Synthesis and electronic properties of acetylene- and butadiyne-linked 3,3′-porphycene dimers

Abstract

The butadiyne- and acetylene-linked 3,3′-porphycene dimers 1 and 2 were synthesized from the common intermediate, 3-ethynyl-2,7,12,17-tetrahexylporphycene 4. The butadiyne-linked dimer 1 was prepared from 4 by copper mediated Glaser-type homo-coupling. The acetylene-linked dimer 2 was synthesized by Sonogashira coupling of 4 and 2,7,12,17-tetrahexyl-3-iodoporphycene 5. These porphycene dimers were characterized by 1 H and 13 C NMR spectroscopies, mass spectroscopy, X-ray diffraction analysis, UV-vis absorption and fluorescence spectra, cyclic voltammetry and differential pulse voltammetry. Crystal structure of 1showed a coplanar structure of two porphycene units. The absorption spectra in CH 2 Cl 2 indicated the small interaction between the porphycene units through the linkage at 3,3′-positions. The electrochemical measurement showed two one-electron oxidation potentials and four one-electron reduction potentials indicating the electric interaction between the porphycene units.