Some Chemistry of Diynyl-Tungsten Complexes

Abstract

Reactions between W(CCCÅ≡CH)(CO)₃Cp (1) and {Mo(CO)₂Cp}₂,Pt (η-C₂H₄)(PPh₃)₂ and 1,4-I₂C₆H₄ [the latter catalysed by Pd⁰/Cu^I] have given M₂{μ-HC₂CÅ≡C[W(CO)3₃Cp]}(CO)₄Cp₂(2), Pt{η²-HC₂CÅ≡C[W(CO)₃-Cp]}(PPh₃)₂ (3) and 1,4-{[W(CO)₃Cp]CÅ≡CCÅ≡C}₂C₆H₄ (5), respectively. The adduct Co₂{μ-PhC₂CÅ≡C[W(CO)₃-Cp]}(μ-dppm)(CO)₄(6) was obtained from W(CÅ≡CCÅ≡CPh)(CO)₃Cp (4) and Co₂(μ-dppm)(CO)₆. Substitution of one CO ligand in W(CÅ≡CCÅ≡CSiMe₃)(CO)₃Cp (7), prepared from the CuI-catalysed reaction of WCl(CO)₃Cp with HCÅ≡CCÅ≡CSiMe₃in tetrahydrofuran/NHEt₂, by bis(diphenylphosphino)methane/Me₃NO gave W(CÅ≡CCÅ≡CSiMe₃)(CO)₂(dppm-P)Cp (8). Treatment of (7) with RuCl(PPh₃)₂Cp afforded {Cp(OC)₃W}CÅ≡CCÅ≡C-{Ru(PPh₃)₂Cp} (9), which reacts at the W–CÅ≡C– triple bond with tetracyanoethylene (tcne) to give{Cp(OC)₃3W}{C[=C(CN)₂]C[=C(CN)₂]CÅ≡C}{Ru(PPh₃)₂Cp} (10), and with Fe₂(CO)₉ to form the cluster Fe₂2W{μ₃-C₂CÅ≡C[Ru(PPh₃)Cp]}(CO)₈Cp (11). The molecular structures of (1), (2), (6), (8), (10) and (11) have been determined by single-crystal X-ray diffraction.