The structure of liquid ethanol: A neutron diffraction and molecular dynamics study

A comprehensive neutron scattering study has been performed using selective hydrogen-deuterium substitution on the hydroxyl, methyl, and methylene hydrogen atoms in pure ethanol at room temperature. In this experiment we have directly measured 10 structure factors of the possible 21 partial structure factors that exist for liquid ethanol. The data has been used to obtain details on the conformation of the liquid ethanol molecule in the liquid state. The intermolecular structure were compared to molecular dynamics simulations using the Jorgensen potential for four- and nine-site liquid ethanol molecules. All ten neutron structure factors are in good agreement with the simulation results, although there are some small differences in the structural detail. The neutron structure factors show that hydrogen bonding dominates the structure of liquid ethanol at room temperature, which is consistent with the existence of winding chains predicted by the simulation. (C) 2000 American Institute of Physics. [S0021-9606(00)50813-7].