7Li/31P NMR studies of lithiated arylacetonitriles in THF-HMPA solution:: Characterization of HMPA-solvated monomers, dimers, and separated ion pairs
7Li/31P NMR studies of lithiated arylacetonitriles in THF-HMPA solution:: Characterization of HMPA-solvated monomers, dimers, and separated ion pairs
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DOI：
10.1021/ja002318x
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发表时间：
2000-12-27
影响因子：
15
通讯作者：
Lo, CWS
中科院分区：
文献类型：
--
作者：
Carlier, PR;Lo, CWS
研究了苯乙腈和1-萘乙腈锂化物在THF和HMPA-THF溶液中的结构。在纯THF中，Li-7 NMR线宽研究表明，这些物种作为接触离子对存在; HMPA滴定研究证实了这一结论。在0.25-2当量HMPA的存在下，通过P-31和Li-7 NMR光谱检测HMPA-溶剂化的单体和二聚体接触离子对。最后，在4-6当量的添加HMPA下，Li-7 NMR谱提供了形成HMPA溶剂化的分离离子对的直接证据。
The structures of lithiated phenylacetonitrile and 1-naphthylacetonitrile were studied in THF and HMPA-THF solution. In pure THF, Li-7 NMR line width studies suggest that these species exist as contact ion pairs; HMPA titration studies confirm this conclusion. In the presence of 0.25-2 equiv of HMPA, HMPA-solvated monomeric and dimeric contact ion pairs are detected by P-31 and Li-7 NMR spectroscopy. Finally, at 4-6 equiv of added HMPA, Li-7 NMR spectra provide direct evidence for the formation of HMPA-solvated separated ion pairs.