A: Chem., 2002, 182–183, 419; R. Sheldon, Chem. Commun.,
2001, 2399.
P. A. Z. Suarez, J. E. L. Dullius, S. M. O. Einloft, R. F. de Souza
and J. Dupont, Polyhedron, 1996, 15, 1217.
M. F. Sellin, P. B. Webb and J. Cole-Hamilton, Chem. Commun.,
2001, 781; F. Favre, H. Olivier-Bourbigou, D. Commereuc and
L. Saussine, Chem.Commun., 2001, 1360; C. C. Brasse, U. Englert,
A. Salzer, H. Waffenschmidt and P. Wasserscheid, Organometal-
lics, 2000, 19, 3818; W. Keim, D. Vogt, H. Waffenschmidt and
P. Wasserscheid, J. Catal., 1999, 186, 481; Y. Chauvin, L.
Mussmann and H. Olivier, Angew. Chem., Int. Ed. Engl., 1996,
34, 2698.
B. Cornils and E. G. Kuntz, in Aqueous-Phase Organometallic
Catalysis Concepts and Applications, ed. B. Cornils and W. A.
Herrmann, Wiley-VCH, New York, 1998, p. 271.
J. Dupont, S. M. Silva and R. F. de Souza, Catal. Lett., 2001,
77, 131.
R. P. J. Bronger, S. M. Silva, P. C. J. Kamer and P. W. N. M. van
Leeuwen, Chem. Commun., 2002, 3044; P. Wasserscheid, H.
Waffenschmidt, P. Machnitzki, K. W. Kottsieper and O. Stelzer,
Chem. Commun., 2001, 451.
P. C. J. Kamer, P. W. N. M. van Leeuwen and J. N. H. Reek, Acc.
Chem. Res., 2001, 34, 895; S. C. van der Slot, P. C. J. Kamer,
P. W. N. M. van Leeuwen, J. Fraanje, K. Goubitz, M. Lutz
neutral activated alumina to remove peroxide impurities. The
disodium salt of 2,7-bissulfonate-4,5-bis(diphenylphosphino)-
9,9-dimethylxanthene (sulfoxantphos, ligand 1) and the 1-n-
butyl-3-methylimidazolium hexafluorophosphate ionic liquid
(BMIꢀPF6) were synthesised as described in the literature.12,18
and contained less than 1.4 mg Lꢂ1 of chloride19 and less than
0.1 wt % of water,20 as determined by known methods. Note
that the presence of water in the reaction mixture involving
hydrogen and transition metal complexes causes decom-
position of the ionic liquid with formation of phosphates
and HF.21
All other reagents were commercial samples and were used
as purchased. Gas chromatographic analyses were performed
on an Interscience HR GC Mega 2 apparatus (split/splitless
injector, J & W Scientific, DB1 30 m column, film thickness
3.0 mm, carrier gas: He, FID detector, external standard: dibutyl
ether). The mass spectra were obtained on a JEOL JMS-SX/
SX102A. The NMR was performed on a Varian DRX 300.
Infrared spectra were recorded on a Nicolet 510 FT-IR spec-
trophotometer. High-pressure IR spectra were measured using
a 50 mL homemade stainless steel autoclave equipped with
mechanical stirrer and ZnS windows.22 Syngas (CO–H2 , 1 : 1,
99.9%), CO (99.9%) and H2 (99.9%) were purchased from
Air Liquide.
2
3
˚
The BMIꢀPF6 employed was dried over 4 A molecular sieves
4
5
6
7
´
and A. L. Spek, Organometallics, 2000, 19, 2504; I. del Rıo, O.
Pamies, P. W. N. M. van Leeuwen and C. Claver, J. Organometal.
`
´
Chem., 2000, 608, 115; M. Dieguez, C. Claver, A. M. Masdeu-
Bulto, A. Ruiz, P. W. N. M. van Leeuwen and G. C. Schoemaker,
´
´
´
Organometallics, 1999, 18, 2107; A. Castellanos-Paez, S. Castillon,
C. Claver, P. W. N. M. van Leeuwen and W. G. J. de Lange,
Organometallics, 1998, 17, 2543.
High pressure FT-IR (HP-IR) experiments
8
9
L. A. van der Veen, P. C. J. Kamer and P. W. N. M. van
Leeuwen, Organometallics, 1999, 18, 4765.
In a typical experiment a high pressure IR autoclave was filled
with the previously prepared catalyst solution, 4 equiv. of
ligand and 4.0 mg of Rh(acac)(CO)2 in 15 mL of BMIꢀPF6
The autoclave was purged three times with the desired gas mix-
ture, pressurised with the amount of syngas or gas mixture
needed for the experiment and heated to 100 ꢁC. Catalyst
formation was followed and was usually complete within 2 h.
L. A. van der Veen, M. D. K. Boele, F. R. Bregman, P. C. J.
Kamer, P. W. N. M. van Leeuwen, K. Goubitz, J. Fraanje, H.
Schenk and C. Bo, J. Am. Chem Soc., 1998, 120, 11 616; L. A.
van der Veen, P. H. Keeven, G. C. Schoemaker, J. N. H. Reek,
P. C. J. Kamer, P. W. N. M. van Leeuwen, M. Lutz and A. L.
Spek, Organometallics, 2000, 19, 872.
10 M. Kranenburg, Y. E. M. van der Burgt, P. C. J. Kamer and
P. W. N. M. van Leeuwen, Organometallics, 1995, 14, 3081.
11 D. J. Brauer, K. W. Kottsieper, C. Liek, O. Stelzer, H.
Waffenschmidt and P. Wasserscheid, J. Organometal. Chem.,
2001, 630, 177.
12 M. S. Goedheijt, P. C. J. Kamer and P. W. N. M. van Leeuwen,
J. Mol. Catal. A: Chem., 1998, 134, 243.
13 J. M. Brown and A. G. Kent, J. Chem. Soc., Perkin Trans. 2,
1987, 1597.
Hydroformylation. For the hydroformylation reactions, after
1 h at 100 ꢁC, 2.5 mL of 1-octene was introduced into the HP-
IR autoclave and the spectra were collected. The products were
analysed by gas chromatography and mass spectrometry.
14 A. J. Sandee, V. F. Slagt, J. N. H. Reek, P. C. J. Kamer and
P. W. N. M. van Leeuwen, Chem. Commun., 1999, 1633.
15 J. L. Anthony, E. J. Maginn and J. F. Brennecke, J. Chem. Phys.
B, 2002, 106, 7315.
16 A. Berger, R. F. de Souza, M. R. Delgado and J. Dupont, Tetra-
hedron: Asymmetry, 2001, 12, 1825.
High pressure NMR (HP-NMR) experiments
In a typical experiment the high pressure sapphire tube
(f ¼ 10 mm) was filled with the previously prepared catalytic
solution, 1 equiv. of ligand and 10 mg of Rh(acac)(CO)2 in 3
mL of BMIꢀPF6 The tube was purged three times with syngas
and then pressurized with the amount of desired gas. Next, the
tube was placed in the NMR spectrometer and the spectra
were recorded.
17 C. Bianchini, H. Man Lee, A. Meli and F. Vizza, Organometallics,
2000, 19, 849.
´
18 P. A. Z. Suarez, C. S. Consorti, R. F. de Souza and J. Dupont,
Org. Synth., 2002, 79, 236.
19 K. Sweeny and D. G. Peters, Electrochem. Commun., 2001, 3,
712; U. Schroder, J. D. Wadhawan, R. G. Compton, F. Marken,
P. A. Z. Suarez, C. S. Consorti, R. F. de Souza and J. Dupont,
New J. Chem., 2000, 24, 1009.
20 V. Gallo, P. Mastrorilli, C. F. Nobile, G. Romanazzi and G. P.
Suranna, J. Chem. Soc., Dalton Trans., 2002, 4339.
21 J. Dupont, G. S. Fonseca, A. P. Umpierre, P. F. P. Fichtner and
S. R. Teixeira, J. Am. Chem. Soc., 2002, 124, 4228.
22 A. van Rooy, Thesis, University of Amsterdam, 1995.
References
1
For recent reviews in ionic liquid organometallic catalysis see: J.
Dupont, R. F. de Souza and P. A. Z. Suarez, Chem. Rev., 2002,
102, 3667; H. Olivier-Bourbigou and L. Magna, J. Mol. Catal.
1296
New J. Chem., 2003, 27, 1294–1296