Professor of Chemistry
It is probably safe to say that five years ago most chemists had never heard of ionic liquids, a class of materials which is the principal focus of our work. But, in that short period of time interest in these unorthodox materials has grown at a phenomenal rate. The scope of demonstrated or proposed applications of ILs is extraordinary, ranging from their use as non-volatile, non-flammable solvents to catalysts, materials for aiding separations, advanced heat transfer fluids, lubricants and anti-statics. Surpassing in magnitude the number of potential uses is the number of possible IL compositions, estimated by Seddon (Queen's University, Belfast ) to be in the billions.
In the absence of predictive computational methods to direct their design, the discovery-based development of new IL will remain vital to the field. It is this effort – the design, synthesis, and evaluation of new ionic liquids – that is the principal focus of our work (supported largely by Chevron).
Our efforts to create new ionic liquids fall into three overarching categories. The first is in the area of “task-specific” ionic liquids (TSILs), a subgroup of ionic liquids first described by us in 1999 and first referred to as TSILs in 2000. TSIL – type ionic liquids may be distinguished from more “conventional” ionic liquids in that the anion, cation or both of the salt contains within its structure a “functional group” which (by design) imbues the salt with a specific chemical attribute. One such family of ionic liquids that has been prepared by our group contains appended amine groups, which allow the ionic liquids to act as scavengers for CO 2 , a process of considerable commercial importance. An ORTEP of one such amine cation (here as its BPh 4 - salt) is shown below [X-ray structure courtesy of Professor Robin Rogers, University of Alabama ].
The second general area of ionic liquids development by our group concerns the identification of recognizably non-toxic ions for evaluation in the formulation of ionic liquids. While the overwhelming focus of most IL research worldwide has to date centered on their eventual use as inductrial solvents, we believe that appropriately non-toxic ionic liquids are tremendously promising materials for use in consumer products. By in large, our energies in this effort have been focussed on the identification of anions which might be suitable for IL formulation but which do not contain fluorine, a common component of most IL-anions. So far, we have established that the “docusate” anion (a common drug and cosmetic ingredient on the FDA GRAS list) is quite compatible with the formation of ionic liquids, as are the active (anionic) ingredients in saccharine and acesulfame based artificial sweeteners.
Most recently our attention has turned to examining the use of a long-neglected boron-centered cation type – the “boronium ion” –in creating new ionic liquids. Our first success in this regard was recently reported in Chemical Communications (2005) and the development of new boronium based materials is an area of growing interest on our part. Boronium ions are both isosteric and isoelectronic to classical ammonium ions, but differ substantially in the distribution of charge within their structures compared to their classical ammonium analogs. In the boronium ions, the positive charge is more extensively delocalized than in the conventional counterpart. This is readily seen in the computed electron distributions of an imidazolium-boronium ion and its conventional counterpart (1 and 1C respectively in the Figure below).
Finally, it bears noting that our department – as well as the Davis group – is solely undergraduate in nature (no graduate students, no postdoctoral fellows); The high tempo of research activity in our group and the department overall is a testimony to the talents and work ethic of our students!
We invite you to learn more about Davis group research activities by exploring the links on this page.
Recent Journal Publications
Four of these publications (preceded by an asterisk) were recently determined by Thomson/ISI Web of Science to be in the top 1% of the most frequently cited papers in ionic liquids chemistry. USA undergraduate co-authors are underlined.
- “Exploiting Isolobal relationships to create new ionic liquids: novel room-temperature ionic liquids based upon ( N -alkylimidazole)(amine)BH 2 + boronium ions” Phillip A. Fox , Scott T. Griffin, W. Matthew Reichert , E. Alan Salter, Ashley B. Smith , Morgan D. Tickell , Benjamin F. Wicker , Eugene A. Cioffi, James H. Davis, Jr., Robin D. Rogers , Andrzej Wierzbicki, Chem. Commun. , 2005 , 3679-3681. Reprint
- “Task-Specific Ionic Liquids.” James H. Davis, Jr. Chemistry Letters , 2004 , 33 , 1072-1077. Reprint
- “Sweet success: ionic liquids derived from non-nutritive sweeteners.” Elke B. Carter, Stephanie L. Culver , Phillip A. Fox , Russell D. Goode , Ioanna Ntai , Morgan D. Tickell , Rachel K. Traylor , Norris W. Hoffman and James H. Davis, Jr., Chemical Communications , 2004 , 630-631. Reprint
- * “From Curiosities to Commodities: Ionic Liquids Begin the Transition.” James H. Davis, Jr. and Phillip A. Fox . Chemical Communications , 2003 , 1209-1214. Reprint
- * “Novel Brønsted Acidic Ionic Liquids and Their Use as Dual Solvent-Catalysts.” Amanda C. Cole , Jessica L. Jensen , Ioanna Ntai , Kim Loan T. Tran , Kristin J. Weaver , David C. Forbes and James H. Davis, Jr. J. Am. Chem. Soc ., 2002 , 5962-5963. Reprint
- * “CO 2 Capture by a Task Specific Ionic Liquid.” Eleanor D. Bates , Rebecca D. Mayton , Ioanna Ntai and James H. Davis, Jr. J. Am. Chem Soc . 2002 , 124 , 926. Reprint
- “Task Specific Ionic Liquids Incorporating Novel Cations for the Coordination and Extraction of Hg 2+ and Cd 2+ : Synthesis, Characterization and Extraction Studies.” A.E.Visser, R.P. Swatloski, W.M. Reichert, R. Mayton , S.Sheff , A. Wierzbicki, J.H. Davis, Jr. and R.D. Rogers. Envir. Sci. Technol ., 2002 , 36 , 2523-2529. Reprint
- “Base Promoted Reactions in Ionic Liquids. Knoevenagel and Robinson Annulation Reactions” D.W. Morrison , D.C. Forbes and J.H. Davis, Jr. Tetrahedron Letters , 2001 , 42 , 6053-6057. Reprint
- * “Task-specific ionic liquids for the extraction of metal ions from aqueous solutions.” A.E.Visser, R.P. Swatloski, W.M. Reichert, R. Mayton , S.Sheff , A. Wierzbicki, J.H. Davis, Jr. and R.D. Rogers. Chemical Communications , 2001 , 135-136. Reprint
- “Novel fluorous ionic liquids function as surfactants in conventional room-temperature ionic liquids.” T.L.Merrigan , E.D.Bates , S.C.Dorman and J.H.Davis, Jr. Chemical Communications 2000 , 2051-2052. Reprint
- “Thiazolium-Ion Based Organic Ionic Liquids (OILS). Novel OILS which Promote the Benzoin Condensation.” K.J. Forrester and J.H.Davis, Jr. Tetrahedron Letters 1999 , 40 , 1621-1622. Reprint
- “Novel Organic Ionic Liquids (OILS) Incorporating Cations Derived from the Antifungal Drug Miconazole.” K.J. Forrester , T.L. Merrigan and J.H. Davis, Jr. Tetrahedron Letters , 1998 , 39 , 8955-8958. Reprint
- “Azolidene Carbenes Derived from Biologically Relevant Molecules. Synthesis and Characterization of Iridium Complexes of Imidazolidene Ligands Based upon the Antifungal Drugs Econazole and Miconazole.” M.A.Bernard , C.H.Lake and J.H.Davis, Jr . Inorganic Chemistry , 1998 , 37 , 5412-5413. Reprint
- “Hydroboration of (1R)-(+)- a -Pinene and (1S)-(-)- b -Pinene with B 10 H 12 (SMe 2 ) 2 : A Straightforward Approach to the Preparation of Optically Active 6-(alkyl)- nido -B 10 H 13 Derivatives.” M.A.Millan and J.H.Davis, Jr. Tetrahedron Asymmetry , 1998 , 9 , 709-712. Reprint
- “Synthesis and Computational Evaluation of A Boronium Ion Analogue of the Tropane Ring System.” J.D.Madura and J.H.Davis, Jr. Tetrahedron Letters , 1996 , 37 , 2729-2730. Reprint
The chapter cited in reference 8 (below) was the first to introduce the term “task-specific” ionic liquids (TSILs), a concept proposed by our group in a 1999 Tetrahedron Letters paper
- “Task-specific Ionic Liquids for Separations of Petrochemical Relevance.” James H. Davis, Jr. ACS Symposium. Ser. in press. R. D. Rogers & K. R. Seddon, eds.; ACS: Washington, 2004.
- “Commercially Available Salts as Building Blocks for New Ionic Liquids.” James H. Davis, Jr. and Phillip A. Fox. Ionic Liquids: Progress and Prospects ACS Symp. Ser. 856 R. D. Rogers & K. R. Seddon, eds.; ACS: Washington , 2003; pp 100-107.
- “Ionic Liquids Derived from Natural Products and Other Novel Chemistries: Synthesis and Chemistry of Ionic Liquids Composed of Functionalized Ions.” James H. Davis , Jr. Green Industrial Applications of Ionic Liquids: Proceedings of the NATO Advanced Research Workshop , R.D. Rogers, ed.; Kluwer, Dordrecht . 2002.
- “Working Salts: Syntheses and Uses of Task-Specific Ionic Liquids” James H. Davis, Jr. ACS Symp. Ser. 818, R.D. Rogers & K.R. Seddon, eds.; ACS: Washington , 2002; pp 247-259. “Synthesis of Task-Specific Ionic Liquids (TSIL)” James H. Davis, Jr. Ionic Liquids , P. Wasserscheid and T. Welton, eds.; Wiley-VCH: New York , 2002.
- “Envisioning the Second Generation of Ionic Liquid Technology: Design and Synthesis of Task-specific Ionic Liquids (TSILs).” A.Wierzbicki and J.H.Davis,Jr. Paper No.14F, Proceedings of the Symposium on Advances in Solvent Selection and Substitution for Extraction , March 5-9, 2000, Atlanta, Georgia. AIChE , New York , 2000.
Patents & Commercial Licenses
- Application (SAX-005.060) “Boronium Ion Based Ionic Liquids” (2005).
- Serial # 60/53987 "Ionic Liquids with Sweeteners and Other Novel Anions" (2004)
- Utility Serial #10/642,348/ PCT USO 3 25815 "Ionic Liquids Containing a Sulfonate Anion" (2002) [Licensed to SACHEM, Inc.]
- Utility Serial# 10/407,473 / PCT USO 3 10318/ EPO 03736453.6-2104 - "Functionalized Ionic Liquids and Methods of Use Thereof" (2002) [Licensed to Merck KGaA]
Davis Group in the News
- “Ionic Liquids Make Splash in Industry” Chemical & Engineering News , August 1, 2005
- "Saccharine Solution to a Toxic Problem." Chemistry World, April, 2004, p. 15.
- “Sweeteners for Ionic Liquids” Chemical & Engineering News , March 15, 2004 , p. 10.
- “Scrubbing Task for Ionic Liquids” Chemical & Engineering News , February 11, 2002 , p. 8.
- “Ionic liquids: An industrial cleanup solution” Environmental Science & Technology October 1, 2001 pp 410A–413A.
- “Faster, Better, Cleaner? New liquids take aim at old-fashioned chemistry” Science News , September 8, 2001 .
- “Environmental Solutions” Scientific American , August 2001.
- “With a Splash of Salt, Industry May Reap Environmental Advantages” The New York Times , April 24, 2001 .
- “Ionic Liquids in a Renewable Ferment” Chemical & Engineering News , April 2, 2001 .
- “New Horizons for Ionic Liquids” Chemical & Engineering News , January 1, 2001 .
- “Ionische Flüssigkeiten – innovative Lösungsmittel” Nachrichten aus der Deutscher Chemiker , January 2001.
- “Eyes on Ionic Liquids” Chemical & Engineering News , May 15, 2000 .