Synthesis, Characterization, and Some Properties of Cp*W(NO)(H)(畏3-allyl) Complexes

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• 作者：Rhett A. Baillie ; Aaron S. Holmes ; Guillaume P. Lef猫vre ; Brian O. Patrick ; Monica V. Shree ; Russell J. Wakeham ; Peter Legzdins ; Devon C. Rosenfeld
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：June 15, 2015
• 年：2015
• 卷：54
• 期：12
• 页码：5915-5929
• 全文大小：788K
• ISSN：1520-510X

文摘

Sequential treatment at low temperatures of Cp*W(NO)Cl₂ in THF with 1 equiv of a binary magnesium allyl reagent, followed by an excess of LiBH₄, affords three new Cp*W(NO)(H)(畏³-allyl) complexes, namely, Cp*W(NO)(H)(畏³-CH₂CHCMe₂) (1), Cp*W(NO)(H)(畏³-CH₂CHCHPh) (2), and Cp*W(NO)(H)(畏³-CH₂CHCHMe) (3). Complexes 1鈥?b>3 are isolable as air-stable, analytically pure yellow solids in good to moderate yields by chromatography or fractional crystallization. In solutions, complex 1 exists as two coordination isomers in an 83:17 ratio differing with respect to the endo/exo orientation of the allyl ligand. In contrast, complexes 2 and 3 each exist as four coordination isomers, all differing by the orientation of their allyl ligands which can have either an endo or an exo orientation with the phenyl or methyl groups being either proximal or distal to the nitrosyl ligand. A DFT computational analysis using the major isomer of Cp*W(NO)(H)(畏³-CH₂CHCHMe) (3a) as the model complex has revealed that its lowest-energy thermal-decomposition pathway involves the intramolecular isomerization of 3a to the 16e 畏²-alkene complex, Cp*W(NO)(畏²-CH₂鈺怌HCH₂Me). Such 畏²-alkene complexes are isolable as their 18e PMe₃ adducts when compounds 1鈥?b>3 are thermolyzed in neat PMe₃, the other organometallic products formed during these thermolyses being Cp*W(NO)(PMe₃)₂ (5) and, occasionally, Cp*W(NO)(H)(畏¹-allyl)(PMe₃). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by single-crystal X-ray crystallographic analyses.