The structure of liquid 1,2 dichloroethane by neutron diffraction. I. Molecular structure, full pair correlation function, and temperature effects

Neutron diffraction measurements have been made in liquid 1,2 dichloroethane-d4 (DCE) at temperatures of −20, 21, and 70 °C. The intramolecular structural parameters have been determined by analysis of the high momentum transfer region of the derived structure factor as well as the relative populations of trans and gauche conformers. The separation between intra- and intermolecular contributions is achieved by means of previously reported procedures based upon maximum entropy estimation techniques. The full (composite) single-particle pair correlation function has been evaluated and show significant structural features up to 15 Å. A tentative assignment is made based upon results from a Monte Carlo simulation. The temperature variation produced some marked changes due to both the density decrease at high temperatures as well as to the displacement of the conformational equilibrium.