Effects of cations on electrode processes of Cobalt–Schiff base complexes and their organometallic derivatives

Abstract

In the dipolar aprotic solvent NN-dimethylformamide, the anionic species [Co^IL]^– and [Co^IIL(R)]^–, electrochemically generated from the corresponding cobalt(II) and cobalt(III) derivatives, interact strongly with counter cation forming contact ion pairs [L =NN′-o-phenylenebis(salicylideneiminato), NN′-ethylenebis(salicylideneiminato), NN′-ethylenebis(α,α′-dimethylsalicylideneiminato), and NN′-ethylenebis(acetylacetonediiminato)]. There is a linear relation between the reversible E_½(red) values and the ionic potential of the counter cations. Association constants for the complexes (ion pairs) thus formed have been evaluated by polarography. Destabilization effects of the counter cations on the cobalt–carbon bond in the organometallic derivatives have been detected by cyclic voltammetry.