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

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)PP2-],5,10,15,20-tetrakis(4-methoxyphenyl)porphyri [T(4-OMe)PP2-] or 5,10,15,20-tetrakis(4-chlorophenyl)porphyrin [T(4-Cl)PP2-]} have been prepared by treating Eu(acac)(Por) (acac=acetylacetonate), generated in situ from Eu(acac)(3).nH(2)O and H(2)Por, with Li2Pc 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. (C) 1998 Elsevier Science S.A.