标题：H-bonding interactions between simple DNA base cytosine and formamide molecules (model of protein unit): A density functional theory study
作者：Xiao-jian Ma;Chun-fang Su;Zheng-yu Zhou
作者机构：[Ma, X.-J] School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China;[ Su, C.-F] Department of Chemistry, Qufu Normal Uni 更多
通讯作者地址：[Zhou, ZY]Qufu Normal Univ, Dept Chem, Qufu 273165, Shandong, Peoples R China.
来源：Journal of the Indian Chemical Society
关键词：DNA;H-bonding;formamide;cytosine;density functional theory
摘要：The molecular geometry of complexes C-F_n (n = 2-7) of cytosine with formamide molecules was calculated within the density functional theory using the B3LYP function at 6-31G(d) basis set level. It was found that the interaction with formamide molecules forming a locked chain around cytosine results in significant changes in its intramolecular geometry. An obvious effect of hydrogen-bonding cooperativity can be seen during the complex process. The most interesting geometrical change of cytosine upon the complex is the shortening of bond C4-N7 resulting from the strengthening of the conjugation between the π system of the cytosine ring and the lone pair of the nitrogen atom. The significant elongation of C1-08 bond and the presence of weak C-H···O hydrogen bonds are also revealed.