Abstract: The oxidation reactions of(TPP)Ni(Ⅱ) were reinvestigated by cyclic voltammetry and spectroelectrochemistry in the presence of F^- anions in methylene chloride solution.It was found that the addition of F^- led to the appearance of Ni(Ⅱ)/Ni(Ⅲ) redox step at E_1/2=0.60 V(vs.SCE),which were followed by two one-electron oxidation reactions of the porphyrin ring at E_1/2=0.95 V and 1.25 V,respectively.In-situ thin-layer spectra were obtained and assigned to these ring oxidized Ni(Ⅲ) species.An intermediate spectrum of (TPP)Ni(Ⅲ) was observed in a time-resolved thin-layer electrolysis.A box mechanism of F^- coordination-redox reactions was proposed for this system.

Key words: nickel porphyrin, anion coordination, electrochemistry, spectroelectrochemistry