Allyl-lithium: a rapidly equilibrating, unsymmetrical dimer in tetrahydrofuran
Allyl-lithium: a rapidly equilibrating, unsymmetrical dimer in tetrahydrofuran
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烯丙基锂：四氢呋喃中快速平衡的不对称二聚体
DOI：
10.1039/c39870000177
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发表时间：
1987
影响因子：
2.8
通讯作者：
P. V. Schleyer
中科院分区：
文献类型：
--
作者：
W. Winchester;W. Bauer;P. V. Schleyer
同位素扰动样品的低温测量和变温13C nmr研究表明，烯丙基钠和烯丙基钾具有对称结构，但烯丙基锂在四氢呋喃中是不对称的二聚体；这种关联解释了观测到的旋转势垒（10.7 kcal/mol）与分离的烯丙基锂单体（17.7 kcal/mol）之间的差异（1cal = 4.184J）。
Cryoscopic measurements and variable temperature 13C n.m.r. studies on isotopically perturbed samples show allyl-sodium and allyl-potassium to have symmetrical structures, but allyl-lithium to be an unsymmetrical dimer in tetrahydrofuran; this association explains the discrepancy between the observed rotational barrier (10.7 kcal/mol) and that calculated for the isolated allyl-lithium monomer (17.7 kcal/mol)(1cal = 4.184J).