Crystal structure and conformational diversity of fluorinated alkyl tosylates

Crystal structures of fluorinated alkyl tosylates TsOCH₂CF₂CHFCF₃ and TsOCH₂(CF₂)₃CHF₂ have been characterized by X-ray diffraction and quantum chemical calculations. The calculations have revealed the stabilization of head-to-tail conformation for TsOCH₂CHFCF₂CF₃ due to intramolecular F・・・p and C–H・・・π interactions. Alternatively, for TsOCH₂(CF₂)₃CHF₂ these interactions cannot be responsible for the stabilization of head-to-tail conformation, thus the linear conformation is proved to be more stable.