Bonded excimer in stacked adenines:Semiclassical simulations  

作　　者：DOU YuSheng ZHAO WenHui YUAN Shuai ZHANG WenYing TANG Hong 

机构地区：[1]Institute of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing 400065, China [2]Department of Physical Sciences, Nicholls State University, Thibodaux, Louisiana 70310, USA

出　　处：《Science China Chemistry》2012年第7期1377-1383,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (21073242);the Natural Science Foundation of Chongqing (cstc2011jjA00009);the Project of Science Technology Foundation of Chongqing Education Committee (KJ100507);the Research Fund of Chongqing University of Posts and Telecommunications (A2009-63,A2010-17)

摘　　要：The nonradiative decay of a n-stacked pair of adenine molecules, one of which was excited by an ultrafast laser pulse, is studied by semiclassical dynamics simulations. This simulation investigation is focused on the effect of the formation of bonded excimer in stacked adenines on the mechanism of ultrafast decay. The simulation finds that the formation of the bond- ed excimer significantly lowers the energy gap between the LUMO and HOMO and consequently facilitates the deactivation of the electronically excited molecule. On the other hand, the formation of the chemical bond between two stacked adenines re- stricts the deformation vibration of the pyrimidine of the excited molecule due to the steric effect. This slows down the formation of the coupling between the HOMO and LUMO energy levels and therefore delays the deactivation process of the excited adenine molecule to the electronic ground state.The nonradiative decay of a π-stacked pair of adenine molecules,one of which was excited by an ultrafast laser pulse,is studied by semiclassical dynamics simulations.This simulation investigation is focused on the effect of the formation of bonded excimer in stacked adenines on the mechanism of ultrafast decay.The simulation finds that the formation of the bonded excimer significantly lowers the energy gap between the LUMO and HOMO and consequently facilitates the deactivation of the electronically excited molecule.On the other hand,the formation of the chemical bond between two stacked adenines restricts the deformation vibration of the pyrimidine of the excited molecule due to the steric effect.This slows down the formation of the coupling between the HOMO and LUMO energy levels and therefore delays the deactivation process of the excited adenine molecule to the electronic ground state.

关 键 词：stacked adenines bonded excimer semiclassical dynamics simulation 

分 类 号：TN241[电子电信—物理电子学] TQ028.32[化学工程]