PREPARATION, CRYSTAL-STRUCTURE, AND IR-SPECTROSCOPIC INVESTIGATION OF PHOSPHORUS NITRIDE IMIDE, HPN2

Pure and fine crystalline phosphorus nitride imide (HPN2) is obtained by heterogeneous ammonolysis of P3N5 with gaseous NH3 (T = 580-degrees-C, p = 30 bar, 6d). X-ray powder diffraction data has been used to refine the crystal structure of HPN2 by the Rietveld full-profile technique (I42dBAR; a = 461.82(2) pm, c = 702.04(3) pm; Z = 4; 41 reflections observed, 17-degrees < 2-THETA < 125-degrees, CuK-alpha-1, germanium monochromator; R(wp) = 0.072, R(I,hkl) = 0.048). In the solid HPN2 contains a three-dimensional framework of corner-sharing PN4-tetrahedra (P-N: 159.9(4) pm; P-N-P: 130.1(4)-degrees. The hydrogen atoms are covalently bonded to half of the nitrogen atoms. The IR spectrum exhibits six vibrational modes (nu(N-H): 3224; nu(as)(PNP): 1330, 1223; nu(as)(PNHP): 971, 901; delta(PNP): 531 cm-1 .