title: Structure of 1,4-cubanediyldiammonium bis(trinitromethanide).
abstract: 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.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
authors.forename: H L
authors.initials: HL
authors.lastname: Ammon
authors.forename: C S
authors.initials: CS
authors.lastname: Choi
authors.forename: R S
authors.initials: RS
authors.lastname: Damvarapu
authors.forename: S
authors.initials: S
authors.lastname: Iyer
authors.forename: J
authors.initials: J
authors.lastname: Alster
mesh_terms: D001952:Bridged-Ring Compounds / Q000032:analysis*; D055598:Chemical Phenomena; D002621:Chemistry; D008968:Molecular Conformation; D000644:Quaternary Ammonium Compounds / Q000032:analysis*
chemical_list: D001952:Bridged-Ring Compounds; D000644:Quaternary Ammonium Compounds; C063832:1,4-cubanediyldiammonium