Synthesis, characterization, and NMR studies of 1,2,3-triazolium ionic liquids: a good perspective regarding cytotoxicity.

Ionic liquids (ILs) have been extensively studied and are considered green solvents capable of replacing traditional organic solvents. In this study, seven 1,2,3-triazolium derivative ILs have been synthesized. In order to study the effect of the cation nature on the ILs cytotoxicity, their structures were first identified by 1H, 13C NMR 1D, and 2D spectroscopy. DFT calculations have also been performed in a way to help to provide an insightful structural analysis from 13C NMR spectroscopy. The comparison made with the NMR experimental shifts was quite important to show that the 1,2,3-triazolium derivatives have the expected structure shown here. The in vitro cytotoxicity of ILs toward macrophages showed that among the compounds tested, five did not exhibit expressive cytotoxicity on mammalian cells. Besides the well-established relationship between the carbonic chain size of the cation and the cytotoxicity, the log P of the compounds predicts that the toxicity increases with the size of the carbon chain, demonstrating that the most cytotoxic compound is also the most lipophilic one. The low cytotoxicity effect of ILs on mammalian cells points to their potential application in large-scale by industry. Graphical abstract Seven triazolium ILs were synthesized and their in vitro cytotoxicity on murine macrophages showed a relationship with the carbonic chain size.