Preparative and structural studies of diazadiphosphetidines. Part 9. X-Ray and nuclear magnetic resonance investigations of (Ph2FPNMe)n

Abstract

It has been established by X-ray and n.m.r. analyses that the compund (Ph₂FPNMe)_n can be prepared as a dimer with a diazadiphosphetiding ring. The ¹H spectrum of the NMe group may be explained in terms of a slow pseudorotation between two conformations. The two values of ³J_PH(16.78 and 6.17 Hz) are considerably different, and involve coupling paths through axial and equatorial P–N bonds. Crystals of (Ph₂FPNMe)₂ are triclinic, space group P, with a= 9.849(2), b= 14.858(3), c= 8.236 (1)Å, α= 93.53(2), β= 94.70(2), γ= 104.04(2)°, Z= 2. There are two independent crystallographically centrosymmetric molecules within the unit cell. Distorted trigonal-bipyramidal co-ordination is observed at phosphorus with mean bond lengths; P–F 1.683(3), P–N _eq 1.652(3), P–N_ax 1.780(1), and P–C 1.835(4)Å. The Structure was solved by direct methods and refined to R 0.063 for 3 299 diffractometer-measured unique reflections.