Gold Nanoparticles in Organic Capsules: A Supramolecular Assembly of Gold Nanoparticles and Cucurbituril

Abstract

Gold nanoparticles (<or=1 nm) have been encapsulated inside cucurbit[7]uril (CB[7]) by vapor deposition or chemical reduction in aqueous solutions. CB[7] has unique host properties compared with CB[5] and CB[6]. The particle size distribution obtained with CB[5] and CB[6] is similar to that obtained in the absence of CBs and the particles obtained are much too large to be incorporated inside the organic capsules. When gold nanoparticles are prepared inside CB[7] the resulting supramolecular assembly has shape-selective properties for gold interactions with amines, cyanide, and quaternary ammonium ions. Thus, CB[7] has the potential to be used in applications such as selective adsorption, sensing, and catalysis.

From Zeolite to Host-Guest Nanocomposite Materials

“…Therefore, CB[n] macrocycles can be used to stabilize the metal nanoparticles. Corma and co-workers have shown that the size of metal nanoparticles can be controlled by encapsulation in CB [7], which shows unprecedented behavior at stabilizing very small gold nanoparticles [57]. TEM images of gold nanoparticles obtained in the presence and absence of CB are shown in Fig.…”

“…9. TEM images of gold nanoparticles obtained in the absence of CB (top, left) and in the presence of CB [5] (top, right), CB [6] (bottom, left), and CB [7] (bottom, right) [57].…”

Encapsulation of alkyl and aryl derivatives of quaternary ammonium cations within cucurbit[n]uril (n = 6,7) and their inverted diastereomers: density functional investigations

“…A family of cucurbit[n]uril, CB [n], hosts comprising of methylene-bridged glycouril units have attracted considerable attention owing to their potential applications in organic synthesis [1][2][3][4], molecular recognition [5,6], nanoscience [7,8], catalysis [9][10][11], drug delivery vehicles [12] and separation technology [13,14]. The number of glycouril units in cucucrbituril homologues renders varying size to their hydrophobic cavity while portal carbonyl groups on portals provide hydrophilic exterior to these macrocycles.…”

Quantum confinement in PbI2 nanodisks prepared with cucurbit[7]uril

“…8,12,13 Cucurbituril cavities are hydrophobic and can accommodate many guest molecules in a series of inclusion compounds, just like cyclodextrins and calixarenes (see molecular structure in Figure 1). 11 Corma et al 14 have recently synthetized gold nanoparticles using CB cavities as templates, obtaining almost monodisperse particle populations, a very important aspect when one aims at absolute size control. The size control in this level is even more important during the production of quantum dots, since their physical and physicochemical properties are strongly size-and shapedependent.…”