4′,4′,6′,6′-Tetra­chloro-2-(6-methyl­pyridin-2-yl)-1H,2H-spiro­[naphtho­[1,2-e][1,3,2]oxaza­phosphinine-3,2′-[1,3,5,2,4,6]tri­aza­triphosphinine]

The title compound, C(17)H(14)Cl(4)N(5)OP(3), 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 π–π 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⋯π inter­actions are also observed. These interactions link the molecules into a three-dimensional supramolecular network.