Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Weak inter- and intra-molecular C delta+ F delta- center dot center dot center dot C delta+=O delta- interactions were theoretically evaluated in 4 different sets of compounds at different theoretical levels. Intermolecular CH3F center dot center dot center dot C=O interactions were stabilizing by about 1 kcal mol(-1) for various carbonyl containing functional groups. Intramolecular CF center dot center dot center dot C=O interactions were also detected in aliphatic and fluorinated cyclohexane carbonyl derivatives. However, the stabilization provided by intramolecular CF center dot center dot center dot C=O interactions was not enough to govern the conformational preferences of compounds 2-4. (C) 2015 Wiley Periodicals, Inc.371 2533Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)[2014/25903-6]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)