Pentamethylcyclopentadienyl-rhodium and -iridium complexes. Part VII. Mono-, di-, and tri-µ-hydrido-complexes

Abstract

The complexes [M(C₅Me₅)Cl₂]₂, [M(C₅Me₅)X₂]_n(M = Rh or Ir; X = OCOCH₃ or OCOCF₃) are catalysts for the hydrogenation of olefins under ambient conditions. Reaction of these complexes with hydrogen has given the novel compounds [{M(C₅Me₅)}₂HCl₃], [{M(C₅Me₅)}₂HX₂]Y, [{M(C₅Me₅)}₂H₂X]Y, and [{Ir(C₅Me₅)}₂H₃]Y [X = OCOCH₃ or OCOCF₃; Y = PF₆, H(OCOCF₃)₂ or H(OCOCH₃)₂] which contain mono-, di-, and tri-µ-hydrido-ligands. The mono-µ-hydrido-complexes [{M(C₅Me₅)}₂HX₂][HX₂](M = Rh or Ir; X = OCOCH₃) can also be prepared from [M(C₅Me₅)(OCOCH₃)₂] and isopropyl alcohol; in air the isopropyl alcohol is catalytically dehydrogenated to acetone. Hydrolysis of [{M(C₅Me₅)}₂HX₂]⁺(M = Rh, X = OCOCH₃ or OCOCF₃, M = Ir, X = OCOCH₃) leads to complexes which it is suggested contain µ-hydrido-µ-hydroxo-bridges [{M(C₅Me₅)}₂H(OH)X].