Cofacial tris-porphyrins with anthracenic spacer

Abstract

In order to check if the parallel orientation of the chlorophylls in the light harvesting antennae of the photosynthetic system plays a key role in the efficiency of the energy transfer process, we synthesized three rigid tris-porphyrins bearing di-ethynyl-anthracenic spacers. The synthesis of this family of trimers in which porphyrins are held in a cofacial orientation by an anthracenic spacer is here described, as well as the NMR comparison between the different porphyrinic wires. This constitutes a first step toward the elaboration of more sophisticated light collecting devices. More specifically, these trimers, in which the porphyrins are held in a parallel conformation, constitute an approach toward the synthesis of rigid molecular wires.