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U. Schubert:
"New precursor concepts for sol-gel-derived hybrid materials";
Talk: Second International Conference on Multifunctional, Hybrid and Nanomaterials, Strasbourg, France (invited); 2011-03-06 - 2011-03-10; in: "Hybrid Materials 2011 - Programme", Elsevier, (2011), 1 pages.

Modification of metal alkoxide precursors by organic ligands has been used to allow controlling the precursor reactivity, introducing organic functionalities etc. A new approach is to integrate groups which control the mutual arrangement of individual building blocks or the network structure in general.
"Single-source" sol-gel precursors are normally employed to prepare oxide materials containing two different (metallic or semi-metallic) elements. The option to use bimetallic precursors (modules) to pre-organize the individual components and thus to control the structure/texture of the formed mixed metal oxide has hardly been pursued until present. To this end, individual metal-containing moieties are linked through organic groups which are retained during sol-gel processing and degraded afterwards. Examples of such precursors are shown in the Scheme. This concept can also be extended to silicon-free precursors.
Another example is modifying ligands with organic groups having a structure-directing influence. For example, if the group R´ in the oximate-modified titanium alkoxide is a long hydrocarbon chain, surfactant-like properties are complemented. Sol-gel processing of such precursors results in similar gel structures as surfactant-assisted sol-gel processing of the corresponding native alkoxides.

Precursors, Mixed-metal oxides, Organically modified precursors, Structure control