F---H···F hydrogen bond in diphenylguanidinium hydrogen bifluoride

Abstract

The crystal structure of C13H14N3+FHF- is reported. The structure contains the strong hydrogen-bonded system, the bifluoride anion F---H···F-. The geometry of this anion deviates significantly from linearity but has the H atom in an approximate centered position. The F···F distance is 2.293(3) Å, considerably less than twice the van der Waals radius of fluorine, as expected from a very strong hydrogen bond.