Cobalt complexes of Bi- and Tetra-dentate N-substituted o-Mercaptobenzaldimines

Abstract

The synthesis of a number of cobalt(11) and cobalt(111) complexes of bi- and tetra-dentate N-substituted o-mercaptobenzaldimines is reported. The Co¹¹ bidentate complexes are spin-free and the tetra- dentate are spin-paired. 2,2'-Ethylenebis(nitrilomethylidyne)]bis(benzenethiolato-S,N)cobalt(11) (Co-(mben)) does not behave as an oxygen carrier at room temperature, in contradistinction to Co(salen). The complex is easily oxidized in the presence of water to [Co(mben)(H₂O)₂]⁺ ions. A synthetic route to the complexes through the aldehydato complex Co(mb)₂ is described which avoids condensation of the aldimines to cyclic nonanes.