The crystal and molecular structure of difluoroacetamide

The determination of the structure of difluoroacetamide forms part of a general series of investigations on the structure and hydrogen bonding of some simple amides related to acetamide. One particular aspect is a comparison of members of the series CH3CONH2, CH2FCONH2, CHFzCONHz and CF3CONHz. The structure of monofluoroacetamide (Hughes & Small, 1962) in which the fluorine atom is almost exactly coplanar with the amide group and in cis conformation relative to the NHz group, suggested the possibility of intramolecular hydrogen bonding. It is of interest, therefore, to determine the configuration of the two fluorine atoms relative to the amide group in difluoroacetamide.