Abstract
Because of the relative ease to modify, functionalize, and synthesize polysiloxanes, these compounds offer interesting possibilities to greatly influence the properties of a catalytic system. These potentials are illustrated with three catalytic systems. In the first system, siloxane nanocages are shown to exhibit confinement effects by strongly modifying the protonation affinity of internal amine groups and by changing the activity and product selectivity in a reaction catalyzed by these groups. In the second example, the length of the siloxane backbone of a bis(pyridyl)siloxane ligand is shown to be critical both in stabilizing a Pd acetate complex catalyst in selective oxidation of benzyl alcohol, and in determining the dependence of the reaction rate on the pyridyl concentration in the reaction mixture. In the third example, polysiloxanes are shown to be useful in the preparation of a supported Pd catalyst in which the metal loading and particle size can be independently controlled.
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Acknowledgments
Financial support of the work presented here was primarily from the Department of Energy, Basic Energy Sciences over the years Grant No. DE-FG02-01ER15184 and DE-FG02-03ER15457. Contribution from the Dow Chemicals Company is also acknowledged. The authors also acknowledged many delightful discussions with former students and post-doctoral fellows, including those who did not participate in the cited references.
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Missaghi, M.N., Kung, M.C. & Kung, H.H. Polysiloxanes in Catalysis and Catalyst Preparation: Opportunities for Control of Catalytic Processes. Top Catal 55, 99–107 (2012). https://doi.org/10.1007/s11244-012-9778-2
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DOI: https://doi.org/10.1007/s11244-012-9778-2