Alkane Elimination Reactions between Yttrium Alkyls and Tungsten Hydrides

Abstract

AbstractAlkane elimination of the yttrium monoalkyl [Cp2Y(CH2SiMe3)(thf)] (Cp = cyclopentadienyl, thf = tetrahydrofuran, Me = methyl) with the tungsten hydrido carbonyl complex [HW(CO)3Cp] in THF gave rise to the trinuclear complex [{CpW(CO)2(μ‐CO)}2YCp(thf)3] (1). In the course of the reaction, one Cp ligand per yttrium was redistributed, thus leading to the formation of [Cp3Y] as a side product. To avoid the observed ligand redistribution, other solvents were investigated. The reaction of [Cp2Y(CH2SiMe3)(thf)] with [HW(CO)3Cp] in acetonitrile afforded the dinuclear complex [{CpW(CO)2(μ‐CO)}YCp2(NCMe)2] (2). The reaction of the yttrium dialkyl complex [Y(CH2SiMe3)2(OC6H3tBu2‐2,6)(thf)2] with [HW(CO)3Cp] in toluene gave the polymeric compound [{CpW(CO)2(μ‐CO)}2Y(OC6H3tBu2‐2,6)]n (3), whereas reaction in THF gave the molecular compound [{CpW(CO)2(μ‐CO)}2Y(OC6H3tBu2‐2,6)(thf)3] (4). The reaction of the yttrium trialkyl complex [Y(CH2SiMe3)3(thf)2] with [HW(CO)3Cp] in THF led to the formation of [{CpW(CO)2(μ‐CO)}3Y(thf)5] (5). Reaction of [(Ap*)Y(CH2SiMe3)2(thf)] {Ap*H = (2,6‐diisopropylphenyl)‐[6‐(2,4,6‐triisopropylphenyl)pyridin‐2‐yl]amine} with [HW(CO)3Cp] in THF was unexpectedly accompanied by the loss of the Ap* ligand and resulted in the formation of 5 too. Isocarbonyl linkage is the dominating interaction between the Y and the W complex moieties. All compounds were characterized by NMR and IR spectroscopy as well as elemental analysis. Complexes 1, 2, 4, and 5 were additionally characterized by X‐ray crystal structure analysis (X‐ray diffraction).