Abstract
X‐ray absorption near edge structure (XANES) has been utilized to monitor electronic and structural changes of iron phthalocyanine adsorbed on a high area carbon substrate as a function of the applied potential. Cyclic voltammetry in exhibited two reversible electron‐transfer processes at 0.40 and vs. corresponding to redox processes and , respectively. Fine structures found for microcrystalline powder were largely diminished upon adsorption of the carbon. Polarization of the electrode at showed a transition at as a shoulder on the main absorption edge and a weak 1s → 3d pre‐edge peak. The absorption edge position, , was shifted from 7121.8 to due to the oxidation of iron and structural distortion, and the 1s → 3d transition was enhanced by polarizing at . XANES obtained for the reduced form of at was very similar to that of except that the white line became more intense and the transition almost disappeared. This was explained by the reduction of the Pc ring to form . The transferred electron is considered to be delocalized through the π system of the macrocyclic ligand. ©1999 The Electrochemical Society