中文摘要：

采用多组态CASSCF和MS-CASPT2方法研究了电子效应调控的1,2-二氰基-1,2-二噻吩基乙烯顺-反异构化反应。结果显示：在中性1,2-二氰基-1,2-二噻吩基乙烯的旋转过程中经历的偏离C=C旋转路径、由其他振动模式主导的圆锥交叉S_1/S_0-CI对其旋转速度和旋转单向性有一定的阻碍作用;阳、阴离子的D_0和D_1态在θ=90°处相交,由D_1→D_0的无辐射跃迁无势垒,旋转保持了良好的转速和方向。研究证明了电子效应对光异构化过程的有效调控。

英文摘要：

The electron-induced 1,2-dicyano-1,2-dithienylethene photoisomerization process were studied by CASSCF and MS-CASPT2.The results showed that the S1→S0decay of neutral 1,2-dicyano-1,2-dithienylethene needs to readjust the geometry to reach the S1/S0 conical intersections,which resulted from carbon-pyramidalization mode and is therefore away from the C C torsional coordinates.As results,it slows down the speed of C C rotation and hinders its directionality;while in cationic and anionic isomerization processes,the D1 and D0 PESs intersect along the rotary path,therefore,the nonadiabatic D1→D0decay is barrierless.Consequently,the speed and directionalityof C C rotation is maintained.This study proved that the electron can effectively tune the photoisomerization,and shed light on the design of light-driven molecular rotary motors.