Heterobinuclear cobalt-oxomolybdenum-thiocyanate complexes of dithiocarbamates or 8-quinolinol

摘要

The heterobinuclear complexes of [CoMoO_2(NCS)(L)_3(H_2O)] (L = diethyldithiocarbamate, 4-morpholinyldithiocarbamate or 8-molybdate with ammonium thioicyanate in the presence of hydrazinium sulphate and cobalt(II) nitrate with the respective ligands in DMF. The magnetic moment, EPR and PES data suggest the presence of molybdenum(V) and low-spin cobalt(III). The crystal field splitting parameters have been evaluated from the electronic spectral data. The infrared spectra suggest the presence of N-bonded thiocyanate ligand (2040 and 780 cm~(-1)), dithiocarbamate ligands (1500 and 960 cm~(-1)) and (Mo = O) (910 cm~(-1)) in the molecule. The extensive splitting in each peak observed in the ~1H NMR spectra of the complexes indicate the restrictede rotation of the alkyl side chain of the bidentate dithiocarbamate groups. The redox behaviour of the complexes in DMF is discussed from the cyclic voltammetry data. The thermal decomposition and infrared spectral studies confirm the presence of coordinated water molecule. The proposed structure consists of an octahedral cobalt(III) and an octahedral oxomolybdenum(V) bridged by an oxo and a thiocyanate groups.