title: Structure of phenoxathiin (phenothioxin), C12H8OS, at 223 K.
abstract: Mr = 200.25, orthorhombic, P2(1)2(1)2(1), a = 7.758(2), b = 20.506(3), c = 5.896(2) A, V = 938.0(4) A3, Z = 4, Dx = 1.42 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 2.88 cm-1, F(000) = 416, T = 223 K, R = 0.044 for 1414 unique reflections having I greater than 3 sigma I. The phenoxathiin molecule is constituted of two very nearly regular planar hexagonal carbocyclic (benzenoid) rings joined to a non-planar heterocyclic ring. The heterocyclic ring geometry is described in terms of two intersecting planes between which the dihedral angle, the molecular fold angle, is 142.3 degrees. The angle at S (C-S-C) is 97.7(1) degrees, while the angle at O (C-O-C) is 117.4(2) degrees. The overall mean C-C distance in the carbocyclic rings is 1.387(7) A. The absence in this structure of the type of disorder previously found in the dibenzofuran structure is readily understandable since eight sets of close approaches involving each molecule were found in the present structure. These close approaches involve S and O atoms as well as H atoms.
authors.affiliation: Department of Chemistry, Ohio State University, Columbus 43210.
authors.forename: L J
authors.initials: LJ
authors.lastname: Fitzgerald
authors.forename: J C
authors.initials: JC
authors.lastname: Gallucci
authors.forename: R E
authors.initials: RE
authors.lastname: Gerkin
mesh_terms: D006571:Heterocyclic Compounds / Q000737:chemistry*; D007364:Intercalating Agents / Q000737:chemistry*; D015394:Molecular Structure; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D006571:Heterocyclic Compounds; D007364:Intercalating Agents; C068135:phenoxathiin