Ionic liquids find emerging interest among inorganic and materials chemists. For instance, ionic liquids have been applied as templating agents in the synthesis of zeolites and nanoparticles.[1] Metal containing ionic liquids are regarded as promising new materials with properties of ionic liquids and which can provide additional intrinsic magnetic, catalytic or e.g. spectroscopic properties depending on the respective included metal ion.[2] Lanthanide-doped ionic liquids have been reported as novel materials with luminescent properties and good photochemical stability.[3] Furthermore, ionic liquids have been introduced as interesting reaction media for the synthesis of inorganic compounds with unusual properties as well as for the synthesis of coordination polymers and for the crystallization and crystal engineering of novel coordination compounds.[4] The great number and variety of available ionic liquids can offer unique possibilities to the inorganic and materials chemist.
At QUILL, we are continuously exploring applications of ionic liquids in inorganic, nuclear and materials chemistry. For example, ionic liquids have been applied for the synthesis and production of mesoporous or nanocrystalline materials.[5],[6] The reported methods emphasize the applicability of ionic liquids as versatile components in microemulsions and as solvents for the synthesis of nanomaterials. Furthermore, coordination chemistry in ionic liquids as well as metal catalysis and the stabilisation of nanoclusters have been in the focus of QUILL research.[7]-[9] The use of ionic liquids for a cleaner nuclear waste management has been investigated in extensive fundamental as well as application oriented studies at QUILL.[10]-[15] Recently, we reported on ionic liquids containing boron cluster anions (see Figure 1). Depending on the type of boron cluster anions, these compounds exhibit a high thermal stability up to 480°C (type [Cnmim]2[B12Cl12], n = 2, 4, 8, 10, 12, 14, 16, 18) and low glass transition temperatures (type [Cnmim][Co(C2B9H11)2], n = 2, 4, 6, 8, 10, 12, 14). Currently, we are actively investigating the application of ionic liquids as media for the synthesis of nanomaterials and the use of metal-containing ionic liquids as catalysts. Furthermore, we explore speciation as well as electrochemical and physicochemical properties of a range of chlorometallate ionic liquids; depending on the metal and composition of the liquid, these compounds offer a range of Lewis acidity strengths and are tested at QUILL as Lewis acidic catalysts in a number of reactions.
References
1. a) Adams, C.J., Bradley, A.E. and Seddon, K.R., "The synthesis of mesoporous materials using novel ionic liquid templates in water", Aust. J. Chem., 2001, 54, 679-681;
b) Y. Zhou, Y., Antonietti, M. Adv. Mater.2003, 15, 1452;
c) Nakashima, T., Kimizuka, N., J. Am. Chem. Soc. 2003, 125, 6386;
d) Taubert, A., Angew. Chem., Int. Ed.2004, 43, 5380;
2. a) Y. Yoshida, J. Fujii, G. Saito, T. Hiramatsu, N. Sato, J. Mater. Chem.2006, 16, 724;
b) P. Nockemann, B. Thijs, N. Postelmans, K. Van Hecke, L. Van Meervelt, K. Binnemans, J. Am. Chem. Soc.2006, 128, 13658;
c) I. J. B. Lin, C.S. Vasam, J. Organomet. Chem.2005, 690, 3498;
d) S. Tang, A. Babai, A.V. Mudring, Angew. Chem Int. Ed., 2008, 120, 7743.
3. a) K. Driesen , P. Nockemann, K. Binnemans, Chem. Phys. Lett. 2004, 395, 306;
b) E. Guillet, D. Imbert, R. Scopelliti, J.-C. Bünzli, Chem. Mater.2004, 16, 4063;
c) A. Babai, A.-V. Mudring, Chem. Mater. 2005, 17, 6230;
d) S. Arenz, A. Babai, K. Binnemans, K. Driesen , R. Giernoth, A.-V. Mudring , P. Nockemann, Chem. Phys. Lett.2005, 402, 75;
e) P. Nockemann , E. Beurer , K. Driesen, R. Van Deun, K. Van Hecke, L. Van Meervelt, K. Binnemans, Chem. Commun.2005, 4345.
4. a) A. V. Mudring, A. Babai, S. Arenz, R. Giernoth, Angew. Chem. Int. Ed.2005, 44, 5485;
b) A. Babai, A. V. Mudring, Inorg. Chem.2006, 45, 3249;
c) C. C. Hines, V. A. Cocalia, R. D. Rogers, Chem. Commun.2008, 226;
d) B. Mallick, H. Kierspel, A. V. Mudring, J. Am. Chem. Soc.2008, 130, 10068;
e) P. Nockemann, B. Thijs, K. Van Hecke, L. Van Meervelt, K. Binnemans, Cryst. Growth Des.2008, 8, 1353.
5. Goharshadi, E.K., Ding, Y., Jorabchi, M.N., Nancarrow, P., “Ultrasound-assisted green synthesis of nanocrystalline ZnO in the ionic liquid [hmim][NTf2]”, Ultrason. Sonochem., 2009, 16, 120-123.
6. Rodil, E., Aldous, L., Hardacre, C. and Lagunas, M.C., "Preparation of AgX (X = Cl, I) nanoparticles using ionic liquids", Nanotechnology, 2008, 19, 105603/105601-105603/105608.
7. Hines, C.C., Cordes, D.B., Griffin, S.T., Watts, S.I., Cocalia, V.A. and Rogers, R.D., "Flexible coordination environments of lanthanide complexes grown from chloride-based ionic liquids", New J. Chem., 2008, 32, 872-877.
8. Ott, L.S., Cline, M.L., Deetlefs, M., Seddon, K.R. and Finke, R.G., "Nanoclusters in Ionic Liquids: Evidence for N-Heterocyclic Carbene Formation from Imidazolium-Based Ionic Liquids Detected by 2H NMR", J. Am. Chem. Soc., 2005, 127, 5758-5759.
9. Hamill, N.A., Hardacre, C. and McMath, S.E.J., "In situ XAFS investigation of palladium species present during the Heck reaction in room temperature ionic liquids", Green Chem., 2002, 4, 139-142.
10. Deetlefs, M., Hussey, C.L., Mohammed, T.J., Seddon, K.R., van den Berg, J.-A. and Zora, J.A., "Uranium halide complexes in ionic liquids: an electrochemical and structural study", Dalton Trans., 2006, 2334-2341.
11. a) Bradley, A.E., Hardacre, C., Nieuwenhuyzen, M., Pitner, W.R., Sanders, D., Seddon, K.R. and Thied, R.C., "An EXAFS, X-ray diffraction, and electrochemical investigation of 1-alkyl-3-methylimidazolium salts of [{UO2(NO3)2}2(m4-C2O4) ]2-", in Ionic Liquids IIIA: Fundamentals, Progress, Challenges, and Opportunities, Eds. R.D. Rogers and K.R. Seddon, ACS Symposium Series, Vol. 901 (American Chemical Society, Washington, 2005, pp. 32-46.
b) Bradley, A.E., Hardacre, C., Nieuwenhuyzen, M., Pitner, W.R., Sanders, D., Seddon, K.R. and Thied, R.C., "A Structural and Electrochemical Investigation of 1-Alkyl-3-methylimidazolium Salts of the Nitratodioxouranate(VI) Anions [{UO2(NO3)2}2(m4-C2O4)]2-, [UO2(NO3)3]-, and [UO2(NO3)4]2", Inorg. Chem., 2004, 43, 2503-2514.
12. Pitner, W.R., Bradley, A.E., Rooney, D.W., Sanders, D., Seddon, K.R., Thied, R.C. and Hatter, J.E., "Ionic liquids in the nuclear industry: Solutions for the nuclear fuel cycle", in Green Industrial Applications of Ionic Liquids, Eds. R.D. Rogers, K.R. Seddon and S. Volkov, NATO Science Series II: Mathematics, Physics and Chemistry, Vol. 92 (Kluwer, Dordrecht, 2003), pp. 209-226.
13. Downard, A., Nieuwenhuyzen, M., Seddon, K.R., van den Berg, J.-A., Schmidt, M.A., Vaughan, J.F.S. and Welz-Biermann, U., "Structural Features of Lithium Organoborates", Cryst. Growth Des., 2002, 2, 111-119.
14. Bradley, A.E., Hatter, J.E., Nieuwenhuyzen, M., Pitner, W.R., Seddon, K.R. and Thied, R.C., "Precipitation of a Dioxouranium(VI) Species from a Room Temperature Ionic Liquid Medium", Inorg. Chem., 2002, 41, 1692-1694.
15. Baston, G.M.N., Bradley, A.E., Gorman, T., Hamblett, I., Hardacre, C., Hatter, J.E., Healy, M.J.F., Hodgson, B., Lewin, R., Lovell, K.V., Newton, G.W.A., Nieuwenhuyzen, M., Pitner, W.R., Rooney, D.W., Sanders, D., Seddon, K.R., Simms, H.E. and Thied, R.C., "Ionic liquids for the nuclear industry: A radiochemical, structural, and electrochemical investigation", in Ionic Liquids: Industrial Applications for Green Chemistry, Eds. D. Rogers Robin and R. Seddon Kenneth, Vol. 818 (American Chemical Society, Washington D.C., 2002, pp. 162-177.
16. Leal, J.P., Minas da Piedade, M.E., Canongia Lopes, J.N., Tomaszowska, A.A., Esperana, J.M.S.S., Rebelo, L.P.N., Seddon, K.R., “Bridging the Gap between Ionic Liquids and Molten Salts: Group 1 Metal Salts of the Bistriflamide Anion in the Gas Phase”, J. Phys. Chem. B, 2009, 113, 3491–3498.
