Dendrimer stabilized nanoparticles

Figure 11.11 (a) Scheme for synthesis of dendrimer-stabilized nanoparticles. (Reproduced... 

Up to now templating and stabilizing of various mono and bimetallic dendrimer-encapsulated nanoparlicles, such as Ag [40], Au [41], Co [42], Pd [43], Ni [44], Cu [45], Ag-Pd [46], Au-Ag [47], Pd-Au [48], and so on, have been reported. There are also some review articles and book chapter covering this topic [ 14]. In this section some recent examples of dendrimer- stabilized nanoparticles are presented. 

The authors reported the catalytic performance of this dendrimer-stabilized nanoparticle in C-C CTOsscoupUng reactions, including the Suzuki-Miyaura, Sonogashira and Heck, and reduction of 4-nitrophenol. 

It is worthwhile to point out that dendrimers can also be used as normal capping agents during the synthesis of nanoparticles that do not reside inside the cavities of dendrimers [59,60]. These dendrimer-stabilized nanoparticles, capped with several dendrimer molecules, are usually much bigger than DENs and will not be discussed in this book chapter. 

Application in Catalysis of Click Dendrimers and Dendrimer-Stabilized Nanoparticles... 

Click-dendrimer-stabilized nanoparticles are a new family of dendrimer-stabilized nanoparticles that is particularly suitable for catalytic studies [59, 66],... 

Esumi K (2003) Dendrimers for Nanoparticle Synthesis and Dispersion Stabilization. 227 31-52 Famulok M, Jenne A (1999) Catalysis Based on Nucleid Acid Structures. 202 101-131 Fechter MH, see de Raadt A (2001) 215 327-345... 

Esumi K (2003) Dendrimers for Nanoparticle Synthesis and Dispersion Stabilization. 227 31-52... 

D. X. Liu, J. X. Gao, C. J. Murphy, and C. T. Williams, In situ attenuated total reflection infrared spectroscopy of dendrimer-stabilized platinum nanoparticles adsorbed on alumina, J. Phys. Chem. B 108, 12911-12916(2004). 

Thiol-functionalized dendrimers have also been used as surface stabilizers to obtain dendrimer stabilized Au NPs (DSNs) of very small size (1.5-2.1 nm). The study shows that dendrimer molecules are highly flexible and can undergo a conformational change to accumulate thiol terminal groups on one side of the molecule interacting with the nanoparticle surface [124] (Scheme 3.19). 

Abstract We review the preparation, characterization, and properties of dendrimer-templated bimetallic nanoparticles. Polyamidoamine (PAMAM) dendrimers can be used to template and stabilize a wide variety of mono- and bimetallic nanoparticles. Depending on the specific requirements of the metal system, a variety of synthetic methodologies are available for preparing nanoparticles with diameters on the order of 1-3 nm with narrow particle size distributions. The resulting dendrimer-encapsulated nanoparticles, or DENs, have been physically characterized with electron microscopy techniques, as well as UV-visible and X-ray photoelectron spectroscopies. 

Other one-phase preparations of bimetallic nanoparticles include NOct4(BHEt3) (Oct = octyl, Et = ethyl) reduction of platinum and ruthenium chlorides to give Pt/Ru(l/1) nanoparticles by Bonnemann et al. [102-104], sono-chemical reduction of gold and palladium ions to provide Au/Pd nanoparticles by Mizukoshi et al. [105,106], and NaBH4 reduction of PtCl - and PdCl - dendrimer complexes to give dendrimer-stabilized Pd/Pt nanoparticles by Crooks et al. [107]. 

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