N,N-二甲基苯胺和1,1-二氯-2-苯基环丙烷的光诱导电子转移反应

Photoinduced Electron Transfer Reaction between N,N dimethylaniline and 1,1 Dichloro 2 phenylcyclopropane

Ｎ，Ｎ－二甲苯胺（１）和１，１－二氯－２－苯基环丙烷（２）的乙腈溶液在紫外光照射下产生Ｎ－甲基苯胺（３，２４％），１－氯－２－苯基环丙烷（４，７９％），双［４－（Ｎ，Ｎ－二甲胺基）苯基］甲烷（５，４０％）和Ｎ－［４′－（Ｎ′，Ｎ′－二甲胺基）苄基］－Ｎ－甲基苯胺（６，７％）等产物．荧光淬灭的实验结果表明２可以扩散控制速率（ｋｑ＝３．９×１０９Ｌ／ｍｏｌｓ－１）淬灭１的荧光．１和２之间电子转移的自由能变化（ΔＧ）为－１．０１ｅＶ．因此可以认为反应是通过如下的光诱导电子转移机理进行的．

U.v. irradiation of N,N dimethylaniline (1) and 1,1 dichloro 2 phenylcyclopropane (2) in acetonitrile gives both demethylation product N methylaniline ( 3, 24 %) and dechlorination product 1 chloro 2 phenylcyclopropane (4, 79 %), together with coupling products of 1, i.e., 4,4′ methylenebis(N,N dimethylaniline) (5, 40 %), N [4′ (N′,N′ dimethylaminobenzyl)] N methylaniline (6, 7 %), 2,4 bis[4′ (N′,N′ dimethylaminobenzyl)] N,N dimethylaniline (7, 6 %) and N,4 bis[4′ (N′,N′ dimethylaminobenzyl)] N methylaniline (8, 3 %). The fluorescence quenching experiment shows that the fluorescence of 1 is quenched by 2 with diffusion controlled rate (k q  = 3.9×10 9 L / mol·s -1 ). The free energy change (ΔG) for the electron transfer between 1 and 2 is calculated to be -1.01 eV. A photoinduced electron transfer mechanism is proposed: