An x-ray study of some simple derivatives of ethane.—Part I

Abstract Hexachlorethane.-C2Cl6. Molecular weight, 236·76. This substance is typical of the halogen derivatives of ethane and will therefore be considered in some detail. Trimorphism.-C2Cl6 is orthorhombic at ordinary temperatures, but at about 46°C, it changes over to a triclinic form and at 71° the triclinic form becomes cubic. The process is reversible:— Rhombic 45·1 - 46·6 ⇄ 43·1 triclinic 71·1 ⇄ 71·1 cubic.