Abstract This work focuses on the influence of the position of the alkyl chain cation on the thermal behavior and on the values of the heat capacities, for ionic liquids with pyridinium cation and bis(trifluoromethylsulfonyl)imide anion To achieve this objective, thermal properties such as, melting, freezing, cold crystallization and glass transition temperatures and heat capacities (in the temperature range from 293.15K to 363.15K) have been experimentally determined for several ionic liquids using differential scanning calorimetry. The ionic liquids chosen were: 1-alkyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide (1,2) CnMpyNTf2 (n = 2,3,4) and 1-alkyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide (1,4) CnMpyNTf2 (n = 2,3,4). The results obtained were compared with those published by the group in a previous paper concerning 1-alkyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide (1,3) CnMpyNTf2 (n = 2,3,4) ionic liquids. Moreover, the results from this essay were also compared with literature values. Three thermal behaviors were found for the studied ionic liquids: those characterized by the presence only glass transition, those presenting only freezing and melting transitions and those with subcooling phenomenon.

中文翻译：

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烷基链阳离子位置对热行为的影响：(1,2) 和 (1,4) 吡啶鎓双（三氟甲基磺酰基）亚胺 - 基于离子液体

摘要 这项工作的重点是烷基链阳离子的位置对热行为和热容量值的影响，对于具有吡啶鎓阳离子和双（三氟甲基磺酰基）亚胺阴离子的离子液体，为了实现这一目标，热性能如已经使用差示扫描量热法通过实验确定了几种离子液体的熔化、冷冻、冷结晶和玻璃化转变温度和热容量（在 293.15K 到 363.15K 的温度范围内）。选择的离子液体是：1-烷基-2-甲基吡啶鎓双（三氟甲基磺酰基）酰亚胺（1,2）CnMpyNTf2（n = 2,3,4）和1-烷基-4-甲基吡啶鎓双（三氟甲基磺酰基）酰亚胺（1,4 ) CnMpyNTf2 (n = 2,3,4)。获得的结果与该小组在先前关于 1-烷基-3-甲基吡啶鎓双（三氟甲基磺酰基）亚胺 (1,3) CnMpyNTf2 (n = 2,3,4) 离子液体的论文中发表的结果进行了比较。此外，本文的结果也与文献值进行了比较。对于所研究的离子液体，发现了三种热行为：特征在于仅存在玻璃化转变的特征、仅呈现凝固和熔融转变的特征以及具有过冷现象的特征。