<p><strong>ACIDIC IONIC LIQUIDS </strong></p><p><strong>REFERENCES ACIDIC&nbsp;IONIC LIQUIDS </strong></p><p>1-(4-sulfobutyl)-3-methylimidazolium trifluoromethanesulfonate, 98% [(CH<sub style="top: 0.08em;">2</sub>)<sub style="top: 0.08em;">4</sub>SO<sub style="top: 0.08em;">3</sub>HMlm][CF<sub style="top: 0.08em;">3</sub>SO<sub style="top: 0.08em;">3</sub>] <br>ImSF1705c <br>1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate, 98% [(CH<sub style="top: 0.08em;">2</sub>)<sub style="top: 0.08em;">4</sub>SO<sub style="top: 0.08em;">3</sub>HMlm][HSO<sub style="top: 0.08em;">4</sub>] <br>ImSF1213c ImSF1808c <br>1-(4-sulfobutyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 98% [(CH<sub style="top: 0.08em;">2</sub>)<sub style="top: 0.08em;">4</sub>SO<sub style="top: 0.08em;">3</sub>HMlm][N(CF<sub style="top: 0.08em;">3</sub>SO<sub style="top: 0.08em;">2</sub>)<sub style="top: 0.08em;">2</sub>] </p><p><strong>Experimental aspect : </strong></p><p></p><p>Hydrophilic Liquid at room temperature Brønsted acids Stable with water and oxygen Non-corrosive Easily recyclable </p><p><strong>Solubility : </strong></p><p></p><ul style="display: flex;"><li style="flex:1"><strong>SOLVENT </strong></li><li style="flex:1"><strong>MISCIBILITY </strong></li></ul><p></p><p></p><ul style="display: flex;"><li style="flex:1">Water </li><li style="flex:1">Miscible </li></ul><p>Hexane Ester immiscible immiscible </p><p><strong>Applications : </strong></p><p>These ionic liquids are used as acid catalysts in the following reactions : Esterification, Oxidation, </p><p>Alkylation, Beckmann Rearrangement, Cyclotrimerisation… </p><p><strong>Esterification of ethanol by acetic acid</strong><sup style="top: -0.46em;"><strong>1</strong></sup>: </p><p>Catalyzed by a Brønsted acidic ionic liquid </p><p>CH<sub style="top: 0.2478em;">3</sub>COOC<sub style="top: 0.2478em;">2</sub>H<sub style="top: 0.2478em;">5 </sub><br>Ethyl acetate <br>Conversion = 60.3% Selectivity = 98.2% </p><ul style="display: flex;"><li style="flex:1">+</li><li style="flex:1">OH <sub style="top: 0.2478em;">2 </sub></li></ul><p>H<sub style="top: 0.2462em;">2</sub>SO<sub style="top: 0.2462em;">4 </sub></p><p></p><ul style="display: flex;"><li style="flex:1">CH<sub style="top: 0.228em;">3</sub>COOH </li><li style="flex:1">+</li><li style="flex:1">C</li><li style="flex:1"><sub style="top: 0.228em;">2</sub>H<sub style="top: 0.228em;">5</sub>OH </li></ul><p></p><p>60°C, 4 h </p><p></p><ul style="display: flex;"><li style="flex:1">Acetic acid </li><li style="flex:1">Ethanol </li></ul><p>[(CH<sub style="top: 0.248em;">2</sub>)H<sub style="top: 0.248em;">4</sub>SO<sub style="top: 0.248em;">3</sub>HMIm] [HSO<sub style="top: 0.248em;">4</sub>] <br>CH<sub style="top: 0.2461em;">3</sub>COOC<sub style="top: 0.2461em;">2</sub>H<sub style="top: 0.2461em;">5 </sub><br>Ethyl acetate <br>Conversion = 92.8% Selectivity = 100% </p><ul style="display: flex;"><li style="flex:1">+</li><li style="flex:1">OH <sub style="top: 0.2461em;">2 </sub></li></ul><p></p><p>The 1-(4-sulfobutyl)-3-methylimidazoliumhydrogensulfate is a more effective catalyst than a conventional catalyst (sulphuric acid H<sub style="top: 0.13em;">2</sub>SO<sub style="top: 0.13em;">4</sub>). The ester formed is extracted by a simple separation and the acidic ionic liquid may then be recycled without any loss of activity (at the 5<sup style="top: -0.42em;">th </sup>recycling, Conversion=88.5% and Selectivity=100%). </p><p><strong>Cyclotrimerization of aldehydes</strong><sup style="top: -0.46em;"><strong>2</strong></sup><strong>: </strong></p><p>Catalyzed by an acidic ionic liquid with no addition of any organic solvent </p><p>[(CH<sub style="top: 0.2692em;">2</sub>)<sub style="top: 0.2692em;">4</sub>SO<sub style="top: 0.2692em;">3</sub>HMIm] [CF SO<sub style="top: 0.2692em;">3</sub>] </p><p>3</p><p></p><ul style="display: flex;"><li style="flex:1">O</li><li style="flex:1">O</li></ul><p></p><ul style="display: flex;"><li style="flex:1">3</li><li style="flex:1">O</li></ul><p>O</p><p>25°C, 1 h </p><p>2, 4, 6-triisopropyl-1, 3, 5-trioxane Conversion = 93% Selectivity = 100% <br>Isobutyraldehyde </p><p>The Isobutyraldehyde (60 mol) is catalyzed by the 1-(4-sulfobutyl)-3-methylimidazolium trifluoromethanesulfonate (1 mol) in only one hour at room temperature. The product from the reaction is isolated by liquid-liquid extraction with hexane ant the acidic ionic liquid is easily recycled without any loss of activity (at the 5<sup style="top: -0.42em;">th </sup>recycling, Conversion=93% and Selectivity=100%). </p><p><sup style="top: -0.33em;">1 </sup>Jianzhou Gui, Xiaohui Cong, Dan Liu, Xiaotong Zhang, Zhide Hu b, Zhaolin Sun, Catalysis Communications, 5, 473–477, (2004) <sup style="top: -0.33em;">2 </sup>Jianzhou Gui, Dan Liu, Xiaomei Chen, Xiaotong Zhang, Lijuan Song, and Zhaolin Sun, React.Kinet.Catal.Lett., Vol. 90, No. 1,35−43 (2007) </p>