Inter- and intramolecular CF···C=O interactions on aliphatic and cyclohexane carbonyl derivatives.

Weak inter- and intra- molecular C(δ+)F(δ-)···C(δ+)=O(δ-) interactions were theoretically evaluated in 4 different sets of compounds at different theoretical levels. Intermolecular CH3F···C=O interactions were stabilizing by about 1 kcal mol(-1) for various carbonyl containing functional groups. Intramolecular CF···C=O interactions were also detected in aliphatic and fluorinated cyclohexane carbonyl derivatives. However, the stabilization provided by intramolecular CF···C=O interactions was not enough to govern the conformational preferences of compounds 2-4.