A comparison of choline:urea and choline:oxalic acid deep eutectic solvents at 338 K.

1:2 choline chloride:urea and 1:1 choline chloride:oxalic acid deep eutectic solvents are compared at 338 K using liquid-phase neutron diffraction with H/D isotopic substitution to obtain differential neutron scattering cross sections and fitting of models to the experimental data using Empirical Potential Structure Refinement. In comparison to the previously reported study of choline chloride:urea at 303 K, we observed significant weakening and lengthening of choline-OH⋯Cl- and choline-OH⋯hydrogen-bond acceptor correlations.