Cyclohexane

"Cyclohexane is a cycloalkane with the molecular formula C₆H₁₂. Cyclohexane is used as a nonpolar solvent for the chemical industry, and also as a raw material for the industrial production of adipic acid and caprolactam, both of which being intermediates used in the production of nylon. On an industrial scale, cyclohexane is produced by reacting benzene with hydrogen. Because of its unique chemical and conformational properties, cyclohexane is also used in labs in analysis and as a standard. Cyclohexane has a distinctive detergent-like odor, reminiscent of cleaning product (in which it is sometimes used)."

"Cyclohexane has two crystalline phases. The high-temperature phase I, stable between 186 K and the melting point 280 K, is a plastic crystal, which means the molecules retain some rotational degree of freedom. The low-temperature (below 186 K) phase II is ordered. Two other low-temperature (metastable) phases III and IV have been obtained by application of moderate pressures above 30 MPa, where phase IV appears exclusively in deuteratedcyclohexane (note that application of pressure increases the values of all transition temperatures)."