ELECTROCHEMISTRY OF HEXACOORDINATE SILICON(IV) PORPHYRIN COMPLEXES

Cyclic voltammetry was used to characterize the oxidation-reduction be havior of a series of novel hexacoordinate silicon(IV) porphyrin compl exes. Each (Por)SiX2 [Por=the dianions of the porphyrins: tetrakis(p-t olyl)porphyrin (TTP), tetraphenylporphyrin (TPP), tetrakis(p-trifluoro methylphenyl)porphyrin (TTFP), octaethylporphyrin (OEP); X = F, Cl, O3 SCF3] complex undergoes one to two oxidations and one to two reduction s, all occurring at the porphyrin ring. No silicon(IV) reduction is ob served for any of the porphyrin complexes. The effects of solvent, sup porting electrolyte, substituents on the porphyrin ring, axial ligands , central metal, and ruffling of the porphyrin ring are described.