Electronic effect of the cyclopentadienyl anion as a substituent. The effect of the alkali metal cation, solvent and complexing agents on19F chemical shifts of m- and p-fluorophenylcyclopentadienyl anions
作者:N.A. Ogorodnikova、A.A. Koridze、S.P. Gubin
DOI:10.1016/s0022-328x(00)92606-8
日期:1981.8
of the carbanions M+[C5H4C6H4F-m(-p)]−, where M Li, Na, and K, have been investigated by19F NMR spectroscopy. The effect of the alkali metal cation, the coordinating ability of the solvent, complexing agents (TMEDA, crown-ethers), and concentration on the19F chemical shifts has been studied. The results are discussed in terms of an equilibrium between tight and solvent-separated ion pairs. On the
通过19 F NMR光谱研究了碳负离子M + [C 5 H 4 C 6 H 4 F- m(-p)] -的盐。研究了碱金属阳离子,溶剂的配位能力,络合剂(TMEDA,冠醚)和浓度对19 F化学位移的影响。根据紧密和溶剂分离的离子对之间的平衡来讨论结果。基于Li + -[C 5 H 4 C 6 H]的19 F化学位移数据4 F-米( - p)] -在HMPA溶液,将C的电子效应5 ħ 4 -取代基作为“自由离子”已被确定。