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1.
Two new, Schiff base ligands containing cyclobutane and thiazole rings, 4-(1-methyl-1-mesitylcyclobutane-3-yl)-2-(2,4-dihydroxybenzylidenehydrazino)thiazole (L1H) and 4-(1-methyl-1-mesitycyclobutane-3-yl)-2-(2-hydroxy-3-methoxybenzylidenehydrazino)thiazole (L2H) and their mononuclear complexes with a 1:2 metal-ligand ratio have been prepared with acetate salts of CoII, CuII, NiII and ZnII in EtOH. The structures of the ligands and their complexes have been established by microanalyses, i.r., u.v.–vis., 13C- and 1H-n.m.r. spectra, and by magnetic susceptibility measurements. The complexes are mononuclear. Thermal properties of the ligands and complexes have been studied by t.g.a. and d.s.c. techniques. Antimicrobial activities of the ligands and their complexes have been tested against eight different microorganisms. Some of the complexes and L1H were found to be active against some of the microorganisms studied.  相似文献   

2.
Abstract

A new, thiazole derivative ligand, 4-(1-phenyl-1-methylcyclobutane-3-yl)-2-(2-hydroxy-5-bromo benzylidenehydrazino) thiazole (LH), has been synthesized by the reaction of 2-hydroxy-5-bromobenzaldehyde, thiosemicarbazide and subsequently 1-phenyl-1-methyl-3-(2-chloro-1-oxoethyl) cyclobutane. Mononuclear complexes with a metal-ligand ratio of 1 : 2 have been prepared with Cd(II), Co(II), Cu(II), Ni(II) and Zn(II). The authenticity of the ligand and its complexes was established by elemental analyses, IR, 13C and 1H NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC).  相似文献   

3.
Azo compounds were prepared by the reaction between benzenediazonium chloride and 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid monosodium salt under alkaline conditions. Two new azo-linked Schiff base ligands, 4-(3-methoxysalicylidene)-5-hydroxy-6-(2-hydroxyphenylazo)-2,7-naphthalene disulfonic acid disodium salt (H2L) and 4-(3-methoxysalicylidene)-5-hydroxy-6-(2-hydroxy-4-cholorophenylazo)-2,7-naphthalenedisulfonic acid disodium salt (H2L1), have been synthesized. Also, the new CuII, NiII and CoII complexes of the azo-linked Schiff base ligands were prepared and characterized by infrared spectra, UV–Vis, 1H- and 13C-n.m.r., attached proton test (APT) and distortionless enhancement by polarization transfer (DEPT) and atomic absorption spectroscopy, mass spectrocopy, elemental analyses, thermogravimetric analysis, conductivity and magnetic measurements. It was determined that the synthesized ligands were comprised of six-membered rings due to intramolecular hydrogen bonding. The results suggested that condensation of the azo-derivative compounds and o-vanillin in a 1:1 molar ratio produces mononuclear Schiff base ligands with an ONO donor set. Preliminary histological studies were made. Magnetic moment studies showed that all complexes have a tetrahedral configuration.  相似文献   

4.
Two Schiff base ligands, 2-{E-[(5-phenyl-6H-1,3,4-thiadiazin-2yl)imino]methyne}-1-naphthol (L1H) and 5-nitro-2-{[(5-phenyl-6H-1,3,4-thiadiazin-2-yl)imino]methyne}phenol (L2H) have been prepared from 5-phenyl-6H-1,3,4-thiadiazin-2-amine (A), 2-hydroxynaphthaldehyde (1) and 2-hydroxy-5-nitrobenzaldehyde (2) Mononuclear Co(II), NiII and CuII complexes of the ligands have been prepared by using CoII, NiII and CuII salts with a 1:2 metal:ligand ratio. It was determined that the bidentate behavior of the ligands is accomplished via the phenolic oxygen and the azomethine nitrogen atoms. The structures of the ligands and their complexes were identified by using elemental analyses, i.r., 1H-n.m.r. spectra, electronic spectra, magnetic susceptibility measurements and thermogravimetric analyses (t.g.a.).  相似文献   

5.
Two novel bidentate Schiff base ligands, 2-(2-hydroxy-3,5-dichloro/diboromo) benzaldehyde-[4-(3-methyl-3-mesitylcyclobutyl)-1,3-thiazol-2-yl]hydrazone, L1H, L2H and their transition metal complexes are reported. The new ligands and their complexes have been characterized by elemental analyses, ΛM, infrared, u.v.–vis, 1H- and 13C-n.m.r. spectroscopy, and magnetic susceptibility measurements. The thermal properties of all complexes have been investigated by TG technique. The complexes contain two monoanionic, bidentate NO ligands. It was found that all the complexes are mononuclear. Antimicrobial activities of the ligands and their complexes have been tested against five different microorganisms, and some of the complexes were found to be active against some of the microorganisms studied.  相似文献   

6.
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.
Two new vic-dioxime ligands, (E,E)-N-{4-[(1,4-dioxaspiro[4.4]non-2-ylmethyl)amino]butyl}-N-hydroxy-2-(hydroxyimino)ethanimidamide (L1H2) and (E,E)-N-{4-[(1,4-dioxaspiro[4.5]dec-2-ylmethyl)amino]butyl}-N-hydroxy-2-(hydroxyimino)ethanimidamide (L2H2) containing two different heteroatoms (N,O) have been prepared from anti-chloroglyoxime, N-(1,4-dioxaspiro[4.4]non-2-ylmethyl)butane-1,4-diamine (3) and N-(1,4-dioxaspiro[4.5]dec-2-ylmethyl)butane-1,4-diamine (4). CoII, NiII and CuII complexes of the ligands have a metal:ligand ratio of 1:2 and the ligands coordinate through the two N atoms, as do most of the vic-dioximes. However, ZnII complexes of the ligands have a metal:ligand ratio of 1:1 and the ligands are coordinated only by the N, O atoms of the vic-dioximes. In the CoII complexes two water molecules, and in the ZnII complexes a chloride ion and a water molecule, are also coordinated to the metal ion. The structures of the compounds were determined by a combination of elemental analysis, magnetic moments, molar conductances, thermogravimetric analysis (t.g.a.) and spectroscopic (u.v.–vis., i.r., 1H- and 13C-n.m.r.) data.  相似文献   

8.
Four tridentate ONS ligands, namely 2-hydroxyacetophenonethiosemicarbazone (H2L1), the 2-hydroxyacetophenone Schiff base of S-methyldithiocarbazate (H2L2), the 2-hydroxy-5-nitrobenzaldehyde Schiff base of S-methyldithiocarbazate (H2L3), and the 2-hydroxy-5-nitrobenzaldehyde Schiff base of S-benzyldithiocarbazate (H2L4), and their complexes of general formula [Ni(HL1)2], [ML] (M?=?NiII or CuII; L?=?L1, L2, L3 and L4), [Co(HL)(L); L?=?L1, L2, L3 and L4] and [ML(B)] (M?=?NiII or CuII; L?=?L2 and L4; B?=?py, PPh3) have been prepared and characterized by physico-chemical techniques. Spectroscopic evidence indicates that the Schiff bases behave as ONS tridentate chelating agents. X-ray crystallographic structure determination of [NiL2(PPh3)] and [CuL4(py)] indicates that these complexes have an approximately square-planar structure with the Schiff bases acting as dinegatively charged ONS tridentate ligands coordinating via the phenoxide oxygen, azomethine nitrogen and thiolate sulfur atoms. The electrochemical properties of the complexes have been studied by cyclic voltammetry.  相似文献   

9.
New transition metal complexes of Co(II), Cu(II), Ni(II), and Fe(III) of the ligands 6,6′-(1E,1′E)-(4,5-dimethyl-1,2-phenylene)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(7-hydroxy-5-methoxy-2-methyl-4H-chromen-4-one) H2L1 and 6,6’-(1E,1′E)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(7-hydroxy-5-methoxy-2-methyl-4H-chromen-4-one) H2L2 have been prepared and characterized using physio-chemical and spectroscopic methods. The results obtained for the complexes indicated that the geometries of the metal centres are either square planar or octahedral. Cyclopropanation reactions of unactivated olefins by ethyldiazoacetate (EDA) in the presence of [L1Cu]·H2O, [L2Cu]·2H2O and [L2*Co]·2H2O as catalysts were examined. The results showed that only [L2*Co]·2H2O can act as a catalyst for the cyclopropanation reaction of unactivated olefins with very high selectivity (up to 99% based on EDA).  相似文献   

10.
Four unsymmetrical vic-dioximes: [L1H2] N-(4-butylphenyl)amino-amphi-glyoxime, [L2H2] N-(4-butylphenyl)amino-anti-glyoxime, [L3H2] N-(4-phenylazophenyl)amino-amphi-glyoxime and [L4H2] N-(4-phenylazophenyl)amino-anti-glyoxime have been prepared from amphi-chloroglyoxime, anti-chloroglyoxime, 4-butylaniline and 4-(phenylazo)aniline respectively. The complexes of these vic-dioximes with NiII, CoII, CuII and CdII ions have been investigated. All are insoluble in common solvents. Their i.r. spectra and elemental analyses are given, together with mass and 1H-n.m.r. spectra of the ligands.  相似文献   

11.
Summary Dicyanamide complexes of CuII, NiII and CoII of the type M[N(CN)2]2L2, where L = benzimidazole, 2-methyl- or 2-ethylbenzimidazole, have been prepared and studied by spectroscopy and magnetochemistry. The complexes, except for Co[N(CN)2]2 (benzimidazole)2, are six-coordinate, involving bidentate bridging dicyanamide groups. While the NiII complexes have practically octahedral structures, the CuII complexes are pseudooctahedral with similar tetragonal distortion. The ligand field strength in these complexes depends mainly on the steric effect of the benzimidazole ligands. The CoII complex of benzimidazole is monomeric tetrahedral, but that of 2-ethylbenzimidazole is tetragonal octahedral. The oridging function of dicyanamide in the six-coordinate complexes is realized either through both cyanide or through amide and cyanide nitrogens. The complex Cu[N(CN)2]2 (2-methylbenzimidazole)2 is a weak antiferromagnet (J = -0.1 cm–1), exhibiting under ca. 15 K a long-range antiferromagnetic ordering.  相似文献   

12.
Complexes ML12 and ML22, with M = FeII, CoII, NiII, and 1,3-bis(2-R-tetrazol-5-yl)triazenide ligands L1 (R = Me) and L2 (R = tBu), have been synthesized by the reaction of corresponding 1,3-bis(2-R-tetrazol-5-yl)triazenes with metal(II) salts in basic media and characterized by IR, UV–Vis spectroscopy, thermal and X-ray diffraction analyses. Both 1,3-bis(2-R-tetrazol-5-yl)triazenes were found to deprotonate on coordination and act as tridentate chelating ligands forming distorted MN6 octahedra around metal(II) cations.  相似文献   

13.
Preparation of pentadentate ligands L1, L2, L3 and L4, where L1 = 4-chloro-3-methyl-2[(prolin-1-yl)methyl]-6-[N-phenyl piperazin-1-yl)methyl]phenol, L2 = 4-ethyl-2-[(prolin-1-yl)methyl]-6-[(N-phenyl piperazin-1-yl)methyl]phenol, L3 = 4-chloro-3-methyl-2-[(prolin-1-yl)methyl]-6-[N-methyl piperazin-1-yl]methyl phenol, L4 = 4-methoxy-2-[(prolin-1-yl)methyl]-6-[(N-phenyl piperazin-1-yl)methyl]phenol is described together with that of the corresponding Cu(II) complexes with various bridging motifs like OH, OAc and NO2. The complexes are characterized by elemental analysis, electrochemical and electron paramagnetic spectral studies. Redox properties of the complexes in acetonitrile are highly quasireversible due to the chemical or/and stereochemical changes subsequent to electron transfer. The complexes show resolved copper hyperfine EPR at room temperature, indicating the presence of weak antiferromagnetic coupling between the copper atoms. Strengths of the antiferromagnetic interactions are in the order NO2>OAc>OH.  相似文献   

14.
To explore the coordination abilities of nitronyl nitroxide ligands, two ligands substituted with quinoxaline ( L1 ) and 2‐phenyl‐1, 2, 3‐triazole ( L2 ) and their NiII and ZnII complexes: Ni( L1 )(hfac)2 ( 1 ), Ni( L2 )(hfac)2 ( 2 ), and Zn( L2 )(hfac)2 ( 3 ) (hfac = hexafluoroacetylacetonate), were synthesized and characterized. X‐ray single‐crystal diffraction analysis shows that compound 1 has a mononuclear structure, which is further linked into a three‐dimensional (3D) supramolecular network by C–H ··· F hydrogen‐bonding, C–H ··· π, and π ··· π stacking interactions. Complexes 2 and 3 have similar mononuclear structures, which are further linked into one‐dimensional (1D) supramolecular chains by various intermolecular weak interactions, such as C–H ··· F hydrogen‐bonding, and π ··· π stacking interactions. The results indicate that the steric bulk of L1 and L2 and the existence of hexafluoroacetylacetonate (hfac) play important roles in controlling the formation of the final frameworks of complexes 1 – 3 . Moreover, the luminescent properties of the ligands and their complexes were investigated in detail.  相似文献   

15.
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   

16.
Ge  Qing-Chun  Guo  Yan-He  Lin  Hai  Lin  Hua-Kuan  Zhu  Shou-Rong 《Transition Metal Chemistry》2003,28(5):572-578
The stability constants of ZnII, CuII, NiII and CoII with different tripodal ligands, 1,3,5-tris(2,5-diazaoctxyl)benzene (L1), 1,3,5-tris(2,5-diazanonxyl)benzene (L2) and 1,3,5-tris[3-(2-pyridyl)-2-azapropyl]benzene (L3) have been studied at 25 °C in 0.1 mol dm–3 KNO3 aqueous solution using potentiometric titrations. During the titrations, the ligand concentrations were kept constant at 1 × 10–3 mol dm–3, while 1:1 and 1:3 metal:ligand ratios were used for each system. The results indicated that, in the 1:1 metal:ligand ratio, the binding of MII to the ligand gives rise to several 1:1 complexes differing in their degree of protonation whereas in the 3:1 ratio, polynuclear complexes are formed. Additionally, the ternary complexes of the tripod ligands, with CuII-5-substituted-1, 10-phenanthroline have been investigated and the results show that linear free energy relationship exists in such ternary systems.  相似文献   

17.
Summary The formation of ternary complexes of the MAL3– type [where M = CuII, NiII and ZnII ; A = nitrilotriacetic acid (NTA); L = 1-hydroxy-2-naphthoic acid (1,2 HNA) and 2-hydroxy-1-naphthoic acid (2,1 HNA)] have been studied potentiometrically in 50% v/v aqueous — ethanol (25° and µ = 0.1). Under identical conditions the binary complexes of the 1,2- and 2,1-HNA ligands have also been examined. The values of mixed ligand formation constants KMAL have been found to be lower than KML (first step formation constant of binary complexes) and even less than (second step formation constant of binary complexes).  相似文献   

18.
The reaction of [VO(Acac)2] with 4-methyl-N′-[(2-hydroxy-1-naphthyl)methylidene]benzohydrazide (H2L1) and 4-methyl-N′-[1-(2-hydroxynaphthyl)ethyiidene]benzohydrazide (H2L2), respectively, in methanol, affords two new oxovanadium(V) complexes [VO(OMe)L1]2 (I) and [VO(OMe)L2] (II). Both complexes have been characterized by elemental analysis, IR, and single crystal X-ray diffraction methods. Complex I is a methoxide-bridged dinuclear oxovanadium(V) compound, while complex II is a mononuclear oxovanadium(V) compound. The dinegative hydrazone ligands coordinate to the metal atoms through phenolate, imine, and deprotonated amide donor atoms. The geometry around vanadium atom in I is a distorted VNO5 octahedron, while that in II is a VNO4 square pyramid. Both complexes have effective catalytic property for the sulfoxidation reaction.  相似文献   

19.
Four different types of new ligands Ar[COC(NOH)R] n (Ar=biphenyl, n = 1 H2L1; Ar=biphenyl, n = 2 H4L2; Ar=diphenylmethane, n = 1 H2L3; Ar=diphenylmethane, n = 2 H4L4; R=2-amino-4-chlorophenol in all ligands) have been obtained from 1 equivalent of chloroketooximes Ar[COC(NOH)Cl] n (HL1-H2L4) and 1 equivalent of 2-amino-4-chlorophenol (for H2L1 and H2L3) or 2 equivalent of 2-amino-4-chlorophenol (for H4L2 and H4L4). (Mononuclear or binuclear cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized with these ligands.) These compounds have been characterized by elemental analyses, AAS, infra-red spectra and magnetic susceptibility measurements. The ligands have been further characterized by 1H NMR. The results suggest that the dinuclear complexes of H2L1 and H2L3 have a metal:ligand ratio of 1:2; the mononuclear complexes of H4L2 and H4L4 have a metal:ligand ratio of 1:1 and dinuclear complexes H4L2 and H4L4 have a metal:ligand ratio of 2:1. The binding properties of the ligands towards selected transition metal ions (MnII, CoII, NiII, CuII, ZnII, PbII, CdII, HgII) have been established by extraction experiments. The ligands show strong binding ability towards mercury(II) ion. In addition, the thermal decomposition of some complexes is studied in nitrogen atmosphere.  相似文献   

20.
The reactions of zinc(II) chloride and two Schiff base ligands derived from rimantadine and 5-chlorosalicylaldehyde/4-methoxysalicylaldehydes, generated two novel complexes [Zn(L1)2Cl2] (I) and [Zn(L2)2Cl2] (II), where L1 = 2-((1-(1-adamantan-1-yl)ethyl)-iminomethyl)-4-chlorophenol, L2 = 2-((1-(1-adamantan-1-yl)ethyl)iminomethyl)-5-methoxyphenol. The complexes were characterized by the means of IR, 1H NMR, elemental analysis, molar conductance and thermal analysis. A single-crystal X-ray diffraction analysis reveals that both complexes crystallize in orthorhombic system, space group Fdd2 for I and Pbcn for II. In two complexes crystals, each asymmetric unit consists of one zinc(II) ion, two corresponding Schiff base ligands and two chlorine atoms; the central zinc atom lies on a twofold rotation axis and is four-coordinate via two chlorine atoms and two oxygen atoms from the Schiff base ligands, forming a distorted tetrahedral geometry.  相似文献   

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