Premium
Density functional theory study on the ionization potentials and electron affinities of thymine–formamide complexes
Author(s) -
Sun Haitao,
Tang Ke,
Li Yanmin,
Su Chunfang,
Zhou Zhengyu,
Wang Zhizhong
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.21951
Subject(s) - thymine , chemistry , formamide , electron affinity (data page) , hydrogen bond , density functional theory , ionization energy , dissociation (chemistry) , ionization , basis set , monomer , computational chemistry , affinities , crystallography , electron , chemical physics , molecule , stereochemistry , ion , physics , organic chemistry , dna , biochemistry , polymer , quantum mechanics
Abstract The effect of hydrogen bond interactions on ionization potentials (IPs) and electron affinities (EAs) of thymine–formamide complexes (T–F) have been investigated employing the density functional theory B3LYP at 6‐311++G(d, p) basis set level. All complexes experience a geometrical change on either electron detachment or attachment, and the change might be facilitated or hindered according to the strength of the hydrogen‐bonding interaction involved. The strength of hydrogen bonds presents an opposite changing trend on the two processes. A more important role that H‐bonding interaction plays in the process of electron attachment than in the process of electron detachment can be seen by a comparison of the IPs and EAs of complexes with that of isolated thymine. Futhermore, the EAs of isolated thymine are in good agreement with the experimental values (AEA is 0.79 eV, VEA is −0.29 eV [Wetmore et al., Chem Phys Lett 2000, 322, 129]). The calculated total NPA charge distributions reveal that nearly all the negative charges locate on thymine monomer in the anions and even in the cationic states, there are a few negative charges on thymine monomer. An analysis of dissociation energies predicts the processes T–F + → T + + F and T–F − → T − + F to be the most energetically favorable for T–F + and T–F − , respectively. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009