Concomitant polymorphs: structural studies on the trimorphic dithiadiazolyl radical, ClCNSSN

The radical ClCNSSN (1) exhibits a rigid geometry which limits structural variation in the solid state to differences in packing motifs. Sublimation of 1 (75 degreesC, 10(-2) Torr) leads to the isolation of three distinct polymorphs; 1alpha (monoclinic, P2(1)/n) crystallises as cisoid dimers with two molecules in the asymmetric unit, 1beta (monoclinic, P2(1)/c) crystallises as twisted dimers with four molecules in the asymmetric unit and 1gamma (monoclinic, P2(1)/c) crystallises as cisoid dimers (similar to 1alpha), but with eight molecules in the asymmetric unit. Despite their structural variations, all three structures exhibit similar structure-directing motifs based upon electrostatic Sdelta+...Ndelta- contacts.