Better Than the Best Polar Solvent: Tuning the Polarity of 1,2,4‐ Triazolium‐Based Ionic Liquids

Abstract In search of better replacement for highly polar volatile organic solvents, ionic liquids (ILs) with high polarity and high polarizability were synthesized using N‐1 substituted 1,2,4‐triazolium‐based cation with trifluoromethanesulfonate as the counter anion. The temperature dependence polarity of the synthesized ILs has been investigated using solvatochromic dyes and expressed in terms of and Kamlet‐Taft parameters (dipolarity/polarizability ( π *), hydrogen bond donor acidity ( α ), and hydrogen bond basicity ( β ) in the range of (293.15−353.15) K. The introduction of the –SO 3 H functional group and triazole ring on the cation has revealed high polarity ( >1.2) and high polarizability ( π *> 3.2). Furthermore, to understand the extent of intermolecular interaction temperature dependence refractive indices have been measured in the temperature range (293.15−343.15) K and a positive correlation was observed with polarity parameter. Finally, the impact of structure variants in terms of the N‐1 functionalized 1,2,4‐triazole ring has been analyzed over the studied properties which is scrutinized to understand the solvation capability and intermolecular interaction in ILs.