Conformation of 1,2-dimethoxyethane in water

To understand the conformation of 1,2-dimethoxyethane (DME) in water, a system of two kinds of molecules, DME and H2O, was focused. The interaction of various conformers of DME with water was studied by means of ab initio molecular orbital calculation with 6-31G(d) basis set. It is shown that there are two forms of interactions between the two molecules in the system, the close touched (H2O attaches to the two oxygen atoms of DME) and the open touched (H2O attaches to one oxygen atom of DME) structures. The conformation of DME is remarkably influenced by the interactions. Instead the ttt conformer is preferred in the gas state, with a close touched H2O the tgt conformer becomes the most stable one. The obtained hydration energies show that the stabilized order of DME conformers by water is tgt>tgg'>ttt.