Low Temperature E.p.r. Studies of Free Radicals in the Ultraviolet Catalyzed Addition of Hydrogen Bromide to Olefins
Low Temperature E.p.r. Studies of Free Radicals in the Ultraviolet Catalyzed Addition of Hydrogen Bromide to Olefins
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低温EP
DOI：
10.1021/ja00865a008
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发表时间：
1962
影响因子：
15
通讯作者：
L. Piette
中科院分区：
文献类型：
--
作者：
P. Abell;L. Piette
在77 K下，由光解的溴化氢得到的溴原子与环戊烯、环己烯、2-丁炔、3-己炔、顺式-2-丁烯、3-己烯和乙烯基环己烷的加成。产生的自由基的特征在于它们的电子顺磁共振光谱。的自由基的光谱进行分析，以确定它们是否与溴烷基自由基的“桥接”模型一致。讨论了自由电子附近各种氢原子的超精细相互作用。一般来说，对称或桥接结构似乎提供了光谱的最佳解释。溴化氘的实验证实溴原子的进攻是反应的初始事件。
The addition of bromine atoms from photolyzed hydrogen bromide to cyclopentene, cyclohexene, 2-butyne, 3-hexyne, cis-h'a «5-2-butene, 3-hexene and vinylcyclohexane at 77 K. produces radicals which havebeen characterized by their electron paramagnetic resonance spectra. The spectra of the radicals are analyzed as to whether or not they are consistent with a “bridged” model for the bromoalkyl radical. The hyperfine interaction of the various hydrogens adjacent to the free electron is discussed. In general the symmetrical or bridged structures seem to offer the best interpretation of the spectra. Experiments with deuterium bromide verify the attack of the bromine atom as the initial event in the reaction.