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Green Chemistry Presentation. Ionic Liquid. Presented by :Xin Huang. Development. Outline. Definition. Advantage. Applications. Ionic liquid in synthesis. Examples. Conclusion. What are Ionic Liquids. Common Definition.
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Green Chemistry Presentation Ionic Liquid Presented by :Xin Huang
Outline Definition Advantage Applications Ionic liquid in synthesis Examples Conclusion
Common Definition • Ionic Liquids (ILs) is the generic term for a class of materials, consisting entirely of ions and being liquid below 100°C. • If they are liquid at room temperature, we call them room temperature ionic liquids (RTILs).
Typical Cation and Anion Typical IL Cations * [PF6]- for moisture stable, water immiscible IL * [BF4]- for moisture stable, but water miscible IL * [AlCl4-] (or other Lewis acids) decomposes in water
Discovery and History Paul Walden • * The description of a low melting point salt - 1914 • Ethyl ammonium nitrate • * The first room temperature ionic liquid -1951 • N-ethylpyridinium bromide- aluminium chloride melt • * The most stable and conductive salts -1982 • 1,3-dialkylimidazolium salts • * The hydrophobic ionic liquids - 1992 • 1-ethyl-3-methylimidazolium tetrafluoroborate
Advantage • Easy separation • Very low vapor pressure • Non-flammable substance • High thermally stable • High mechanically stable • Electrochemically stable • Low toxicity • Non-volatility
Comparison of organic solvents with ionic liquids Plechkova, N. V.; Seddon K. R. Chem. Soc. Rev. 2008, 37, 123–150
Ionic Liquids in Organic Synthesis Friedel–Crafts Alkoxycarbonylation Olefin dimerization Diels-Alder Oxidations • Catalytic • Hydrogenetions • Hydroformylations • Heck reactions • Suzuki coupling • Stille Coupling
12 principles of Green Chemistry • 1. Waste Prevention • 2. Atom Economy • 3. Less Hazardous Chemical Process • 4. Designing Safer Chemicals • 5. Safer Solvents and Auxiliaries • 6. Energy Efficiency • 7. Renewable Feedstocks • 8. Reduce Derivatives • 9. Catalysis • 10. Design for Degradation • 11. Real-time Analysis for Pollution Prevention • 12. Safer Chemistry for Accident Prevention
Journal of Fluorine Chemistry A novel pyrrolidinium ionic liquid with 1,1,2,2 tetrafluoro 2 (1,1,2,2-tetrafluoroethoxy) ethanesulfonate anion as a recyclable reaction medium and efficient catalyst for Friedel–Crafts alkylations of indoles with nitroalkenes Jin-Hong Lin, Cheng-Pan Zhang, Zhi-Qiang Zhu, Qing-Yun Chen, Ji-Chang Xiao *
Flow chart AlCl3
Green Aspects • The yeild for preparing Ionic liquid is as high 99%. (Principle 2) • Seperation of Ionic liquid is easy , just by filtration. • Reaction condition is mild .(Principle 12) • No byproducts in the preparation .(Principle 8)
Green Aspects • The high concentration of highly acidic species that can be immobilized in ionic liquids and that leads to a highly reactive catalytic phase allowing for fast reactions under mild conditions. In fact, acidic ionic liquids catalyze all reactions that are conventionally catalyzed by AlCl3, but without suffering the disadvantage of the low solubility of AlCl3 in many solvents. (Principle #3,5,9) • The liquid nature of the catalytic phase eliminates the heat and mass transfer problems frequently encountered with heterogeneous Friedel–Crafts-catalysts and make the reaction get high yield .(Principle 2) • The miscibility gap of most ionic liquids with alkylated aromatics allows for product isolation by simple decantation.(Principle #1,7)
Green Aspects • Ionic liquid also act as solvent in this reaction ,it prevents the waste of solvent. (Principle 1) Ionic liquid can be used directly for the next run after removing the solvent. Principle 7
Conclusion • Ionic liquids ,as the new materials of multifunction , are widely used in various of fields. • Environmently-friendly reaction process have vigorously been studied from the standpoint of green chemistry and based on the properities of easy separation , low toxicity , selective miscibility , ILS play an important role in organic synthesis as the green alternative solvent. • Withe the development of multifunctional ILS , we can expect IlS would apply in more fields .