一种室温离子液体与水相互作用的密度泛函理论研究

采用量子化学计算中的密度泛函理论(DFT),在B3LYP/6-31+G(d,p)计算水平上研究了离子液体1-乙基-3-甲基咪唑四氟硼酸盐(Emim]BF4)及其与水分子形成的复合物的稳定构型和相互作用能;经振动频率分析得到了Emim]BF4及其与水的复合物的红外光谱.计算结果表明,相对于水分子与阳离子的作用而言,水分子与阴离子的作用对离子液体结构的影响更大.与此同时,实验测得的Emim]BF4的红外光谱与计算结果吻合.

Density functional theory study of interaction between a room temperature ionic liquid and water molecules

The stable geometries of room temperature ionic liquid 1-ethyl-3-methyl-imidazole tetrafluoroborate {BF4}and its composite with water {BF4-H2O} as well as the interaction energies between BF4 and H2O were investigated by density functional theory（DFT） at the B3LYP/6-31＋G（d,p） level.The infrared（IR） spectra for the most stable BF4 and its complex with H2O were obtained through analyzing the vibrational frequency.The computed results indicate that the interaction between water and anion has more obvious influence on the structure of the ionic liquid than the interaction between water with cation.In the meantime,the experimentally measured IR spectrum of BF4 ionic liquid well conforms to the computed one.