ELECTRON-TRANSFER MECHANISM OF METAL ANTH RAQUINONECYANINE

The synthesis of novel metal phthalocyanine derivatives, metal anthraq uinonecyanine, was reported in our previous paper. In this paper, we p resent a study of the electron transfer mechanism of the same derivati ves in an organic solvent. Electrochemical measurements, involving cyc lic voltammetry, chronoamperometry and chronocoulometry, were carried out for the above-mentioned compounds. A pair of reversible peaks and three irreversible peaks were observed in the cyclic voltammograms. Th e former peaks were attributed to the reduction of the anthraquinonecy anine ring in the metal anthraquinonecyanines. On the other hand, the latter ones were interpreted to result from the reduction of the centr al metal. It was found that the mode of the electron transfer in the o xidation process is different from that in the reduction one and the r eaction rate of the oxidation is slower than that of the reduction. Fu rther, it was shown that the electron transfer process in the vicinity of the electrode surface is a diffusion controlled one which involves some weak adsorption and is followed by a succeeding chemical reactio n.