Some cobalt(II) complexes of 2,2'-Dithiodipyridine and 4,4'-Dithiodipyridine

Abstract

The following cobalt(11) complexes containing the chelate 2,2'-dithiodipyridine (αdtp) and the isomeric chelate 4,4'-dithiodipyridine (γdtp)* have been prepared and investigated: Co(αdtp)X₂ (X = Cl, Br,I and NCS), Co(γdtp)Cl₂ and Co(γdtp)₂X₂ (X = I and NCS). All, except the first three, are described for the first time. Physicochemical investigations indicate that the complexes Co(αdtp)X₂ (X = Cl,Br and I) are tetrahedral monomers and Co(αdtp)(NCS)₂ is an octahedral polymer. Co(γdtp)Cl₂, appears to be tetrahedral whereas Co(γdtp)₂X₂ (X = I and NCS) are octahedral polymers. Although the complete interpretation of the spectra is rendered difficult by the ligand bands occurring at lowfrequencies, far-infrared spectra have provided evidence that both nitrogen atoms in αdtp and γdtp are coordinated in these complexes.