title: Form III of 2,2',4,4',6,6'-hexanitroazobenzene (HNAB-III).
abstract: The crystal structure of form III of the title compound, HNAB [systematic name: bis(2,4,6-trinitrophenyl)diazene], C12H4N8O12, has finally been solved as a pseudo-merohedral twin (monoclinic space group P2(1), rather than the orthorhombic space group C222(1) suggested by diffraction symmetry) using a dual space recycling method. The significant differences in the room-temperature densities of the three crystalline forms allow examination of molecular differences due to packing arrangements. An interesting relationship with the stilbene analog, HNS, is discussed. Interatomic separations are compared with other explosives and/or nitro-containing compounds.
authors.affiliation: PO Box 5800, MS 1411, Sandia National Laboratories, Albuquerque, New Mexico 87185-1411, USA. marodri@sandia.gov
authors.forename: Mark A
authors.initials: MA
authors.lastname: Rodriguez
authors.forename: Charles F
authors.initials: CF
authors.lastname: Campana
authors.forename: A David
authors.initials: AD
authors.lastname: Rae
authors.forename: Edward
authors.initials: E
authors.lastname: Graeber
authors.forename: Bruno
authors.initials: B
authors.lastname: Morosin