The temperature-induced phase transition and molecular conformation of the imidazole ionic liquid 1-butyl-3-methylimidazolium bis{( trifluoromethyl) sulfonyl} imide( [BMIM][TFSI]) was studied by differential scanning calorimetry( DSC) and raman spectroscopy. The results show that the sample remains liquid state when cooling down from room tempenture to 190 K. Fuether cooling to 184 K,the super-cooling liquid sample transforms into the glassy state. During the warming process,the exothermic peak appears at a...