1-甲基-3-乙基咪唑缬氨酸盐离子液体[C_2mim][Val]的热化学  

Thermochemistry on 1-Methyl-3-ethylimidazolium Valine Ionic Liquid [C_2mim][Val]

作　　者：关伟[1,2] 王彩霞[1,2] 王珍 陈三平[1] 高胜利[1] 

机构地区：[1]天然与合成功能分子教育部重点实验室西北大学化学与材料科学学院,西安710069 [2]辽宁大学化学院,沈阳110036

出　　处：《化学学报》2011年第11期1280-1286,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.20773056和20873100);博士后基金资助项目

摘　　要：用中和法合成了氨基酸离子液体1-甲基-3-乙基咪唑缬氨酸盐([C2mim][Val]).在298.15±0.01K下,利用恒温溶解反应热量计测定了不同含水量的[C2mim][Val]溶解成不同质量摩尔浓度溶液的溶解焓,△solHm(w),借助标准加入法(SAM)和Archer方法得到了无水离子液体[C2mim][Val]的标准摩尔溶解焓,△solH(?).利用RB-Ⅱ型精密转动弹热量计测定了该离子液体的燃烧热,计算了其标准摩尔燃烧焓△cH(?)和标准摩尔生成焓△fH(?);并结合该离子液体的标准摩尔溶解焓和乙基咪唑阳离子[C2mim]+在水溶液中的标准摩尔生成焓,计算了[Val]^-离子在水溶液中的标准摩尔生成焓.利用RD496-Ⅲ型热导式微量热量计测定了不同质量摩尔浓度[C2mim][Val]水溶液的稀释焓,根据扩展的Debye-Huckel方程计算得到的相对表观摩尔焓(?)和根据Pitzer离子相互作用模型的计算值在实验误差范围内很好一致.An amino acid ionic liquid, [C2mim][Val] （1-methyl-3-ethylimidazolium α-aminoisovaleric acid salt）, was prepared by the neutralization method. Using the solution-reaction isoperibol calorimeter, the molar solution enthalpies of ionic liquid [C2mim][Val], △solHm（w）, with known initial mass fractions of water, w2, and with different molalities were determined at 298.15±0.01 K. In terms of standard addition method （SAM） and Archer＇s method, the standard molar enthalpy of solution for [C2mim][Val] without water, △solH, was obtained. The combustion energy of the ionic liquid was determined using an RB-Ⅱ type the rotating-bomb combustion calorimeter. The standard molar enthalpy of combustion, △cH（）, and the standard molar enthalpy of formation, △fH, were calculated. In terms of standard molar enthalpy of solution, △fH, and the standard molar enthalpy of formation for cation of [C2mim]＋, the standard molar enthalpy of formation for anion of [Val] in water solution were calculated. Using an RD496-Ⅲ heat conduction microcalorimeter, the molar enthalpies of dilution, △DHm（mi→mf）, of aqueous [C2mim][Val] with various molalities were measured. The values of apparent relative molar enthalpy, were calculated using extended Debye-Huckel equation, which are in good agreement with that calculated using Pitzer＇s ion-interaction model.

关 键 词：缬氨酸 离子液体 溶解焓 燃烧焓 稀释焓 

分 类 号：O642.1[理学—物理化学]