Stereochemistry of phosphorus compounds. Part I. The crystal and molecular structure of 1,3-di-t-butyl-2-trans-4-dichloro-2,4-dioxo-cyclodiphosphazane
The structure of the title compound has been determined from 841 X-ray intensity data measured on a diffractometer. Crystals are tetragonal, space group P42/n, a= 13·428(5), c= 8·152(3)Å, Z= 4. The structure was solved by Patterson and Fourier methods and refined by full-matrix least-squares to R 0·036. The crystals are built of discrete monomeric molecules, which exhibit exact Ci symmetry. The chlorine atoms thus adopt a mutually trans-configuration. Selected bond lengths are : P–Cl 2·007(2), P–O 1·448(3), mean P–N 1·661(5), mean N–C 1·507(5)Å.