作者:Jeffrey T. Banks、Keith U. Ingold、Ernest W. Della、John C. Walton
DOI:10.1016/0040-4039(96)01825-4
日期:1996.10
Absolute rate constants for reactions of bicyclo[1.1.1]pent-1-yl radicals with α-methylstyrene (1.4 × 107 M−1 s−1) and 1,4-cyclohexadiene (4.6 × 105 M−1 s−1) at 25° C were measured by laser flash photolysis. This bridgehead radical is more reactive than tert-butyl which we attribute to its high s-character and the absence of steric shielding of the radical center.
绝对速率常数为双环[1.1.1]的反应戊-1-基自由基与α甲基苯乙烯(1.4×10 7中号-1小号-1)和1,4-环己二烯(4.6×10 5中号-1小号- 1)在25℃下通过激光闪光光解法测量。该桥头基自由基比叔丁基更具反应性,我们将其归因于叔丁基的高s特性以及自由基中心没有空间屏蔽。