The difluoromethylenephosphonate moiety as a phosphate mimic: X-ray structure of 2-amino-1,1-difluoroethylphosphonic acid

Abstract

The synthesis and structure of 2-amino-1,1-difluorophosphonic acid (3) are described, providing the first X-ray crystal structure determination of a difluoromethylenephosphonate moiety; the structure allows an isosteric comparison to be drawn between the phosphate C–O–P bond angle and the phosphonate C–CF₂–P and C–CH₂–P bond angles with particular reference to the use of phosphonates as phosphate mimics in biological systems.