1,3-Dipentafluorophenyl-2,2,2,4,4,4-hexazido-1,3-diaza-2,4-diphosphetidine (1) was synthesized by the reaction of [(C 6 F 5 )NPCl 3 ] 2 with trimethylsilyl azide in CH 2 Cl 2 and characterized by multinuclear NMR and vibrational spectroscopy. The molecular structure of the compound was determined by single-crystal X-ray structure analysis.[(C 6 F 5 )NP(N 3 ) 3 ] 2 crystallizes in the monoclinic space group P2 1 /n with a = 9.6414(2), b = 7.4170(1) and c = 15.9447(4) A Ê , b = 94.4374(9)°, with 2 formula units per unit cell. The bond situation in [(C 6 F 5 )NP(N 3 ) 3 ] 2 has been studied on the basis of NBO analysis. The antisymmetric stretching vibration of the azide groups is discussed. The structural diversity of 1 and 1,3-diphenyl-2,2,2,4,4,4-hexazido-1,3-diaza-2,4-diphosphetidine in solution and in the solid state depending on the aryl substituent at the nitrogen atom is discussed.