E. De Canck

Heterogeneous Ru(III) oxidation catalysts via ‘click’ bidentate ligands on a Periodic Mesoporous Organosilica support

S. Clerick, E. De Canck, K. Hendrickx, V. Van Speybroeck, P. Van der Voort
Green Chemistry
18, 6035–6045
2016
A1

Abstract 

A 100% monoallyl ring-type Periodic Mesoporous Organosilica (PMO) is prepared as a novel, versatile and exceptionally stable catalytic support with a high internal surface area and 5.0 nm pores. Thiol-ene ‘click’ chemistry allows straightforward attachment of bifunctional thiols (-NH2, -OH, -SH) which, exploiting the thioether functionality formed, give rise to ‘solid’ bidentate ligands. [Ru(acac)2(CH3CN)2]PF6 is attached and complex formation on the solid is studied via theoretical calculations. All resulting solid catalysts show high activity and selectivity in alcohol oxidation reactions performed in green conditions (25°C/ water). The PMO catalysts do not leach Ru during reaction and are thus easily recuperated and re-used for several runs. Furthermore, oxidation of poorly water-soluble (±)-menthol illustrates the benefits of using hydrophobic PMOs as catalytic supports.

Quantification of silanol sites for the most common mesoporous ordered silicas and organosilicas: total versus accessible silanols

M. Ide, M. El-Roz, E. De Canck, A. Vicente, T. Planckaert, T. Bogaerts, I. Van Driessche, F. Lynen, V. Van Speybroeck, F. Thibault-Starzyk, P. Van der Voort
Physical Chemistry Chemical Physics (PCCP)
15, 642-650
2013
A1

Abstract 

IR and NMR spectroscopy were used to determine the silanol content in the most common mesoporous ordered silicas: MCM-41, MCM-48, SBA-15 and SBA-16. In addition, a spray dried MCM-41 and an ethene bridged PMO are investigated. The results are compared with a commercial chromatographic silica (Nucleosil). The complete distribution of surface and bulk silanols, and of isolated, geminal and vicinal silanols for all these materials is presented. A distinction is made between the total silanol number and the reachable or surface silanol content. The latter is determined by controlled reactions with simple silanes. All mesoporous ordered silicas, and especially the thick walled SBA-type materials and the PMO contain a surprisingly high amount of total silanol sites, albeit that up to 90% if these silanols are buried inside the walls and are not reachable for small silanes.

Heterogeneous Ru(III) oxidation catalysts via ‘click’ bidentate ligands on a Periodic Mesoporous Organosilica support

ISBN/ISSN:
Talk

Conference / event / venue 

Multifunctional, Hybrid and Nanomaterials, 5th International conference
Lisbon, Portugal
maandag, 6 maart, 2017 t/m vrijdag, 10 maart, 2017

Generation of S-containing bidentate ligands on a Periodic Mesoporous Organosilica (PMO) support: heterogenization of Ru(III) as a selective oxidation catalyst in water

ISBN/ISSN:
Poster

Conference / event / venue 

Doctoral Symposium, Faculty of Sciences
Ghent
donderdag, 17 maart, 2016
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