Crystal structure of (1,4-diphenyl-4<i>H</i>-1,2,4-triazol-3-yl)phenylamine difluorophosphate, and a survey of the difluorophosphate anion (PO<sub>2</sub>F<sub>2</sub> <sup>−</sup>)
Acta crystallographica. Section E, Crystallographic communications