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Strong bactericidal activities against various bacteria were observed in the reaction system of iron(III) octacarboxyphthalocyanine ( Fe III - oapc ) and tert-butyl hydroperoxide (tert-BuOOH). The kinetics of the decomposition of tert-BuOOH catalysed by Fe III -oapc were studied in buffered solutions between pH 5 to 12 using gas chromatography analysis. The rate of catalytic decomposition of tert-BuOOH followed second-order kinetics in tert-BuOOH concentrations. The second-order rate constant (k2) had a maximum value at pH 11. Oxygen evolution was observed at high tert-BuOOH concentration, while oxygen consumption was observed at low tert-BuOOH concentration. The former indicates plural radical chain reactions of the tert-butoxyl radical and the latter suggests decomposition of the tert-butoxyl radical to acetone and methyl radical. By the electron spin resonance spin trapping method using 5,5-dimethyl-1-pyrroline-N-oxide and α-phenyl-N-tert-butylnitrone it was found that the radical species generated in the reaction system is tert-butoxyl radical, which plays crucial roles in bactericidal activities.

The bactericidal activity of an electrochemical system with a cobalt(II) phthalocyanine-modified Ti electrode was studied. In the presence of NaBO 3, strong bactericidal activity was observed against E. coli with electroreduction for 30 min. If an unmodified Ti electrode was used, no bactericidal activity was observed in the electrochemical system. By the ESR spin-trapping method using 5,5-dimethyl-1-pyrroline-N-oxide as the spin-trapping reagent, the radical species generated in the electrocatalytic reaction was found to be hydroxyl radical, which acts as the potent cytocidal species in the system.