Some unusual features in the behaviour of cyclohexane in confined geometry studied by neutron scattering

The dynamic characteristics of cyclohexane C6H12 was studied in the liquid and plastic crystal phases by spectroscopic means and analyzed in terms of unhindered rotator model. The transition from the liquid to the plastic crystal at 6.55°C involved a low entropy change and lead to a face centred cubic (fcc) crystal with a large defect concentration. The results showed unexpected characteristics concerning the behavior of cyclohexane in mesoporous solids and the orientational correlations between the molecules were affected by the confined geometry and contributed directly to large depression in the phase transition temperatures.