4 S. W. Kohl, L. Weiner, L. Schwartsburd, L. Konstantinovski,
L. J. W. Shimon, B. D. Yehoshoa, M. A. Iron and D. Milstein,
Science, 2009, 324, 74–77.
5 N. S. Lewis and D. G. Nocera, Proc. Natl. Acad. Sci. U. S. A.,
2006, 103, 15729–15735.
6 D. G. Nocera, Inorg. Chem., 2009, 48, 10001–10017.
7 R. Eisenberg and H. B. Gray, Inorg. Chem., 2008, 47, 1697–1699.
8 A. E. Farrell, R. J. Plevin, B. T. Turner, A. D. Jones, M. O’Hare
and D. M. Kammen, Science, 2006, 311, 506–508.
9 BP Statistical Review of World Energy June 2009, BP p.l.c.,
London, UK, 2009.
10 M. Konigsmann, N. Donati, D. Stein, H. Schonberg, J. Harmer,
¨
¨
A. Sreekanth and H. Grutzmacher, Angew. Chem., Int. Ed., 2007,
¨
46, 3567–3570.
11 K. Fujita, N. Tanino and R. Yamaguchi, Org. Lett., 2007, 9,
109–111.
12 A. Gabrielsson, P. V. Leeuwen and W. Kaim, Chem. Commun.,
2006, 4926–4927.
Fig.
3 DFT calculated structures and transition states of the
oxidative addition of the O–H and methylene C–H of EtOH to
[PNPPr ]Ir(I). Only the EtOH and immediate coordination sphere are
i
shown (Ir shown in green, P purple, N blue, O red, C gray, H white).
13 T. Iwai, T. Fujihara and Y. Tuji, Chem. Commun., 2008,
6215–6217.
14 P. Serp, M. Hernandez, B. Richard and P. Kalck, Eur. J. Inorg.
Chem., 2001, 2327–2336.
15 P. J. Alaimo, B. A. Arndtsen and R. G. Bergman, Organometallics,
2000, 19, 2130–2143.
16 K. A. Bernard and J. D. Atwood, Organometallics, 1998, 7,
235–236.
The mechanism shown in Scheme 1 for the decarbonylation
of ethanol to methane, dihydrogen and carbon monoxide is
consistent with the foregoing observations.
In summary, we have observed room temperature
i
decarbonylation of EtOH by [PNPPr ]Ir(I) to generate H2
i
and trans-[PNPPr ]Ir(H)(Me)(CO), which quantitatively
17 L. Vaska and J. W. DiLuzio, J. Am. Chem. Soc., 1961, 83,
2784–2785.
18 S. R. Klei, J. T. Golden, T. D. Tilley and R. G. Bergman, J. Am.
Chem. Soc., 2002, 124, 2092–2093.
undergoes photolytically induced reductive elimination of
i
methane to generate [PNPPr ]Ir(CO). Experiments and
computations indicate the mechanism involves initial oxida-
19 O. V. Ozerov, C. Guo, V. A. Papkov and B. A. Foxman, J. Am.
Chem. Soc., 2004, 126, 4792–4793.
20 D. Morales-Morales, R. Redon, Z. Wang, D. W. Lee, C. Yung,
K. Manguson and C. M. Jensen, Can. J. Chem., 2001, 79, 823–829.
21 S. M. Kloek, D. M. Heinekey and K. I. Goldberg, Organometallics,
2006, 25, 3007–3011.
22 M. T. Whited and R. H. Grubbs, J. Am. Chem. Soc., 2008, 130,
5874–5875.
23 L. Fan, S. Parkin and O. V. Ozerov, J. Am. Chem. Soc., 2005, 127,
tive addition of the hydroxyl moiety of EtOH to the
i
coordinatively unsaturated [PNPPr ]Ir(I) center followed by
dehydrogenation to produce the in situ generated acetaldehyde.
Research was supported by the National Science
Foundation (Grant No. CHE-0750239). ATR and JGM
acknowledge the NIH for NRSA postdoctoral fellowships.
DV acknowledges the Camille and Henry Dreyfus Post-
doctoral Program in Environmental Chemistry for a fellowship.
16772–16773.
i
24 H2 is evolved from the treatment of [PNPPr ]Ir(H)2 with acet-
aldehyde in 71% yield as determined by GC.
Notes and references
25 M. T. Whited and R. H. Grubbs, J. Am. Chem. Soc., 2008, 130,
16476–16477i.
i
z Crystallographic data for trans-[PNPPr ]Ir(H)(Me)(CO): C28H44Ir-
26 trans-[PNPPr ]Ir(H)(Et)(CO) undergoes photolytic reductive
ꢀ
NOP2, M = 664.78, triclinic, space group P1, a = 8.3135(8), b =
elimination under irradiation with lexc Z 338 nm to yield C2H6
i
9.8060(10), c = 17.8528(17), a = 84.829(2)1, b = 83.244(2)1,
g = 75.962(2)1, V = 1399.3(2), Z = 2, m = 4.906 mm–1, T = 100 K,
R1 = 0.0471, wR2 = 0.0732 (based on observed reflections), GooF =
1
and [PNPPr ]Ir(CO) quantitatively as determined by H NMR.
27 A. Vogler, A. Kern and J. Huttermann, Angew. Chem., Int. Ed.
Engl., 1978, 17, 524–525.
¨
1.024, reflections measured = 29 281, Rint = 0.0855, CCDC 740057.
i
y Crystallographic data for [PNPPr ]IrN2ꢁMesNH2: C35H53IrN4P2,
28 J. Sykora and J. Sima, Coord. Chem. Rev., 1990, 107, 1–212.
29 A. S. Goldman, A. H. Roy, Z. Huang, R. Ahuja, W. Schinski and
M. Brookhart, Science, 2006, 312, 257–261.
30 I. Gttker-Schnetmann and M. Brookhart, J. Am. Chem. Soc., 2004,
126, 9330–9338.
ꢀ
M = 783.95, triclinic, space group P1, a = 9.8992(12), b =
11.2251(14), c = 16.388(2), a = 101.780(2)1, b = 93.376(2)1,
g = 93.801(2)1, V = 1773.9(4), Z = 2, m = 3.882 mm–1, T = 100 K,
R1 = 0.0535, wR2 = 0.0944 (based on observed reflections), GooF =
31 K. Zhu, P. D. Achord, X. Zhang, K. Krogh-Jespersen and
A. S. Goldman, J. Am. Chem. Soc., 2004, 126, 13044–13053.
32 M. Gupta, C. Hagen, W. C. Kaska, R. E. Cramer and
C. M. Jensen, J. Am. Chem. Soc., 1997, 119, 840–841.
33 H. F. Luecke, B. A. Arndtsen, P. Burger and R. G. Bergman,
J. Am. Chem. Soc., 1996, 118, 2517–2518.
1.005, reflections measured = 39 573, Rint = 0.0882, CCDC 740058.
i
z Crystallographic data for trans-[PNPPr ]Ir(H)(Et)(CO): C29H46IrNOP2,
M = 678.81, monoclinic, space group P2(1)/n, a = 14.7286(13), b =
12.3197(11), c = 16.0250(14), b = 90.754(2)1, V = 2907.5(4), Z = 4,
m = 4.724 mm–1, T = 100 K, R1 = 0.0226, wR2 = 0.0529 (based on
observed reflections), GooF = 1.002, reflections measured = 67 091,
Rint = 0.0415, CCDC 740056.
34 B. A. Arndtsen and R. G. Bergman, Science, 1995, 270, 1970–1973.
35 P. Rodrı
´
´
guez, M. M. Dıaz-Requejo, T. R. Belderrain, S. Trofimenko,
1 O. V. Ozerov, Chem. Soc. Rev., 2009, 38, 83–88.
2 D. Morales-Morales, D. W. Lee, Z. Wang and C. M. Jensen,
Organometallics, 2001, 20, 1144–1147.
3 R. Dorta, H. Rozenberg, L. J. W. Shimon and D. Milstein, J. Am.
Chem. Soc., 2002, 124, 188–189.
M. C. Nicasio and P. J. Pe
´
rez, Organometallics, 2004, 23, 2162–2167.
36 M. T. Whited, Y. Zhu, S. D. Timpa, C. Chen, B. M. Foxman,
O. V. Ozerov and R. H. Grubbs, Organometallics, 2009, 28, 4560–4570.
37 D. P. Paterniti, R. J. Roman and J. D. Atwood, Organometallics,
1997, 16, 3371–3376.
ꢀc
This journal is The Royal Society of Chemistry 2010
Chem. Commun., 2010, 46, 79–81 | 81