scholarly journals From Monolayer-Protected Gold Cluster to Monolayer-Protected Gold-Sulfide Cluster: Geometrical and Electronic Structure Evolutions of Au60Sn(SR)36 (n = 0–12)

ACS Omega ◽  
2020 ◽  
Vol 5 (27) ◽  
pp. 16901-16911
Author(s):  
Jing Li ◽  
Pu Wang ◽  
Yong Pei
Keyword(s):  
Electronic Structure ◽  
Gold Cluster ◽  
Gold Sulfide ◽  
Sulfide Cluster

Electronic Structure and Photochemical Properties of a Monolayer-Protected Gold Cluster

2004 ◽  
Vol 108 (32) ◽  
pp. 11904-11908 ◽  
Author(s):  
Katsuyuki Nobusada
Keyword(s):  
Electronic Structure ◽  
Gold Cluster ◽  
Photochemical Properties

scholarly journals Is the largest aqueous gold cluster a superatom complex? Electronic structure & optical response of the structurally determined Au146(p-MBA)57

Nanoscale ◽  
2017 ◽  
Vol 9 (47) ◽  
pp. 18629-18634 ◽  
Author(s):  
Xóchitl López-Lozano ◽  
G. Plascencia-Villa ◽  
G. Calero ◽  
R. L. Whetten ◽  
Hans-Christian Weissker
Keyword(s):  
Electronic Structure ◽  
Gold Cluster ◽  
Optical Response ◽  
The Novel ◽  
Shell Closure ◽  
Electronic Shell ◽  
Novel Structure ◽  
Cluster A

The novel structure-determined Au146(SCH3)57 cluster has no super-atom character, unlike the icosahedral Au144(SCH3)60, and does not derive its stability from an electronic shell closure.

scholarly journals Copper doping of small gold cluster cations: Influence on geometric and electronic structure

2011 ◽  
Vol 135 (22) ◽  
pp. 224305 ◽  
Author(s):  
Sandra M. Lang ◽  
Pieterjan Claes ◽  
Ngo Tuan Cuong ◽  
Minh Tho Nguyen ◽  
Peter Lievens ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Gold Cluster ◽  
Copper Doping ◽  
Small Gold Cluster

scholarly journals From the Superatom to a Large Variety of Supermaterials: A Theoretical Study

2021 ◽  
Author(s):  
◽  
Julia Schacht
Keyword(s):  
Electronic Structure ◽  
Solid State ◽  
Transition Metal ◽  
Gold Cluster ◽  
Functional Materials ◽  
Building Blocks ◽  
Factors Affecting ◽  
Solid State Materials ◽  
The Stability ◽  
The Individual

<p>Metal clusters have been a subject of interdisciplinary research for many years as they act as a bridge between atoms and solid-state materials. In particular, clusters that show distinct thermodynamic stability and unusual atom like behavior, with an electronic shell structure that exhibits a superatomic nature, have attracted considerable attention. The concept of clusters behaving as individual atoms and furthermore mimicking the chemistry of specific elements directly leads to the idea of using those nanoparticles as building blocks for new functional materials. Furthermore, it is interesting that one can change the properties of cluster assembled materials by solely changing the properties of the individual clusters involved.  In this work, various factors affecting superatomic assemblies are identified and critically analyzed within the means of first-principles computations. The icosahedral gold cluster Au₁₃[RS(AuSR)₂]₆ has been chosen as a model system to study the tunability of the electronic structure using single atomic impurities. In this context the doped clusters were found to be tunable such, that they reveal atomic properties, e.g. electron affinities similar to individual halogen atoms. In addition, the choice of ligands protecting the clusters is evaluated regarding the stability of the whole cluster and the involvement of the ligands in creating the superatomic structure. The latter was found to be important when thinking of orbital overlap in superatomic assemblies.  In a next step the knowledge gained is used to investigate cluster-cluster interactions and detect pairs of clusters that are good candidates to create new superatomic materials. Furthermore basic principles regarding cluster assemblies are established and partially tested in an experimental collaboration studing the structure of an Au₉(PPh₃)₈-C₆₀ assembly.  Beyond the investigation of individual gold clusters and gold cluster materials, the electronic structure of binary solid state materials consisting of ligand protected transition metal-chalcogen clusters and fullerenes, as synthesized by Roy et al., is presented. This study shows an intermediate case of non-tunable clusters and furthermore displays the partial loss of the superatomic character of the transition metal chalcogen clusters due to charge transfer.  An experimental collaboration conducted in cooperation with the research group of Prof. Beate Paulus in Berlin proceeds even further and investigates the absorption of water on non-superatomic aluminumoxo fluoride clusters.</p>

scholarly journals From the Superatom to a Large Variety of Supermaterials: A Theoretical Study

2021 ◽  
Author(s):  
◽  
Julia Schacht
Keyword(s):  
Electronic Structure ◽  
Solid State ◽  
Transition Metal ◽  
Gold Cluster ◽  
Functional Materials ◽  
Building Blocks ◽  
Factors Affecting ◽  
Solid State Materials ◽  
The Stability ◽  
The Individual

<p>Metal clusters have been a subject of interdisciplinary research for many years as they act as a bridge between atoms and solid-state materials. In particular, clusters that show distinct thermodynamic stability and unusual atom like behavior, with an electronic shell structure that exhibits a superatomic nature, have attracted considerable attention. The concept of clusters behaving as individual atoms and furthermore mimicking the chemistry of specific elements directly leads to the idea of using those nanoparticles as building blocks for new functional materials. Furthermore, it is interesting that one can change the properties of cluster assembled materials by solely changing the properties of the individual clusters involved.  In this work, various factors affecting superatomic assemblies are identified and critically analyzed within the means of first-principles computations. The icosahedral gold cluster Au₁₃[RS(AuSR)₂]₆ has been chosen as a model system to study the tunability of the electronic structure using single atomic impurities. In this context the doped clusters were found to be tunable such, that they reveal atomic properties, e.g. electron affinities similar to individual halogen atoms. In addition, the choice of ligands protecting the clusters is evaluated regarding the stability of the whole cluster and the involvement of the ligands in creating the superatomic structure. The latter was found to be important when thinking of orbital overlap in superatomic assemblies.  In a next step the knowledge gained is used to investigate cluster-cluster interactions and detect pairs of clusters that are good candidates to create new superatomic materials. Furthermore basic principles regarding cluster assemblies are established and partially tested in an experimental collaboration studing the structure of an Au₉(PPh₃)₈-C₆₀ assembly.  Beyond the investigation of individual gold clusters and gold cluster materials, the electronic structure of binary solid state materials consisting of ligand protected transition metal-chalcogen clusters and fullerenes, as synthesized by Roy et al., is presented. This study shows an intermediate case of non-tunable clusters and furthermore displays the partial loss of the superatomic character of the transition metal chalcogen clusters due to charge transfer.  An experimental collaboration conducted in cooperation with the research group of Prof. Beate Paulus in Berlin proceeds even further and investigates the absorption of water on non-superatomic aluminumoxo fluoride clusters.</p>

EELS Measurement of the Local Electronic Structure of Copper Atoms Segregated to Aluminum Grain Boundaries

1996 ◽  
Vol 54 ◽  
pp. 342-343
Author(s):  
S.J. Splinter ◽  
J. Bruley ◽  
P.E. Batson ◽  
D.A. Smith ◽  
R. Rosenberg
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Thin Layers ◽  
Nominal Composition ◽  
Spatially Resolved ◽  
Service Lifetime ◽  
Heat Treated ◽  
Probe Size ◽  
Local Electronic Structure

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

High-resolution gold labeling

1993 ◽  
Vol 51 ◽  
pp. 330-331
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya ◽  
Kyra Carbone ◽  
Martha Simon ◽  
Beth Lin ◽  
...  
Keyword(s):  
Dihydrofolate Reductase ◽  
Polypeptide Chain ◽  
External Surface ◽  
Gold Cluster ◽  
Macromolecular Complex ◽  
Gold Compound ◽  
Central Cavity ◽  
Chain Folding ◽  
E Coli ◽  
Chaperonin Groel

A recently developed 1.4 nm gold cluster has been found to be useful in labeling macromolecular sites to 1-3 nm resolution. The gold compound is organically derivatized to contain a monofunctional arm for covalent linking to biomolecules. This may be used to mark a specific site on a structure, or to first label a component and then reassemble a multicomponent macromolecular complex. Two examples are given here: the chaperonin groEL and ribosomes.Chaperonins are essential oligomeric complexes that mediate nascent polypeptide chain folding to produce active proteins. The E. coli chaperonin, groEL, has two stacked rings with a central hole ∽6 nm in diameter. The protein dihydrofolate reductase (DHFR) is a small protein that has been used in chain folding experiments, and serves as a model substrate for groEL. By labeling the DHFR with gold, its position with respect to the groEL complex can be followed. In particular, it was sought to determine if DHFR refolds on the external surface of the groEL complex, or whether it interacts in the central cavity.

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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