title: Solvatomorphism of 9,9'-[1,3,4-thiadiazole-2,5-diylbis(2,3-thiophendiyl-4,1-phenylene)]bis[9H-carbazole]: isostructurality, modularity and order-disorder theory.
abstract: During a systematic investigation of the crystallization behaviour of 9,9'-[1,3,4-thiadiazole-2,5-diylbis(2,3-thiophendiyl-4,1-phenylene)]bis[9H-carbazole] (I), six single crystalline solvates were obtained and characterized by X-ray diffraction at 100 K. The structure of the hemi-2-butanone (MEK) solvate contains two crystallographically independent molecules of (I) related by pseudo-inversion symmetry. The structure is polytypic and composed of non-polar (I) layers and polar solvent layers. It can be described according to an extended order-disorder (OD) theory with relaxed vicinity condition. The observed polytype is of a maximum degree of order (MDO). Layer triples of the second MDO polytype are shown by twinning by inversion. The mono-benzene and mono-toluene solvates are isostructural. Whereas the (I) layers are isostructural to those of the idealized description of the hemi-MEK solvate, the solvent layers are non-polar, resulting in a fully ordered structure. The toluene molecule is ordered, the benzene molecule features disorder. The (I) layers in the sesqui-dioxane and sesqui-benzene solvates are isostructural and unrelated to those in the hemi-MEK, mono-benzene and mono-toluene solvates. The solvent layers are isopointal in both sesqui-solvates, but the stacking differs significantly. The hemi-dideuterodichloromethane (DCM-d(2)) solvate is made up of two kinds of (I) rods, spaced by DCM-d(2) molecules. Rods of one kind are similar to analogous rods in the sesqui-dioxane and the sesqui-benzene solvates, whereas rods of the other kind are only remotely related to rods in the hemi-MEK solvate.
authors.affiliation: Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-SC, 1060 Vienna, Austria. bstoeger@mail.tuwien.ac.at
authors.forename: Berthold
authors.initials: B
authors.lastname: Stöger
authors.forename: Paul
authors.initials: P
authors.lastname: Kautny
authors.forename: Daniel
authors.initials: D
authors.lastname: Lumpi
authors.forename: Erich
authors.initials: E
authors.lastname: Zobetz
authors.forename: Johannes
authors.initials: J
authors.lastname: Fröhlich