Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H2L2)

Salicylidene-N-anilinoacetohydrazone (H(2)L(1)) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H(2)L(2)) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H(2)L(1) have octahedral geometry. While the cobalt(II) complexes of H(2)L(2) were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu-O and Cu-N bonds are of high covalency.     

Studies on mononuclear chelates derived from substituted Schiff-base ligands (part 6): synthesis and characterization of a new 3-ethoxysalicyliden- p -aminoacetophenoneoxime and its complexes with cobalt(II), nickel(II), copper(II) and zinc(II)

Schiff-base complexes of cobalt(II), nickel(II), copper(II) and, zinc(II) with 3-ethoxysalicyliden-p-aminoacetophenoneoxime (HL) were prepared and characterized on the basis of elemental analyses, IR, ¹H- and ¹³C-NMR, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses (TGA). A tetrahedral geometry has been assigned to the complexes.     

Polymetallic complexes: Part VI. Schiff base complexes of cobalt(II), copper(II), nickel(II), zinc(II), cadmium(II) and mercury(II)

Summary The doubly bidentate ON-NO donor Schiff base, prepared from salicylaldehyde and 4,4-diaminodiphenylmethane forms complexes with 11 metal: ligand stoichiometric ratios. The cobalt(II), copper(II) and nickel(II) complexes exhibit subnormal magnetic moments. All the six complexes possess high melting points and are sparingly soluble in common organic solvents. A dinuclear octahedral structure is proposed for the cobalt(II), copper(II), nickel(II) and zinc(II) complexes and a dinuclear tetrahedral configuration is suggested for the cadmium(II) and mercury(II) complexes on the basis of analytical, conductance, magnetic susceptibility, molecular weight, i.r. and electronic spectral data.     

THE SYNTHESES AND PROPERTIES OF COBALT(II), NICKEL(II) AND COPPER(II) COMPLEXES WITH SOME 1,4-BENZODIAZEPINES

Abstract

The preparation and characterization of some cobalt(II), nickel(II) and copper(II) complexes with 7-chloro-2-methylamino-5-phenyl-3H-1, 4-benzodiazepin-4-oxide and 1, 3-dihydro-7-nitro-5-phenyl-2H-1, 4-benzodiazepin-2-one are reported. The complexes have been studied by means of magnetic susceptibility measurements, infrared and far infrared spectra, electronic spectra and conductivity measurements. Assignments for the metal-ligand and metal-halide bands have also been made. The evidence suggests that the cobalt(II) and nickel(II) complexes have a pseudotetrahedral symmetry, whereas the copper(II) complexes are octahedral.     

Bis -(3,5-dimethyl-pyrazolyl-1-methyl)-(3-phosphanyl-propyl)-amine complexes of copper(II), nickel(II), and cobalt(II)

A series of Cu(II), Co(II), and Ni(II) complexes of bis-(3,5-dimethyl-pyrazolyl-1-methyl)-(3-phosphanyl-propyl)-amine C₁₅H₂₆N₅P (1), prepared from 3-aminopropylphosphine and 1-hydroxymethyl-3,5-dimethylpyrazole were characterized. The nature of bonding and the geometry of the complexes have been deduced from elemental analysis, infrared, electronic, ¹H NMR, ³¹P NMR spectra, magnetic susceptibility, and conductivity measurements. The studies indicate octahedral geometry for nickel complex and square pyramidal geometry for copper and cobalt complexes. The EPR spectra of copper complex in acetonitrile at 300 K and 77 K were recorded. Biological activities of the ligand and metal complexes have been studied on Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Aspergillus flavus by well-diffusion method. The zone of inhibition values were measured at 37°C for a period of 24 h. The electrochemical behavior of copper complexes was studied by cyclic voltammetry. Catalytic study indicates the copper complex has efficient catalytic activity in oxidation of amitriptyline.     

Synthesis, spectral, magnetic and thermal studies on symmetrically substituted metal(II)-1,3,8,10,15,17,22,24-octafluorophthalocyanines

This publication discuss the synthesis and characterization of pure 1,3,8,10,15,17,22,24-octafluorophthalocyanines of copper(II), cobalt(II), nickel(II) and zinc(II). The complexes are characterized by elemental analysis, electronic spectra, IR spectra, thermal studies and X-ray powder diffraction method to check the purity and integrity of the complexes. The magnetic measurements over the range of magnetic field strength 1.03-2.32 kG showed a variation of magnetic moments with field strength indicating the presence of intermolecular co-operative effect.     

Iron(II), cobalt(II), nickel(II) and copper(II) chelates of 1,1′-Dibenzoylacetylferrocene

Summary 1,1-Dibenzoylacetylferrocene (DBAFc) complexes of iron(II), cobalt(II), nickel(II) and copper(II) have been prepared and characterized. The physical properties of the complexes are discussed on the basis of uv-visible, Mössbauer spectra and magnetic measurements.     

Polymetallic complexes: part VII. bis(benzoin)thiocarbohydrazide complexes of cobalt(II), copper(II) and zinc(II)

Summary Complex compounds of cobalt(II), copper(II) and zinc(II) with bis(benzoin)thiocarbohydrazide have been synthesised. The ligand is probably coordinated to the metal ions as an ONNO tetradentate donor, giving rise to binuclear metal complexes with a halogen bridge. Structures have been assigned on the basis of analyses, conductance, magnetic susceptibility, i.r., electronic spectra and molecular weight data.     

Copper(II), nickel(II), cobalt(II) and oxovanadium(IV) complexes of 1-(3-hydroxy-2-naphthyl)-5-(p-X-phenyl)pent-4-ene-1,3-diones

Complexes of 1-(3-hydroxy-2-naphthyl)-5-(p-X-phenyl)pent-4-ene-1, 3-diones (HXNP) (X = H, Cl, Me or OMe) with divalent metal ions, having the formula M(HXNP)2 (M = Cu, Ni or Co) and M(HXNP)2 · nB (n = 0,2: B = H2O or Py), have been prepared and characterized by elemental analyses, i.r., electronic, 1H-n.m.r. and e.s.r. spectroscopies and by magnetic susceptibility measurements. Spectral assignments show the metal ions to be coordinated through both carbonyl oxygen atoms and the effect of conjugation of the ligand structure (d–* interaction) is strong enough to stabilize the metal ligand bond. The observed hyperfine splitting constants and magnetic moments suggest that the copper complexes are monomers with a slightly distorted planar structure, having more covalent in plane -bonding. The magnetic and spectral properties of the dihydrates and dipyridinates of the cobalt and nickel complexes are commensurate with monomeric high-spin octahedral geometries; polymerization takes place on dehydration–depyridination of nickel(II) complexes. Oxovanadyl complexes of these -diketones have also been prepared; the ligand-to-metal ratio is 2:1 with square pyramidal geometry. The e.s.r. spectra of the complexes show the presence of one unpaired electron in the dxy orbital and the hyperfine splitting constants are sensitive to a change in solvent. The effect of bases on the redox behaviour of copper(II) complexes owing to geometry change is discussed.     

Synthesis and characterisation of nickel(II), cobalt(II), manganese(II), copper(II), zinc(II), dioxouranium(VI) and dioxomolybdenum(VI) complexes of tridentate dibasic ONO donor Schiff bases derived from 2-benzothiazolecarbohydrazide and salicylaldehyde/2-hydroxy-1-naphthaldehyde

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.     

Syntheses,Spectral, Thermal and Electrochemical Studies of 3-Carboxylacetonehydroxamic Acid and its Iron(Ii), Cobalt(Ii), Nickel(Ii), Copper(Ii) and Zinc(Ii) Complexes

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.     

Preparation and structural studies of metal(II)-1,3,8,10,15,17,22,24- octanitrophthalocyanines

Summary An efficient method for preparing pure 1,3,8,10,15,17,22,24-octanitrophthalocyanine derivatives of copper(II) (CuPON), cobalt(II) (CoPON) and nickel(II) (NiPON) has been developed. Elemental analysis, electronic spectra, i.r. spectra, magnetic susceptibility measurements, thermogravimetry and powder X-ray diffraction studies were done in order to check the purity, structural integrity, thermal stability and crystallinity of these complexes. Susceptibility measurements showed a variation in the magnetic moments of the complexes with magnetic field strength, indicating the presence of intermolecular cooperative effects.     

EPR, IR and electronic spectral studies on Mn(II), Co(II), Ni(II) and Cu(II) complexes with a new 22-membered azamacrocyclic [N4] ligand

The complexes of transition metal ions with an azamacrocyclic tetradentate nitrogen donor [N4] ligand viz. 2,6,12,16,21,22-hexaaza;3,5,13,15-tetramethyltricyclo[15.3.1.1(7-11)] docosa;1(21),2,5,7,9,11(22),12,15,17,19-decaene (L) have been synthesized. All the complexes were found to have general composition M(L)X2 [where M = manganese(II), cobalt(II), nickel(II) and copper(II) and X = Cl- & NO3-]. All the complexes are characterized by the elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, 1H NMR, IR, electronic, EPR spectral and cyclic voltammetric studies. An octahedral geometry was assigned for Mn(II), Co(II) and Ni(II) complexes and tetragonal for Cu(II) complexes. The biological actions of the ligand and complexes have been screened in vitro against many bacteria and pathogenic fungi to study their comparative capacity to inhibit the growth.     

香草醛异烟酰腙与钴、镍、铜、锌和镉配合物的合成和性质研究

本文合成了香草醛异烟酰腙(H_2L~Ⅰ)和邻香草醛异烟酰腙(H_2L~Ⅱ)与钴(Ⅱ)、镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)和镉(Ⅱ)的九个新配合物:M(HL~Ⅰ)_2·nH_2O[M(Ⅱ)=Co、Ni、Cu、Zn和Cd,n=0,2]和M(HL~Ⅱ)_2·nH_2O[M(Ⅱ)=Co、Ni、Cu和Zn,n=0-3]。采用元素分析、红外光谱、电子光谱、电导、磁化率、X-射线粉末衍射和热分析研究了两系列配合物的组成和性质。     

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

Summary 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 · 3H₂O, CoL · 2H₂O, CuL, MnL · 2H₂O, ZnL · H₂O, Zr(OH)₂(LH)₂, Zr(OH)₂L · 2MeOH, UO₂L · MeOH and MoO₂L · MeOH (where LH₂ = 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.     

Synthesis,spectroscopic characterization,electrochemical behaviour and thermal decomposition studies of some transition metal complexes with an azo derivative

Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a novel heterocyclic azo derivative, formed by coupling diazotized 2-amino-3-carbethoxy-4,5-dimethylthiophene with acetylacetone were synthesized and characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV–vis, IR, ¹H NMR and EPR spectral data. Spectral studies revealed that the ligand existed in an internally hydrogen bonded azo-enol form rather than the keto-hydrazone form and coordinated to the metal ion in a tridentate fashion. Analytical data revealed that all the complexes exhibited 1:1 metal–ligand ratio. On the basis of electronic spectral data and magnetic susceptibility measurements, suitable geometry was proposed for each complex. The nickel(II) complex has undergone facile transesterification reaction when refluxed in methanol for a long period. The ligand and the copper(II) complex were subjected to X-ray diffraction study. The electrochemical behaviour of copper(II) complex was investigated by cyclic voltammetry. The thermal behaviour of the same complex was also examined by thermogravimetry.     

New complexes of iron(II), cobalt(II), nickel(II) and copper(II) with 2,2′-dipyridylmethane

Summary 2,2-Dipyridylmethane reacts with iron(II), cobalt(II), nickel(II) and copper(II) salts to form complexes of a varied stereochemistry depending upon the metal and the anion involved,Pseudo-tetrahedral, octahedral and square-planar complexes containing this ligand have been prepared and characterized by elemental analysis, conductivity data, room temperature magnetic moments and electronic spectra.     

Spectroscopic studies on Co(II), Ni(II), Cu(II) and Zn(II) complexes with a N4-macrocylic ligands

Complexes of cobalt(II), nickel(II), copper(II) and zinc(II) with a new tetraaza macrocyclic ligand have been synthesized and characterized by microanalyses, molar conductance, magnetic susceptibility, mass, thermogravimetric (TGA), IR, 1H and 13C NMR, electronic and ESR spectral studies. All the complexes are found to have the formula [MLX2]x nH2O and are six-coordinated with distorted octahedral geometry.     

Iron(II), cobalt(III), nickel(II) and copper(II) chelates of furan and thiophene azo-oximes

Summary Complexes of furan and thiophene azo-oximes with iron(II), cobalt(III), nickel(II) and copper(II) have been prepared and characterised. Iron(II), cobalt(III) and copper(II) complexes are diamagnetic in the solid state. The diamagnetism of the copper(II) chelates is suggestive of antiferromagnetic interaction between two copper centres.¹H n.m.r. spectral data suggest atrans-octahedral geometry for the tris-chelates of cobalt(III). Nickel(II) complexes are paramagnetic, in contrast to the diamagnetism of the analogous complexes of arylazooximes. The electronic spectra are suggestive of octahedral geometry for the iron(II), cobalt(III) and nickel(II) complexes, andD _4h -symmetry for copper(II). Infrared data indicate N-bonding of the oximino-group to the metal ions.     

Polymetallic complexes: Part XI,cobalt(II), nickel(II), copper(II), manganese(II), zinc(II), cadmium(II) and mercury(II) complexes with ON−NO tetradentate Schiff base,N,N'-bis(benzoin) benzidine

Summary The ON–NO donor Schiff base,N,N'-bis(benzoin)benzidine forms mono-, di- and tetra-nuclear complexes with metal cations. The cobalt(II) complex is a blue monomei of tetrahedral configuration. The nickel(II) and manganese(II) complexes are dimers and octahedral. A tetranuclear square planar chloro-bridged structure is proposed for the copper(II) complex. A dimeric pentacoordinated square pyramidal configuration is assigned to zinc(II) and a dinuclear tetrahedral stereochemistry is suggested for the cadmium(II) and mercury(II) complexes on the basis of analytical, conductance, magnetic susceptibility, molecular weight, i.r., electronic, d.t.g. and d.t.a. data.