Ionic Liquids Virtual Special Issue - Crystal Growth & Design (ACS

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DOI: 10.1021/cg2001464

2011, Vol. 11 625–626

Ionic Liquids Virtual Special Issue

As part of the 2011 International Year of Chemistry, the American Chemical Society is sponsoring the fourth International Congress on Ionic Liquids (COIL-4; http://coil-4.org/) which will be held in Washington, D.C., on June 15-18, 2011. COIL-4 marks the first opportunity for the United States to host this international meeting, and it comes at a time when interest in ionic liquids has been rapidly growing, in part because of the fascinating set of physical, chemical, and biological property sets these materials possess, and in part from the growing realization of new applications in such key areas as sustainable energy, biomass, biorefineries, renewable fuels and chemicals, materials, pharmaceuticals, separations, catalysis, and biotechnology (to name a few). Today, ionic liquids are generally being defined as salts with melting points below 100 °C, a very broad classification. While examples of compounds meeting this definition have been known for well over 100 years, there has been tremendous growth in the study of ionic liquids over the last 20 years, especially from 1995 onward. Modern interest in ionic liquids originated in efforts by the United States Air Force in applying ionic liquids as electrolytes, and then as a result of suggestions that ionic liquids have unique properties as VOC solvent replacements and materials with new combinations of physical properties. Today, it is often the unique materials properties set, unavailable from molecular compounds or crystalline salts, that are bringing ionic liquids under even more intense scrutiny. Indeed, the potential of ionic liquids to offer insight into new, more complex fundamental chemistry was recognized in the outcomes of a NATO Advanced Research Workshop “Green Industrial Applications of Ionic Liquids” held April 12-16, 2000 on the Island of Crete, Greece. The primary outcome of this meeting clearly suggested new fundamental chemistry was to be found through the detailed study of ionic liquids: “Ionic liquids are intrinsically interesting and worthy of study for advancing science (ionic vs. molecular solvents) with the expectation that something useful may be derived from their study.”1 Unfortunately, misconceptions about ionic liquids threaten to overshadow the high level of science that has led to new fundamental insight and a large number of new applications. Many of these have arisen from a combination of trying to understand all “ionic liquids” from the properties of a single salt and from a misinterpretation of another outcome of the NATO ARW noted above: “Combined with green chemistry, a new paradigm in thinking about synthesis in general, ionic liquids r 2011 American Chemical Society

provide an opportunity for science/engineering/ business to work together from the beginning of the field’s development.”1 Overstatements which try to define ionic liquids as “green” or “toxic” detract from the strategies being employed around the world to understand the unique properties of ionic liquids and to use them to develop sustainable products and processes. Ionic liquids can clearly be designed to be flammable, unstable, or even toxic (properties which have also led to interesting applications). They can also be designed to be nonflammable, stable, and nontoxic, and it is this design choice which has intrigued many scientists and engineers. The high level of worldwide interest in ionic liquids has been reflected in large numbers of publications in areas across the spectrum of science and engineering. This trend has also been evident in ACS publications where in 2010 alone more than 470 publications on the subject have appeared in 30 different ACS journals. This ACS Cross-Journal Virtual Special Issue on Ionic Liquids highlights some of these contributions and provides evidence of the high quality and diversity of interests in this growing field. This virtual issue contains 57 papers from 13 ACS journals including ACS Applied Materials & Interfaces, Analytical Chemistry, Chemistry of Materials, Crystal Growth & Design, Energy & Fuels, Industrial & Engineering Chemistry Research, Inorganic Chemistry, Journal of the American Chemical Society, Journal of Chemical and Engineering Data, The Journal of Physical Chemistry B, The Journal of Physical Chemistry Letters, Langmuir, and Macromolecules. The papers selected from each journal were chosen by that journal’s editor to reflect the scope of ionic liquids publications within their journals; however, these are meant to be examples and it was not possible to include every worthy paper. We now invite you to review the depth and breadth of this selection of ionic liquids papers published in ACS journals in 2010. You will find high quality fundamental science and the application of that science across a surprisingly large range of disciplines. Many of these authors will also be presenting their latest work at COIL-4 where 43 invited (http://coil-4.org/invitedspeakers/) and 54 other oral presentations will be given, along with many posters. This meeting offers an opportunity to find out more about these fascinating materials and to draw one’s own conclusions on the nature and future of this field. We hope that you enjoy this selection taken from the many papers published across the ACS journals in 2010. It should be apparent that there is a home for the best science and the best technology in every field in which ionic liquids are studied within the ACS suite of journals. We encourage you to Published on Web 03/02/2011

pubs.acs.org/crystal

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Crystal Growth & Design, Vol. 11, No. 3, 2011

continue to send us ionic liquids papers which push the boundaries of our understanding.

References (1) Green Industrial Applications of Ionic Liquids; NATO Science Series II. Mathematics, Physics and Chemistry; Rogers, R. D., Seddon, K. R., Volkov, S., Eds.; Kluwer: Dordrecht, 2003; Vol. 92, 553 pp.

Joan F. Brennecke Editor-in-Chief, Journal of Chemical & Engineering Data, University of Notre Dame

Brennecke et al.

George C. Schatz Editor-in-Chief, Journal of Physical Chemistry, Northwestern University Robin D. Rogers* Editor-in-Chief, Crystal Growth & Design, The University of Alabama