title: Structure of 1,5,9-trinitrobishomopentaprismane.
abstract: 2,3,8-Trinitrohexacyclo[5.4.1.0(2,6).0(3,10).-0(4,8).0(9,12)]do dec ane (IV), C12H11N3O6, Mr = 293.2, orthorhombic, Pna2(1), a = 11.467 (1), b = 8.756 (1), c = 11.9339 (8) A, V = 1198.2 (4) A3, Dx = 1.625 g cm-3, Z = 4, Cu K alpha, lambda = 1.54178 A, mu = 11.6 cm-1, F(000) = 608, T = 293 K, final R = 0.061, wR = 0.091 for 1082 reflections with I greater than 3 sigma(I). There are no unusual intermolecular distances and the crystal packing is normal. The crystal density of (IV) is only 2.3% larger than that of 1,5-dinitrobishomopentaprismane (III) at 1.589 g cm-3 despite a 6.7% higher molecular density of (IV) over (III). An analysis of crystal packing and the calculated crystal packing coefficients indicates that the small crystal-density change is the result of more efficient molecular packing in (III) over (IV), which compensates for the lower molecular density of (III). The molecular shape and polarity of (III) lead to efficient crystal packing.
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: L A
authors.initials: LA
authors.lastname: Paquette
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D003516:Cycloparaffins / Q000737:chemistry*; D015394:Molecular Structure; D014961:X-Ray Diffraction
chemical_list: D003516:Cycloparaffins; C073240:1,5,9-trinitrobishomopentaprismane