Electron transfer behavior of monolayer protected nanoclusters and nanowires of silver and gold.

Understanding the electron transfer behavior of nanometer sized, both metallic and semiconducting particles and wires is important due to the fundamental interest in size and shape dependent electronic properties and also because of its applications in nano-electronic devices like single electron transistors and molecular switches. Monolayer protected nanoclusters enable one simple and elegant method of synthesis of these types of metallic and semiconducting materials using interfacial chemistry as has been successfully used in several applications ranging from catalysis to molecular electronics. The success of this type of nanostructured materials is due in part to the well known protecting/stabilizing action of the ligands (also known as surface passivating/capping agents), which facilitate the synthesis and processing of these hydrophobic colloids in solution form.

Effect of RuO2 in the shape selectivity of submicron-sized SnO2 structures.

Several dissimilar types of tin oxide microstructures including bipyramids, cubes, and wires synthesized effectively by means of a simple approach were investigated using X-ray diffraction (XRD), thermogravimetry/differential thermometric analysis (TG-DTA), and X-ray photoelectron spectroscopy (XPS). A possible growth mechanism is proposed using the results of these studies. The texture coefficient values of all the structures, indexed to a tetragonal lattice, exhibit amazing variation in the preferred orientation with respect to their shapes.

Temperature-induced phase transitions of the ordered superlattice assembly of Au nanoclusters.

Superlattices of monolayer protected metallic and semiconducting nanoclusters have attracted significant attention due to their promising applications in nanotechnology. In this paper, we investigate the effect of temperature on the ordered superlattice structure of relatively larger sized Au nanoclusters passivated with dodecanethiol [ca. Au1415(RS)328] with the help of in situ temperature controlled X-ray diffraction (XRD) and infrared spectroscopy (IR) in conjunction with thermogravimetric (TG) and differential scanning calorimetric (DSC) analysis.

Investigation of interparticle interactions of larger (4.63 nm) monolayer protected gold clusters during quantized double layer charging.

In this article, the effect of interparticle interactions of 4.63 nm sized monolayer protected gold clusters (Au MPCs) during quantized double layer (QDL) charging has been investigated using electrochemical techniques. Voltammetry and scanning tunneling microscopy have been used to compare their electron transfer behavior.

Wolff rearrangement of alpha-diazoketones using in situ generated silver nanoclusters as electron mediators.

[reaction: see text] We report Wolff rearrangement of alpha-diazoketones by in situ generated silver nanoclusters (Ag(n)(), 2-4 nm) from silver(I) oxide (Ag(2)O) involving a nonclassical electron-transfer process. Our results show that Ag(n)()(+)/Ag(n)()(0) redox couple allows the initial removal of an electron from alpha-diazoketone and its back-donation after chemical reaction(s). Controlled potential coulometry (CPC) of various alpha-diazoketones results in the realization of Wolff-rearranged carboxylic acids in excellent yields.

Single-electron charging features of larger, dodecanethiol-protected gold nanoclusters: electrochemical and scanning tunneling microscopy studies.

In this report, we demonstrate the single-electron charging features of larger-sized (ca. 3.72 nm) Au nanoclusters protected with dodecanethiol [approximate composition, Au1415(RS)328] using combined electrochemical and scanning tunneling microscopic (STM) studies.