Premium
A theoretical investigation of the interaction between substituted carbonyl derivatives and water: Open or cyclic complexes?
Author(s) -
Chandra Asit K.,
ZeegersHuyskens Thérèse
Publication year - 2012
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.22943
Subject(s) - chemistry , intramolecular force , hyperconjugation , antibonding molecular orbital , natural bond orbital , crystallography , hydrogen bond , lone pair , anomeric effect , molecular orbital , computational chemistry , binding energy , intermolecular force , density functional theory , deprotonation , atomic orbital , stereochemistry , molecule , electron , organic chemistry , atomic physics , ion , physics , quantum mechanics , anomer
The structures and binding energies of complexes between substituted carbonyl bases and water are the B3LYP/6‐311++G(d,p) computational level. The calculations also include the proton affinity (PA) of the O of the CO group, the deprotonation enthalpies (DPE) of the CH bonds along a natural bond orbital analysis. The calculations reveal that stable open CO···H w O w as well as cyclic CH···O w H w ···OC complexes are formed. The binding energies for the open complexes are linearly related to the PAs, whereas the binding energies for the cyclic complexes depend on both the PA and DPE. Different indicators of hydrogen bonds strength such as electron charge density, intramolecular and intermolecular hyperconjugation energy, occupation of orbitals, and charge transfer show significant differences between open and cyclic complexes. The contraction of the CH bond of the formyl group and the corresponding blue shift of the ν(CH) vibration are explained by the classical trans lone pair effect. In contrast, the elongation or contraction of the CH 3 group involved in the interaction with water results from the variation of the orbital interaction energies from the σ(CH) bonding orbital to the σ* and π* antibonding orbitals of the CO group. The resulting blue or red shifts of the ν(CH 3 ) vibrations are calculated in the partially deuterated isotopomers. © 2012 Wiley Periodicals, Inc.