Struktur von C2Cl6N4P2, dem Reaktionsprodukt von Dicyandiamid mit PCl5 / Structure of C 2Cl6N4P2, the Reaction Product of Dicyandiamide with PCl5

Abstract

The reaction product of dicyanodiamide with PC15 (1:2) is 2,2,4-trichloro-2,2-dihydro- 6-trichlorophosphazeno-1.3,5,2λ5-triazaphosphorine and not 2.4,6-trichloro-2,2-dihydro-2- trichlorophosphazeno-1,3,5,2λ5-triazaphosphorine as reported in the literature. This is confirmed by an X-ray structure determination at 90K: Space group P 21/c, a = 17.258(5), b = 9.664(3), c = 15.070(4) Å, β = 114.05(2)°, Z = 8, R = 3.99%. Both molecules of the asymmetric unit show about the same conformation with approximate Cs-m - symmetry as was also obtained by semi-empirical MNDO calculations. The thermal motion analysis establishes that the molecules cannot be described as ′rigid bodies′, and that the easy deformability of the exocyclic C-N-P angles allows the ′rigid′ NPCl3 tetrahedra to perform almost isotropic librations.