Solvatomorphism of 9,9′-[1,3,4-thiadiazole-2,5-diylbis(2,3-thiophendiyl-4,1-phenylene)]bis[9Hcarbazole]: isostructurality, modularity and order–disorder theory

Acta Cryst. (2012). B68, 667-676 (http://doi.org/jwx)

The order–disorder structure of the MEK solvate. The largest regions that are equivalent in all polytypes are indicated to the right by brackets.

The title compound features an unusual tendency to cocrystallize with solvent molecules. The resulting solvates do not feature strong hydrogen bonds, nor are the molecules arranged in framework structures. To describe the structural diversity of six solvates of the title compound, we applied the concept of modularity which was originally developed for inorganics and minerals. Moreover, for one structure we used the formalism of order‐disorder theory to explain the pseudo-symmetry and the twinning of the structure.