Existence of Nearly-Free Hydrogen Bonds in an Ionic Liquid, <i>N</i>,<i>N</i>-Diethyl-<i>N</i>-methyl-<i>N</i>-(2-methoxyethyl) Ammonium Tetrafluoroborate-Water at 77 K

Abstract

When making the glassy water-ionic liquid, N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate [DEME][BF(4)] solution, the water molecule existing as a single molecule without self-associated state is preserved even at 77 K and survives not to form the hydrogen bond network among themselves as in pure H(2)O liquid. The water molecule might loosely interact with BF(4)(-) anions. At water-rich concentration, H(2)O ice crystals and the water molecules in the ionic liquid coexist as a mixture, which may result from microheterogeneities in the solid aqueous ionic liquid solution.