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Ionic Liquid Presented by :Xin Huang Green Chemistry Presentation

Ionic Liquid Presented by :Xin Huang Green Chemistry Presentation

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Ionic Liquid

Presented by :Xin Huang

Green Chemistry Presentation

Development

0 200 400 600 800 1000

No of publications

1995

1997

1999

2001

2003

Year

Outline

Definition Definition

ConclusionConclusion

Examples Examples

Ionic liquid in synthesisIonic liquid in synthesis

AdvantageAdvantage

ApplicationsApplications

What are Ionic Liquids

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 CationsTypical IL Cations

N

R

N NR1 R2

* [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 * 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

Paul Walden

Advantage Easy separation Very low vapor pressure Non-flammable substance High thermally stable High mechanically stable Electrochemically stable Low toxicity Non-volatility

Application

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

Catalytic

Hydrogenetions

Hydroformylations

Heck reactions

Suzuki coupling

Stille Coupling

Friedel–Crafts

Alkoxycarbonylation

Olefin dimerization

Diels-Alder

Oxidations

Diels-Alder reaction

Heck Reaction

Wittig reaction

Suzuki-Miyaura coupling reaction

Stille reaction

Friedel-Crafts reaction

Hydrogenation

Fluorination

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 *

Preparation of pyrrolidinium salts

Reaction

Flow chart

NH

+ H2OHNO3 65~68%

r.t.

60℃, stirred overnight washed with diethyl ether 50ml*3

concentratedyellow solid

TM.

+ CH3OHH(CF2)4O(CF2)2SO3Na/MeOH stirred, 12h

f iltration

r.t.

f iltrateconcentrated

pale yellow liquid

HN

N+

O

-O

+

50℃, stirred extracted

toluene (3 ml*3)upper-layer

concentrated purified

(flash chromatography)

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 .