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Halogen bonding in mono‐ and dihydrated halobenzene
Author(s) -
Hogan Simon W. L.,
van Mourik Tanja
Publication year - 2019
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.25733
Subject(s) - halogen bond , halogen , hydrogen bond , chemistry , counterpoise , molecule , crystallography , dimer , water dimer , hydrogen , computational chemistry , density functional theory , basis set , organic chemistry , alkyl
Density functional theory calculations were performed on halogen‐bonded and hydrogen‐bonded systems consisting of a halobenzene (XPh; X = F, Cl, Br, I, and At) and one or two water molecules, using the M06‐2X density functional with the 6‐31+G(d) (for C, H, F, Cl, and Br) and aug‐cc‐pVDZ‐PP (for I, At) basis sets. The counterpoise procedure was performed to counteract the effect of basis set superposition error. The results show halogen bonds form in the XPh‐H 2 O system when X > Cl. There is a trend toward stronger halogen bonding as the halogen group is descended, as assessed by interaction energy and X•••O w internuclear separation (where O w is the water oxygen). For all XPh‐H 2 O systems hydrogen‐bonded systems exist, containing a combination of CH•••O w and O w H w •••X hydrogen bonds. For all systems except X = At the X•••H w hydrogen‐bonding interaction is stronger than the X•••O w halogen bond. In the XPh‐(H 2 O) 2 system halogen bonds form only for X > Br. The two water molecules prefer to form a water dimer, either located around the CH bond (for X = Br, At, and I) or located above the benzene ring (for all halogens). Thus, even in the absence of competing strong interactions, halogen bonds may not form for the lighter halogens due to (1) competition from cooperative weak interactions such as CH•••O and OH•••X hydrogen bonds, or (2) if the formation of the halogen bond would preclude the formation of a water dimer. © 2018 Wiley Periodicals, Inc.