Mono{hydrotris(mercaptoimidazolyl)borato} complexes of manganese(II), iron(II), cobalt(II), and nickel(II) halides

A series of [Tm(Me)M(mu-Cl)]2 and Tm(R)MCl (Tm(R) = tris(mercaptoimidazolyl)borate; R = Me, tBu, Ph, 2,6-iPr2C6H3 (Ar); M = Mn, Fe, Co, Ni) complexes have been prepared by treatment of NaTm(Me) or LiTm(R) with an excess amount of metal(II) chlorides, MCl2. Treatment of Tm(R)MCl (R = tBu, Ph, Ar) with NaI led to a halide exchange to afford Tm(R)MI. The molecular structures of [Tm(Me)M(mu-Cl)]2 (M = Mn, Ni), [Tm(Me)Ni(mu-Br)]2, Tm(tBu)MCl (M = Fe, Co), Tm(Ph)MCl (M = Mn, Fe, Co, Ni), Tm(Ar)MCl (M = Mn, Fe, Co, Ni), Tm(Ph)MI (M = Mn, Co), and Tm(Ar)MI (M = Fe, Co, Ni) have been determined by X-ray crystallography. The Tm(R) ligands occupy the tripodal coordination site of the metal ions, giving a square pyramidal or trigonal bipyramidal coordination geometry for Tm(Me)M(mu-Cl)]2 and a tetrahedral geometry for the Tm(R)MCl complexes, where the S-M-S bite angles are larger than the reported N-M-N angles of the corresponding hydrotris(pyrazolyl)borate (Tp(R)) complexes. Treatment of Tm(Ph)2Fe with excess FeCl2 affords Tm(Ph)FeCl, indicating that Tm(R)2M as well as Tm(R)MCl is formed at the initial stage of the reaction between MCl2 and the Tm(R) anion.     

Gas chromatography of ternary complexes of manganese(II), iron(II), cobalt(II) and nickel(II) with hexafluoroacetylacetone and DI-n-butylsulphoxide

The gas Chromatographic behaviour of the ternary complexes of selected bivalent first-row transition metal ions with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione H(HFA), and di-n-butylsulphoxide, DBSO, was studied. Calibration plots of peak area vs. amount of metal injected were linear over a range of 60–900 ng for manganese(II), iron(II), cobalt(II) and nickel(II). The average relative standard deviation was less than 3·0% for all the metals studied. Detection limits of 60, 109, 112 and 115ng for cobalt(II), nickel(II), iron(II) and manganese(II), respectively, were obtained with flame-ionization detection. Various liquid phases, including OV-1, SE-30, and Dexsil 300 were used. The best results were obtained on columns of 5% Dexsil 300. No appreciable thermal decomposition was observed on stainless-steel or glass columns, but the best formed peaks were obtained on all-glass columns. The elution of the metallic species was confirmed by venting the exit gases from the gas chromatograph directly into an atomic-absorption spectrophotometer.     

Copper(II), nickel(II), cobalt(II), manganese(II), iron(III) and oxovanadium(IV) complexes of biacetylmonoquinolylhydrazone (BAMQH)

Octahedral complexes of the general composition [M(II)(BAMQH)₂]X₂ (where M = Cu(II), Ni(II), Co(II); X = Cl⁻, I⁻, ClO⁻₄ and BAMQH is biacetalmonoquinolylhydrazone); [M(II)(BAMQH)Cl₂.H₂O] (where M = Mn(II), Fe(III)) and penta-coordinated [VO(BAMQH)₂]SO₄ have been synthesized and characterized by magnetic susceptibility, optical and ESR studies in the polycrystalline and frozen states. [Ni(II)(BAMQH)₂]Cl₂ has tetrahedral geometry. Bidentate nature of the ligand is assumed in [Ni(II)(BAMQH)₂]Cl₂ and [VO(BAMQH)₂]SO₄ complexes.     

N-benzamidosalicylaldimine complexes of copper(II), nickel(II), cobalt(II), iron(II), manganese(II), oxyvanadium(IV) and oxytitanium(IV)

Summary N-benzamidosalicylaldimine (H₂L) complexes of Cu^II, Ni^II, Co^II, Fe^II, Mn^II. VO_IV and TiO_IV have been prepared. The ligand probably coordinates to the metal from the hydroxyl, carbonyl and imino groups.     

Synthesis and characterization of biacetyldihydrazone complexes of cobalt(II), copper(II), nickel(II) and iron(III)

Summary Biacetyldihydrazone (BdH) complexes [M(BdH)₃](ClO₄)₂ (M=Co^IIor Cu^II) and [M(BdH)₃](NO₃)_2,3 (M = Ni^IIor Fe^III) have been prepared and characterized by chemical analysis, conductance measurements, electronic, i.r. and e.p.r. spectral studies and magnetic subsceptibilities measurements. A mononuclear octahedral configuration is proposed for all complexes studied.     

Synthesis and thermodynamics of lead(II), manganese(II), and cobalt(II) pivalate complexes

Manganese and cobalt oxopivalates and lead pivalate have been synthesized, mass spectral and thermogravimetric analysis have been performed. Sublimation enthalpies of cobalt and manganese oxopivalates have been determined for the first time, while the sublimation enthalpy of lead pivalate has been found to agree well with literature data. Low sublimation enthalpy, high volatility, and monomolecular composition of gas phase allow one to use these complexes as precursors for preparing oxide films and materials by MOCVD method.     

Synthesis and chemical characterization of biologically important complexes of vanillin thiosemicarbazone with manganese(II), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), and mercury(II)

Summary Vanillin thiosemicarbazone (VTSC) has been used to isolate the complexes of the types [M(VTSC)₂(H₂O)₂]X₂ (M=Mn^II, Fe^II, Co^II, or Ni^II and X=Cl) and [M(VTSC)X₂]H₂O (M=Cu^II, Zn^II, Cd^II or Hg^II and X=Cl). Probable structures of these complexes are suggested on the basis of elemental analysis, molar conductance, magnetic moment and electronic and i.r. spectral data. The fungicidal activity of VTSC and the isolated complexes has been evaluated on pathogenic fungi,Alternaria (Sp.),Paecilomyces (Sp.) andPestalotia (Sp.).On leave from the University of Myosore.     

Structural elucidation of manganese(II), iron(III), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of a new multidentate dihydrazino quinoxaline derivative

Summary Manganese(II), iron(III), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of a new multidentate oxygen-nitrogen donor, bis(N-salicylidene)-2,3-dihydrazino-1,4-quinoxaline (H₂BSDHQ) were prepared and characterised by elemental analysis, conductance, thermal, spectral and magnetic data. H₂BSDHQ deprotonates to give a dibasic ONNO donor set in a trivalent iron(III) complex, which binds to the divalent metal ions in a bis-tridentate fashion, using two monobasic ONN donor sets, and resulting in polymeric complexes. Octahedral geometries are proposed for all these complexes, and preliminary studies show that they possess potential antimicrobial activity.     

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.     

Chromium(III), manganese(II), iron(III), cobalt(II), nickel(II) and copper(II) complexes with a pentadentate, 15-membered new macrocyclic ligand

Complexes of Cr^III, Mn^II, Fe^III, Co^II, Ni^II and Cu^II containing a macrocyclic pentadentate nitrogen–sulphur donor ligand have been prepared via reaction of a pentadentate ligand (N₃S₂) with transition metal ions. The N₃S₂ ligand was prepared by [1 + 1] condensation of 2,6-diacetylpyridine with 1,2-di(o-aminophenylthio(ethane. The structures of the complexes have been elucidated by elemental analyses, molar conductance, magnetic susceptibility measurements, i.r., electronic and e.p.r. spectral studies. The complexes are of the high spin type and are six-coordinate.     

Spectral and magnetic studies on manganese(II), cobalt(II) and nickel(II) complexes with Schiff bases

Mn(II), Co(II) and Ni(II) complexes of 2-methylcyclohexanone thiosemicarbazone(MCHTSC L(1)) and 2-methylcyclohexanone-(4)N-methyl-3-thiosemicarbazone (MCHMTSC L(2)), general composition [M(L)(2)X(2)] (where M = Mn(II), Co(II), Ni(II), L = L(1) or L(2) and X = Cl(-), NO(3)(-), and [(1/2)SO(4)(2-)) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, UV-vis, IR, EPR, and mass spectral studies. Various physico-chemical techniques suggest an octahedral geometry for all the complexes.     

Synthesis and characterisation of complexes of iron(II,III), cobalt(II,III) and nickel(II) with dinitrosoresorcinol

Summary Complexes of Fe^II, Fe^III, Co^II, Co^III and Ni^II with dinitroso resercinol (DNR) have been isolated and characterised. Ni studies showed that the metals are coordinated to the oxygens of one hydroxyl and one nitroso group, the second hydroxyl and nitroso groups remaining uncoordinated. The magnetic moments of the Fe^II and Ni^II complexes are commensurate with tetrahedral (or disorted octahedral) structures, while the others are ocahedral, however, the electronic spectra suggest ocahedral stereochemistries for all the complexes.     

N-acetyl-DL-leucinate cobalt(II), nickel(II) and zinc(II) complexes

Summary Complexes of the type M(AcLeu)₂ · B₂ (M = Co^II, Ni^II or Zn^II; B = H₂O, py, 3-pic, 4-pic; AcLeu =N-acetyl-DL-leucinate ion) and M(AcLeu)₂ B (M = Co^II or Zn^II and B = o-phen) were prepared and investigated by means of magnetic and spectroscopic measurements. The i.r. spectra of all the complexes are consistent with bidentate coordination of the amino acid to the metal ion. The room temperature solid state electronic spectra indicate that the symmetry of this species is closer toD _4h and that MO₆ and MO₄N₂ chromophores are present in the M(AcLeu)₂ · 2 H₂O and M(AcLeu)₂B_n · x H₂O (B = py, 3-pic, 4-pic, n=2 and x=0 for M = Ni^II; B = o-phen, n=1 and x=0 for M = Co^II; B = py, 3-pic, 4-pic, n=1 and x=1 for M = Co^II) complexes, respectively. By comparing the Dq values of the amino acid and those of other N-substituted amino acids previously studied, a spectrochemical series of the the cobalt(II) and nickel(II) complexes is proposed. The¹ H n.m.r. spectra of the zinc(II) complexes confirm the proposed stereochemistry.     

Three heterotrinuclear Schiff base complexes of nickel(II) with cobalt(II), copper(II) and manganese(II)

The title compounds, bis­(di­methyl­form­amide)‐1κO,3κO‐bis{μ‐2,2′‐[2,2′‐di­methyl­propane‐1,3‐diyl­bis­(nitrilo­methylidyne)]­diphenolato}‐1κ⁴N,N′,O,O′:2κ²O,O′;2κ²O,O′:3κ⁴N,N′,O,O′‐di‐μ‐nitrito‐1:2κ²N:O;2:3κ²O:N‐dinickel(II)­cobalt(II), [CoNi₂(NO₂)₂(C₁₉H₂₂N₂O₂)₂(C₃H₇NO)₂], (I), ‐copper(II), [CuNi₂(NO₂)₂(C₁₉H₂₂N₂O₂)₂(C₃H₇NO)₂], (II), and ‐manganese(II), [MnNi₂(NO₂)₂(C₁₉H₂₂N₂O₂)₂(C₃H₇NO)₂], (III), consist of centrosymmetric linear heterotrinuclear metal complexes. The three complexes are isostructural. There are three bridges across the Ni–M atom pairs (M is Co²⁺, Cu²⁺ or Mn²⁺) in each complex, involving two O atoms of a μ‐N,N′‐bis­(salicyl­idene)‐2,2′di­methyl‐1,3‐propane­diaminate ligand and an N—O moiety of a μ‐nitrito group. The coordination sphere around each metal atom, whether Co²⁺, Cu²⁺, Mn²⁺ or Ni²⁺, can be described as distorted octahedral. The Ni?M distances are 2.9988 (5) Å in (I), 2.9872 (5) Å in (II) and 3.0624 (8) Å in (III).     

3- and 4-Pyridinecarboxylic acidN-oxide complexes with manganese(II), cobalt(II) and nickel(II) chlorides

Summary During interaction of ethanol-triethyl orthoformate solutions of nicotinic or isonicotinic acidN-oxides (LH and LH, respectively) with MCl₂ (M = Mn, Co, Ni), only one true adduct, of the Ni(LH)₃Cl₂ · 2 H₂O type was obtained. In all other cases, partial substitution of Cl^– ions with the corresponding pyridinecarboxylateN-oxide anionic ligands (L or L) occurred. As a result, mixed ligands (LH-L or LH-L) were precipitated, as follows: Mn(LH)₂LCl, Co(LH)LCl, Mn(LH)LCl · 4H₂O, Co(LH)LCl · H₂O and Ni₂(LH)LCl₃ · 6 H₂O. The insolubility of the new complexes in all common solvents, combined with the pronounced tendency of the 3- and 4-pyridinecarboxylates and theirN-oxides to function as bidentate bridging ligands, favours bi- or polynuclear structures. Spectral data suggest that Ni(LH)₃Cl₂ · 2 H₂O is hexacoordinate, and the rest of the new complexes pentacoordinate. Bi- or polynuclear structures, involving double -M-(L)₂-M- or-M-(LH)₂-M- and single -M-(L)-M- or-M(L)-M-(LH)-M- bridges, were proposed on the basis of the overall evidence; additional features of the proposed structural types are: exclusively coordinated chloro ligands, in all cases; aqua ligands [Co(LH)LCl · H₂O]; lattice water [Ni(LH)₂Cl₂ · 2H₂O]; both lattice and coordinated H₂O [Mn(LH)LCl · 4H₂O, and Ni₂(LH)LCl₃ · 6H₂O]; and, with the exception of Ni₂(LH)LCl₃ · 6 H₂O, terminal, unidentate, N-O oxygen-bonded LH or LH ligands.Abstracted in part from the Ph.D. Thesis (in preparation) of L. S. Gelfand, Drexel University.     

Activation volumes for peroxodisulphate oxidation of cobalt(III), iron(II) and nickel(II) complexes

Summary Dependences of rate constants on pressure (in aqueous solution up to 1.25 kbar) are reported for peroxodisulphate oxidation of hexacyanoferrate(II), tris(2,2-bipyridyl)iron(II), tris(1,10-phenanthroline)iron(II), bis(1,4,7-triazacyclononane)nickel(II) and bis(1,2-ethanediamine)cysteinatocobalt(III) and its thioglycollato-analogue, and for periodate oxidation of the two last-named complexes. Derived activation volumes are reported and discussed in terms of intrinsic and solvational contributions. Rate laws and pressure effects on reactivity are reported for the reaction of peroxodisulphate with pentacyanoferrates(II) containing N-alkylpyrazinium ligands.     

Electro-oxidation and electro-reduction of some iron (II), cobalt(II) and nickel(II) polypyridyl complexes in acetonitrile

Cyclic voltammetry and controlled potential coulometry studies of 2,2′-bipyridyl, 4,4′-dimethyl-2,2′-bipyridyl and 2,2′, 2″-terpyridyl complexes of Fe(II), Co(II) and Ni(II) in acetonitrile are described. E_1/2 values for M(III)/M(II) and M(II)/M)I) couples are compared and crystal field effects discussed. A series of M(I) and M(III) polypyridyl complexes have been prepared by controlled potential electrolysis; these include a number of 3+ and 1+ oxidation state complexes of nickel which have not previously been isolated — [Ni(bipy)₃]-(ClO₄)₃, [Ni(dimbipy)₃](ClO₄)₃, [Ni(terpy)₂](ClO₄)₃ and [Ni(bipy)₂]ClO₄.     

Synthesis,characterization and antibacterial activities of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes with soluble Vitamin K3 thiosemicarbazone

A thiosemicarbazone derivative of the Vitamin K₃ has been synthesized. Five transition metal complexes of the thiosemicarbazone have been prepared and characterized by i.r., u.v.–vis., molar conductance and thermal analyses. All of the complexes possess strong inhibitory action against G(+) Staphylococcus aureus, G(–) Hay bacillus, and G(–) Eschericha coli. The antibacterial activities of the complexes are stronger than those of the thiosemicarbazone itself.     

Synthesis of four new vic-dioximes and their nickel(II), cobalt(II), copper(II) and cadmium(II) complexes

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 Ni^II, Co^II, Cu^II and Cd^II 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.