X-ray absorption spectroscopy study on the electrochemical reduction of Co((DO)(DOH)(pn))Br-2

The reduction process of Co-III((DO)(DOH)(pn))Br-2 has been studied by X-ray absorption spectroscopy. A structural rearrangement takes place during the first reduction step, from Co-III to Co-II. It involves the cleavage of both axial bromide ligands. However, the reduction from Co-II to Co-I proceeds with retaining of the coordination geometry. These findings have also been confirmed by an 'ad hoc' electrochemical experiment. (C) 2000 Elsevier Science Ltd. All rights reserved.