A modification of synthesis of amino acid ionic liquids (AAILs) based on 1-alkyl-3-methylimidazolium cation and L-Serinate anion [Cnmim][Ser] (n = 8, 10, 12) was developed. The structures of the AAILs based on serinate were confirmed by 1H NMR and 13C NMR spectroscopies. The electrical conductivity in aqueous mixtures of ionic liquids from the family 1-alkyl-3-methylimidazolium serinate [Cnmim][Ser] (n = 8, 10, 12) at 298.15 K were measured. The results of the electrical conductivity study clearly show that the general features of micellar aggregation of relatively long-chain imidazolium IL are analogous to those in the case of traditional surfactants. Critical micelle concentrations (cmc) of AAILs, degree of counterion binding ( β ), standard Gibbs energy of micellization (Δ G °m) for them were estimated from the experimental data. The dependences of the cmc, β and Δ G °m, on the length of the alkyl chain of the cations were discussed. These compounds were initially screened for biology activity by a simple zone of inhibition study against Staphylococcus aureus ATCC 5638 (gram-positive bacteria), Escherichia coli ATCC 25922 (gram-negative bacteria) and Candida albicans ATCC 885653 (fungus). The data obtained have shown that among AAILS the [C10mim][Ser] is more effective against this bacteria.
amino acid ionic liquid, 1-alkyl-3-methylimidazolium cation, electrical conductivity, micellization, antibacterial effect
1. Bowers J., Butts C.P., Martin P.J., Vergara-Gutierrez M.C., Heenan R.K. Aggregation behavior of aqueous solutions of ionic liquids. Langmuir, 2004, vol. 20, pp. 2191-2198, DOI: 10.1021/la035940m.
2. Dong B., Li N., Zheng L.Q., Yu L., Inoue T. Surface adsorption and micelle formation of surface active ionic liquids in aqueous solution. Langmuir, 2007, vol. 23, pp. 4178-4182, DOI: 10.1021/la0633029.
3. Jungnickel C., Luczak J., Ranke J., Fernandez J.F., Muller A., Thoming J. Micelle formation of imidazolium ionic liquids in aqueous solution, Colloids Surf.-Physicochem. Eng. Asp., 2008, vol. 316, pp. 278-284, DOI: 10.1016/j.colsurfa.2007.09.020.
4. Luczak J., Hupka J., Thoming J., Jungnickel C. Self-organization of imidazolium ionic liquids in aqueous solution, Colloids Surf. -Physicochem. Eng. Asp., 2008, vol. 329, pp. 125-133, DOI: 10.1016/j.colsurfa.2008.07.012.
5. Cornellas A., Perez L., Comelles F., Ribosa I., Manresa A., Garcia M.T. Self-aggregation and antimicrobial activity of imidazolium- and pyridinium-based ionic liquids in aqueous solution. J. Colloid Interface Sci., 2011, vol. 355, pp. 164-171, DOI: 10.1016/j.jcis.2010.11.063.
6. Garcia M.T., Gathergood N., Scammells P.J. Biodegradable ionic liquids Part II. Effect of the anion and toxicology. Green Chem., 2005, vol. 7, pp. 9-14.
7. Fukumoto K., Yoshizawa M., Ohno H. Room temperature ionic liquid from 20 natural amino acids. J. Am. Chem. Soc., 2005, vol. 127, pp. 2398-2399.
8. Lopp M., Boroznyak R.V. Synthesis of 1-butyl-3-methylimidazolium hydroxide and glutamate: Modification of Fukumoto’ Method. Zhurnal nauchnyh publikacij aspirantov i doktorantov, 2011, vol. 11, pp. 1-10. (in Russ.)
9. Alopina E., Safonova E., Pukinsky I., Smirnova N. Liquid-liquid equilibria in aqueous mixtures of alkylmethylimidazolium glutamate with potassium carbonate and some physicochemical properties of aqueous [Cnmim][Glu] (n = 4, 6, 8) solutions. J. Chem. Eng. Data, 2016, vol. 61, pp. 2013-2019.
10. Dobryakov Y., Tuma D., Maurer G. Activity Coefficients at Infinite Dilution of Alkanols in the Ionic Liquids 1-Butyl-3-methylimidazolium Hexafluorophosphate, 1-Butyl-3-methylimidazolium Methyl Sulfate, and 1-Hexyl-3-methylimidazolium Bis(trifluoromethylsulfonyl) Amide Using the Dilutor Technique. J. Chem. Eng. Data, 2008, vol. 53, pp. 2154-2162.
11. Ghanem Ou.B., Mutalib M.I.A., Lévêque J.-M., Gonfa G., Kait C., El-Harbawi M. Studies on the Physicochemical Properties of Ionic Liquids Based On 1-Octyl-3-methylimidazolium Amino Acids. J. Chem. Eng. Data, 2015, vol. 60, pp. 1756-1763.
12. Hoffmann H., Ulbricht W. Kinetic and thermodynamic measurements on aggregation of perfluorinated surfactants. Z. Phys. Chem.-Frankf., 1977, vol. 106, pp. 167-184.
13. Wang J.J., Wang H.Y., Zhang S.L., Zhang H.H., Zhao Y. Conductivities, volumes, fluorescence, and aggregation behavior of ionic liquids [C4mim][BF4] and [Cnmim] Br (n=4, 6, 8, 10, 12) in aqueous solutions. J. Phys. Chem. B, 2007, vol. 111, pp. 6181-6188.
14. Hiemenz P.C., Rajagopalan R. Principles of Colloid and Surface Chemistry. Marcel Dekker Inc, New York, 1997.
