Showing papers by "Doyle Britton published in 2012"

3,5-Dichloro-4-cyanobenzoic Acid Co-crystals with Carbon Tetrachloride, Naphthalene, and Anthracene

Abstract: The title compound, C8H3Cl2NO2 (M), forms co-crystals with carbon tetrachloride, M/CCl4; naphthalene, M/1/2C10H8; and anthracene, M/1/2C14H10. Cell parameters for M/CCl4: a = 8.8657(10) A, b = 8.9393(10) A, c = 10.2658(12) A, α = 66.622(2)°, β = 69.510(2)°, γ = 71.968(2)°, space group P-1. Cell parameters for M/1/2C10H8: a = 8.0304(13) A, b = 9.0112(14) A, c = 9.4742(15) A, α = 112.282(3)°, β = 100.378(3)°, γ = 91.968(3)°, space group P-1. Cell parameters for M/1/2C14H10 a = 5.8893(7) A, b = 7.3885(9) A, c = 15.4098(18) A, α = 87.972(2)°, β = 82.242(2)°, γ = 78.085(2)°, space group P-1. In each case the benzoic acid groups interact to form dimers of M with an R 2 2 (8) motif. The dimers are linked together through CN···Cl intermolecular interactions with an R 2 2 (10) motif to form chains or sheets. With the exception of one CN···CCl4 interaction, the other molecule in each co-crystal is packed between chains (carbon tetrachloride) or in holes in the sheets (naphthalene and anthracene). 3,5-Dichloro-4-cyanobenzoic, which has interwoven sheets in the pure state, can be directed into planar layers, with a co-crystalline partner.

Four polymorphs (polytypes) of 5,6-dimethylbenzofurazan 1-oxide

Abstract: 5,6-Dimethylbenzofurazan 1-oxide (Me2BF), C8H8N2O2, occurs in four polymorphic forms that are polytypes of each other. Each polymorph of Me2BF contains molecules disordered about pseudo-twofold axes and arranged head-to-tail in ribbons, with the ribbons forming approximately planar layers held together by weak C—H⋯N and C—H⋯O interactions. Adjacent layers interact in different ways in the different polymorphs. In addition to twinning in the individual polymorphs, four examples of allotwining, that is, oriented overgrowths between different polymorphs, were found.