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Influence of substitution on the strength and nature of CH···N hydrogen bond in XCCH···NH 3 complexes
Author(s) -
Roohi Hossein,
Bagheri Sotoodeh
Publication year - 2011
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.22460
Subject(s) - chemistry , natural bond orbital , atoms in molecules , hydrogen bond , ab initio , molecule , computational chemistry , bond strength , hydrogen atom , hydrogen , interaction energy , atom (system on chip) , basis set , ab initio quantum chemistry methods , bond order , crystallography , density functional theory , bond length , group (periodic table) , organic chemistry , adhesive , layer (electronics) , computer science , embedded system
The effect of substitution on the strength and nature of CH···N hydrogen bond in XCCH···NH 3 (X = F, Cl, Br, OH, H, Me) and NCH···NH 3 complexes were investigated by quantum chemical calculations. Ab initio calculations were performed using MP2 method with a wide range of basis sets. With tacking into account the BSSE and ZPVE, the values of BEs decrease. Replacement of the nonparticipatory hydrogen atom of HCCH by the electronegative atoms (F, Cl, and Br), lead to the BEs increases. The BE corresponding to the replacement of the nonparticipatory hydrogen atom of HCCH by the OH and CH 3 groups decreases. A far greater enhancement of the interaction energy arises from replacement of HCCH by the more acidic HCN. The natural bond orbital analysis and the Bader's quantum theory of atoms in molecules were also used to elucidate the interaction characteristics of these complexes. The electrostatic nature of H‐bond interactions is predicted from QTAIM analysis. In addition, the relationship between the isotropic and anisotropic chemical shifts of the bridging hydrogen and binding energy of complexes as well as electron density at N···H BCPs were investigated. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011