Determination and Correlation of Solubilities of Four Novel Benzothiazolium Ionic Liquids with PF6^- in Six Alcohols

• Published in: 中国化学工程学报：英文版 2014-04 (4), p.435-446
• Main Author: 何志坚 王小敏 姚田 宋航 姚舜
• Format: Article
• Language: English
• Subjects: 温度敏感性; 温度范围; 溶解度数据; 溶解度测定; 甲醇; 离子液体; 苯并噻唑
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(14)60056-2

Four novel benzothiazolium ionic liquids with 6PF- （[C1Bth][PF6], [C4Bth][PF6], [C5Bth][PF6] and [C6Bth][PF6]） were synthesized, and the rang of their melting points were determined between 358.35 K-424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected‘S’ type ten-dency. Then, the solubilities of the four ionic liquids in six lower alcohols （methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol） were measured in the temperature rang of 253.15-383.15 K at at-mospheric pressure with static analytical method, respectively. It was found that [C6Bth][PF6] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C4Bth][PF6] in methanol was very sensi-tive for temperature in 313.15-333.15 K, which was so-called “temperature-sensitivity”. This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids （ILs） become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation andλh equation, respectively. It was found that the result of correlation using two divided tem-perature ranges was better than that of using the whole temperature range.