Synthesis and reactivity of the first η6-rhodium(I) and η6-iridium(I) complexes of 2,6-bis(trimethylsilyl)phosphinines

Article abstract of DOI:10.1002/ejic.200390095

It 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)Rh^I 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)Rh^I and -Ir^I 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 (ν⁵-phosphacyclohexadieny1)Rh^I and -Ir^I 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 -Rh^I complexes allows the rationalization of the large difference in reactivity of these complexes. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.