共查询到20条相似文献,搜索用时 31 毫秒
1.
《Journal of Coordination Chemistry》2012,65(10):903-911
3-Carboxylacetonehydroxamic acid (CAHA) and its iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized and characterized by elemental analysis, UV-Vis and IR spectra and magnetic susceptibility. The pK a1 and pK a2 values of the ligand in aqueous solution were found to be 6.5 ± 0.1 and 8.6 ± 0.1, which correspond to dissociation of carboxyl and hydroxamic protons, respectively. The dianion CAH acts as a tetradentate ligand through the hydroxamate and carboxylate groups and coordinates to the divalent metal ions, forming coordination polymers with a metal-to-ligand ratio of 1 : 1 in the solid state. FTIR spectra and thermal decomposition of the ligand and its metal complexes were recorded and briefly discussed. The electrochemical behavior of the complexes was investigated by square wave voltammetry and cyclic voltammetry at neutral pH. In contrast to the solid state, the iron(II) and copper(II) cations form stable complex species with a metal-to-ligand ratio of 1 : 2 in solution. The iron(II), cobalt(II) and nickel(II) complexes show two-electron irreversible reduction behavior, while the copper(II) and zinc(II) complexes undergo quasi-reversible and reversible electrode reactions, respectively. The stability constants of the complexes were determined by square wave voltammetry. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(20):3619-3628
A bidentate iminophenol (HL = 2-((4-methoxyphenylimino)methyl)-4,6-di-tert-butylphenol derived from condensation of 4-methoxyaniline and 3,5-di-tert-butyl-2-hydroxybenzaldehyde) was mixed with divalent metal salts to form the corresponding mononuclear metal complexes [MII(L)2] (M = Co (1), Cu (2), and Zn (3)). The complexes are characterized by different spectroscopic and analytical tools. X-ray crystal structures of the complexes revealed homoleptic mononuclear complexes with MN2O2 coordination. The cobalt(II) (1) and zinc(II) (3) complexes display a pseudo-tetrahedral coordination geometry, whereas the copper(II) complex (2) exhibits a distorted square-planar coordination. The zinc(II) complex (3) emits at 460 nm with a twofold enhancement of emission with respect to the free iminophenol. 相似文献
3.
《Journal of Coordination Chemistry》2012,65(6):525-534
Acetamidomalondihydroxamate (K2AcAMDH) and its manganese(II), iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized and characterized by elemental analysis, UV–VIS, IR and magnetic susceptibility. The pK a1 and pK a2 values of the dihydroxamic acid in aqueous solution were found to be 8.0?±?0.1 and 9.7?±?0.1. The dihydroxamate anion AcAMDH behaves as a tetradentate bridging ligand through both hydroxamate groups, forming complexes with a metal to ligand ratio of 1?:?1 in the solid state. The FTIR spectra and thermal decompositions of the ligand and its metal complexes were recorded. The redox behavior of the complexes was investigated in aqueous solution by square wave voltammetry and cyclic voltammetry at neutral pH. In contrast to the solid state, in solution the copper(II) and zinc(II) ions form stable complex species with a metal to ligand ratio of 1?:?2. The iron(II) and nickel(II) complexes show a two-electron irreversible reduction behavior, while the copper(II) and zinc(II) complexes undergo reversible electrode reactions. The stability constants of the complexes were determined by square wave voltammetry. 相似文献
4.
《Journal of Coordination Chemistry》2012,65(17):3117-3126
A ligand containing different coordination groups, 5-([1,10]phenanthroline-[4,5-f]imidazo-2-yl)-8-hydroxyquinoline (PhenI8Q) has been synthesized and two corresponding polymeric metal complexes Cu(II) (1) and Zn(II) (2) were prepared by coordination polymerization of the ligand with copper(II) and zinc(II) halides, respectively. The ligand was characterized by 1H-NMR, 13C-NMR, and Fourier transform-infrared (FT-IR) and its corresponding polymeric metal complexes 1 and 2 were characterized by FT-IR, UV-Vis, elemental analysis, thermal gravimetric analysis, and conductivity measurements. The absorption spectra and luminescence of the ligand, 1, and 2 were investigated by UV-Vis and fluorescence spectroscopy at room temperature. Compared with the ligand, the fluorescence spectra of the polymeric metal complexes exhibit blue shifts in dimethyl sulfoxide (DMSO) solution and bathochromic shifts in the solid state. Complexes 1 and 2 emit blue light with emission maximum (λ f max) at 449 and 431 nm in DMSO solution and at 485 and 484 nm in the solid state, respectively. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(4):700-712
A new azohydrazone, 2-hydroxy-N′-2-hydroxy-5-(phenyldiazenyl)benzohydrazide (H3L) and its copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), cadmium(II), mercury(II), vanadyl(II), uranyl(II), iron(III), and ruthenium(III) complexes have been prepared and characterized by elemental and thermal analyses as well as spectroscopic techniques (1H-NMR, IR, UV-Vis, ESR), magnetic, and conductivity measurements. Spectral data showed a neutral bidentate, monobasic bidentate, monobasic tridentate, and dibasic tridentate bonding to metal ions via the carbonyl oxygen in ketonic or enolic form, azomethine nitrogen, and/or deprotonated phenolic hydroxyl oxygen. ESR spectra of solid vanadyl(II) complex (2), copper(II) complexes (3–5), and (7) and manganese(II) complex (10) at room temperature show isotropic spectra, while copper(II) complex (6) shows axial symmetry with covalent character. Biological results show that the ligand is biologically inactive but the complexes exhibit mild effect on Gram positive bacteria (Bacillus subtilis), some octahedral complexes exhibit moderate effect on Gram negative bacteria (Escherichia coli), and VO(II), Cd(II), UO(II), and Hg(II) complexes show higher effect on Fungus (Aspergillus niger). When compared to previous results, metal complexes of this hydrazone have a mild effect on microorganisms due to the presence of the azo group. 相似文献
6.
Ram A. Lal Debajani Basumatary Arjun K. De Arvind Kumar 《Transition Metal Chemistry》2007,32(4):481-493
The present study shows that the reaction of different salts of the same metal with sterically crowded dihydrazone bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (CH2LH4) in ethanol/aqueous media gives complexes of different stereochemistry. While the reaction of zinc(II) and copper(II) sulphate
with dihydrazone yields tetrahedral complexes, the zinc(II) and copper(II) chlorides give square pyramidal and distorted octahedral
complexes, respectively. On the other hand, nickel(II) sulphate and chloride, both give high-spin octahedral complexes with
dihydrazone, manganese sulphate gives low-spin octahedral and manganese(II) chloride gives high-spin octahedral complexes.
The reaction of these complexes with KF has been investigated. All of the products have been characterized by analytical,
magnetic moment and molar conductivity data. The structures of the complexes have been established by spectroscopic studies. 相似文献
7.
Magdy Shebl 《Journal of Coordination Chemistry》2016,69(2):199-214
A new Schiff base, H2L, was prepared by condensation of 4,6-diacetylresorcinol with o-phenylenediamine in molar ratio 1?:?1. The ligand reacted with copper(II), nickel(II), cobalt(II), iron(III), zinc(II), oxovanadium(IV), and dioxouranium(VI) ions in the absence and presence of LiOH to yield mononuclear and homobinuclear complexes. The mononuclear dioxouranium(VI) complex [(HL)-(UO2)(OAc)(H2O)]·5H2O was used to synthesize heterobinuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, 1H-, and 13C-NMR, electronic, ESR and mass spectra, conductivity, and magnetic susceptibility measurements as well as thermal analysis. In the absence of LiOH, mononuclear complexes (1, 4, and 9) were obtained; in the presence of LiOH, binuclear complexes (3, 5, 7, and 10) as well as mononuclear complexes (2, 6, and 8) were obtained. In the mononuclear complexes, the coordinating sites are the phenolic oxygen, azomethine nitrogen, and amino nitrogen. In addition to these coordinating sites, the free carbonyl and phenolic OH are involved in coordination in binuclear complexes. The metal complexes exhibited octahedral, tetrahedral, and square planar geometries while the uranium is seven-coordinate. The antimicrobial and antioxidant activities of the ligand and its complexes were investigated. The ligand and the metal complexes showed antitumor activity against Ehrlich Acites Carcinoma. 相似文献
8.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1979,35(6):577-584
Several complexes of cobalt(II), nickel(II), copper(II), copper(I), zinc(II), cadmium(II)and mercury(II) acetate, tetrafluoborate, sulphate and nitrate with benzoxazole-2-thione have been prepared and characterized by chemical analyses, ligand-field spectra, magnetic susceptibility measurements, molecular conductances and vibrational spectra (conventional and far i.r.). In the light of spectroscopic investigation it is possible to distinguish whether the anions present are coordinated to the transition metal ion or are present as free ions. Spectroscopic parameters of the cobbalt(II) and nickel(II) complexes are compared with similar chromophores containing sulphur, oxygen and nitrogen donor atoms. The evidence suggests that the sulphato- and nitrato-derivatives of cobalt and nickel are tetrahedral, the nickel tetrafluoroborato-derivative resulted octahedral, while the nickel acetato-complex and the complexes of the cobalt acetate and tetrafluoroborate resulted square planar and in predominantly planar environment respectively. The zinc, cadmium and mercury derivatives with a 1:2 and 1:3 metal:ligand molar ratio have a tetrahedral symmetry with the exception of[Znbot2Ac2] which resulted hexacoordinate with the acetato groups acting as symmetrical chelates. The complexes [ZnbotSO4] and [CdbotSO4] have a linear structure with the sulphate group acting as unidentate with a C3ν symmetry, polymeric structures with the sulphate anion functioning probably as chelate and of symmetry lower than C2ν being excluded from the i.r. evidence. Allocation for the possible metal-ligand and metal-anion modes have also been made. 相似文献
9.
《Journal of Coordination Chemistry》2012,65(13):2220-2228
A new series of Cu(II), Ni(II), and Co(II) complexes have been synthesized from 3-formylchromoniminopropylsilatrane (C19H24O5N2Si) (2) and 3-formylchromoniminopropyltriethoxysilane (1). Silatrane ligand (C19H24O5N2Si) (2) has been synthesized by the reaction between 3-aminopropyltriethoxysilane and 3-formylchromone followed by a treatment with triethanolamine. The nature of bonding and the geometry of the complexes have been deduced from elemental analyses, magnetic susceptibility, infrared, electronic, 1H NMR, 13C NMR, and ESR spectral studies. The electronic absorption spectra and magnetic susceptibility measurements of the complexes indicate square planar geometry for Cu(II) and Ni(II) and tetrahedral geometry for Co(II). The redox behavior of copper complexes was studied by cyclic voltammetry. The biological activity of the ligand and metal complexes has been studied on Klebsiella pneumoniae, Staphylococcus aureus, Escherichia Coli, and Bacillus subtilis by the well diffusion method using acetonitrile as solvent. The zone of inhibition values were measured at 37°C for 24 h. Antimicrobial screening tests show better results for the metal complexes than the ligand. 相似文献
10.
Giuseppe Marcotrigiano Ledi Menabue Gian Carlo Pellacani 《Transition Metal Chemistry》1978,3(1):108-112
Summary Tetrahalometallates of the type (Etmorphl1)21MX4 (M = Co11, Ni11 or Zn11 and with X = Cl, Br or l; M = CuII with X = CI or Br) and mixed tetrahalocuprates, Etmorphll)2[CUXmY4–m] (X = Cl; N' = 13r; m = 1,2,3) of theN-ethylmorpholinium cation were prepared and investigated by means of spectroscopic and magnetic measurements. While the cobalt(II), nickel(II) and zinc(II) complexes appear to be essentially, tetrahedral, the copper(II) complexes are discussed on the basis of a distorted ('flattened') tetrahedral symmetry. The electronic spectra of the complexes are assigned on this basis. The far i.r. spectra of the complexes show bands which are unambiguously assignable to the metal-halogen stretching modes. The effects of the counter cation on the geometry around the metal ion, compared with that of the morpholinium and piperidinium cations, are discussed in relation to the pKa of the amine. 相似文献
11.
Summary The syntheses of several new coordination complexes of nickel(II), cobalt(II), manganese(II), copper(II), zinc(II), dioxouranium(VI) and dioxomolybdenum(VI) with new Schiff bases derived from 2-benzothiazolecarbohydrazide and salicylaldehyde or 2-hydroxy-1-naphthaldehyde are described. These complexes have been characterised by elemental analyses, electrical conductance, magnetic susceptibility, molecular weight, i.r. and electronic spectra. The Schiff bases behave as dibasic and tridentate ligands coordinating through the ONO donor system and form complexes of the types NiL · 3H2O, MnL · 2H2O, CoL · 2H2O, CuL, ZnL · H2O, UO2L · MeOH and MoO2L · MeOH (where LH2 = Schiff base). The copper(II) complexes exhibit subnormal magnetic moments indicating the presence of an antiferromagnetic exchange interaction, whereas the nickel(II), cobalt(II) and manganese(II) complexes behave normally at room temperature. Zinc(II), dioxouranium(VI) and dioxomolybdenum(VI) complexes are diamagnetic; the zinc (II) complexes are tetrahedral, the copper(II) complexes are square planar, all the other complexes are octahedral. Thev(C=N),v(C-O),v(N-N) andv(C-S) shifts have been measured in order to locate the Schiff base coordination sites. 相似文献
12.
《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(16):3719-3719
The cover picture shows how differing coordination algorithms control the molecular architecture of complexes of the pyridazine‐containing, two‐armed, acyclic Schiff base ligand L2 (left, prepared from one equivalent of 3,6‐diformylpyridazine and two equivalents of d‐anisidine). Two very different complexes of L2 self‐assemble from tetrahedral copper(I ) versus octahedral zinc(II ), nickel(II ), and cobalt(II ) controlled 1 : 1 reactions with L2. In both cases the metal ions are bridged by the pyridazine moieties in L2, but in the case of the tetrahedral copper(II ) the result is a tetrametallic [2×2] grid complex ([CuI4(L2)4]4+: top right), whilst in the case of the octahedral metal(II ) ions dimetallic side‐by‐side complexes, [MII2(L2)2(X)4]y+ (M = Mn, Co, Ni, Zn; X = solvent or anion), are formed (bottom right). The cover image was kindly generated by M. Crawford (University of Otago) with Strata Studio Pro (Strata). More details are given by S. Brooker and co‐workers on p. 3772 ff. 相似文献
13.
《Journal of Coordination Chemistry》2012,65(2):223-228
The crystal structures and thermal behaviour of bis(N-pyrrolidine-N′-(2-chloro-benzoyl)thioureato)zinc(II) (ZnL2) and its copper(II) analogue (CuL2) are reported. In both structures, the metal atoms are coordinated by two oxygen and two sulfur atoms to form neutral trans-square planar (Cu) and distorted tetrahedral (Zn) species. The thermal decomposition of the complexes was investigated by TG and DTA. 相似文献
14.
《Journal of Coordination Chemistry》2012,65(3):515-523
Two new isostructural copper(II)–zinc(II) complexes, [CuZnLBr2] (1) and [CuZnLCl2] (2) (H2L = N,N′-bis(4-methoxysalicylidene)cyclohexane-1,2-diamine), have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Both complexes crystallize in the P-1 space group. The Cu in each complex is four-coordinate square planar with two imines and two phenolates of L. The Zn in each complex is four-coordinate tetrahedral with two phenolates of L and two halides (Br for 1 and Cl for 2). The superoxide dismutase (SOD) activity of the complexes indicates that both complexes are rudimentary models for SOD. 相似文献
15.
Two new series of copper(II), nickel(II), cobalt(II), zinc(II), iron(III), chromium(III), vanadyl(IV) and uranyl(VI) complexes
with two bifunctional tridentate Schiff base, H4L1 and H2L2 ligands have been prepared. The Schiff base, H4L1 and H2L2, ligands were synthesized by the condensation of 4,6-diacetylresorcinol with o-aminophenol or o-phenylenediamine. The ligands are either di- or tetra-basic with two symmetrical sets of either OON or NNO tridentate chelating
sites. The ligands and their metal complexes have been characterized by elemental analysis, 1H-n.m.r., FT-IR, mass, electronic, esr spectra and thermal gravimetric analysis and magnetic susceptibility. With the exception
of CoII ion with H2L2 which afforded a trinuclear complex, a variety of binuclear complexes for the rest of the metal complexes were obtained with
the ligands in its di- or tetra-deprotonated forms. The bonding sites are the azomethine and amino nitrogen atoms, and phenolic
oxygen atoms. The metal complexes exhibit different geometrical arrangements such as square planar, tetrahedral, square pyramid
and octahedral arrangement. 相似文献
16.
Siham Slassi Abdelkrim El-Ghayoury Mohammed Aarjane Khalid Yamni Amina Amine 《应用有机金属化学》2020,34(4):e5503
Newly synthesized mononuclear copper(II) and zinc(II) complexes containing an azo Schiff base ligand (L), prepared by condensation of 2-hydroxy-5-(o-tolyldiazenyl)benzaldehyde and propylamine, were obtained and then characterized using infrared and NMR spectroscopies, mass spectrometry and X-ray diffraction. Ligand L behaves as a bidentate chelate by coordinating through deprotonated phenolic oxygen and azomethine nitrogen. The copper and zinc complexes crystallize in triclinic and orthorhombic systems, respectively, with space groups P−1 and Pca21. In these complexes, the Cu(II) ion is in a square planar geometry while the Zn(II) ion is in a distorted tetrahedral environment. The photochemical behaviors of ligand L, [Cu(L)2] and [Zn(L)2] were investigated. The azo group in L underwent reversible trans–cis isomerization under UV and visible irradiation. This process was inhibited for the complexes. In addition, ligand L and its copper and zinc complexes were assessed for their in vitro antibacterial activities against four pathogenic strains. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(24):3961-3968
A series of new Co(II), Ni(II), and Cu(II) complexes of Schiff base derived from coumarin have been prepared and characterized by analytical and spectral methods. The Schiff base is synthesized by the condensation of 2,6-diaminopyridine and 3-acetylcoumarin in 1 : 1 stoichiometric ratio. All complexes have 1 : 1 metal : ligand ratio except the nickel complex, where it was found to be 1 : 2. UV-Vis spectra and magnetic moment studies confirm the existence of tetrahedral and octahedral geometries around cobalt(II) and nickel(II) metal ions, respectively, but copper(II) chloride/nitrate/sulfate complexes have square-planar geometry and copper(II) acetate complex is distorted octahedral. ESR spectra of copper complexes at room temperature and liquid nitrogen temperature were tetragonal. All the complexes were found to be more active against bacteria except Ni(II) complex; only CuLSO4 and CuL(CH3COO)2 have shown the enhanced activity against fungi. 相似文献
18.
《Journal of Coordination Chemistry》2012,65(2-3):243-255
Abstract The stoichiometrics and stability constants of the nickel(II), copper(II) and zinc(II) complexes of l-amino-3-methylthiopropanephosphonic acid (MetP) and 1-amino-ethanephosphonic acid (a-AlaP) have been determined pH-metrically at 25°C at an ionic strength of 0.2 mol dm?3 (KC1). From the stability data and the absorption spectra of the complexes it has been established that simple aminophosphonic acids coordinate to the nickel(II) and copper(II) ions forming chelate complexes in which the metal binding mode is bidentate with the {NH2, PO3 2-} donor set. 31P and 1H NMR measurements showed that MetP and α-AlaP exhibit similar properties in the presence of zinc(II) ions, but the ligand reacts to form a cyclic phosphonoamidate in neutral and slightly alkaline solution in the Zn(II)-α-AlaP system and at slightly acidic conditions in the Zn(II)-MetP system. This difference reveals that the latter ligand at pH > 7 prefers Zn(II) coordination involving all possible (amino, phosphonate and thioether sulfur) donor groups. 相似文献
19.
Muharrem Kaya Cengiz Yenikaya Alper Tolga Colak Ferdag Colak 《Russian Journal of General Chemistry》2008,78(9):1808-1815
Two different metal complexes of [Co(HL)(L)(Ac)2]·4H2O (I) and [Ni2(L)2(Ac)2]·4H2O (II), have been synthesized with newly prepared amine-imine-oxime ligand [HL = 3-(4′-aminobiphenyl-4-ylimino)-butan-2-one oxime,
Ac = CH3COO−]. This ligand HL was prepared by the condensation of diacetylmonoxime with benzidine. The structure of the ligand and complexes
have been proposed by elemental analyses, IR, 1H, and 13C NMR, electronic spectra, magnetic susceptibility measurements, mass spectra, molar conductivity and thermo gravimetric analysis.
The molar conductance measurements of the complexes in DMF solution correspond to non electrolytic nature for the complexes.
Octahedral and tetrahedral geometries have been determined to the complexes of Co(III) and binuclear Ni(II) respectively.
The ligand and its metal complexes were tested in vitro for their biological effects. Their activities against two gram-positive
(Bacillus subtilis and Staphylococcus aureus) and one fungal specie (Candida albicans) were found. They were inactive against tested gram negative bacteria.
The text was submitted by authors in English. 相似文献
20.
《Journal of Coordination Chemistry》2012,65(9):787-795
The first 2-pyridylethanol (pyet) complexes of manganese(II), iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) saccharinates, were synthesized and characterized by elemental analyses, magnetic measurements, UV-Vis, and IR spectroscopic techniques. Crystal and molecular structures of the iron(II) and copper(II) complexes were determined by single crystal X-ray diffractometry. The experimental data showed that all the complexes are mononuclear with a general formula [M(H2O)2(pyet)2](sac)2, where sac is the saccharinate anion. All the metal ions are octahedrally coordinated by two aqua and two pyet ligands. The pyet ligand acts as a bidentate ligand through its amine nitrogen and hydroxyl oxygen atoms forming a six-membered chelate ring, while the sac ions remain outside the coordination sphere. All the complexes are isomorphous with a monoclinic space group P21/n and Z = 2. 相似文献