High-pressurein-situcrystallization, structure and phase transitions in 1,2-dichloroethane

AbstractThe single crystal of 1,2-dichloroethane, C2H4Cl2wasin-situcrystallized in a Merrill-Bassett diamond-anvil cell, and its structure determined at 0.7 GPa and 280 K. The crystals are monoclinic, space groupP21/c. The C2H4Cl2molecules in thes-transconformation are located at the inversion centers. The —H2C—CH2—ethylene group is disordered in two sites, with equal occupancies, one rotated by 180° to the other about the Cl⋯Cl axis of the molecule. The crystal cohesion forces have been attributed mainly to Cl⋯Cl intermolecular interactions, and their role in the mechanism of the phase transition at 177 K has been analysed. It was found that the order-disorder phase transition in the struc…