Synthesis and Reactivity of the First η6‐Rhodium(I) and η6‐Iridium(I) Complexes of 2,6‐Bis(trimethylsilyl)phosphinines

Abstract

AbstractIt has been shown that 2 equiv. of 2,3,5,6‐tetraphenylphosphinine (2) react with [Rh(COD)2][BF4] to yield the bis(η1‐phosphinine)RhI complex 6, whose X‐ray crystal structure is presented. On the other hand, 2,6‐bis(trimethylsilyl)phosphinines 4 and 5 react with Rh+ and Ir+ precursors to yield the first (η6‐phosphinine)RhI and ‐IrI complexes 7−10, and 11−12, respectively. The X‐ray crystal structure of complex 8 is presented. Reaction of these η6‐phosphinine complexes with water or ethanol yields the first (η5‐phosphacyclohexadienyl)RhI and ‐IrI complexes 13−17, resulting from the formal 1,1‐addition of RO− and H+. DFT calculations comparing isoelectronic (η6‐phosphinine)‐ and (η6‐benzene)Fe0 and ‐RhI complexes allows the rationalization of the large difference in reactivity of these complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)