Crystal Structure of Hexamethylcyclotriphosphazene-Iodine (1:1 Adduct)

Abstract

Crystals of the title compound, N3P3Me6•I2, are triclinic, a = 10.707(13), b = 8.873(5), c = 8.871(6) Å, α = 96.65(6), β = 103.91(12), γ = 97.81(12)°, Z = 2, space group [Formula: see text] The structure was determined with MoKα diffractometer data by Patterson and Fourier syntheses, and was refined by full-matrix least-squares methods to R = 0.053 for 1934 observed reflexions. One atom of the iodine molecule is weakly bonded to nitrogen, N—I = 2.417(7), I—I = 2.823(1) Å, N—I—I = 177.8(2)°. The six-membered phosphazene ring is slightly non-planar, with a chair conformation. The two P—N bonds involving the nitrogen atom bonded to iodine are longer, mean 1.64 Å, than the other four P—N bonds, mean 1.598 Å Other mean dimensions are: P—C = 1.789 Å, N—P—N = 114.7, P—N—P = 124.0, C—P—C = 104°.