Structural studies of cyclohexane, C6D12 by neutron diffraction

Neutron diffraction measurements have been made on liquid C6D12 at temperatures of 6, 20 and 270C. The data at high Q-values have been fitted to a molecular form-factor and the bond-lengths are in good agreement with values obtained from other sources. The 'boat' and 'chair' conformations give comparable fits although there is a slight preference for the 'boat' structure. The composite inter-molecular pair correlation function was evaluated and shows spatial features extending to 25 A. The temperature variation produced no marked change in the structural features but showed a shift in the long-range oscillatory structure arising from the density variation. Separation of intra- and inter-molecular contributions for short distances (r < 5 A) is achieved and shows a peak at 2.7 A for correlations between neighbouring molecules. (author)