotency has been discussed. 相似文献
17.
《Polyhedron》1987,6(5):1021-1025
Two novel series of complexes of types [La(DAPCH)X2]X and [La(DAPTC)X2]X (DAPCH = a potentially pentadentate ligand derived from 2,6-diacetylpyridine and carbohydrazide; DAPTC = a potentially tridentate ligand derived from 2,6-diacetylpyridine and thiocarbohydrazide; X = Cl, Br or NO3) have been synthesized and characterized by elemental analyses, conductance measurements and IR spectral data. All these complexes contain terminal hydrazinic nitrogen atoms with an unshared electron pair and may take part in nucleophilic condensations. Therefore, the reactions of these complexes with 2,6-diacetylpyridine have also been studied which cause ring closure and formation of macrocyclic ligand complexes. Two types of cyclic products, viz. mononuclear [La(mac)X2]X, [La(mac′)X2]X and binuclear [La2(mac)X4]X2, [La2(mac′)X4]X2 (mac- = macrocyclic ligand derived from DAPCH and 2,6-diacetylpyridine; mac′ = macrocyclic ligand derived from DAPTC and 2,6-diacetylpyridine; X = Cl, Br or NO3) have been isolated by carrying out the reactions by different methods. The IR spectra of these cyclic products are reported. 相似文献
18.
Natarajan Raman Arumugam Sakthivel Ramaraj Jeyamurugan 《Central European Journal of Chemistry》2010,8(1):96-107
Few novel binuclear Schiff base metal complexes [M2LCl3], where M = Cu(II) and Zn(II); L= 2,6-bis-({2-[(3-hydroxy-4-nitrobenzylidene)amino]ethylimino}methyl)-4-methylphenol (BHEM),
2,6-bis-({2-[(3,4-dimethoxybenzylidene)amino]ethylimino} methyl)-4-methylphenol (BDEM) and 2,6-bis-({2-[(2,3,5-trichlorobenzylidene)amino]ethylimino}methyl)-4-methylphenol
(BTEM), have been synthesized and characterized by analytical and spectral data. The data suggest that BHEM/BDEM/BTEM ligands
afford square-pyramidal/distorted square-pyramidal geometry on metalation with Zn(II)/Cu(II). The binding behaviour of these
complexes with DNA has been investigated using electronic absorption spectroscopy as well as viscosity and voltammetric measurements;
the results show that they interact with DNA through intercalating way. From the DNA cleavage study of these complexes, investigated
by gel electrophoresis, we found that they efficiently cleave supercoiled pUC19 DNA in the presence of a reducing agent (3-mercaptopropionic
acid) and on irradiation with UV light of 360 nm wavelength. The mechanism reveals that singlet oxygen (1O2) plays a significant role in the photo cleavage. The superoxide dismutase (SOD) mimetic activity of the synthesized complexes
demonstrates that most of the complexes have promising SOD-mimetic activity. The antimicrobial study indicates that the complexes
inhibit the growth of bacteria and fungi more than the free ligands. 相似文献
19.
New Schiff base chelates of Cu(II), Co(II), Ni(II) and Zn(II) derived from benzil-2,4-dinitro-phenylhydrazone with aniline
have been synthesised. Microanalytical data, molar conductance, and magnetic susceptibility values have been obtained, and
IR,1H NMR,13C NMR, UV-Vis, CV and EPR spectral studies have been carried out to suggest tentative structures for the complexes 相似文献
20.
Renu Sharma Meena Nagar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2863-2875
A series of new mixed ligand complexes of Zn(II), Cd(II), and Hg(II) with cis-3,7-dimethyl-2,6-octadienthiosemicarbazone (CDOTSC; LH) and N-phthaloyl amino acids (AH) have been synthesized by the reaction of metal dichloride with ligands CDOTSC and N-phthaloyl derivative of DL-glycine (A1H), L-alanine (A2H), or L-valine (A3H) in a 1:1:1 molar ratio in dry refluxing ethanol. All the isolated complexes have the general composition [M(L)(A)]. The plausible structure of these newly synthesized complexes has been proposed on the basis of elemental analyses, molar conductances, molecular weight measurement, and various spectral (IR, 1H NMR, and 13C NMR) studies, and four coordinated geometries have been assigned to these complexes. All the complexes and ligands have been screened for their antibacterial activity. 相似文献