Heteroleptic triple-decker (phthalocyaninato)-(porphyrinato)europium(III) complexes: synthesis and electrochemical study

Abstract

The heteroleptic triple-decker complexes Eu 2(Pc)(Por) 2 and Eu 2(Pc) 2(Por) {Pc = dianion of phthalocyanine; Por = dianions of 5,10,15,20-tetrakis(4-tert-butylphenyl)porphyrin [T(4-Bu)PP 2]}], 5,10,15,20-tetrakist(4-methoxylphenyl)porphyrin {T(4-OMe)PP 2−} or 5,10,15,20-tetrakis(4-chlorophenyl)porphyrin [T(4-Cl)PP 2−]} have been prepared by treating Eu(acae)(Por) (acac = acetylacetonate), generated in situ from Eu(acac) · nH 2O and H 2O and H 2Por, with Li 2Pc in 1,2,4-trichlorobenzene. These sandwich compounds undergo four reversible one-electron oxidations and up to three reversible one-electron reductions as revealed by cyclic voltammetry. The effect of substituents at the periphery of porphyrins on the redox potentials of complexes are discussed.