Ionic LiquidsIonic Liquids from Exotic to designer molecules for Chemical Processesfrom Exotic to designer molecules for Chemical Processes

Jelliarko Palgunadi Ph.D

1Presented in the Dept. of Chemical Engineering, Widya Mandala University, October 26, 2013.Presented in the Dept. of Chemical Engineering, Widya Mandala University, October 26, 2013.

Cation Anion

1. http://www.electrochem.org/dl/interface/spr/spr07/spr07_p38.pdf

Ionic Liquids (ILs) are… Ionic Liquids (ILs) are…

• Composed entirely of ions (organic cation and anion)• Induced largely by packing frustration of asymmetric cations)• But liquid at low temperature (<100 )℃

• Composed entirely of ions (organic cation and anion)• Induced largely by packing frustration of asymmetric cations)• But liquid at low temperature (<100 )℃

milestonesmilestones

1914 First reported by Walden, ethylammonium nitrate (m.p. 12 )℃Gained no interest at all at that time

1967 Swain, tetra-n-hexylammonium benzoateAs a solvent for electrochemical reactions

1970s Osteryoung, WilkesOpened an area of room temperature ionic liquid

1980s Seddon and Chauvin, chloroaluminate ionic liquid Used as a solvent for biphasic catalysis

1992 Wilkes, a series of imidazolium salts "Designer solvent", "Innovative liquid", "Neoteric Solvent"

A breakthrough, applied to a wide range of applications

IL's structure can be tailored for specific applications.

Outstanding FeaturesOutstanding Features

No effective vapor pressure

Non-flammable

High ionic conductivity

Wide liquid range up to 300℃

Thermally stable up to 200 ºC

Ability to dissolve a wide range of inorganic, organometallic compounds

Ability to capture small molecules (H2, CO, CO2, and O2)

Immiscibility with some organic solvents, e.g. alkanes, BTX

Highly polar yet non-coordinating

Polarity and hydrophilicity/lipophilicity can be easily tailored

Properties of Imidazolium-based ILsProperties of Imidazolium-based ILs

6

ApplicationsApplicationsApplicationsApplications

Synthesis of Imidazolium-based ILsSynthesis of Imidazolium-based ILs

NNMe

NNMe R

NNMe R

R-Cl

Cl

KPF6 or

HPF6 / NaOH

PF6

Alkyl HalideAlkyl Halide

Dialkyl CarbonateDialkyl Carbonate

NNEt

NNEt Me

in CH3OH

+ CH3OCOCH3

OOCOCH3

O

Trifluoroalkyl EsterTrifluoroalkyl Ester

NNEt

NNEt Me

in CH3OH

OY

+ CH3OY

Y = SCF3

O

O

CCF3

O

,

1,3-dibutylimidazolium (41%), 1-butyl-3-methylimidazolium (50%), 1,3-dimethylimidazolium (9%)

HCHOO O

MeNH2

i) HBF4

ii) n-BuNH2 NNMe n-Bu

BF4

One pot synthesisOne pot synthesis

Fluorinated Ionic Liquids - CationFluorinated Ionic Liquids - Cation

NNMe (CF2)xCF3

PF6

Thermally stable, water insolubleHigh density New surfactants

J. H. Davis, et al. Chem. Comm.. 2000, 2051

Fluorinated ILsAnionFluorinated ILsAnion

[emim]Cl + (n+1)HF [emim] F·(HF)n + HCl

. Air stable• Low melting point (-90 ℃)• Low viscosity (4.9 cP)• High conductivity (120 mScm-1)• Liquid range (350 ℃)• Wide electrochemical window (3.3 V)

NN NNMF5 (M =Nb, Ta)

- HFHnFn+1 (n = 2,3) MF6

[emim]NbF6 [emim]TaF6

m.p (℃) 1 2Conductivity (mScm-1) 8.5 7.1Viscosity (cP). 49 51

R. Hagiwara, et al. J. Fluorine Chem 2000, 105, 221; 2002, 115, 133

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Natural product ILNatural product IL

Letters in Organic Chemistry, Volume 6, 2009, 264

BASILTM (Biphasic Acid Scavenging utilizing Ionic Liquids) is an auxiliary for acid scavenging – The first commercial process employing ILs by BASF

BASIONICTM - A broad portfolio of Ionic Liquids by BASF

Sweet Success of ILsSweet Success of ILsSweet Success of ILsSweet Success of ILs

BASF uses N-methylimidazolium chloride, which has a melting point of 75 °C. to scavenge acid that is formed in the process of alkoxyphenylphosphines production.

Chemical & Engineering News, Volume 81, Number 13

Applications of ILs in Chemical Reaction and Separationstate of the art

Applications of ILs in Chemical Reaction and Separationstate of the art

Reaction MediaReaction Media

Immobilization of precious catalyst & recycling Biphasic reaction Enhancement of reaction rates Selectivity improvement Stabilization of catalysts

Immobilization of precious catalyst & recycling Biphasic reaction Enhancement of reaction rates Selectivity improvement Stabilization of catalysts

PurposesPurposes

Ionic liquid

Starting material

Catalyst

Starting material Product Catalyst

Productmixture

Catalyst

heating cooling

ProductsCatalystCatalyst recycle

Immobilization of Precious Catalyst & RecyclingImmobilization of Precious Catalyst & Recycling

OH

NHAc

Rh[(cod)( )-diop]PF6

[bmim]SbF6/i-PrOH+ H2

OH

NHAc

¥á-acetamidocinnamic acid (S)-phenylalanine, 64% ee

Y. Chauvin et al., Angew. Chem., Int. Ed. 1995, 34, 2698

HydrogenationHydrogenation

+ H2, [Rh(nbd)(PPh3)2]

in [bmim][A-]

[A-] = BF4, PF6, SbF6

5 times faster than in acetone

83%

Biphasic reaction, higher ee, easy catalyst separation

OxidationOxidation

C. E. Song, et al. Chem. Comm. 2000, 837

N N

O O

Mn

But But

But But

Cl

H H

(R,R)-1

Run 1 2 3 4 5

Yield (%) 86 73 73 60 53

% ee 96 90 90 89 88

O O(R,R)-1 4mol%, NaOCl

[bmim]PF6 CH2Cl2(1:4, v/v), 0oC, 2 h

O2,2-dimethylchromene

Higher reaction rate (6 h in conventional solvent), higher ee

HydroformylationHydroformylation

H

O

H

O

+ CO/H2, [PtCl2(PPh3)2]

in [bmim]Cl / SnCl2, [x(SnCl2) = 0.51]

120oC, 90 bar CO/H2

+

n : iso = 19 : 1

P. Wasserscheid, et al. J. Mol. Catal. A: Chemical 2000, 164, 61

TOF = 126 h-1

1-octene

Higher n/iso ratioBiphasic reactionEasy catalyst/product separation

n-nonanal

Dimerization “Difasol Process” by IFP (France)Dimerization “Difasol Process” by IFP (France)

butenes isooctenes[bmim]Cl-AlCl3-EtAlCl2

NiCl2L2

(L = PPh3 or pyridine)

Y. Chauvin et al., French Patent, FR 2,611,700

97% selectivity

The first commercial biphasic process in ionic liquidImproved yield, Lower catalyst consumption

N

N

H3C

i) 3-phenylpropyl chloride, 70¡É, 1dii) NaPF6, acetone, rt, 2d

N

N

H3CPF6

M-J. Kim, et al., J. Org. Chem. 2002, 67, 6845

BiocatalysisBiocatalysis

Ionic liquid-coated Enzyme (ILCE)

[pmim]PF6, m.p. 53℃

Lipase + [pmim]PF6 i) mixing at 60℃ii) cooling

Enhanced enantioselectivity (2-fold compared to the conventional lipase) Easy catalyst recycling

R

+[emim]Cl/AlCl3 (1:2)

CH3COCl

R

O

CatalystsCatalysts

K. R. Seddon et al., Chem. Comm. 1998, 2097

Chloroaluminate Ionic Liquid System: Friedel-Crafts Alkylation and Acylation

Chloroaluminate Ionic Liquid System: Friedel-Crafts Alkylation and Acylation

para isomer 99%

Enhanced regioselectivity (4-fold compared to the conventional catalyst)

-10~0 , 0.25~ 1 h℃

R = OMe, Me, Cl

RNH2 + CO +12

(RNH)2CO + H2OCatalyst

Catalyst:

N

N

R1

CH3

Se

O

O

OR2 or [R34P][SeO2(OCH3)]

R2: CH3, C2H5, CH2CF3, Ph; R3: C2H5, n-C4H9

R: aliphatic, alicyclic, aromatic; R1: CH3, C2H5, n-C4H9;

O2CH3OH

H. S. Kim, Y. J. Kim, et al. Angew. Chem., Int. Ed. 2002, 41, 4300

Imidazolium and Phosphonium Alkylselenite Ionic Liquids SystemImidazolium and Phosphonium Alkylselenite Ionic Liquids System

Non-phosgene processNon-phosgene process

Imidazolium Zinc Tetrahalides Ionic Liquids SystemImidazolium Zinc Tetrahalides Ionic Liquids System

ZnX2Y2X ZnY22

+2

1: R = CH3; 2: R = C2H5; 3: R = n-C4H9; 4: R = CH2C6H5a: X = Y = Cl; b: X = Cl, Y = Br; c: X = Y = Br

NNR CH3

NNR CH3

(1,3-dimethylimidazolium)2ZnCl2Br2 ,1b

TOF = 2700-3400 h-1

O O

R

OO

R

+ CO2

catalyst: 1b

H. S. Kim, et al. J. Catal..2003

10 h-1 for (MePh3)P+I-

J.H. Davis, et al., J. Am. Chem. Soc., 2002, 124, 926

Gas Extraction – CO2Gas Extraction – CO2

Separation MediaSeparation Media

Olefin/Paraffin Separation Olefin/Paraffin Separation

butane /1-butene= 50/50 (mol %)

Ag+ / [bmim]BF4Ag+(1-butene)

/ [bmim]BF4

butane >1-butene

C. L. Munson, et al. US Patent Number 6,339,182

Porous Membrane Support

PoreFTC/Ionic Liquid

Facilitated Transport MembranFacilitated Transport Membran

Supported Ionic Liquid Membrane (SILM) Supported Ionic Liquid Membrane (SILM)

Porous Membrane Support

Pore FTC/H2O

Supported Liquid Membrane (SLM) Supported Liquid Membrane (SLM)

Drawback: vaporization of H2O Non-volatile

FTC: Facilitated Transport Carrier

diisopropylamine/triethylamine/hexylamine Mixture

[bmim]PF6/PVDF diisopropylamine

C. A. M. Afonso, et al. Angew. Chem., Int. Ed. 2002, 41, 2771

Liquid-Liquid ExtractionLiquid-Liquid Extraction

SILM SystemSILM System

Extraction of actinides (Am3+, UO22+, Pu4+) from wastewater

at nuclear processing site

Extraction of actinides (Am3+, UO22+, Pu4+) from wastewater

at nuclear processing site

Metal Ion Extraction TSILs Metal Ion Extraction TSILs

R. D. Rogers, K. R. ACS Symposium Series 818. 2002

NN NH

NH

CH3O

BF4

NN NH

P

PhPh

O

PF6

Extraction of heavy metals (Hg2+ or Cd2+) from aqueous wasteExtraction of heavy metals (Hg2+ or Cd2+) from aqueous waste

Dispersion media for nanoparticles

IL have been found as good synthesis and dispersion media for metal nanoparticles, carbon allotropes (CNTs, fullerenes, graphene).

Plausible applications including coatings and nanoparticle incorporation into plastic resins.

http://pubs.acs.org/doi/abs/10.1021/ic702071w?journalCode=inocajwww.iolitec.dehttp://pubs.rsc.org/en/content/articlelanding/2010/cp/b920568n

Dispersion & Preparation of NanoparticlesDispersion & Preparation of Nanoparticles

S. Dai, et al. Chem. Comm. 2000, 243

NanoparticlesNanoparticles

Ionic Liquid = [bmim]Tf2N (Tf2N = trifluoromethanesulfonylamide)

Allows a long aging process No shrinkage of the sol-gel network due to the negligible vapor pressure of ILReduce a gelation time: 30min < 1minElimination of risky super critical drying step

H2, [IrCl(cod)]2

[bmim]PF6

Nano CatalysisNano Catalysis

J. Dupont, et al. J. Am. Chem. Soc. 2002, 124, 4228

TOF: 6,000 h-1

Biphasic reaction, Higher turnoversEasy catalyst/product separationFormation of stable Ir0 nanoparticles as an active hydrogenation catalystCatalyst reuse (7 times) without loss of initial activities

Product was extracted out of ionic liquid by scCO2 and recycled several timesProduct was extracted out of ionic liquid by scCO2 and recycled several times

D. J. Cole-Hamilton, et al. Chem.Comm. 2001, 781

scCO2 – IL Hybrid SystemscCO2 – IL Hybrid System

Problems to be SolvedProblems to be Solved

• Difficulty in purification (halides, H2O)• High cost ($ 10/g $ 40 ~ 80/L)• Toxicity• Insufficient long-term stability to hydrolysis

• Difficulty in purification (halides, H2O)• High cost ($ 10/g $ 40 ~ 80/L)• Toxicity• Insufficient long-term stability to hydrolysis

… and many more.

From Academia to MarketFrom Academia to Market