−78°. The facile isomerization of the radical cation is in agreement with PM3 calculations proposing an activation barrier of only 17 kJ/mol. As a consequence, quantitative cis trans isomerization of 1,1′-azonorbornane can effectively be accomplished by addition of catalytic amounts of one-electron oxidants. This is the first evidence for a radical-cation-catalyzed cis trans isomerization of azo compounds
ESR和循环伏安法研究表明,顺式-1,1'-偶氮降
冰片烷(顺式-1)自由基阳离子向反式-自由基离子的异构化在溶液中进行得太快,因此即使在-78时也无法直接研究顺式-自由基离子°。自由基阳离子的容易异构化与PM 3计算相符,后者提出的活化势垒仅为17 kJ / mol。结果,可以通过添加催化量的单电子氧化剂来有效地实现1,1'-偶氮降
冰片烷的定量顺式 反式异构化。这是自由基阳离子催化的顺 式反式的第一个证据 偶氮化合物的异构化。