A Geometrical Isomeric Pair of Novel Cobalt(III) Complexes Containing Diphenylphosphine: cis- and trans-[Co(dtc)2(PHPh2)2]BF4 (dtc = N,N-Dimethyldithiocarbamate)

The stable title cobalt(III) complexes containing PHPh2 have been prepared and investigated for their crystal structures and spectroscopic properties. The cis-isomer was converted photochemically to the trans-isomer, which isomerized thermally to the original cis-isomer. The structural parameters and the ligand-field strengths of the PHPh2 complexes were not predictable from the σ-donicity of PHPh2.