Theoretical Study of the C−F/π Interaction:  Attractive Interaction between Fluorinated Alkane and an Electron-Deficient π-System

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2004-08, Vol.108 (32), p.6744-6749
• Main Authors: Kawahara, Shun-ichi, Tsuzuki, Seiji, Uchimaru, Tadafumi
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp047646o

A molecular interaction between a methane/fluoromethane molecule and a benzene/hexafluorobenzene molecule was theoretically studied. Attractive interaction between the fluorine atom of the fluoromethane and the π-system of the hexafluorobenzene was observed (C−F/πF interaction, −2.43 kcal/mol in MP2/aug-cc-pVDZ). The attractive C−F/πF interaction energy was larger than that of the interaction between methane and benzene (C−H/πH interaction, −1.47kcal/mol). On the other hand, the very weak repulsive interaction was observed between the fluorine atom of the fluoromethane and the benzene (C−F/πH interaction, +0.12 kcal/mol). The interaction energies between methane and benzene (C−H/πH interaction, −1.47 kcal/mol) and between methane and hexafluorobenzene (C−H/πF interaction, −1.36 kcal/mol) were almost the same.