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G. Kickelbick:
"Phosphonate and Phosphate Coupling Agents as a Tool for Tailoring the Surface of Metal Oxide Nanoparticles";
Talk: 3^rd EuCheMS Chemistry Congress, Nürnberg (invited); 2010-08-29 - 2010-09-02; in: "Programme - Abstracts", (2010), 1 pages.

Metal oxide nanoparticles represent an important compound class in nanotechnology, due to their optical, electronic, catalytic and magnetic properties.
Their surface-functionalization with organic molecules is an important task for reasons of stability against agglomeration, compatibilization with specific environments, or for self-assembly interactions. Often applied compounds for the modification of metal oxide surfaces are silane coupling agents. However in a number of cases the Si-O-M bond lacks stability, for example against hydrolysis. In addition, silane coupling agents show self condensation phenomena in solution.
Much better results can be achieved by surface-functionalization with phosphonate and phosphate molecules which show a high selectivity towards metal oxide surfaces combined with the formation of a strong chemical bond.
This paper will give an overview on the synthesis of phosphonate and phosphate coupling agents with a variety of functional groups. These molecules were used for the surface-functionalization of a variety of transition metal oxides, such as early transition metal or lanthanide oxides. Depending on the structural features the molecules show a controllable kinetics towards surface-bonding and the formation of strong multidentate bonds to the surface. The focus of the paper lies on two functional materials that benefit from the advantageous properties of phosphonate and phosphate coupling agents. On the one hand surface functions on nanoparticles that cause an antenna effect will be presented. Such molecules can be used for energy conversion from the organic surface groups to emitting centers of the oxide particles. On the other hand we will reveal how anisotropic surfacefunctionalization and the synthesis of Janus particles can profit from the benefits of these molecules.