Premium
Spectroscopic Measurement of a Halogen Bond Energy
Author(s) -
Zhang Xinxing,
Liu Gaoxiang,
Ciborowski Sandra,
Wang Wei,
Gong Chu,
Yao Yifan,
Bowen Kit
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201906279
Subject(s) - halogen bond , chemistry , halogen , non covalent interactions , atom (system on chip) , density functional theory , molecule , ion , crystallography , binding energy , x ray photoelectron spectroscopy , hydrogen bond , computational chemistry , atomic physics , organic chemistry , alkyl , physics , nuclear magnetic resonance , computer science , embedded system
Halogen bonding (XB) has emerged as an important bonding motif in supramolecules and biological systems. Although regarded as a strong noncovalent interaction, benchmark measurements of the halogen bond energy are scarce. Here, a combined anion photoelectron spectroscopy and density functional theory (DFT) study of XB in solvated Br − anions is reported. The XB strength between the positively‐charged σ‐hole on the Br atom of the bromotrichloromethane (CCl 3 Br) molecule and the Br − anion was found to be 0.63 eV (14.5 kcal mol −1 ). In the neutral complexes, Br(CCl 3 Br) 1,2 , the attraction between the free Br atom and the negatively charged equatorial belt on the Br atom of CCl 3 Br, which is a second type of halogen bonding, was estimated to have interaction strengths of 0.15 eV (3.5 kcal mol −1 ) and 0.12 eV (2.8 kcal mol −1 ).