ionic liquids (il), use and specific task as solvent in catalytic reaction

Thibaut GutelIngénieur ESCOM

Ionic liquids (IL),use and specific task as

solvent in catalytic reaction

Directeur Jean-Marie Basset

Directeurs de thèse : Catherine SANTINI et Yves CHAUVIN

12-10-2007

Laboratoire C2P2

Equipe

2

Contents : IL, solvent for catalytic reactions

INTRODUCTION

RESULTS

A) Synthesis of IL

B) Behaviour of ionic compounds in IL

C) Behaviour of unsaturated substrates in IL

D) Generation of metal nanoparticles in IL

CONCLUSION

OUTLOOK

3

What are ionic liquids (IL) ?

IL are molten salts but Tmp < 100°C

Molten salts

Ionic liquids

Wasserschied et al. Ionic liquid in synthesis, 2003, Wiley-VCH

N P

N

N N

N

N

N

N

R1

R2

R1

R2

R4 R4

R3 R3

R1 R2

R1 R3 R1 R3

R1R2R2

ammoniun phosphonium pyrrolidinium

imidazolium triazolium pyridinium

Organic Cations

C+ Inorganic anions Organic anions

F-, Cl-, Br-, I- CH3CO2-, CH3SO4

-, C6H5SO3-

BF4-, PF6

-, SbF6-, AsF6

- CF3CO2-, C(CF3SO2)3

-

NO3-, ClO4

- CF3SO3- (=OTf)

AlxCl(3x+1), AlxEtxCl(2x+1) N(SO2CF3)2- (=NTf2)

CuCl2, AuCl4, ZnCl3-, SnCl3

- BR4-, R3BOH

Organic/Inorganic Anions

A-

106 possible associations of C+ / A-

4

Use of IL as solvent in industry

1995 : DifasolTM (IFP-Axens)

1995 : Synthesis of 2,5-dihydrofurane (Eastman Chem Co)

2003 : BASILTM (BASF) synthesis of phosphite

P

Cl

Cl

+ 2 EtOH

N NMe

P

OEt

OEt

+ N NMeH

Cl

[Ni]BMIMAlCl4

C8=

C4=

Favre et al. Petrol. Tech. 2002, 441, 104-109.

Maase et al. In PCT Int. Appl.; Basf: Germany, 2003; Vol. 2003062171, p 60

O O(C8H17)3(C18H37)P+I-

[Sn(C8H17)3]IFalling et al. In U.S. Pat.; Eastman Kodak Co., USA, 1993; p 8.

5

Why are IL interesting in catalysis ?

Low vapor pressure and non-flammable

Safety and ecological considerations

Low melting point and high thermal stability

Process optimization

Non-miscible with alkanes and/or water

Multiphase catalysis and immobilization of the catalyst

Tunable physico-chemical properties

Adjustment of viscosity, density or acidity

Welton et al. Ionic liquid in catalysis, Coord. Chem. Rev, 2004, 248, 2459-2477

Olivier-Bourbigou et al. Multiphase Homogeneous Catalysis, 2005, Wiley-VCH, 413-431

new opportunity as solvent for catalytic reaction

6

IL used as reaction media

Solvent IL solubilize reactants without modification

But IL are difficult to purify…

Presence of halide decrease activity in Michael addition

Handy et al. Tetrahedron Lett., 2003, 44, 8395-8397

increase activity in Heck reaction

Gallo et al. Dalton Trans., 2002, 4339–4342

Presence of water decomposition of water sensitive complex

increase activity of ruthenium catalyst

Daguenet et al. Organomet., 2004, 23, 6080-6083

7


Ligand IL act as a ligand for the catalyst

Reactivity of C2-H : In situ formation of N-heterocyclic carbene

Presence of functional group : Coordination on PdNP

PdCl2

NN CNCl-

Pd NP

N

N

NC

Cl-

NN

CN

Cl-

Fei et al. Organomet. 2007, 26, 1588-1598

N

N

R

R

+ MLn

N

N

R

R

MLn-x

x

HMagna et al. Organomet., 2003, 22, 4418-4425

Hahn et al. Angew. Chem. Int. Ed., 2006, 45, 1348-1352


8


Ligand IL act as a ligand for the catalyst

Catalyst IL intervene as (co-)catalyst

Organocatalyst : Diels-Alder cycloaddition

Lewis acid : catalyst in Friedel-Crafts acylation

RCOCl + Al2Cl7- RCO+ + 2AlCl4

-

Stark et al. Dalton trans, 1999, 1, 63-66

R

X

O

BMIMAl2Cl7

R

O

Welton et al. Coord. Chem. Rev. 2004, 248, 2459-2477 N

N

R

R

O

O H


9

Goal : Study of IL as solvents for catalytic reactions

Ionic liquids

Substrate Catalytic system

IL are non-innocent solvents

But IL are associations of C+/A- organized in 3D structure

10

IL, an association of C+/A- organized in 3D structure

Ionic exchange ?

C1+A1

- + C2+A2

- C1+A2

- +

C2+A1

-

Ionic

catalyst

IL

C+A- 3D organisation

Trapping ?

-cation Interaction ?

+

Unsaturated

substrates

Segregation in microdomains

Supramolecular matrix ?

11

Contents : IL, solvents for catalytic reactions

A) Synthesis of IL1. Choice of IL

2. Synthesis of IL


1. Study of ionic exchange in 23Na NMR

2. Influence of the catalytic activity


1. Study of aromatics/IL system by NMR

2. Study of aromatics/IL system by molecular dynamics


1. Influence of temperature

2. Influence of stirring

3. Influence of alkyl chain length at 0°C

12

A) IL used in this work

NNR1

R2

Me

H H

N

SO2

SO2 CF3

CF3

IL R1 R2

EMIMNTf2 C2H5 H

BMIMNTf2 C4H9 H

HMIMNTf2 C6H13 H

OMIMNTf2 C8H17 HDMIMNTf2 C10H21 H

BMMIMNTf2 C4H9 CH3

Why ?

Hydrophobic and liquid at room temperature

Planar cation

Non-coordinating anion

Easy to synthesize and to purify

C+ Alkylmethylimidazolium (R1R2MIM)

A- Bis(trifluoromethylsulfonyl)imide (NTf2)

13

1) Quaternisation of imidazole by halides

R1, R2 et R3 = alkyl

X= Cl or Br

2) Anion metathesis

R1, R2 et R3 = alkyl

X= Cl, Br, I

MY=LiNTf2, NaOTf, NaPF6, NaBF4

Good yield (75-80%)

Very high purity (halide < 50ppm and water < 50ppm)

A) Synthesis of imidazolium based IL

NNR1 R3NNR1 R3-X

X

R2 R2

Reflux

NNR1 R3 MY

X

R2

NNR1 R3

Y

R2

-MX

Magna, L. Thèse LCOMS, 2002

14


A) Synthesis of IL

1. Choice of IL

2. Synthesis of IL

B) Behaviour of ionic compounds in IL1. Study of ionic exchange in 23Na NMR









Ionic exchange ?

Ionic

catalyst

IL

C+A-

15

B) Dissolution of catalytic system in IL

Catalytic activity depends on the nature of IL with TPPMSNa

Catalyst dissolves in IL

3 BMIMBF4 + K3Co(CN)5 (BMIM)3Co(CN)5 + 3 KBF4

Suarez et al. Inorg. Chim. Acta, 1997, 207-209

Parshall et al. J. Am. Chem. Soc., 1972, 94, 8716-8719

PtCl2 Pt(SnCl3)53- + HPt(SnCl3)4

3-

Et4NSnCl3

CNCN

3PN

Ni(COD)2 / TPPMS-Na+

BMMIM+A-

373K / 3h

2M3BN

Vallée et al. J. Mol. Cat. A, 2004, 214, 71-81

IL Conversion in 3PN (%)

BMMIM+Cl

- 0

BMMIM+ZnCl3

- 17

BMMIM+Zn3Cl7

- 47

BMIM+OTf

- 27

BMMIM+BF4

- 27

BMIM+BF4

- 22

BMMIM+NTf2

- 96

BMIM+NTf2

- 88

BMMIM+PF6

- 93

16

B) Solvation of sodium salt in IL

Question : Na+A1- + C+A2

- ???

A1- : TPPMS-, AcO-

C+ : EMIM+, BMIM+, BMMIM+, Et4N+, Et4P+

A2- : Cl-, Br-, OTf-, BF4

-, PF6-, NTf2

-

Techniques : Study in 23Na NMR at solid state

Parameters : 1) Influence of temperature

2) Presence of water

17

B) Exchange reaction monitored by 23Na NMR

(ppm)-80-60-40-200204060

(ppm)-80-60-40-200204060

(ppm)-80-60-40-200204060

TPPMS-Na+

+ BMMIM+PF6-

120°C

(ppm)-80-60-40-200204060

Na+Cl- (ref)

Na+PF6 -

TPPMS-Na+

TPPMS-Na+

+ BMMIM+PF6-

100°C

TPPMS-Na+ + BMMIM+PF6- TPPMS-BMMIM+ +

Na+PF6-

IL

TPPMS-Na+

P

SO3 Na

TPPMS-Na+

=0ppm

= -27ppm

= -17ppm

18

B) Conclusion on ionic exchange

1) Exchange reaction is governed by the nature of anion

A2- = Cl- ; Br- ; OTf- total exchange C+/Na+

A2- = PF6- ; BF4

- partial exchange C+/Na+

A2- = NTf2

- no exchange C+/Na+

The exchange reaction can be predicted by the Hard and Soft Acid Base theory

2) In the case of partial exchange, this reaction is temperature dependent

higher temperature increases the rate of exchange

3) This ionic exchange is water independent

addition of water doesn’t increase the ratio of exchange

Na+A1- + C+A2

- C+A1- + Na+A-

19

Catalytic activity depends on the nature of IL

A- = Cl- ; Br- ; OTf- total exchange BMMIM+/Na+ low conversion

A- = PF6- ; BF4

- partial exchange BMMIM+/Na+ no recycling

A- = NTf2- no exchange BMMIM+/Na+ high conversion

Mobility of phosphine ligand is reduced after exchange

NiL4 NiL3 + L with L : TPPMS-BMMIM+ << TPPMS-Na+

DOSY measurements : D=6.91x10-12m2.s-1 D=10x10-

12m2.s-1

B) Explanation of the catalytic activity

CNCN

3PN

Ni(COD)2 / TPPMS-Na+

BMMIM+A-

373K / 3h

2M3BN

Vallée et al. J. Mol. Cat. A, 2004, 214, 71-81

NiL4

NiL3

L

CN

NiL2

CN

NiL2

NiL2

NC

L

3PN2M3BN

L

20

A) Synthesis of IL

1. Choice of IL

2. Synthesis of IL




C) Behaviour of unsaturated substrates in IL1. Study of aromatics/IL system by NMR







-cation Interaction

IL C+A-

3D Organized

21

A rigid network of H-bonded anions and cations

Holbrey et al. Dalton Trans., 2004, 226-2271

3D-Organization still presents at liquid state

Billard et al. Inorg. Chem. 2003, 42, 1726-1733

Dibrov et al. Acta Cryst., 2006, C62, o19±o21

C) IL, a highy organized network of C+ / A-

6,11Å

15,6Å

NNMe

H

Me

H H

NTf2

NNEt

Et

Et

H H

NTf2

22

Molecular dynamics of MMIMPF6

Formation of liquid clathrates of Benzene/MMIMPF6

C) Behaviour of aromatics in IL

Holbrey et al. Chem. Com., 2003, 476-477

Hadracre et al. J. Chem. Phys., 2003, 118,273-278

Deetlefs et al.. J. Phys. Chem. 2005, 109, 1593-1598

Harper et al. Mol. Phys. 2004, 102, 85-94

5.0ILArR

5.0ILArR

23

-cation interaction plays a crucial role in biochemistry

Binding energy of 10 to 30 kcal.mol-1

-cation interaction in chemistry

C) -cation interaction in chemistry

+

Ma et al. Chem. Rev., 1997, 97, 1303-1324Hunter et al. PNAS, 2002, 99, 4873-4876

Yamada et al. Tetrahedron Lett., 2004, 45, 7475-7478Yamada et al. J. Am. Chem. Soc, 2004, 126, 9862-9872

24

Question : Behaviour of unsaturated substrates in IL

Toluene IL : BMIMNTf2 and BMMIMNTf2

Techniques : 1) 1H NMR, ROESY and DOSY

2) Molecular dynamics

in collaboration with Dr Padua

Parameter : Influence of molar ratio (R) of toluene

R= moles of toluene for one mole of IL

C) Solvation of unsaturated substrates/IL system

25

C) Evolution of 1H chemical shifts

NNCH3

H

H2C

CH2

H2C

CH33

2

4 5

6

7

8

9

H H

CH3

H

H

H

H

H

HMe

Har

Har

Har

Har

Har

CD2Cl2

IL+ R To

BMIMNTf2

R=0.1

R=0.5

R=1

R=2

R=3

[ppm][ppm]10 8 6 4 2

BMIMNTf2

R=0.1

R=0.5

R=1

R=2

R=3

[ppm][ppm]10 8 6 4 2

96 7 8

96 7 8

9

2

7 8

9

7 8

96 7 8

4,5

4,5

4,5

4,5

4,5

6

6

3

3

3

3

3

2

2

2

2

Har

Har

Har

Har

Har

3 97 8

HMe

HMe

HMe

HMe

HMe

26

C) Evolution of 1H chemical shifts

BMMIMNTf

BMMIMNTf

R=0.1

R=0.5

R=1

R=2

R=3

[ ppm ] [ ppm ] 10 8 6 4 2

2

R=0.1

R=0.5

R=1

R=2

R=3

[ ppm ] [ ppm ] 10 8 6 4 2 [ ppm ] [ ppm ] 10 8 6 4 2

9 6 7 8

9 6 7 8

9

2

7 8

9 7 8

9 6 7 8 4,5

4,5

4,5

4,5

4,5

6

6

3

3

3

3

3

2

2

2

2 Har

Har

Har

Har

Har

3 9 7 8

HMe

HMe

HMe

HMe

HMe

4,5 6 2

NNCH3

CH3

H2C

CH2

H2C

CH33

2

4 5

6

7

8

9

H H

CH3

H

H

H

H

H

HMe

Har

Har

Har

Har

Har

27

C) Study of To/BMMIMNTf2 by ROESY NMR

Selective irradiation

C H 3

N N M e

M e

H H


C H 3

N N M e

M e

H H

ITo-IL measured rTo-IL ?

Ämmälahti et al. Magn. Reson, 1996,122, 230-232

Study of intermolecular interaction

61)(

ILTo

refrefILTo

IIrr

CH3

CH2

CH2CH2

CH3HIm

HAr

MeTo

28

Relative integrals in ROESY 1D

0,00

0,01

0,02

0,03

0,04

0,1 0,5 1 2 3

molar ratio R

Rel

ativ

e in

tegr

als

N NH3C

N NH3C

CH3

H

H2C

H2C

H(3)

H(3)

H(6)

H(6)

C) ROESY experiments

Evaluation of intermolecular distances

Chipot et al. J. Am. Chem. Soc., 1996, 118, 2998-3005

Deetlefs et al. J. Phys. Chem. B, 2005, 109, 1593-1598

61)(

ILTo

refrefILTo

IIrr

Estimation of minimum and maximum distances between H(Me) of toluene and H(3) & H(6) of

BMMIM

0,00

1,00

2,00

3,00

4,00

5,00

6,00

0,10 0,50 1,00 2,00 3,00

molar ratio (R)

dis

tan

ce (

A)

H(3) min

H(6) min

H(3) max

H(6) max

3.5Å

Benzene/DMIMPF6

N N M e B u

M e

H H


N N M e B u

M e

H H

2,3 < rref < 3,6Å Iref known


29

C) Molecular dynamics and radial distribution

Estimation of intermolecular distances (Pr Padua)

NNCH3

H

H2C

CH2

H2C

CH3

H HH3C

H H

H

HH

N

NH3C

CH3

CH2

H2CCH2

H3C

H

H

CH3

HH

H

H H1ILArR

30

C) To/BMIMNTf2 vs To/BMMIMNTf2

Evolution of 1H NMR at R = 0.1 to 1

To/BMIMNTf2 No evolution

To/BMMIMNTf2 Linear shift

ROESY experiments

To/BMIMNTf2 No interaction detected

To/BMMIMNTf2 Strong interaction at R=0.5 and 1

DOSY results

To/BMIMNTf2 Fast diffusion of toluene

To/BMMIMNTf2 Slow diffusion of toluene

Molecular dynamics

To/BMIMNTf2 Toluene close to alkyl chain

To/BMMIMNTf2 Toluene close to imidazolium ring

31

C) Conclusion on interaction To/IL

+

32

Contents : IL, solvent for catalytic reactions

A) Synthesis of IL

1. Choice of IL

2. Synthesis of IL







D) Generation of metal nanoparticles in IL1. Influence of temperature



IL

3D organisation


Supramolecular matrix ?

33

Nanoclusters present unique properties between the bulk and the molecular species

Successful control of the size of MNP using rigid materials such as polymers or dendrimers

Astruc et al. Angew. Chem. Int. Ed., 2005, 7852 – 7872

Philippot et al. C.R Chimie, 2003, 1019–1034

IL are good media for the stabilization of MNP

Silveira et al. Chem. Eur. J. 2004, 10, 3734-3740

But no predictive synthesis of resulting size of MNP

D) Interest of metal nanoparticles (MNP)

Ionic liquid size (nm)BMIMPF6 2.6+/-0.4

BMIMBF4 2.5+/-0.4BMIMOTf 1.9+/-0.6

H2(4bar), 75°C

18h, ILRu(COD)(COT) Ru(NP)

34

Molecular dynamics of RMIMPF6 (R=CnH2n+1MIMPF6)

EMIMPF6 (n=2) BMIMPF6 (n=4) HMIMPF6 (n=6) OMIMPF6

(n=8)

X-Ray Diffraction of RMIMCl

D) IL generates microphase segregation

Canongia Lopes et al. J. Phys. Chem, 2006, 110, 3330-3335

Triolo et al. J. Phys. Chem, 2007, 110, 4641-4644

NNCH3

H

CnH2n+1

H H

Cl-max

2Q

L

35

D) Solvation of polar and nonpolar substrates in IL

Nonpolar substrates in nonpolar domains of IL

Polar substrates in polar domains of IL

Canongia Lopes et al.J. Phys. Chem, 2006, 110, 16816-16818

Hexane BMIMPF6 in BMIMPF6

Molecular Dynamics

and calorimetry

Jiang et al. J. Phys. Chem., 2007, 111, 4812-4818

OMIMNO3 H20 (20% mole) H20 (50% mole) H20 (80% mole)

36

D) Crystal Growth of RuNP in IL

Hypothesis : Ru(COD)(COT) is nonpolar

1) preferentially dissolved in nonpolar domains

2) local concentration increases when n increases

Ru

37

D) Crystal Growth of RuNP in IL

Hypothesis : Ru(COD)(COT) is nonpolar

Question : Control of RuNP size by microphase segregation ?

Study : Crystal growth of RuNP in various IL

Parameters : 1) Influence of temperature

2) Influence of stirring

3) Influence of the alkyl chain length

38

D) Synthesis of RuNP in BMIMNTf2 (n=4)

H2(4bar)

Stirring, 25°CBMIMNTf2

Ru(COD)(COT) Ru(NP)

0 1 2 3 4 50

10

20

30

40

50

60

70

Dis

trib

utio

n

Mean size (nm)

2.4 0.4nm

Gutel et al. J. Mat. Chem., 2007, 17, 3290-3292

39

D) Synthesis of RuNP in BMIMNTf2 (n=4) + COA

H2(4bar)

Stirring, 25°CBMIMNTf2

Ru(COD)(COT) + COA (1eq) Ru(NP)

12nm

BMIMNTf2 + COA swelling of nonpolar domains

Synthesis of RuNP in BMIMNTf2 / COA

RuNP : 7 nm

Instead

of 2.4 nmRu(COD)(COT)

dissolves preferentially in

nonpolar domains

40

0,5 1,0 1,5 2,0 2,5 3,0 3,50

10

20

30

40

50

60

70

80

Dis

tribu

tion

Mean size (nm)

25°C2.4+/-0.3nm

0°C0.9+/-0.4nm

D) Influence of temperature in BMIMNTf2 (n=4)


Temperature decreases

RuNP size decreases

H2(4bar)

Stirring, TBMIMNTf2

Ru(COD)(COT) Ru(NP)

41

D) Influence of stirring in BMIMNTf2 (n=4)

0,0 0,5 1,0 1,5 2,0 2,50

10

20

30

40

50

60

70

80

dist

ribut

ion

mean size (nm)

BMIMNTf2, 0°C, stirred

BMIMNTf2, 0°C, unstirred

Presence of stirring

RuNP size similar

RuNP agglomerated


H2(4bar)

0°CBMIMNTf2

Ru(COD)(COT) Ru(NP)

Stirred1.1+/-0.2nm

unstirred0.9+/-0.4nm

42

D) Conclusion of RuNP in BMIMNTf2

1) The crystal growth takes place in nonpolar domains of IL

2) The control of RuNP size is more efficient when 3D organization is more

maintained

Influence of the alkyl chain length at 0°C and in absence of stirring

43

D) Influence of alkyl chain length at 0°C, unstirred

0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,00

5

10

15

20

25

30

Dis

tribu

tion

Mean size (nm)

1 2 3 4 50

5

10

15

20

25

30

35

40

Dis

tribu

tion

Mean size (nm)

0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,00

10

20

30

40

50

60

70

Dis

tribu

tion

mean size (nm)

1 2 3 4 50

10

20

30

40

50

Dis

trib

utio

n

Mean size (nm)

Aggregation

EMIMNTf2 (n=2)2.30.6nm

BMIMNTf2

n=41.10.2nm

HMIMNTf2

n=61.90.6nm

OMIMNTf2

n=82.30.8nm

DMIMNTf2

n=10

Gutel et al. Angew. Chem. Int. Ed., Submitted

44

D) Influence of alkyl chain length at 0°C

Nature of IL 0°CEMIMNTf2 2.3 +/-0.6BMIMNTf2 1.1 +/- 0.2HMIMNTf2 1.9 +/-0.6OMIMNTf2 2.3 +/- 0.8

Gutel et al. Angew. Chem. Int. Ed., Submitted

0 1 2 3 4 50

10

20

30

40

50

60

70

80

Dis

trib

utio

n

Size (nm)

EMIMNTf2

BMIMNTf2

HMIMNTf2

OMIMNTf2

45

0

0,5

1

1,5

2

2,5

0 2 4 6 8 10Alkyl chain length (n carbons)

Mea

n s

ize

(nm

)

RuNP

Nonpolar domains (lit.)

N=38

N=201

N=586

D) Influence of alkyl chain length at 0°C

Polar medium

Linear crystal growthin nonpolar domains Interconnection of

nonpolar domains

46

D) The crystal growth in IL

47

CONCLUSION : IL, a non-innocent solvent

1) Ionic exchange is governed by the nature of anion and can be predicted by the Hard and Soft Acid Base theory

2) Ionic exchange modify the nature of the catalytic system and consequently the reactivity (isomerization of 2M3BN)

Ionic exchange

Na+A1- + C+A2

- C+A1- + Na+A-

Ionic

catalyst

IL

C+A-

48


3D organisation -cation Interaction

+

Unsaturated

substrates

IL

C+A-

49



Supramolecular matrix

IL

C+A- 3D organisation

50

Outlook

-cation interaction could be used for :

1) Separation of aromatics / alkanes

2) Stereoselective synthesis

IL could be used as a matrix for nanomaterials :

1) Generalization for other metal nanoparticles

2) Design of IL ANR CALIST Collaboration C2P2/LCC/LTSP/LECA

PhD student (Paul Campbell)

51

Academic Collaboration La lyonnaise des LI

NMR Mme Olivier-Bourbigou

M. Fenet (LRMN) M. Vallée

Mmes Baudouin et Lucas

Dr. Lefebvre

Mass spectrometry M. Simonato

M. Bouchu (LSM)

Microscopy (TEM)

M. Collière et Dr Philippot (LCC)

Dr Pelzer (Fritz-Haber Institut) M.Galland

Molecular dynamics M.Simonato

M. Bayard

Dr Padua (Université de Clermont-Ferrand)

Thanks

52

Thank you

Thank you !

53

D) Stabilization of RuNP in IL

N NBu Me

N

N

Bu

Me

H -NTf2

N

N

Bu

Me

H

HH

RuNP

HH

Steric stabilization Electronic stabilization (DLVO theory)

IL acts as a ligand IL is a electronic protective shell

Fonseca et al. J. Colloid Interface Sci., 2006, 301, 193–204Starkey Ott et al. J. Am. Chem. Soc , 2005, 127, 5758-5759

54

B) Hydrogenation CYD

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 1 2 3 4

Time (h)

Con

vers

ion

(%

)

BMIMNTf2 BMMIMNTf2

4Å

3,5Å

[Rh(COD)(PPh3)2][NTf2]

H2 (1.2 bar) / T IL

ionic liquids (il), use and specific task as solvent in catalytic reaction

Documents

use of il

catalyst catalyst il

modificationbut il

study of il

il interesting

catalytic reactions

reaction media solvent

innocent solventsbut