Click Functionalization of Gold Nanoparticles Using the Very Efficient Catalyst Copper(I) (Hexabenzyl)tris(2-aminoethyl)- amine Bromide

Whereas previous click functionalization (Huisgen-type copper-catalyzed alkyne-azide cycloaddition, CuAAC) of various gold nanoparticles (AuNP) had systematically proven to be very difficult, tedious, providing low yields with the use of high amounts of copper sulfate+sodium ascorbate the classic Sharpless catalyst, the new catalyst copper(I) (hexabenzyl)tris(2-aminoethyl)amine bromide, {[Cu(I)(Hexabenzyl)Tren]Br} is shown here to be very efficient for the introduction of a large variety of organic, organometallic, dendronic and polymeric molecular fragments of various sizes, topologies and hydrophilicities. Indeed, 0.10.15 equiv. of this catalyst in toluene was used in each reaction under ambient conditions for 8 to 48 h with good yields without AuNP aggregation. The new functional AuNP have been characterized by 1H NMR, IR and UV-vis. (plasmon band) spectroscopy, cyclic voltammetry (CV), dynamic light scattering (DLS) and transmission electron microscopy (TEM).