Synthesis and electrochemical investigation of covalently linked porphyrin dimers containing a beta-brominated subunit. Crystal structure of H-2[tripp-tpp(Br-8)]H-2

Ten meso-tetraphenylporphyrin-type heterodimers containing a partly or completely beta-brominated subunit were synthesized and characterized by UV-visible spectroscopy, cyclic voltammetry and spectroelectrochemistry, showing the presence of low electronic interactions between the two subunits. The investigated compounds are represented as M[(tripp-tpp(Br-4)]M and M[tripp-tpp(Br-8)]M (M = 2H, Zn, Ni, Co and Cu) where tripp-tpp(Br-4) is the tetraanion of 1-[5-(10,15,20-triphenylporphyrinyl)]-4-[10-(2,3,12,13-tetrabromoporphyrinyl)]-benzene and tripptpp(Br-8) is the tetraanion of 1-[5-(10,15,20-triphenylporphyrinyl)]-4-[10-(2,3,7,8,12,13,17,18-octabromoporphyrinyl)] -benzene. One of the synthesized dimers, H-2[tripp-tpp(Br-8)]H-2, was characterized by a single-crystal X-ray investigation. Copyright (C) 2003 Society of Porphyrins & Phthalocyanines.