K.B. Pandeya

Some metal complexes of phenyldithiocarbazic acid

Abstract Phenyldithiocarbazate (C 6 H 5 NHNHCSS − ) (L) complexes of vanadium(IV), chromium(III), iron(III), cobalt(III), cobalt(II), nickel(II), palladium(II), copper(I), zinc(II), cadmium(II), mercury(II) and uranium(VI) have been prepared and characterized by elemental analyses, magnetic and spectroscopic techniques. The complexes are of the type M(L) n , where n is the oxidation state of the metal ion. For vanadium(IV) and uranium(VI) complexes M stands for VO 2+ and UO 2 2+ ions.

Substituted anilines and α-naphthylamine carbodithiota-nickel(II) complexes and their pyridine adducts

Abstract Ortho-, para- and meta-methoxy aniline-, p-brome and p-iodoaniline-, 2,4-dimethylaniline-, chloro, methylaniline- and α-naphthylamine-carbodithioate complexes of nickel(II) have been prepared and characterised by analytical, magnetic and spectroscopic techniques. All these complexes are square planar bis-chelates. These bis-chelates react with pyridine to form pseudo-octahedral adducts.

Synthesis and X-Band Electron Paramagnetic Resonance Study of an Imidazolato Bridged Binuclear Copper(II) - Glycylglycine Complex

Abstract EPR Spectra of an imidazolato-bridged binuclear copper(II) complex of glycylglycine are described. Spectra of related mononuclear complexes, viz., aquoglycylglycinatocopper(II) and imidazoleglycylglycinatocopper(II), are also described.

E.s.r. spectra of mixed ligand manganese(II) dithiocarbamates

SummaryE.s.r. spectra of mixed ligand manganese(II) complexes of the type Mn(dtc)2(B), where dtc = pipyridyl dithiocarbamate (pip-dtc) or morpholyl dithiocarbamate (morph-dtc) and B = 2,2′-dipyridyl (dipy) or 1,10-phenanthroline (phen), are described. The results are comparable to those calculated for D=0.19 cm−1, λ=0.04, giso = 2.00 and for magnetic field directions parallel to principal D-tensor axes.

Oxovanadium(IV) complexes of cyclohexanone semicarbazone and cyclohexanone thiosemicarbazone

SummaryOxovanadium(IV) complexes, VOL2X2 (X = Cl, Br and 0.5 SO4), have been synthesised and characterised by elemental analysis, room temperature magnetic moment, electronic, i.r. and electron spin resonance studies. The complexes are hexacoordinate and have a distorted octahedral structure.

X-band e.p.r. spectra of imidazole/imidazolate bridged polynuclear copper(II) complexes

X-band e.p.r. spectra of polycrystalline, polynuclear complexes of the type [(dien)Cu-im- Cu(dien)]n(ClO4)n and [(dien)Cu-imH- Cu(dien)]n(ClO4)2n are described, where dien = diethylenetriamine, imH and im are imidazole (and 2-methyl- and 2-ethylimidazole) respectively. All the complexes show e.p.r. spectra characteristic of S=1, which yield the value of the zero field splitting parameter, D, in the 0.030±0.001cm−1 range.

Ion-exchange properties of hydrous ceric oxide—I: Sorption of some metal ammines

Abstract The sorption of ammines of Co(III), Ni(II), Cu(II), Zn(II) and Cd(II) on hydrated ceric oxide has been studied at different pH values and ionic concentrations of the external solution. In each case, qA and Kd values increase with an increase in pH, attain a maximum and then show a fall. With an increase in the exchanging ion concentration, qA first increases, attains a maximum and then decreases. The selectivity quotients (KAstaggeredB) of the exchanger material towards competing pairs -Cu2+Ni2+, Co3+Ni2+, Zn2+Ni2+ and Cd2+Ni2+ of the complex ions have been evaluated at pH = 10·5, where most of the exchanging ions show the maximum sorption. The sorption capacity and selectivity (at pH = 10·5) follow the order, Co3+ > Cu2+ > Zn2+ > Ni2+ > Cd2+.

Synthesis and Characterization of Cobalt(III) Complexes with Thiophene-2-carboxylaldehyde Thiosemicarbazone

Abstract Cobalt(III) complexes of thiophene-2-carboxyal-dehyda thiosemicarbazone (ligand), of general formulae, Co(ligand)2.X3, Co(ligand)X3.H2O (where X = NO− 3, Cl−, Br−, I− and CH3COO−) and Co(ligand-H)3 have been prapared and characterised. The complexes are diamagnetic. Ligand field parameters have been calculated from the electronic spectra. IR spectra show that the ligand acts as a bidantats. Octahedral geometry has been suggested for all these complexes.

EPR spectra of a spin-crossover iron(III) dithiocarbamate

Abstract Variable temperature (298-4.2 K) EPR spectra of a tris(dithiocarbamato)iron(III) complex involving 6 A 1g ⇌ 2 T 2g spin-crossover have been described. Results favour a solid solution model for the spin-crossover.

Stereochemical Studies on Cobalt (II) and Nickel (II) Complex of Some Semi Carbazones

Abstract Cobalt (II) and nickel (II) complexes of acetone semicarbazone and ethylmethylketone semicarbazone have been synthesised and characterised by elemental analysis, magnetic susceptibility measurements, IR and electronic spectral studies. All cobalt(II) complexes are octahedral. Nickel(II) complexes, on the other hand, show stereochemical variations depending upon the aims involved; thiocyanato and nitrato complexes are six-coordinate octahedral and chloro and sulphato complexes are five coordinate trigonal bipyramidal