Singlet-triplet mechanistic duality in the photosubstitution of nitrophenyl ethers with ethyl glycinate. The role of single electron transfer.
作者:Jorge Marquet、Albert Cantos、Marcial Moreno-Mañas、Eduard Caýon、Iluminada Gallardo
DOI:10.1016/s0040-4020(01)90795-1
日期:1992.1
Mechanistic studies show that 4-nitroveratrole and 4,5-dinitroveratrole undergo nucleophilic aromtic photosubstitution with ethyl glycinate through an SN2Ar* route. However, in the first case the photoreaction takes place through a singlet excited state whereas for 4,5-dinitroanisole a triplet excited state is involved. Electrochemical data for the present photoreactions reagents and for 4-nitroanisole
机理研究表明,4- nitroveratrole和4,5- dinitroveratrole通过S经历与甘氨酸乙酯亲核aromtic photosubstitution Ñ 2AR *路线。然而,在第一种情况下,光反应通过单重激发态发生,而对于4,5-二硝基苯甲醚则涉及三重激发态。报告了涉及我们先前描述的相关光反应的本光反应试剂和4-硝基苯甲醚的电化学数据。针对硝基苯基醚与胺类亲核试剂的亲核芳香族光合反应,提出了一种由直接崩解控制的机制(在单线态激发态阶段进行电子转移竞争)。