Correlation between Structure and Thermal Properties of N-vinyl-3-alkylimidazolium Magnetic Ionic Liquids

Abstract

Influence of structural variations of N-vinylimidazolium tetrahalogenidoferrate (III) magnetic ionic liquids (MILs) on thermal properties was investigated. Using Gaussian09/B3PW91/6-311G (2d, p) density functional methods, the microstructure of the MILs were analyzed. With differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA), the thermal properties of the MILs were performed. The results showed that the interaction energies of ion pairs decreased, the crystallization temperature increased first and then decreased, and the surfusion first decreased and then increased with the elongation of the alkyl chain length on cation; with the increase of Br atom, the interaction energies of ion pairs increased; the interaction energies of ion pairs increased in the MILs with the same cation or anion, the nature of polarity of MILs increased and the melting point rose; as the cation or anion in MILs had a smaller size, it could have the solidsolid transition temperature. The results indicated that the decomposition temperature with the same type of MILs increased with the interaction energies of ion pairs. The interaction energy of ion pairs can be used to illuminate the correlation between the thermal properties and the structure of MILs. ILs possesses the properties of macromolecular.

Keywords

magnetic ionic liquids / microstructure / melting point / glass transition / crystallization / thermostability

References

[1] Armand M, Endres F, MacFarlane D R, et al. Ionic-Liquid Materials for the Electrochemical Challenges of the Future[J]. Nat. Mater., 2009, 8: 621-629.

[2] Hallett J P, Welton T. Room-Temperature Ionic Liquids: Solvents for Synthesis and Catalysis. 2[J]. Chem. Rev., 2011, 111: 3 508-3 576.

[3] Sawant A D, Raut D G, Darvatkar N B, et al. Recent Developments of Task-Specific Ionic Liquids in Organic Synthesi[J]. Green Chem. Lett. Rev., 2011, 4: 41-54.

[4] Dupont J, Itoh T, Lozano P, et al. Environmentally Friendly Syntheses Using Ionic Liquids[M], 2015 New York: CRC Press.

[5] van F R, Sheldon R A. Biocatalysis in Ionic Liquids[J]. Chem. Rev., 2007, 107: 2 757-2 785.

[6] Kuchenbuch A, Giernoth R. Ionic Liquids Beyond Simple Solvents: Glimpses at the State of the Art in Organic Chemistry[J]. Chemistry Open, 2015, 4: 677-681.

[7] Tang S, Baker G A, Zhao H. Ether- and Alcohol Functionalized Task-Specific Ionic Liquids: Attractive Properties and Applications[J]. Chem. Soc. Rev., 2012, 41: 4 030-4 066.

[8] Naushad M, Alothman Z A, Khan A B, et al. Effect of Ionic Liquid on Activity, Stability, and Structure of Enzymes: a Review[J]. Int. J. Biol. Macromol., 2012, 51: 555-560.

[9] Patel R, Kumari M, Khan A B. Recent Advances in the Applications of Ionic Liquids in Protein Stability and Activity: A Review[J]. Appl. Biochem. Biotechnol., 2014, 172: 3 701-3 720.

[10] Patel D D, Lee J M. Applications of Ionic Liquids[J]. Chem. Rec., 2012, 12: 329-355.

[11] Lei Z, Dai C, Zhu J, et al. Extractive Distillation with Ionic Iquids: A Review[J]. AIChE J, 2014, 60: 3 312-3 329.

[12] De Los R, F J H Fernandez. Ionic Liquids in Separation Technology[M], 2014 Oxford: Elsevier.

[13] Rodríguez H. Ionic Liquids for Better Separation Processes[M], 2016 Berlin-Heidelberg: Springer-Verlag.

[14] Vidal L, Riekkola M L, Canals A. Ionic Liquid-Modified Materials for Solid-Phase Extraction and Separation: A Review[J]. Anal. Chim. Acta, 2012, 715: 19-41.

[15] Rogers R D, Seddon K R. Ionic liquids-solvents of the future[J]. Science, 2003, 302: 792-793.

[16] Hayashi S. Hiro-o Hamaguchi. Discovery of a Magnetic Ionic Liquid [bmim]FeCl₄[J]. Chem. Lett., 2004, 33: 1 590-1 591.

[17] Brown R J C, Dyson P J, Ellis D J. 1-Butyl-3-methylimidazolium Cobalt Tetracar-bonyl [bmim][Co(CO)₄]: a Catalytically Active Organometallic Ionic Liquid[J]. Chem. Commun., 1993 1-862.

[18] Noguera G, Mostany J, Agrifoglio G, et al. Room Temperature Liquid Salts of Cr and Mo as Self-supported Oxidants[J]. Adv. Synth. Catal., 2005, 347: 231-234.

[19] Misuka V, Breuch D, Löwe H. Paramagnetic Ionic Lliquids as “liquid fixed-bed” Catalysts in Flow Application[J]. Chem. Eng. J., 2011, 73: 536-540.

[20] Wang H Y, R Y L, Z X, et al. Fe-containing Magnetic Ionic Liquid as an Effective Catalyst for the Glycolysis of Poly(ethylene terephthalate)[J]. Catal. Commun., 2010, 11: 763-767.

[21] Pei X W, Yan Y, Yan L Y, et al. A Magnetically Responsive Material of Single-walled Carbon Nanotubes Functionalized with Magnetic Ionic Liquid[J]. Carbon, 2010, 48: 2 501-2 505.

[22] Kim J Y, Kim J T, Song E A, et al. Polypyrrole Nanostructures Selfassembled in Magnetic Ionic Liquid as a Template[J]. Macromolecules, 2008, 41: 2 886-2 889.

[23] Li L, Huang Y, Yan G, et al. Poly(3,4-ethylenedioxythiophene) Nanospheres Synthesized in Magnetic Ionic Liquid[J]. Mater. Lett., 2009, 63: 8-10.

[24] Lee S H, Ha S H, You C Y, et al. Recovery of Magnetic Ionic Liquid [bmim]FeCl₄ Using Electromagnet[J]. Korean J. of Chem. Eng., 2007, 24: 436-437.

[25] Akitsu T, Einaga Y. Novel Photo-induced Aggregation Behavior of a Supra-Molecular System Containing Iron(III) Magnetic Ionic Liquid and Azobenzene[J]. Inorg. Chem. Commun., 2006, 9: 1 108-1 110.

[26] Xie Z L, Jelicic A, Wang F P, et al. Transparent, Flexible, and Paramagnetic Ionogels Based on PMMA and the iron-based Ionic Liquid 1-butyl-3-methylimidazolium Tetrachloroferrate (III) [Bmim] [FeCl₄][J]. J. Mater. Chem., 2010, 20: 9 543-9 549.

[27] Tian T, Hu X L, Guan P, et al. Investigation of Surface and Solubility Properties of N-vinyl-imidazolium Tetrahalogenidoferrate (III) Magnetic Lonic Liquids Using Density Functional Theory[J]. J. Chem. Eng. Data, 2016, 62(2): 721-730.

[28] Tang Y M, Hu X L, Guan P, et al. Investigation of Surface Properties and Solubility of 1-Vinyl-3-alkyl/esterimidazolium Halide Ionic Liquids by Density Functional Methods[J]. J. Chem. Eng. Data, 2014, 59(8): 2 464-2 471.

[29] Peppel T, Köckerling M, Geppert-Rybczyńska M, et al. Lowviscosity Paramagnetic Ionic Liquids with Doubly Charged [Co(NCS)₄]^2- Ions[J]. Angew. Chem. Int. Ed., 2010, 49: 7 116-7 119.

[30] Yoshida Y, Otsuka A, Saito G, et al. Conducting and Magnetic Properties of 1-Ethyl-3-methylimidazolium (EMI) Salts Containing Paramagnetic Irons: Liquid [EMI][Fe^IIICl₄] and Solid [EMI]2[Fe^IICl₄] [J]. Bull. Chem. Soc. Jpn., 2005, 78: 1 921-1 928.

[31] Tang Y M, Hu X L, Guan P, et al. Physicochemical Characterization of Paramagnetic Ionic Liquids 1-Viny-3-alkylimidazoliumtetrahalogen Idoferrate (III) [VRIM][FeCl_mBr_4-m]. J. Phys. Org. Chem., 2014, 27(6): 498-503.

[32] Nakajima H, Ohno H. Preparation of Thermally Stable Polymer Electrolytes from Imidazoliumtype Ionic Liquid Derivatives[J]. Polymer, 2005, 46: 11 499-11 504.

[33] Yoshida Y, Saito G. Influence of Structural Variations in 1-Alkyl-3-methylimidazolium Cation and Tetrahalogenoferrate(III) Anion on Physical Properties of the Paramagnetic Ionic Liquids[J]. J. Mater. Chem., 2006, 16: 1 254-1 262.