Crystal structure of 3,3'-biisoxazole-5,5'-bis(methyl-ene) dinitrate (BIDN).

The mol-ecular structure of the title energetic compound, C8H6N4O8, is composed of two planar isoxazole rings and two near planar alkyl-nitrate groups (r.m.s deviation = 0.006 Å). In the crystal, the mol-ecule sits on an inversion center, thus Z' = 0.5. The dihedral angle between the isoxazole ring and the nitrate group is 69.58 (8)°. van der Waals contacts dominate the inter-molecular inter-actions. Inversion-related rings are in close slip-stacked proximity, with an inter-planar separation of 3.101 (3) Å [centroid-centroid distance = 3.701 (3) Å]. The measured and calculated densities are in good agreement (1.585 versus 1.610 Mg m(-3)).