Crystal structure of 8,8-dichloro-1,2,10,11,13,14-hexahydro-6l5,8l5, 10l5-6,10- nitrilo[1,3,5,7,2,4,6]tetraazatriphosphonino-bis[1,3,2]oxazaphosphorine

The title compound, C₆H₁₂N₅O₂P₃Cl ₂, a cyclotriphosphazene, has a spiro-ansa-spiro architecture in which the bicyclic system is in the sofa conformation. The asymmetric unit contains one half a molecule. Two P and two N atoms are capable of representing stereogenic centres (meso form). It belongs to the space group Pnma with cell parameters a = 11.6949(2), b = 13.6816(3), c = 8.576(2)Å. 2005