Electron-diffraction study and CNDO/2 calculations of the molecular structure of diaminodifluorophosphorane in the gas phase

Abstract

The moleculargeometryofdiaminodifluorophosphorane, PF₂H(NH₂)₂, in the gas phase, has been studied by electron diffraction. A trigonal-bipyramidal structure is found, with axial fluorine atoms. Principal parameters are : r_a( P–N) 164.0(5) pm; r_a(P–F) 164.3(5) pm: HPF 89.3(8)°; HPN 118.8(5)°. Assuming these parameters, CNDO/2 calculations suggest that the P(NH₂) groups are planar, and perpendicular to the equatorial plane of the trigonal bipyramid, and that the PNH angles are 124°. The molecule therefore has C_2v symmetry.