SPECTRAL STUDIES OF COBALT(III) COMPLEXES OF HETEROCYCLIC 3-AZACYCLO-THIOSEMICARBAZONES AND THE STRUCTURE OF THE ACETYLPYRAZINE 3-AZABICYCLO[3.2.2]NONYLTHIOSEMICARBAZONE COMPLEX

Cobalt(III) complexes of 2-acetylpyridine 3-pyrrolidinyl-, 3-piperidin yl-, 3-hexamethyleneiminyl- and 3-azabicyclo-[3.2.2]nonylthiosemicarba zone, [Co(Lpo)(2)]BF4, [Co-(Lpip)(2)]BF4, [Co(Lhexim)(2)]BF4 and [Co(L bcn)(2)]BF4, respectively; 2-formylpyridine 3-piperidinyl-, 3-hexameth yleneiminyl- and 3-azabicyclo[3.2.2]nonylthiosemicarbazone, [Co(pip)(2 )]BF4, [Co(hexim)(2)]BF4 and [Co(bcn)(2)]BF4, respectively; and aceylp yrazine 3-azabicyclo[3.2.2]nonylthiosemicarbazone, [Co(Pzbcn)(2)]BF4, have been synthesized and their spectral properties measured. The H-1- and C-13-n.m.r. spectra show the uncomplexed thiosemicarbazones to be mixtures of as many as three isomers, and that the two ligands in the cobalt(III) complexes are nearly identical. The crystal structure of [Co(Pzbcn)(2)]BF4 shows the two ligands coordinated in a mer-configura tion. Bond lengths and angles in this complex are compared with data p reviously reported for thiosemicarbazone complexes.