HYDROGEN-BONDING INTERACTIONS OF THE TRIFLUOROMETHYL GROUP - 2-TRIFLUOROMETHYLVINYL ALCOHOL

As part of our investigation of intramolecular hydrogen bonding and it s geometrical consequences, ab initio molecular orbital calculations o n 2-trifluoromethylphenol and 2-trifluoromethylvinyl alcohol and their parent structures were performed at the MP2/6-31+G* level of theory. The intramolecular hydrogen bonding in 2-trifluoromethylvinyl alcohol appears stronger than that in 2-trifluoromethylphenol as witnessed by the shorter F ... H interaction (1.96 Angstrom) and the greater bond length changes in the rest of the molecule, as compared with the respe ctive parent molecules. Beyond the geometrical characteristics, the en ergetics of hypothetical isodesmic reactions and the small shift of th e O-H stretching frequency indicate that these C-F ... H-O interaction s are rather weak. (C) 1997 John Wiley & Sons, Inc.