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 po...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.展开更多
基金Supported by the National Natural Science Foundation of China(No.20573042)
文摘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.
