LITHIUM QUADRUPOLE COUPLING-CONSTANTS AND THE STRUCTURES OF ORGANIC LITHIUM COMPOUNDS IN SOLUTION
LITHIUM QUADRUPOLE COUPLING-CONSTANTS AND THE STRUCTURES OF ORGANIC LITHIUM COMPOUNDS IN SOLUTION
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DOI：
10.1021/ja00252a009
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发表时间：
1987-09-02
影响因子：
15
通讯作者：
DEBROSSE, CW
中科院分区：
文献类型：
--
作者：
JACKMAN, LM;SCARMOUTZOS, LM;DEBROSSE, CW
根据7Li和13C的自旋晶格弛豫数据，确定了7Li在芳基锂酰胺、苯酚和烯醇酸盐中的四极分裂常数（QSC），定义为（1+ v2/'i） 1/2 {e1Qqzz/h)，以及几种有机锂化合物在醚和叔胺溶剂中的四极分裂常数。考虑了各向异性旋转扩散对QSC表观值的影响。QSC的取值范围为40 ~ 350khz。给出了QSC与锂的聚集度和溶剂化度之间的经验相关关系。注意到三配位锂和四配位锂之间的QSC存在很大差异。基于点电荷近似计算主场梯度的原始模型再现了经验相关性的定性特征。讨论了聚合锂盐的溶剂化程度。
The quadrupole splitting constants (QSC), defined as (1+ v2/'i) 1/2 {e1Qqzz/h), for 7Li in lithium arylamides, phenolates, and enolates and for several organolithium compounds in ether and tertiary amine solvents are determined from 7Li and 13C spin-lattice relaxationdata. The effect of anisotropic rotational diffusion on the apparent values of QSC is considered. Values of QSC range from 40 to 350 kHz. Empirical correlations between QSC and the degree of aggregation and solvation of lithium are presented. Large differences between QSC fortri-and tetracoordinatedlithium are noted. A crudemodel based on a point charge approximation for calculating the principal field gradients reproduces the qualitative features of the empirical correlations. The degrees of solvation of aggregated lithium salts are discussed.