3,3-Dinitro-azetidinium 2-hy-droxy-benzoate.

In the title gem-dinitro-azetidinium 2-hy-droxy-benzoate salt, C(3)H(6)N(3)O(4) (+)·C(7)H(5)O(3) (-), the azetidine ring is virtually planar, with a mean deviation from the plane of 0.0242 Å. The dihedral angle between the two nitro groups is 87.5 (1)°.

1-(2,4-Dinitro-phen-yl)-3,3-dinitro-azetidine.

In the title compound, C(9)H(7)N(5)O(8), the dihedral angle between the mean plane of the azetidine ring and that of the benzene ring is 26.1 (1)°; the planes of the two nitro groups of the azetidine ring are aligned at 88.7 (1)°.

1-Benzoyl-3,3-dinitro-azetidine.

In the title gem-dinitro-azetidine derivative, C(10)H(9)N(3)O(5), the azetidine ring is almost planar, the maximum value of the endocyclic torsion angle being 0.92 (14)°. The gem-dinitro groups are mutually perpendicular and the dihedral angle between the azetidine and benzene rings is 46.70 (10)°