Experimental Crystal data

R factor = 0.048; wR factor = 0.129; data-to-parameter ratio = 19.5. The title compound, C17H14Cl4N5OP3, is a spiro-phosphazene derivative with bulky naphthalene and pyridine rings. The phosphazene and the six-membered N/O rings are in flattened-boat and twisted-boat conformations, respectively. The naphthalene ring system and the pyridine ring are oriented at a dihedral angle of 18.06 (8). In the crystal, weak – stacking between the pyridine rings and between the pyridine rings and the naphthalene ring system [centroid– centroid distances = 3.594 (2) and 3.961 (2) Å, respectively] occur. Weak C—H interactions are also observed. These interactions link the molecules into a three-dimensional supramolecular network. Related literature For products from the reaction of N3P3Cl6 with bifunctional reagents, see: Beşli et al. (2006). For N/O donor type bifunc-tional reagents used for the reaction of hexachlorocyclo-triphosphazene giving spiro derivatives, see: Beşli et al. (2007)