Phosphido-Borane and Phosphido-Bis(Borane) Complexes of the Alkali Metals, a Comparative Study

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• 作者：Keith Izod ; James M. Watson ; William Clegg ; Ross W. Harrington
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：February 4, 2013
• 年：2013
• 卷：52
• 期：3
• 页码：1466-1475
• 全文大小：482K
• 年卷期：v.52,no.3(February 4, 2013)
• ISSN：1520-510X

文摘

Treatment of the secondary phosphine {(Me₃Si)₂CH}(Ph)PH with BH₃路SMe₂ yields the phosphine-borane {(Me₃Si)₂CH}(Ph)PH(BH₃) (12) as colorless crystals. The reactions between 12 and n-BuLi, PhCH₂Na or PhCH₂K yield the corresponding phosphido-borane complexes [[{(Me₃Si)₂CH}(Ph)P(BH₃)]Li(THF)₂]_{鈭?/sub> (13), [{(Me3Si)2CH}(Ph)P(BH3)][Na(12-crown-4)2] (14), or [[{(Me3Si)2CH}(Ph)P(BH3)]K(pmdeta)]2 (15), respectively, after crystallization in the presence of the appropriate co-ligand. While 13 crystallizes as a chain polymer, 14 crystallizes as a separated ion pair and 15 as a dimer. In both 13 and 15 the phosphido-borane ligands bind the alkali metal cations via both P鈥揗 and B鈥揌路路路M contacts. Unexpectedly, NMR spectroscopy suggests that the separated ion pair 14 undergoes rapid inversion at phosphorus, while 13 and 15 do not. The phosphido-bis(borane) complexes [{(Me3Si)2CH}(Ph)P(BH3)2]Li(12-crown-4) (16b), [[{(Me3Si)2CH}(Ph)P(BH3)2]Na(THF)2]2 (17), and [[{(Me3Si)2CH}(Ph)P(BH3)2]K(THF)0.5]鈭?/sub> (18a) were prepared by treatment of the corresponding in situ-generated phosphido-borane complexes with BH3路SMe2 and crystallization in the presence of the appropriate co-ligand. Compound 16b crystallizes as a monomer, while 17 crystallizes as a dimer and 18a crystallizes as a ribbon polymer. These crystallographic studies reveal entirely new binding modes for both phosphido-borane and phosphido-bis(borane) ligands and allow a direct comparison between these two ligand types.}