Search

The structures of neutral and anionic gold-silver binary clusters and pure gold and silver clusters are investigated. It is shown that the calculated electronic properties and dissociation energy of both pure and binary clusters are in agreement with the available experimental data.

The growth and the simulation of structures produced by a combination of evaporation and lithography are reported. Quasi-one-dimensional (quasi-1D) and one-dimensional structures in which the gold islands are arranged in a single row where the lateral size is only a few nanometers are created with this method.

Various classical molecular dynamics computer simulations are employed to investigate the dealloying effects caused by the centrifugal forces in the rotating multicomponent liquid CuAu nanoclusters. The results of the analysis shows that the fluctuations occurring during the rotation highly counteract the dealloying effects of the system by mixing the constituents properly, leading to a stationary state in the system.

Triangular Au and disk-shaped Au-Cu alloy nanocrystals are prepared in thin SiO2 film matrixes, by sol-gel spin-coating followed by annealing at 800 degree C in 10%H2-90%Ar. The transmission electron microscope images bring out evidence of the shapes of the embedded nanocrystals.

Fuel-free magnetically driven propulsion of flexible Au/Ag/Ni nanowires, with a gold ' head' and nickel ' tail' , linked by a partially dissolved and weakened silver bridge, is presented. The new magnetic nanowire swimmers are prepared in large scale using a simple template electrodeposition protocol and have offered considerable promise for diverse practical applications.

An autoprogrammed synthesis of unique Au@Pd@Pt triple-layered core-shell structured nanoparticles consisting of an Au core, Pd inner layer and nanoporous Pt outer shell is described. The synthesis has used the temporal separations of the depositions of Au, Pd, and Pt that has afforded step-by-step formation of triple-layered core-shell colloids.

A combination of the x-ray emission spectroscopy and atomic force microscopy techniques is employed to explain the chemical interaction taking place between the Au/VIA/V layer structure and the n-AlN epilayers. The interaction mechanism employed in the system is also analyzed.

The transmission electron microscopy and associated analytical techniques are applied to determine the microstructure of AuNiAlTi/[Al.sub.0.84][In.sub.0.16]N/AlN/GaN Ohmic contacts annealed from 700 to 900 degree [Celsius]. The formation of TiN contact inclusions that had penetrated through the AlInN layers into the GaN layers underneath are found to act as a conduction path between the metal contacts and the two-dimensional electron gas of heterojunction field-effect transistor devices.

Octahedral core-shell nanoparticles are prepared by a one-step aqueous synthesis method where both metal precursors are present simultaneously by using cetyltrimethylammonium chloride as both reductant and stabilizer.

The mechanisms involved in the Au[X.sub.3]-mediated selective head-to-head dimerization of difluoropropargyl amides are discussed. The results show that the formation of these amides can be easily rationalized by the reductive elimination of the divinylgold species.

The synthesis and magnetic properties of multifunctional CoPtAu alloy nanoparticles of three compositions by a modified polyol process are described. The x-ray diffraction and transmission electron microscopy analyses have shown the formation of the alloy nanostructure comprising Au-rich and Pt-rich nanophases, with a narrow distribution of particle sizes and have provided the structural arrangements.

Complex ac susceptibility measurements are described on composite Au-[Fe.sub.3][O.sub.4] nanoparticles of two different configurations, 'dumbbell' and 'flower' configurations. The Neel-Arrhenius model has failed to describe the blocking behavior of both types of particles and the Vogel-Fulcher model has fit the dumbbell particles indicating the importance of weak interparticle interactions in the system.

Dumbbell-like Au-[Fe.sub.3][O.sub.4] nanoparticles (NPs) are made and coupled with Herceptin and a platin complex. The studies have shown that the dumbbell-like Au-[Fe.sub.3][O.sub.4] NPs are promising nanocarriers for highly sensitive diagnostic and therapeutic applications.

The synthesis and structural characterization of the first cyanoaurate-based organotin polymer [Me.sub.3]Sn[Au[(CN).sub.2]] displaying unusual ion-exchange properties are described. A series of metal-exchange experiments are performed in which the polymer is soaked in aqueous solutions of bivalent transition-metal cations.

The results of liquid diffusion microgravity an experiment using a Pd 1 wt % gold alloy is compared to estimates derived from molecular dynamics simulations and several Enskog hard sphere corrected expressions for the diffusion coefficient. The results obtained provide insight into the transient g-perturbations, called 'g-jitter', resulting from vibration of the space platform.

The different ways in which selectivity can be controlled in homogenous Au catalysis are discussed. Several ligand classes have emerged as privileged structures for Au-mediated reactions and some guidelines are provided for Au-catalyzed reactions.

The article demonstrates the theoretical prediction of a face-fused bi-icosahedral [Au.sub.23] structure as the Au core of the thiolate-protected [Au.sub.38] cluster. The Au:Sr clusters are shown to exhibit a modest optical gap and an excellent stability, as compared to the other clusters.

The synthesis, structural characterization, and molecular studies of a series of structurally diverse gold and silver complexes ranging from large 12-membered macrometallacycles [[(NHC).sub.2][M.sub.2] to ionic [(NHC).sub.2][M.sup.+][Cl.sup.-] (M = Au, Ag) type complexes are reported. The complexes were obtained by modification of the N-substituent of a functionalized sidearm of the N-heterocyclic carbene ligand.

[Au[{C[(NHMe).sub.2]}.sub.2](As[F.sub.6]) has formed colorless crystals that have displayed a blue or green luminescence, depending on the crystallization conditions. The blue-glowing crystals have ordered stacks of cations with some variation in structural arrangement, whereas the green-glowing crystals have disorder in their stacking pattern.

Photoelectron spectroscopy and low energy electron diffraction are used for examining the thermal behavior of the Au/c-[Si.sub.3][N.sub.4]/Si(111) interface. The comparison of the spectra has revealed that the Au-Si reaction has occurred in the silicon matrix and on top of the nitride layer, due to silicon atom segregation.

Effective synthetic routes are developed for peripherally substituted bis-gold(III) hexaphyrins starting from [26]hexaphyrin(1.1.1.1.1.1). Reversible aromatic-to-antiaromatic changes of hexaphyrin bis-gold(III) complexes upon two-electron reduction and oxidation have quantified the affect of the aromaticity upon two-photon absorption (TPA) value.