Synthesis Brust-Schiffrin

Figure3.9 Brust-Schiffrin method for the synthesis of monolayer protected gold clusters. Reproduced from reference [62] by permission of The Royal Society of Chemistry.

As mentioned above, the grafting to technique enables in a one-pot reaction the synthesis of Au NPs stabilized by sulfur-containing polymers, which bear functional groups such as dithioester, trithioester, thiol, thioether and disulfide at the end of a polymer chain or in the middle. This method leads to nanoparticles similar to those obtained by the Brust-Schiffrin method in which alkanethiol-protected Au NPs of small size are obtained. This grafting to technique leads to very stable nanomaterials that also present a high surface graft density of polymer brush on the Au NP surface. 

For example, Wuelfing et al. reported on the synthesis of Au NPs using the thiolated polymer, a-methoxy-co-mercapto-poly(ethylene glycol) (PEG-SH), as stabilizer in a modification of the Brust-Schiffrin method using a 1/12 polymer thiol/ AuC14 ratio. Transmission electron microscopy showed that the product had modestly polydisperse Au cores of average diameter 2.8 1 nm. This nanomaterial led to characteristics uniquely different from alkanethiolate MPCs, notably aqueous solubility, thermal and chemical stability, ligand footprint size, and ionic conductivity [66]. 

Scheme 1 The one- and two-phase Brust-Schiffrin method for the synthesis of thiol-capped gold nanoparticles, and the first step of the reaction prior to the reduction step with NaBIL [63]...

Fig.1 a The Brust-Schiffrin solution phase gold nanoparticle synthesis, followed by b place exchange process developed by Murray... 

The Brust—Schiffrin Method Two-Phase Synthesis and Stabilization by Thiols... 

THE BRUST-SCHIFFRIN MFTHOD TWO-PHASE SYNTHESIS AND STABILIZATION BY THIOLS ... 

Fig. 4.5 Brust-Schiffrin method for two-phase synthesis of AuNPs by reduction of gold salts in presence of external thiol hgands (Reprinted with permission from Saha et al. 2012, Copyright 2012 American Chemical Society)...

In the twentieth century, various methods for the preparation of gold colloids (AuNPs) were reported and reviewed [41] among them, the Brust-Schiffrin method for AuNPs synthesis [42], published in 1994, has had considerable impact on the field since it allowed, for the first time, the facile synthesis of thermally stable and air-stable AuNPs of reduced dispersity and controlled size. 

Disclosing the binding motif of multiblock RAFT polymers on AuNPs from citrate reduction raises the questimi of whether the polymer binding can vary for different types of AuNPs. It is known that AuNPs from the two-phase Brust-Schiffrin synthesis can assemble into spherical particle networks when treated with low molecular weight crosslinking agent [106, 107]. When tetraocty-lammonium bromide-capped AuNPs from this two-phase method are functionalized in toluene dispersion with multiblock RAFT polymers of styrene, the formation of spherical AuNP assemblies can be observed by TEM (Fig. 9) [108]. It can be concluded from these TEM images that the particle density inside... 

Brust, M., Walker, M., Bethell, D., Schiffrin, D.J. and Whyman, R. (1994) Synthesis of thiol-derivatized gold nanopartides in a 2-phase liquid—liquid system. Journal of the Chemical Society, Chemical Communications (7), 801—802. 

M. Brust, M. Walker, D. Bethell, D. J. Schiffrin, and R. Whyman, Synthesis of thiol-derivatised gold nanoparticles in a 2-phase liquid-liquid system, J. Chem. Soc.—Chem. Commun. 801-802 (1994). 

Brust, M. Walker, M. Bethel , D, Schiffrin, D. J, Whyman, R. Synthesis of Ttiol-Derivatised Gold Nanoparticles in a Two-Phase Liquid-Liquid System, J. Chem. See., Chem. Commun. 1994. 801-802,... 

Brust M, Walker M, BetheU D, Schiffrin DJ, Whyman R (1994) Synthesis of thiol-derivatised gold nanoparticles in a two-phase liquid-liquid system. 1 Chem Soc Chem Commun 7 801-802 Burda C, Chen X, Narayanan R, H-Sayed MA (2005) Chemistry and properties of nanocrystals of different shapes. Chem Rev 105 1025-1102... 

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