COBALT(III) COMPLEXES OF FORMYLPYRAZINE AND ACETYLPYRAZINE N(4)-SUBSTITUTED THIOSEMICARBAZONES

Cobalt(III) complexes of acetyl- and formylpyrazine N(4)-substituted t hiosemicarbazones have been synthesized and characterized by spectral and physical techniques. The crystal structure of the bis{formylpyrazi ne N(4)-methylthiosemicarbazone}cobalt(III) complex shows the two liga nds coordinated in a mer-configuration, and the orientation of the thi osemicarbazone moiety's N(4)-methyl is Z with respect to the thiolato sulfur in both ligands. Included is the crystal structure of the bis{2 -acetylpyridine N(4)-propylthiosemicarbazone}cobalt(III) complex in wh ich the two thiosemicarbazone ligands are also in the mer-configuratio n, but one ligand has the propyl group oriented Z with respect to the thiolato sulfur and the other E. Both complexes' bond lengths and bond angles are compared with other cobalt(III) thiosemicarbazone complexe s.