<i>Cis</i>−<i>Trans</i> Isomerization and Oxidation of Radical Cations of Stilbene Derivatives
作者:Tetsuro Majima、Sachiko Tojo、Akito Ishida、Setsuo Takamuku
DOI:10.1021/jo960598m
日期:1996.1.1
barrier to c-t unimolecular isomerization for c-3(*+)-5(*+) and 8(*+) than for c-1(*+), 2(*+), and 6(*+) due to the single bond character of the central C=C double bond for c-3(*+)-5(*+) and 8(*+) with a p-methoxyl group but not for c-1(*+), 2(*+), and 6(*+) without a p-methoxyl group because of the contribution of a quinoid-type structure induced by charge-spin separation. The isomerization proceeds via
从顺式二苯乙烯衍生物(cS(S = RCH = CHC(6)H(5):1,R = C(6)H(5); 2,R = 4-CH(3)C(6)H( 4); 3,R = 4-CH(3)OC(6)H(4)(= An); 4,R = 2,4-(CH(3)O)(2)C(6)H( 3); 5,R = 3,4-(CH(3)O)(2)C(6)H(3); 6,R = 3,5-(CH(3)O)(2)C( 6)H(3); 7,AnCH = C(CH(3))C(6)H(5); 8,AnCH = CHAn))转化为反式异构体(tS),并用O(2)氧化S分别在Ar饱和的1,2-二氯乙烷(DCE)中的cS和O(2)饱和的DCE中的S的伽马射线辐射中研究的结果。根据产物分析,建议c-3(* +)-5(* +)和8(* +)的ct单分子异构化的障碍比c-1(* +),2( * +)和6(* +),这是因为带有对甲氧基的c-3(*