Theoretical Studies on Structures and Electron Affinities of 5-and 6-Halouracils  

作　　者：WANG Hui-ping XU Wen-guo ZHANG Hong-xing 

机构地区：[1]State Key Laboratory of Theoretical Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130021, P R. China [2]Institute for Chemical Physics, Beijing Institute of Technology, Beijing 100081, P. R. China

出　　处：《Chemical Research in Chinese Universities》2009年第3期388-396,共9页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.20573042)

摘　　要：The molecular structures and electron affinities of 5- and 6-halouracils（XU, X=F, Cl, Br） were determined by means of five different density functional methods. The basis set used in this work is of double-（plus polariza- tion（DZP） quality with additional diffuse s- and p-type functions, denoted DZP＋＋. The geometries were fully optimized with each density functional theory（DFT） method, and discussed. Three different types of the neutral-anion energy separations reported in this work are the adiabatic electron affinity（AEA）, the vertical electron affinity（VEA）, and the vertical detachment energy（VDE）. An excellent agreement between our B3LYP results and those obtained by other calculations regarding the structural modifications and electron affinities of neutral and anion 5XU was found. The differences in charge distribution between uracil and halogenated uracils were indicated, thus the ability to form the hydrogen bonds of halogenated uracils was discussed. It shows the applicability of the DFT/DZP＋＋ method to predict the similar molecular models at a highly economical computational cost.The molecular structures and electron affinities of 5- and 6-halouracils（XU, X=F, Cl, Br） were determined by means of five different density functional methods. The basis set used in this work is of double-（plus polariza- tion（DZP） quality with additional diffuse s- and p-type functions, denoted DZP＋＋. The geometries were fully optimized with each density functional theory（DFT） method, and discussed. Three different types of the neutral-anion energy separations reported in this work are the adiabatic electron affinity（AEA）, the vertical electron affinity（VEA）, and the vertical detachment energy（VDE）. An excellent agreement between our B3LYP results and those obtained by other calculations regarding the structural modifications and electron affinities of neutral and anion 5XU was found. The differences in charge distribution between uracil and halogenated uracils were indicated, thus the ability to form the hydrogen bonds of halogenated uracils was discussed. It shows the applicability of the DFT/DZP＋＋ method to predict the similar molecular models at a highly economical computational cost.

关 键 词：Electron affinity Vertical electron affinity Vertical detachment energy Halouracil Charge distribution 

分 类 号：O561.1[理学—原子与分子物理] TN103[理学—物理]