SUBSTITUENT EFFECT ON SPECTROCHEMICAL PROPERTIES OF COBALT(II) HALIDE COMPLEXES WITH N-MONOSUBSTITUTED 1,3-IMIDAZOLIDINES-2-THIONE

By reacting cobalt(III) halides with N-methyl and N-ethyl,1,3-eimidazolidine-2-thione, CoL2X2 complexes (X = Cl, Br, I) are obtained. The infrared spectra show them to be S-bonded to the metal; the νCoS vibrations are located within 340-320 cm-1. Colours, magnetism and electronic spectra support a tetrahedral stereochemistry. Using the average ligand field approximation, Dq and B′ values for [COL4]2+ are evaluated and the ligands are inserted in the spectrochemical and nephelauxetic series. The Dq values seem to depend on the electron releasing effect of the alkyl groups. © 1978.