Preparation, spectroscopic properties, and molecular structure, determined by electron diffraction, of bis(difluorophosphino)carbodi-imide, F2P·N:C:N·PF2

Abstract

The title compound has been prepared by the reaction of bromodifluorophosphine with silver cyanamide and shown by i.r., Raman, n.m.r., and mass spectroscopy to be a carbodi-imide, and not a cyanamide derivative. The molecular structure of the compound in the gas phase has been determined by electron diffraction. Principal parameters are: r(P–F) 1·562 + 0·002, r(P–N) 1·680 ± 0·006, r(NC) 1·240 ± 0·005 Å, and P–N–C 132·8 ± 0·5°. The overall symmetry of the molecule is C₂, the dihedral angle being ca. 55°, and the PF₂ groups are trans with respect to the carbodi-imide group.