Cyanoporphyrins. Co-ordinating and electrochemical properties

Abstract

Successive substitutions in the pyrrole rings of tetraphenylporphyrin by up to four cyano-groups lead to large additive anodic shifts of the redox potentials. These shifts are large than those observed with other electron-withdrawing substituents. The stoicheiometry and stability of the complexes formed from metallotetracycanoporphyrins (Cu, Ni, Ag) and nitrogenous bases (pyridine, piperidine) are determined. A novel five-co-ordinate silver(II) porphyrin is reported.