Solution chemistry of silver porphyrins. Oxidation of 5,10,15,20-tetra(3′-N-methylpyridinio)porphyrinatodisilver(I)

Abstract

Peroxodisulphate oxidation of a silver(I) complex of 5,10,15,20-tetra(3′-N-methylpyridinio)-porphyrin, believed to be 2:1 (metal : ligand), to the silver(II) complex has been investigated at 25 °C and I= 0.1 mol dm^–3. This reaction was found to be first order each in silver(I) and peroxodisulphate ions and zero order in porphyrin. The second-order rate constant for the oxidation is computed to be 3.45 × 10^–2 dm³ mol^–1 s^–1, which is in agreement with independently determined rate constants for the reaction of Ag⁺ with S₂O₈^2–.