Molecular aggregation phenomena in solution: an energy dispersive X-ray diffraction study of concentrated imidazole water solutions

An energy dispersive X-ray diffraction study of concentrated imidazole water solutions is reported. It reveals the presence of extended solute–solute aggregates. Such results can be interpreted in terms of a branch of a pseudo-helix of imidazole dimers interacting with water molecules. The mean distance between molecules in the dimer is ∼3.7 Å, while the mean distance between dimers is 4.75–4.95 Å depending on concentration. The model structure functions and theoretical radial distribution functions fit the experimental data.