Stereochemistry of phosphorus compounds. Part II. Crystal and molecular structure of 1,3-di-t-butyl-2,4-dichlorodiazadiphosphetidine

The crystal and molecular structure of the title compound has been determined by X-ray analysis. Crystals are orthorhombic, space group Pbca, with Z= 8 in a cell of dimensions a= 15·818(7), b= 15·742(6), c= 11. 608(6)A. The structure was solved by direct methods and refined to R 0·098 by the method of full-matrix least-squares, by use of 926 intensity data measured on a diffractometer. The crystals contain discrete molecules of almost exact C8 symmetry. The [P–N]2 ring is slightly puckered and the chlorine atoms are mutually cis. There are no significant differences between chemically equivalent bond lengths, and mean values are P–N 1·689(4) P–Cl 2·105(9), N–C 1. 498(11), and C–C 1·564(8)A.