Conformational polymorphs of 1,1,2,2-tetrachloroethane: pressure vs.temperatureElectronic supplementary information (ESI) available: Detailed experimental and structural description. CCDC 811781and 811782. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c1cc10689a

Directional ClCl type I and II interactions govern the low-density aggregation of 1,1,2,2-tetrachloroethane molecules in synclinalconformation in the crystalline state at low temperature, whereas the dense molecular packing in high-pressure is achieved for the antiperiplanarconformers and electrostatically less favored ClCl contacts. The mechanism of transformation between loose and dense associations involves the collapse of ClCl contacts and conformational conversion. [ABSTRACT FROM AUTHOR]