Paper
Dalton Transactions
substrate cis-cyclooctene. Hydrolysis of 2 under hydrothermal
conditions reproducibly gives a microcrystalline material with
the composition [Mo2O6(pent-pp)] (3). Although the structure
of 3 is presently unknown, characterisation data point towards
a polymeric molybdenum oxide hybrid in which the organic
ligands are coordinated to oxomolybdenum(VI) centres. When
material 3 is used in catalytic olefin epoxidation, it acts as a
source of soluble active species, which include but may not be
limited to the oxodiperoxo complex [MoO(O2)2(pent-pp)].
While most of the molybdenum oxide/organic hybrid
materials studied recently by us in catalytic olefin epoxidation
behave in a similar manner to 3, i.e., the materials act as a
source of soluble active species, some materials act as hetero-
geneous catalysts. By modifying the synthesis procedures and/
or the organic ligands employed it may be possible to obtain
porous materials that function effectively as heterogeneous cat-
alysts. This would be a major breakthrough and is currently a
focus of study in our laboratory.
I. S. Gonçalves, A. D. Lopes and M. Pillinger, Chem.–Eur. J.,
2002, 8, 2370; (b) M. Groarke, I. S. Gonçalves,
W. A. Herrmann and F. E. Kühn, J. Organomet. Chem., 2002,
649, 108; (c) A. M. Al-Ajlouni, A. A. Valente, C. D. Nunes,
M. Pillinger, T. M. Santos, J. Zhao, C. C. Romão,
I. S. Gonçalves and F. E. Kühn, Eur. J. Inorg. Chem., 2005,
1716; (d) A. Günyar, M.-D. Zhou, M. Drees, P. N. W. Baxter,
G. Bassioni, E. Herdtweck and F. E. Kühn, Dalton Trans.,
2009, 8746; (e) A. M. Al-Ajlouni, A. Günyar, M.-D. Zhou,
P. N. W. Baxter and F. E. Kühn, Eur. J. Inorg. Chem., 2009,
1019; (f) S. M. Bruno, C. C. L. Pereira, M. S. Balula,
M. Nolasco, A. A. Valente, A. Hazell, M. Pillinger,
P. Ribeiro-Claro and I. S. Gonçalves, J. Mol. Catal. A: Chem.,
2007, 261, 79; (g) S. M. Bruno, J. A. Fernandes,
L. S. Martins, I. S. Gonçalves, M. Pillinger, P. Ribeiro-Claro,
J. Rocha and A. A. Valente, Catal. Today, 2006, 114, 263;
(h) A. C. Coelho, M. Nolasco, S. S. Balula, M. M. Antunes,
C. C. L. Pereira, F. A. A. Paz, A. A. Valente, M. Pillinger,
P. Ribeiro-Claro, J. Klinowski and I. S. Gonçalves, Inorg.
Chem., 2011, 50, 525.
6 G. Barea, A. Lledos, F. Maseras and Y. Jean, Inorg. Chem.,
1998, 37, 3321.
Acknowledgements
We are grateful to the Fundação para a Ciência e a Tecnologia
(FCT, project ref. PTDC/EQU-EQU/121677/2010), QREN,
FEDER, COMPETE, the European Union (EU), and the Associ-
ate Laboratory CICECO (PEst-C/CTM/LA0011/2013) for contin-
ued support and funding. The NMR spectrometers are part of
the National NMR Network (REDE/1517/RMN/2005), supported
by POCI 2010 and the FCT. The FCT is acknowledged for finan-
cial support towards the purchase of the single-crystal diffracto-
meter. We thank the FCT and the EU for a post-doctoral grant
to P.N. (SFRH/BPD/73540/2010) cofunded by MCTES and the
European Social Fund through the program POPH of QREN,
and for a PhD grant to T.R.A. (SFRH/BD/64224/2009).
7 (a) W. R. Thiel and J. Eppinger, Chem.–Eur. J., 1997, 3, 696;
(b) W. R. Thiel, M. Angstl and T. Priermeier, Chem. Ber.,
1994, 127, 2373; (c) W. R. Thiel, M. Angstl and N. Hansen,
J. Mol. Catal. A: Chem., 1995, 103, 5; (d) W. R. Thiel and
T. Priermeier, Angew. Chem., Int. Ed. Engl., 1995, 34, 1737.
8 (a) H. Arzoumanian, R. Bakhtchadjian, G. Agrifoglio,
R. Atencio and A. Briceño, Transition Met. Chem., 2006, 31,
681; (b) C. C. L. Pereira, S. S. Balula, F. A. A. Paz,
A. A. Valente, M. Pillinger, J. Klinowski and I. S. Gonçalves,
Inorg. Chem., 2007, 46, 8508; (c) T. R. Amarante,
A. C. Gomes, P. Neves, F. A. A. Paz, A. A. Valente,
M. Pillinger and I. S. Gonçalves, Inorg. Chem. Commun.,
2013, 32, 59; (d) S. Gago, P. Neves, B. Monteiro, M. Pessêgo,
A. D. Lopes, A. A. Valente, F. A. A. Paz, M. Pillinger,
J. Moreira, C. M. Silva and I. S. Gonçalves, Eur. J. Inorg.
Chem., 2009, 4528.
References
1 Metal Oxide Catalysis, ed. S. D. Jackson and J. S. J. Har-
greaves, Wiley-VCH, Weinheim, 2009; M. B. Gawande,
R. K. Pandey and R. V. Jayaram, Catal. Sci. Tecnol., 2012, 2,
9 T. R. Amarante, P. Neves, C. Tomé, M. Abrantes,
A. A. Valente, F. A. A. Paz, M. Pillinger and I. S. Gonçalves,
Inorg. Chem., 2012, 51, 3666.
1113; H. Kuhlenbeck, S. Shaikhutdinov and H.-J. Freund, 10 M. Abrantes, T. R. Amarante, M. M. Antunes, S. Gago,
Chem. Rev., 2013, 113, 3986.
F. A. A. Paz, I. Margiolaki, A. E. Rodrigues, M. Pillinger,
A. A. Valente and I. S. Gonçalves, Inorg. Chem., 2010, 49, 6865;
M. Abrantes, I. S. Gonçalves, M. Pillinger, C. Vurchio,
F. M. Cordero and A. Brandi, Tetrahedron Lett., 2011, 52, 7079.
2 F. E. Kühn, A. M. Santos, I. S. Gonçalves, C. C. Romão and
A. D. Lopes, Appl. Organomet. Chem., 2001, 15, 43;
K. Jeyakumar and D. K. Chand, J. Chem. Sci., 2009, 121,
111; R. Sanz and M. R. Pedrosa, Curr. Org. Synth., 2009, 6, 11 S. Figueiredo, A. C. Gomes, P. Neves, T. R. Amarante,
239; R. G. de Noronha and A. C. Fernandes, Curr. Org.
Synth., 2012, 16, 33; S. C. A. Sousa, I. Cabrita and
A. C. Fernandes, Chem. Soc. Rev., 2012, 41, 5641.
F. A. A. Paz, R. Soares, A. D. Lopes, A. A. Valente,
M. Pillinger and I. S. Gonçalves, Inorg. Chem., 2012, 51,
8629.
3 F. E. Kühn, A. M. Santos and M. Abrantes, Chem. Rev., 12 H. Brunner and T. Scheck, Chem. Ber., 1992, 125, 701.
2006, 106, 2455; K. R. Jain, W. A. Herrmann and 13 T. Kottke and D. Stalke, J. Appl. Crystallogr., 1993, 26, 615.
F. E. Kühn, Coord. Chem. Rev., 2008, 252, 556.
14 APEX2 Data Collection Software, Version 2.1-RC13, Bruker
4 R. Coltan and I. B. Tomkins, Aust. J. Chem., 1965, 18, 447.
AXS, Delft, The Netherlands, 2006.
5 (a) F. E. Kühn, M. Groarke, É. Bencze, E. Herdtweck, 15 Cryopad, Remote monitoring and control, Version 1.451,
A. Prazeres, A. M. Santos, M. J. Calhorda, C. C. Romão,
Oxford Cryosystems, Oxford, United Kingdom, 2006.
6068 | Dalton Trans., 2014, 43, 6059–6069
This journal is © The Royal Society of Chemistry 2014