Abstract
We have investigated the states of water molecule in the 1-butyl-3-methylimidazolium nitrate ([bmim][NO_3])-D_2O mixtures in the wide concentrations (X(mol%IL)) by Raman spectroscopy. From Raman OD stretching spectral analyses of D_2O at 298K and 77K, we found that water molecules in the [bmim][NO_3]-D_2O mixtures have three different states against the [bmim][NO_3] concentration; (i) the bulk-like water (X〜10), (ii) strong hydrogen bonded water in [bmim][NO_3] (X=10〜30), and (iii) the hydrated water with [bmim][NO_3] (X>30), respectively.
