Doubly N-confused porphyrin: A new complexing agent capable of stabilizing higher oxidation states

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.