Dendrimers, supramolecular catalysis

Nanotechnology is a multidisciplinary field of applied science and technology covering a broad range of topics from materials science, colloidal science, appfied physics, supramolecular chemistry, and even mechanical and electrical engineering. Chapter 9 describes the synthesis and applications of phosphorus-containing dendrimers in catalysis, materials science, and the biological fields. 

Ribaudo F, van Leeuwen PWNM, Reek JNH (2006) Supramolecular Dendritic Catalysis Noncovalent Catalyst Anchoring to Fimctionalized Dendrimers. 20 39-59 Richmond TG (1999) Metal Reagents for Activation and Functionalization of Carbon-Fluorine Bonds. 3 243-269... 

Keywords Dendrimers Transition metal catalysis Supramolecular chemistry ... 

Whether dendritic catalysis can compete successfully in commercial applications with other strategies that allow recycling of the catalyst remains to be seen. Dendrimer supports are still relatively expensive, but for applications that do not require the well-defined structure of the dendrimer support, hy-perbranched polymers can offer a cheaper alternative. A recent novel strategy in this research area that might provide the added value required to make the step towards commercial applications involves the noncovalent functionalization of dendritic support with catalysts (Fig. 1). This offers several advantages above the traditional covalent approaches. In this chapter we will review the progress in the area of supramolecular dendritic catalysis. 

Supramolecular Dendritic Catalysis Noncovalent Catalyst Anchoring to Functionalized Dendrimers... 

Fig. 5.6 Didier Astruc (bom 1946 in Versailles) studied chemistry at the University of Rennes, where he received his Ph.D. with Professor Rene Dabard in 1975. He then moved to MIT as a NATO Postdoctoral Fellow, where he worked with the 2005 Nobel laureate Richard R. Schrock. After being a Lecturer and Master Lecturer at the University Institute for Technology of Saint-Nazaire, he worked for the CNRS at Rennes where he became Maitre de Recherche in 1982. Since 1983 he is Professor of Chemistry at the University of Bordeaux I and has been promoted to the exceptional class of university professors in 1996. His research interests comprise preparative and mechanistic organometallic chemistry, catalysis, and electron transfer processes. More recently, he has developed the synthesis and supramolecular electronics of organometallic dendrimers. He is the author of Electron Transfer and Radical Processes in Transition-Metal Chemistry and of the standard textbook Organometallic Chemistry and Catalysis . A recipient of several major research awards, Didier is also a senior member of the Institut Universitaire de France, a member of the Academia Europeae, London, and the German Academy Leopoldina, and a Fellow of the Royal Society of Chemistry (photo by courtesy from D. A.)...

The unique features of dendritic architecture and the rich chemistry of organo-transition metal complexes have been combined in metallodendrimers to create the potential for a wide range of utilitarian applications. Because dendrimers allow scientists to probe the twilight zone between homogeneous and heterogeneous catalysis as well as to apply the techniques associated with combinatorial-type chemistry, diverse new areas of the nanoworld have became accessible. Since many new avenues in supramolecular chemistry have been opened by organometalhc complexes, metallodendrimers will continue to play an important role in not only organometalhc chemistry and polymer science, but also in material science. These new interfaces will be rich areas for future science to pursue. 

Astruc, D. Boisselier, E. Ornelas, C. Dendrimers designed for functions From physical, photophysical, and supramolecular properties to applications in sensing, catalysis, molecular electronics, photonics, and nanomedicine. Chem. Rev. 2010,110 (4), 1857-1959. 

One particular asset of structured self-assemblies is their ability to create nano- to microsized domains, snch as cavities, that could be exploited for chemical synthesis and catalysis. Many kinds of organized self-assemblies have been proved to act as efficient nanoreactors, and several chapters of this book discnss some of them such as small discrete supramolecular vessels (Chapter Reactivity In Nanoscale Vessels, Supramolecular Reactivity), dendrimers (Chapter Supramolecular Dendrlmer Chemistry, Soft Matter), or protein cages and virus capsids (Chapter Viruses as Self-Assembled Templates, Self-Processes). In this chapter, we focus on larger and softer self-assembled structures such as micelles, vesicles, liquid crystals (LCs), or gels, which are made of surfactants, block copolymers, or amphiphilic peptides. In addition, only the systems that present a high kinetic lability (i.e., dynamic) of their aggregated building blocks are considered more static objects such as most of polymersomes and molecularly imprinted polymers are discussed elsewhere (Chapters Assembly of Block Copolymers and Molecularly Imprinted Polymers, Soft Matter, respectively). Finally, for each of these dynamic systems, we describe their functional properties with respect to their potential for the promotion and catalysis of molecular and biomolecu-lar transformations, polymerization, self-replication, metal colloid formation, and mineralization processes. 

Supramolecular dendrimers that contain photo- and/or redox-active functions have attracted a great deal of interest due to their potential apphca-tions in molecular recognition, catalysis and hght harvesting [121-123]. Dye molecules are assembled into dendritic superstructures through metal-ligand mediated coordination for serving as photoactive materials. 

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