ALPHA-SILYL-SUBSTITUENT STABILIZATION OF CARBANIONS AND SILYL ANIONS

被引:98
作者
BRINKMAN, EA [1 ]
BERGER, S [1 ]
BRAUMAN, JI [1 ]
机构
[1] STANFORD UNIV, DEPT CHEM, STANFORD, CA 94305 USA
关键词
D O I
10.1021/ja00097a042
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The electron affinities for a series of cr-silyl-substituted silyl and carbon radicals have been measured. These electron affinities (kcal/mol) include the following: EA((Me(3)Si)(2)CH) = 36.0 +/- 0.2, EA(Me(2)HSiSiMe(2)) = 32.3 +/- 0.8, EA((Me(3)Si)(2)SiH) = 44.7 +/- 1.9, and EA((Me(3)Si)(3)Si) = 46.8 +/- 2.0. The electron affinity of the dimethylsilyl radical was also determined to be 24.7 +/- 0.5 kcal/mol. From these electron affinities and the bond dissociation energies, we derive the gas-phase acidities for these compounds. These quantities allow us to compare the stabilization in carbon and silyl anions by or-silyl groups. Ab initio calculations aid in understanding the stabilization mechanism.
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页码:8304 / 8310
页数:7
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