Facile Synthesis of Large meso-Pentafluorophenyl-Substituted Expanded Porphyrins

Abstract

Acid-catalyzed condensation of meso-pentafluorophenyl dipyrromethane 1 (100 mm) and pentafluorobenzaldehyde 2 (100 mm) at 0 degrees C gave a series of expanded porphyrins with even number of pyrrolic subunits up to octadecaphyrin(1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1) 18 in improved yields, particularly for larger expanded porphyrins. The solid-state structure of decaphyrin(1.1.1.1.1.1.1.1.1.1) 10 was revealed by X-ray diffraction analysis to be a crescent-like conformation. The Soret-like absorption bands are increasingly redshifted as the size of the ring increases, but such a trend becomes nearly saturated for hexadecaphyrin(1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1) 16 and 18, which exhibit bands in the near-infrared region at 939 and 953 run, respectively. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).