Open AccessHalogen Bonding versus Hydrogen Bonding: A Molecular Orbital Perspective
Author(s) -
Wolters Lando P.,
Bickelhaupt F. Matthias
Publication year - 2012
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201100015
Subject(s) - lone pair , homo/lumo , density functional theory , halogen , chemistry , natural bond orbital , halogen bond , hydrogen bond , computational chemistry , non bonding orbital , molecular orbital , chemical physics , crystallography , molecule , organic chemistry , alkyl
We have carried out extensive computational analyses of the structure and bonding mechanism in trihalides DX⋅⋅⋅A − and the analogous hydrogen‐bonded complexes DH⋅⋅⋅A − (D, X, A=F, Cl, Br, I) using relativistic density functional theory (DFT) at zeroth‐order regular approximation ZORA‐BP86/TZ2P. One purpose was to obtain a set of consistent data from which reliable trends in structure and stability can be inferred over a large range of systems. The main objective was to achieve a detailed understanding of the nature of halogen bonds, how they resemble, and also how they differ from, the better understood hydrogen bonds. Thus, we present an accurate physical model of the halogen bond based on quantitative Kohn–Sham molecular orbital (MO) theory, energy decomposition analyses (EDA) and Voronoi deformation density (VDD) analyses of the charge distribution. It appears that the halogen bond in DX⋅⋅⋅A − arises not only from classical electrostatic attraction but also receives substantial stabilization from HOMO–LUMO interactions between the lone pair of A − and the σ* orbital of D–X.