Gas-phase acidity, bond dissociation energy and enthalpy of formation of Fluorine-Substituted Benzenes: A theoretical study

Date

2009

Authors

Namazian, Mansoor
Coote, Michelle

Journal Title

Journal ISSN

Volume Title

Publisher

Elsevier

Abstract

A variety of theoretical methods have been used to study the gas-phase acidity of benzene and its eleven fluorine-substituted derivatives: fluorobenzene, three isomers of difluorobenezene, three isomers of trifluorobenzene, three isomers of tetrafluorobenzene and 1,2,3,4,5-pentafluorobenzene. The high-level ab initio methods, G3//B3-LYP and CBS-QB3, are shown to reproduce experimental data to within an average of 1.9 and 1.4 kcal mol-1, respectively. Of the lower-cost methods studied, M05-2X and MP2 showed the best overall performance with mean absolute deviations of just 1.2 and 1.1 kcal mol-1, respectively. The effect of substitution and position on the acidity of the protons in the various compounds are studied and the structure-reactivity trends in these heterolytic C-H bond dissociation energies (BDEs) are compared with the corresponding homolytic C-H BDEs for the same species.

Description

Keywords

Keywords: Ab initio; BDE; CBS-QB3; Deprotonation; DFT; Fluorobenzenes; G3//B3-LYP; Gas- phase acidity

Citation

Source

Journal of Fluorine Chemistry

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1016/j.jfluchem.2009.04.003

Restricted until

2037-12-31