α-substituted Phosphoryl Compounds (I). The Crystal and Molecular Structure of Diethyl[5,6-dichloro-1,3-benzodioxol-(2)]-phosphonate,C11H13O5PCl2

Diethyl5,6-dichloro- 1,3-benzodioxol-(2)]-phosphonate crystallizes in the triclinic space group P l̄ with two molecules per unit cell. The lattice parameters are a = 11.716 Å, b = 8.471 Å, c = 7.644 Å; α = 82.47° β = 95.81°, γ = 95.89°. With X-ray diffraction data collected on an automatic four circle diffractometer, the crystal structure was solved by direct methods and refined by least squares methods to an R value of 0.12 for 2374 measured reflections. The crystal used was im perfect. The substance is a derivative of acetales of formyl phosphoneacid esters. The aim is to find a correlation between the geometry of the structure and NMR data.