Structure of 1,4-cubanediyldiammonium bis(trinitromethanide)

C8H12N2+.2CN3O6-, Mr = 436.27, monoclinic, C2/m, a = 14.298 (2), b = 8.408 (1), c = 7.354 (2) A, beta = 103.42 (2) degrees, V = 859.9 (5) A3, Z = 2, Dx = 1.68 g cm-3, lambda(Mo K alpha) = 0.71069 A (graphite monochromator), mu = 1.66 cm-1, F(000) = 448, T = 293 K, final R = 0.039 for 672 reflections with I greater than or equal to 3 sigma(I). The cubanediyldiammonium cation and trinitromethanide anion have 2/m and m crystallographic symmetries, respectively. The cation is linked to six trinitromethanide anions, three at each end, by a total of 12 N--H...O hydrogen bonds through the six cation H atoms. The cubane cage has a local threefold axis of symmetry along the long axis (N1...N1) of the cation and undergoes a large librational motion, 17 degrees r.m.s. amplitude, about this axis.