Les liaisons phosphore-azote via l'étude cristalline et moléculaire d'un iminodiazaphospholane

Abstract

Iminodiazophospholane 1 was obtained as monoclinic crystals, space group P21/c with a = 10.243(9), b = 17.236(5), c = 11.992(9) Å, and Z = 4. The structure was determined by single-crystal X-ray diffraction and was refined up to R = 0.056[Formula: see text]for 1342 reflections. The geometry of the molecule is that of a distorted tetrahedron with [Formula: see text] angles varying from 91.8° (ring angle) to 121.7° for [Formula: see text]. The diazophospholane ring has an envelope conformation where one of the 2 carbon atoms is at the tip. The three tricoordinated nitrogen atoms have a planar structure; the lone pairs on the two ring nitrogens have parallel orientation and both are orthogonal to the lone pair of the exocyclic nitrogen atom (N7). The P—N bond lengths are relatively short, falling between 1.620 Å and 1.669 Å, while the P2=N6 bond of 1.539 Å is among the smallest values ever reported. The multiplicities of the P—N bonds were assigned on the basis of an empirical method: 0.10 for the two cyclic P—N, 0.25 for the exocyclic P—N, and 0.60 for [Formula: see text] [Journal translation]