4,4′,4′′,4′′′-({4′λ 5 ,6λ 5 ,6′λ 5 -Spiro[dibenzo[ d , f ][1,3,2]dioxaphosphepine-6,2′-[1,3,5,2,4,6]triazatriphosphinine]-4′,4′,6′,6′-tetrayl}tetrakis(oxy))tetrabenzaldehyde

The complete molecule of the title compound, C 40 H 28 N 3 O 10 P 3 , is generated by crystallographic twofold symmetry, with one P and one N atom lying on the rotation axis. The central P 3 N 3 ring is close to planar, with an r.m.s. deviation of the six fitted atoms of 0.077 Å. The 2,2′-biphenoxy moiety generates a seven-membered spirocyclic structure with an endocyclic C—C—C—C torsion angle about the central biphenoxy C—C bond of 38.5 (4)°. The formyl-substituted phenyl rings subtend dihedral angles of 56.83 (10) and 61.02 (13)° with respect to the phosphazene core. The C=O and C—H groups of the formyl groups are disordered over two orientations in a 0.640 (4):0.360 (4) ratio. No directional interactions beyond normal van der Waals contacts could be identified in the crystal.