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The effect of methyl group on the cooperativity between three types of hydrogen bond: OH···O, CH···O, and OH···π
Author(s) -
Li Qingzhong,
An Xiulin,
Luan Feng,
Li Wenzou,
Gong Baoan,
Cheng Jianbo,
Sun Jiazhong
Publication year - 2007
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.21531
Subject(s) - chemistry , cooperativity , hydrogen bond , methyl group , hydrogen , bond energy , crystallography , low barrier hydrogen bond , ab initio , triple bond , acetylene , binding energy , group (periodic table) , computational chemistry , double bond , molecule , atomic physics , organic chemistry , physics , biochemistry
The effect of the methyl group on the cooperativity between three types of hydrogen bond (OH···O, CH···O, and OH···π) in cyclic complex involving an acetylene and two waters has been studied on the basis of high‐level ab initio calculations. The total interaction energy of three hydrogen bonds increases as the number of methyl group in the complex increases. The binding distances of OH···π and OH···O hydrogen bonds shorten, while that of CH···O hydrogen bond elongates with increasing methyl group. This indicates that addition of methyl group leads to enhancement of OH···π and OH···O hydrogen bonds, and weakening of CH···O hydrogen bond, as also shown in frequency shift, chemical shifts, charge populations, and stabilization energies of orbital interactions. Although the presence of methyl group has a complicated effect on different type of hydrogen bond, the cooperativity of three hydrogen bonds increases in general with the addition of methyl group. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008