Abstract
A series of transition metal substituted polyoxometalates (POM) have been anchored to propylamine-functionalized mesoporous silica (silicaNH2). These include V, Co and Mn Keggin-type anions such as [PMo10V2O40]5− and [PMo11VO40]4−, or [SiW11CoII(H2O)O39]6− and [SiW11MnIII(H2O)O39]5−, and sandwich-type anions, [(PW9O34)2 Co II4 (H2O)2]10− and [(PW9O34)2Mn II4 (H2O)2]10−. Experiments at different initial pHi of aqueous suspension of silica were performed for the Co and Mn substituted Keggin anions. The novel silicaNH2-POM materials having between 12–17% (w/w) of polyoxometalate were characterized by elemental analysis, solid-state 29Si, 13C and 31P n.m.r., diffuse reflectance spectroscopy, FTIR spectroscopy, thermal analyses, and BET surface area measurements. The elemental analyses and spectroscopic results pointed to the integrity of POM structures after immobilization on the silica support while the latter one showed a slight decrease of BET surface area. Results of the visible diffuse reflectance spectroscopy for the Co-substituted Keggin anion revealed the coordination of cobalt centers in the cluster with the nitrogen atom of amine groups in modified silica at pHi ≥ 5.5 or the electrostatic bonding between polyoxoanion and protonated C3H6NH +3 group at pHi = 3.5. For the Co-substituted sandwich anion, external Co centres of the polyoxoanion have coordinated with the amine groups of modified silica under the experimental conditions used. 31P MAS n.m.r. showed a shifting of phosphorus atom resonances in H5[PMo10V2O40] and H4[PMo11VO40] to a single resonance at ca. − 4.1 ppm (Δv 1/2 ~ 70 Hz) when these POM were immobilized on the functionalized silica under weak acidic conditions (pH 3), evidencing electrostatic interaction of POM clusters with the C3H6NH +3 groups.
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References
Pope M.T. (1983). Heteropoly and Isopolyoxometalates. Springer-Verlag, New York
C.L. Hill (Ed.), Chem. Rev., 98 (1998), special issue on polyoxometalates.
M.T. Pope and A. Muller (Eds), Polyoxometalate Chemistry: From Topology via Self-assembly to Applications, Kluwer, Dordrecht, 2001.
Izumi Y., Hasebe R. and Urabe K. (1983). J. Catal. 84: 402
Marme F., Coudurier G. and Védrine J. (1998). Microporous Mesoporous Mater. 22: 151
Kozhevnikov I.V., Kloestra K.R., Sinnema A., Zandbergen H.W. and van Bekkum H. (1996). J. Mol. Catal. A 114: 287
Ghanbari-Siakhali A., Philippou A., Dwyer J. and Anderson M. (2000). Appl. Catal. A 192: 57
Molnár A., Keresszegi C. and Torok B. (1999). Appl. Catal. A 189: 217
Damyanova S., Dimitrov L., Mariscal R., Fierro J.L.G., Petrov L. and Sobrados I. (2003). Appl. Catal. A 256: 183
Izumi Y., Ono M., Kitagawa M., Yoshida M. and Urabe K. (1995). Microporous Mater. 5: 255
Izumi Y., Urabe K. and Onaka M. (1997). Catal. Today 35: 183
Guo Y., Wang Y., Hu C., Wang Y., Wang E., Zhou Y. and Feng S. (2000). Chem. Mater. 12: 3501
Li D., Guo Y., Hu C., Mao L. and Wang E. (2002). Appl. Catal. A 235: 11
Guo Y., Yang Y., Hu C., Guo C., Wang E., Zou Y. and Feng S. (2002). J. Mater. Chem. 12: 3046
Schroden R.C., Blanford C.F., Melde B.J., Johnson B.J.S. and Stein A. (2001). Chem. Mater. 13: 1074
Johnson B. and Stein A. (2001). Inorg. Chem. 40: 801
Guo Y., Hu C., Jiang C., Yang Y., Jiang S., Li X. and Wang E. (2003). J. Catal. 217: 141
Kholdeeva O., Vanina M.P., Tomofeeva M.N., Maksomovskaya R.I., Trubitsina T.A., Melgunov M.S., Burgina E.B., Mrowiec-Bialon J., Jarzebski A.B. and Hill C.L. (2004). J. Catal. 226: 363
Li L., Liu C., Geng A., Jiang G., Guo Y. and Hu C. (2006). Mater. Res. Bull. 41: 319
Khenkin A.M., Neumann R., Sorokin A.B. and Tuel A. (1999). Catal. Lett. 63: 189
Kala Raj N.K., Deshpande S.S., Ingle R., Rajá T. and Manikandan P. (2004). Catal. Lett. 98: 217
W. Kaleta and K. Nowinska, Chem. Commun., 535, (2001).
Kozhevnikov I.V. (1998). Chem. Rev. 98: 171
Neumann R. (1998). Progress Inorg. Chem. 47: 317
Tsigdinos G.A. and Hallada C.J. (1968). Inorg. Chem. 7: 437
Weakley T.J.R. and Malik S.A. (1967). J. Inorg. Nucl. Chem. 29: 2935
Tourné C.M., Tourné G.F., Malik S.A. and Weakley T.J.R. (1970). J. Inorg. Nucl. Chem. 32: 3875
Finke R.G., Droege M.W. and Domaille P.J. (1987). Inorg. Chem. 26: 3886
Petterson L., Andersson I., Selling A. and Grate J. (1994). Inorg. Chem. 33: 982
Kato C., Tanabe A., Negishi S., Goto K. and Nomiya K. (2005). Chem. Lett. 34: 238
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Gamelas, J.A.F., Evtuguin, D.V. & Esculcas, A.P. Transition metal substituted polyoxometalates supported on amine-functionalized silica. Transition Met Chem 32, 1061–1067 (2007). https://doi.org/10.1007/s11243-007-0277-4
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DOI: https://doi.org/10.1007/s11243-007-0277-4