Raman Spectroscopic Study on the Conformation of 1,2-Dimethoxyethane in the Liquid Phase and in Aqueous Solutions

The conformation of 1,2-dimethoxyethane in the liquid phase and in aqueous solutions was studied by Raman spectroscopy. The conformation-sensitive Raman bands of 1,2-dimethoxyethane, located in the wavenumber region 300−600 cm-1, were analyzed by means of the band decomposition based on normal coordinate analysis. The populations of the conformers of 1,2-dimethoxyethane, their relative energies, and their relative entropies in the liquid phase were estimated and compared with the relevant data for the gas phase of 1,2-dimethoxyethane. The condensed phase effects on the conformation of 1,2-dimethoxyethane were discussed on the basis of the experimental data. The populations of the conformers at 318 K in aqueous solutions with different concentrations were estimated. It was revealed that the populations of the TTT and TGG‘ conformers of 1,2-dimethoxyethane decrease on increasing concentration of water, while the populations of the TGT and TGG conformers increase. The entropies of the less hydrophilic TTT an...