Structural and electronic effects of adsorbed Bi on the metallic atomic chains in Au/Si(111)5 × 2

2021 ◽  
Vol 558 ◽  
pp. 149859
Author(s):  
D.A. Olyanich ◽  
T.V. Utas ◽  
L.V. Bondarenko ◽  
A.Y. Tupchaya ◽  
D.V. Gruznev ◽  
...  
Keyword(s):  
Electronic Effects ◽  
Atomic Chains

scholarly journals Structural and electronic effects of adatoms on metallic atomic chains in Si(111)5 × 2-Au

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Eui Hwan Do ◽  
Se Gab Kwon ◽  
Myung Ho Kang ◽  
Han Woong Yeom
Keyword(s):  
Electronic Effects ◽  
Atomic Chains

Formation and properties of metallic atomic chains and wires

2020 ◽  
Author(s):  
Aleksei G. Syromyatnikov ◽  
Sergei V. Kolesnikov ◽  
Aleksandr M. Saletsky ◽  
Andrey L. Klavsyuk
Keyword(s):  
Atomic Chains

On the Crystal Chemistry of Inorganic Nitrides: Crystal-Chemical Parameters and Opportunities in the Exploration of Their Compositional Space

2020 ◽  
Author(s):  
Olivier Charles Gagné
Keyword(s):  
Functional Properties ◽  
A Priori ◽  
Lone Pair ◽  
Length Variation ◽  
Electronic Effects ◽  
Statistical Knowledge ◽  
Redox Active ◽  
Multiply Bonded ◽  
Jahn Teller ◽  
Compositional Space

The scarcity of nitrogen in Earth’s crust, combined with challenging synthesis, have made inorganic nitrides a relatively-unexplored class of compounds compared to their naturally-abundant oxide counterparts. To facilitate exploration of their compositional space via <i>a priori</i> modeling, and to help <i>a posteriori</i> structure verification not limited to inferring the oxidation state of redox-active cations, we derive a suite of bond-valence parameters and Lewis-acid strength values for 76 cations observed bonding to N<sup>3-</sup>, and further outline a baseline statistical knowledge of bond lengths for these compounds. We examine structural and electronic effects responsible for the functional properties and anomalous bonding behavior of inorganic nitrides, and identify promising venues for exploring uncharted compositional spaces beyond the reach of high-throughput computational methods. We find that many mechanisms of bond-length variation ubiquitous to oxide and oxysalt compounds (e.g., lone-pair stereoactivity, the Jahn-Teller and pseudo Jahn-Teller effects) are similarly pervasive in inorganic nitrides, and are occasionally observed to result in greater distortion magnitude than their oxide counterparts. We identify inorganic nitrides with multiply-bonded metal ions as a promising venue in heterogeneous catalysis, e.g. in the development of a post-Haber-Bosch process proceeding at milder reaction conditions, thus representing further opportunity in the thriving exploration of the functional properties of this emerging class of materials.<br>

scholarly journals Substituent Effects on EI-MS Fragmentation Patterns of 5-Allyloxy-1-aryl-tetrazoles and 4-Allyl-1-aryl-tetrazole-5-ones; Correlation with UV-Induced Fragmentation Channels

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3282
Author(s):  
Alina Secrieru ◽  
Rabah Oumeddour ◽  
Maria L. S. Cristiano
Keyword(s):  
Theoretical Calculations ◽  
Substituent Effects ◽  
Radical Cations ◽  
Electronic Effects ◽  
Diverse Range ◽  
The Matrix ◽  
Electron Impact Mass ◽  
Fragmentation Patterns ◽  
Tetrazole Derivatives ◽  
Impact Mass

1,4- and 1,5-disubstituted tetrazoles possess enriched structures and versatile chemistry, representing a challenge for chemists. In the present work, we unravel the fragmentation patterns of a chemically diverse range of 5-allyloxy-1-aryl-tetrazoles and 4-allyl-1-aryl-tetrazolole-5-ones when subjected to electron impact mass spectrometry (EI-MS) and investigate the correlation with the UV-induced fragmentation channels of the matrix-isolated tetrazole derivatives. Our results indicate that the fragmentation pathways of the selected tetrazoles in EI-MS are highly influenced by the electronic effects induced by substitution. Multiple pathways can be envisaged to explain the mechanisms of fragmentation, frequently awarding common final species, namely arylisocyanate, arylazide, arylnitrene, isocyanic acid and hydrogen azide radical cations, as well as allyl/aryl cations. The identified fragments are consistent with those found in previous investigations concerning the photochemical stability of the same class of molecules. This parallelism showcases a similarity in the behaviour of tetrazoles under EI-MS and UV-irradiation in the inert environment of cryogenic matrices of noble gases, providing efficient tools for reactivity predictions, whether for analytical ends or more in-depth studies. Theoretical calculations provide complementary information to articulate predictions of resulting products.

Steric and Electronic Effects on the Interaction of Xe and Kr with Functionalized Zirconia Metal–Organic Frameworks

2021 ◽  
pp. 504-510
Author(s):  
David C. Fairchild ◽  
Mohammad I. Hossain ◽  
Jesus Cordova ◽  
T. Grant Glover ◽  
Fernando J. Uribe-Romo
Keyword(s):  
Metal Organic Frameworks ◽  
Electronic Effects ◽  
Metal Organic

scholarly journals Topological Atomic Chains on 2D Hybrid Structure

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3289
Author(s):  
Tomasz Kwapiński ◽  
Marcin Kurzyna
Keyword(s):  
Tight Binding ◽  
Wide Band ◽  
Hybrid Structure ◽  
Spectral Density Function ◽  
Hybrid Structures ◽  
Function Technique ◽  
Edge States ◽  
Surface Singularities ◽  
Atomic Chains ◽  
Topological States

Mid-gap 1D topological states and their electronic properties on different 2D hybrid structures are investigated using the tight binding Hamiltonian and the Green’s function technique. There are considered straight armchair-edge and zig-zag Su–Schrieffer–Heeger (SSH) chains coupled with real 2D electrodes which density of states (DOS) are characterized by the van Hove singularities. In this work, it is shown that such 2D substrates substantially influence topological states end evoke strong asymmetry in their on-site energetic structures, as well as essential modifications of the spectral density function (local DOS) along the chain. In the presence of the surface singularities the SSH topological state is split, or it is strongly localized and becomes dispersionless (tends to the atomic limit). Additionally, in the vicinity of the surface DOS edges this state is asymmetrical and consists of a wide bulk part together with a sharp localized peak in its local DOS structure. Different zig-zag and armachair-edge configurations of the chain show the spatial asymmetry in the chain local DOS; thus, topological edge states at both chain ends can appear for different energies. These new effects cannot be observed for ideal wide band limit electrodes but they concern 1D topological states coupled with real 2D hybrid structures.

scholarly journals An Electrochemical Evaluation of Novel Ferrocene Derivatives for Glutamate and Liver Biomarker Biosensing

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 254
Author(s):  
Geok Hong Soon ◽  
Mary Deasy ◽  
Eithne Dempsey
Keyword(s):  
Film Studies ◽  
Redox Potentials ◽  
Signal Loss ◽  
Electronic Effects ◽  
Ferrocene Derivatives ◽  
Electroactive Films ◽  
Glutamate Oxidase ◽  
Electronic Effects Of Substituents ◽  
Glutamyl Transpeptidase

Here, we present an evaluation of two new monosubstituted ferrocene (Fc) derivatives, 3-(1H-pyrrol-1-yl)propanamidoferrocene and 1-hydroxy-2-[2-(thiophen-3-yl)-ethylamino]ethylferrocene, as glutamate oxidase mediators, together with their preparation and characterisation. Taking into consideration the influence of the electronic effects of substituents on the redox potentials of the Fc species, two candidates with pyrrole or thiophene moieties were proposed for investigation. Film studies involved potential sweeping in the presence of pyrrole or 3,4-ethylenedioxythiophene monomers resulting in stable electroactive films with % signal loss upon cycling ranging from 1 to 7.82% and surface coverage (Γ) 0.47–1.15 × 10−9 mol/cm2 for films formed under optimal conditions. Construction of a glutamate oxidase modified electrode resulted in second-generation biosensing with the aid of both cyclic voltammetry and hydrodynamic amperometry, resulting in glutamate sensitivity of 0.86–1.28 μA/mM and Km (app) values over the range 3.67–5.01 mM. A follow-up enzyme assay for liver biomarker γ-glutamyl transpeptidase realised unmediated and mediated measurement establishing reaction and incubation time investigations and a realising response over <100 U/L γ-glutamyl transpeptidase with a sensitivity of 5 nA/UL−1.

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