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RESEARCH PRODUCT

Yttrium Hydrido Complexes that Contain a Less “Constrained Geometry” Ligand:  Synthesis, Structure, and Efficient Hydrosilylation Catalysis

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σ-Bond metathesis of the new linked amino-cyclopentadiene (C5Me4H)CH2SiMe2NHCMe3 with Y(CH2SiMe3)3(THF)2 gave the alkyl-yttrium complex [Y(η5:η1-C5Me4CH2SiMe2NCMe3)(CH2SiMe3)(THF)] (1) in 66% yield. Compound 1 was characterized by NMR spectroscopy and X-ray crystal structure analysis. By hydrogenolysis, 1 was quantitatively converted into the dimeric hydride [Y(η5:η1-C5Me4CH2SiMe2NCMe3)(THF)(μ-H)]2 (2). X-ray crystal structure analysis revealed a Y2H2 core connected to two [Y(η5:η1-C5Me4CH2SiMe2NCMe3)(THF)] fragments in a skewed manner, with a relatively long yttrium−yttrium distance of 3.7085(8) A. In solution, two diastereomers were observed by 1H NMR spectroscopy at −78 °C. Dimer 2 was shown to efficiently catalyze the hydrosilylation of 1-decene with PhSiH3 to give the terminal silane nC10H21SiH2Ph exclusively. Although the product of addition of the yttrium-hydride complex 2 to styrene, [Y(η5:η1-C5Me4CH2SiMe2NCMe3){CH(CH3)Ph}(THF)] (3), contains a 1-phenethyl ligand derived from internal addition, hy...