scholarly journals Temperature dependent chiroptical response of sigmoidal gold clusters: probing the stability of chiral metal clusters

2018 ◽  
Vol 9 (25) ◽  
pp. 5614-5622 ◽  
Author(s):  
Ping Guo ◽  
Biao Yang ◽  
Li Zhang ◽  
Liang Zhao
Keyword(s):  
Metal Clusters ◽  
Gold Cluster ◽  
Gold Clusters ◽  
Cluster Compounds ◽  
Structural Factors ◽  
Temperature Dependent ◽  
Cluster Stability ◽  
The Stability

Three chiral gold cluster compounds are herein selected to probe how structural factors influence the cluster stability upon heating.

Gold Cluster Crystals

2000 ◽  
Vol 6 (S2) ◽  
pp. 326-327
Author(s):  
J.F. Hainfeld ◽  
R.D. Powell ◽  
F.R. Furuya ◽  
J.S. Wall
Keyword(s):  
Metal Ion ◽  
Gold Cluster ◽  
Gel Filtration ◽  
Size Variation ◽  
Gold Clusters ◽  
Cluster Compounds ◽  
Statistical Process ◽  
3 Dimensional ◽  
X Ray Crystallography ◽  
Gold Compounds

Gold clusters are gold compounds with a core of gold atoms and organic groups covalently bound to the surface gold atoms. An example is undecagold, Au11(P(C6H5)3)7, whose structure was solved by x-ray crystallography using 3-dimensional crystals. These differ from colloidal gold, which are suspensions of metal particles, usually formed by metal ion reduction; although the particles may be approximately the same size, they vary due to the statistical process of formation. Gold clusters are compounds with a definite formula, and should all be perfectly identical. However, it is known that there is a family of stable gold cluster compounds, such as Au6, Au11, Au13, AU55, Au67, etc. In a given preparation of gold clusters, there is usually some mixture of these, thus leading to some size variation. Methods such as gel filtration column chromatography and ultrafiltration can be used to separate most of these species, so that relatively pure preparations may be achieved.

Structure of Small Gold Clusters with Si Doping Using DFT (AunSi, n=1-10, 19)

2013 ◽  
Vol 24 ◽  
pp. 203-212 ◽  
Author(s):  
Priyanka ◽  
Sumali Bansal ◽  
Keya Dharamvir
Keyword(s):  
Density Functional ◽  
Gold Cluster ◽  
Chemical Reactivity ◽  
Gold Clusters ◽  
Functional Theory ◽  
Si Doped ◽  
Silicon Doped ◽  
The Stability ◽  
Almost All ◽  
Homo Lumo

The structures of silicon doped gold clusters AunSi (n = 1-10 and 19) have been investigated using first principle calculations based on density functional theory (DFT). Calculations indicate that the stability of a gold cluster increases with the introduction of a Si atom. In all the low lying geometries, Si prefers peripheral positions. For every ground state configuration with n > 3 (n = 6 and 9 being exceptions) Si has tetra-coordination. In almost all of the tetra coordinated geometries the coordination unit including Si, is in the form of a square pyramid with gold atoms forming the square base. Electronic properties such as HOMO-LUMO gap, ionization potential and electron affinity have also been calculated and support the relative stability of clusters with even n. The study of Au20 cage doped with Si atom has been done .Similar to smaller Si doped gold clusters; the Si atom prefers an exohedral position. The doping of Si atom has enhanced the stability and chemical reactivity of Au20 cluster.

Studies of the Chemical Properties of Size Selected Metal Clusters: Kinetics and Saturation

1990 ◽  
Vol 206 ◽  
Author(s):  
Donald M. Cox ◽  
Robert O. Brickman ◽  
Kathleen Creegan ◽  
Andrew Kaldor
Keyword(s):  
Metal Clusters ◽  
Gold Cluster ◽  
Chemical Properties ◽  
Gold Clusters ◽  
Transition Metal Clusters ◽  
Experimental Conditions ◽  
Au Clusters ◽  
Hydrogen Deuterium ◽  
Small N ◽  
Small Clusters

ABSTRACTOur studies of small (n=2−40) gas phase transition metal clusters (cations, neutrals and anions) have revealed a number of size-dependent chemical and physical properties. This paper will discuss results involving activated dissociative molecular chemisorption of hydrogen (deuterium) and small alkanes on cationic, neutral and anionic platinum and gold clusters. For example, we have yet to find any size gold cluster anion to exhibit measurable reactivity towards di-deuterium, but reactivity is observed on small (n<15) gold cations and very small (n<9) neutral gold clusters. Methane or ethane chemisorption occurs most readily only on small Pt and Au cluster cations and least rapidly, if at all, on cluster anions. The larger Pt and Au clusters are found to be non-reactive towards the alkanes under our experimental conditions.At the other extreme, at steady state, small clusters of Pt, Rh, Ni, Pd, V, Nb, and Ta are hydrogen “rich” exhibiting H/M stoichiometrics >> 1. These results are consistent with a limited data base on supported clsutes obtained via EXAFS measurements and have important implications for catalytic reactions involving hydrogen and light hydrocarbons.

scholarly journals Gold cluster compounds

Gold Bulletin ◽  
1984 ◽  
Vol 17 (1) ◽  
pp. 5-12 ◽  
Author(s):  
D. Michael P. Mingos
Keyword(s):  
Gold Cluster ◽  
Cluster Compounds

Observing the real time formation of phosphine-ligated gold clusters by electrospray ionization mass spectrometry

2017 ◽  
Vol 19 (26) ◽  
pp. 17187-17198 ◽  
Author(s):  
Marshall R. Ligare ◽  
Grant E. Johnson ◽  
Julia Laskin
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Real Time ◽  
Electrospray Ionization Mass Spectrometry ◽  
Gold Cluster ◽  
Gold Clusters ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Real Time Monitoring ◽  
The Real

Real-time monitoring of the gold cluster synthesis by electrospray ionization mass spectrometry reveals distinct formation pathways for Au8, Au9 and Au10 clusters.

Optimizing molecule-like gold clusters for light energy conversion

2016 ◽  
Vol 4 (6) ◽  
pp. 2075-2081 ◽  
Author(s):  
Kevin G. Stamplecoskie ◽  
Abigail Swint
Keyword(s):  
Excited State ◽  
Energy Conversion ◽  
Metal Clusters ◽  
Light Harvesting ◽  
Photovoltaic Performance ◽  
Gold Clusters ◽  
Light Energy ◽  
Light Energy Conversion

As light harvesting materials, Au18SR14 metal clusters are highlighted for their favourable excited-state properties leading to better photovoltaic performance.

Temperature-Dependent Mechanical Stability of Retained Austenite in Thermomechanically Processed 3Mn Steel

2021 ◽  
Vol 1016 ◽  
pp. 762-767
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański
Keyword(s):  
Retained Austenite ◽  
Mechanical Stability ◽  
Electron Backscatter Diffraction ◽  
Tensile Tests ◽  
Trip Effect ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Static Tensile ◽  
The Stability ◽  
Backscatter Diffraction

The temperature-dependent mechanical stability of retained austenite in medium-Mn transformation induced plasticity 0.17C-3.3Mn-1.6Al-1.7Al-0.22Si-0.23Mo thermomechanically processed steel was investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) methods. Specimens were deformed up to rupture in static tensile tests in a temperature range 20–200°C. It was found that deformation temperature affects significantly the intensity of TRIP effect. In case of specimens deformed at temperatures higher than 60°C, a gradual temperature-related decrease in the stability of γ phase was noted. It indicates a progressive decrease of the significance of the TRIP effect and at the same time the growing importance of the thermally activated processes affecting a thermal stability of retained austenite.

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