Doubly N-Confused Porphyrin: A New Complexing Agent Capable of Stabilizing Higher Oxidation States

Abstract

A doubly N-confused porphyrin (N2CP), 2-ethoxy-5,10,15,20-tetrapentafluorophenyl-3,7-diaza-21,22-dicarbaporphyrin, and its Ag(III) and Cu(III) complexes were synthesized for the first time, via an acid-catalyzed condensation of pentafluorobenzaldehyde and meso-pentafluorophenyl-2,3‘-dipyrromethane. 1H NMR and single-crystal X-ray diffraction analyses reveal the arrangement of the three hydrogens (two CH and one NH) in the core of N2CP both in solution and in the solid state, respectively. The diamagnetic silver(III) complex has a square-planar tetracoordination and short Ag(III)−C bond distances of 1.987(8) and 2.011(8) Å. Similarly, the diamagnetic Cu(III) complex shows a square-planar coordination with Cu(III)−C bond distances of 1.939(3) and 1.934(4) Å. The trianionic nature of the N2CP ligand and a possibility of stabilizing the higher oxidation state by “confusion” are discussed.