Angelini Guido, Campestre Cristina, Scotti Luca, Gasbarri Carla
Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
Department of Oral Science, Nano and Biotechnology, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
Molecules. 2017 Jul 29;22(8):1273. doi: 10.3390/molecules22081273.
BMIM PF₆ (1-butyl-3-methylimidazolium hexafluorophosphate) and BMIM Tf₂N (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) are two room-temperature ionic liquids widely employed and investigated as reaction media. Despite the presence of the same imidazolium ring in their structure they are different in many chemical and physical properties due to the nature of the anions. The thermal isomerization of an electronically activated azobenzene have been used as reaction model to compare the behavior of PF₆ and Tf₂N. Rotation is the mechanism by which the investigated azobenzene is converted into the isomer spontaneously in the dark both in BMIM PF₆ and in BMIM Tf₂N. The kinetic rate constants of the process have been determined at different temperatures and the activation energies of the reaction have been calculated according to the Arrhenius and Eyring equations. The results presented herein highlight different solute-solvent interactions involving the PF₆ and Tf₂N anions during the isomerization.
BMIM PF₆（1-丁基-3-甲基咪唑六氟磷酸盐）和BMIM Tf₂N（1-丁基-3-甲基咪唑双（三氟甲基磺酰）亚胺）是两种被广泛用作反应介质并进行研究的室温离子液体。尽管它们结构中存在相同的咪唑环，但由于阴离子的性质，它们在许多化学和物理性质上有所不同。电子活化偶氮苯的热异构化已被用作反应模型，以比较PF₆和Tf₂N的行为。旋转是所研究的偶氮苯在黑暗中于BMIM PF₆和BMIM Tf₂N中自发转化为异构体的机制。已在不同温度下测定了该过程的动力学速率常数，并根据阿伦尼乌斯方程和艾林方程计算了反应的活化能。本文给出的结果突出了异构化过程中涉及PF₆和Tf₂N阴离子的不同溶质-溶剂相互作用。
