Activation and Transformation of Ethane by Au2 VO3 + Clusters with Closed-Shell Electronic Structures

2015 ◽  
Vol 22 (5) ◽  
pp. 1825-1830 ◽  
Author(s):  
Ya-Ke Li ◽  
Zi-Yu Li ◽  
Yan-Xia Zhao ◽  
Qing-Yu Liu ◽  
Jing-Heng Meng ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Closed Shell

scholarly journals Methane activation by gold-doped titanium oxide cluster anions with closed-shell electronic structures

2016 ◽  
Vol 7 (7) ◽  
pp. 4730-4735 ◽  
Author(s):  
Yan-Xia Zhao ◽  
Xiao-Na Li ◽  
Zhen Yuan ◽  
Qing-Yu Liu ◽  
Qiang Shi ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Electronic Structures ◽  
Active Sites ◽  
Closed Shell ◽  
Methane Activation ◽  
Cluster Anions ◽  
Oxide Cluster

The complementary active sites of Au+ and O2− ions on gold-doped titanium oxide clusters activate methane under thermal collision conditions.

scholarly journals A Coloring Study of the Ga Richest Alkali Gallides: New In- and Hg-Containing Gallides with the RbGa7- and the K3Ga13-Type Structure

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1052
Author(s):  
Martha Falk ◽  
Marco Wendorff ◽  
Caroline Röhr
Keyword(s):  
Fermi Level ◽  
Chemical Bonding ◽  
Electronic Structures ◽  
Alkali Metals ◽  
Closed Shell ◽  
Cluster Compounds ◽  
Partial Substitution ◽  
Powder Form ◽  
Site Specific ◽  
Potassium Compound

The Ga-rich gallides of the alkali metals present an interesting, yet still scarcely investigated case of polyanionic cluster compounds with subtle variations in the character of their chemical bonding. In the present work, the Ga richest phases K3Ga13, RbGa7, and CsGa7, which are formally electron-precise Zintl/Wade cluster compounds, are systematically studied with respect to a partial substitution of Ga by In and Hg. The pure hepta-gallides AGa7 (A = Rb/Cs; R3¯m), which were formerly obtained from Ga-rich melts in powder form only, were crystallized from Hg-rich melts. Herein, up to 9.9/13.6% (Rb/Cs) of Ga could be substituted by In, which partly takes the four-bonded [M2] dumbbells connecting layers of Ga-icosahedra. Even though the structures are electron precise, the pseudo band gap does not coincide with the Fermi level. In the most Ga-rich potassium compound K3Ga13 (Cmcm) only 1.2% of In and 2.7% of Hg could be incorporated. Although Rb3Ga13 remains unknown, ternary variants containing 5.2 to 8.2% In could be obtained; this structure is also stabilized by a small Hg-proportion. The likewise closed-shell 3D polyanion consists of all-exo-bonded Ga-icosahedra and closo [Ga11] clusters, which are connected by two tetrahedrally four-bonded Ga− and a trigonal-planar three-bonded Ga0. The aspects of the electronic structures and the site-specific Ga↦Hg/In substitution in the polyanion (“coloring”) are discussed for the title compounds and other mixed Ga/In trielides.

Electronic structures and spectral properties of double- and triple-decker phthalocyanine complexes in a localized molecular orbital view

2001 ◽  
Vol 05 (01) ◽  
pp. 87-101 ◽  
Author(s):  
NAOTO ISHIKAWA
Keyword(s):  
Molecular Orbital ◽  
Electronic Spectra ◽  
Electronic Structures ◽  
Closed Shell ◽  
Spectroscopic Properties ◽  
Excitation Energies ◽  
Absorption Bands ◽  
Near Ir ◽  
Resonance Band ◽  
Ir Bands

This paper reviews the studies on the electronic structures and spectroscopic properties of sandwich-type complexes M ( Pc )2 and M 2( Pc )3. The subjects discussed are as follows. (1) Electronic spectra of closed-shell Pc dimers and trimers. The complexes with closed-shell systems, such as [ Lu ( Pc )2]−, Sn ( Pc )2 and Lu 2( Pc )3, can be thought of as stacked systems composed only of Pc 2−. The excited states of these complexes can be described by locally excited and charge transfer configurations. The coupling terms of the configurations are written using orbitals localized on each Pc ring. Assignments of the observed absorption bands are discussed. Computational studies on the band assignments were carried out using a localized molecular orbital (LO) basis which maximizes orbital populations on one of the Pc rings. (2) Electronic structures of πelectron-deficient Pc dimers and trimers. Oxidation of [ Lu ( Pc )2]− or Lu 2( Pc )3 yields systems with π-electron deficiency or π-hole(s) residing on multiple Pc sites. The delocalized nature of the π-hole in Lu ( Pc )2 is elucidated by comparison of the electronic spectra of symmetric and asymmetric dimers composed of Pc and Nc ( H 2 Nc ≡ naphthalocyanine ). The band assignments of the dimer radicals are discussed. The Pc trimer radical shows an intense absorption band at about 5000 cm−1, which is 2000 cm−1 lower than the valence resonance band of Lu ( Pc )2. The two-electron-deficient complexes [ Lu ( Pc )2]+ and [ Lu 2( Pc )3]2+ also show intense near-IR bands at higher energy than the corresponding monoradical species. The interactions that determine the excitation energies of the near-IR bands of the π-electron-deficient species are elucidated.

scholarly journals Probing the Validity of the Zintl−Klemm Concept for Alkaline-Metal Copper Tellurides by Means of Quantum-Chemical Techniques

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2178 ◽  
Author(s):  
Sabrina Smid ◽  
Simon Steinberg
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Electronic Structures ◽  
Quantum Chemical ◽  
Closed Shell ◽  
Alkaline Metal ◽  
Crystal Orbital ◽  
Structural Preferences ◽  
Valence Electrons ◽  
Chemical Techniques

Understanding the nature of bonding in solid-state materials is of great interest for their designs, because the bonding nature influences the structural preferences and chemical as well as physical properties of solids. In the cases of tellurides, the distributions of valence-electrons are typically described by applying the Zintl−Klemm concept. Yet, do these Zintl−Klemm treatments provide adequate pictures that help us understanding the bonding nature in tellurides? To answer this question, we followed up with quantum-chemical examinations on the electronic structures and the bonding nature of three alkaline-metal copper tellurides, i.e., NaCu3Te2, K2Cu2Te5, and K2Cu5Te5. In doing so, we accordingly probed the validity of the Zintl−Klemm concept for these ternary tellurides, based on analyses of the respective projected crystal orbital Hamilton populations (−pCOHP) and Mulliken as well as Löwdin charges. Since all of the inspected tellurides are expected to comprise Cu−Cu interactions, we also paid particular attention to the possible presence of closed-shell interactions.

The Nature of Oxide Surfaces: Topographic and Electronic Structure

1993 ◽  
Vol 51 ◽  
pp. 966-967
Author(s):  
Dawn A. Bonnell ◽  
Yong Liang
Keyword(s):  
Transition Metal Oxides ◽  
Electronic Structures ◽  
Recent Progress ◽  
Spatial Localization ◽  
Level Of Detail ◽  
Scanning Tunneling ◽  
Oxide Surfaces ◽  
Tunneling Microscopy ◽  
Considerable Effort ◽  
Complete Understanding

Recent progress in the application of scanning tunneling microscopy (STM) and tunneling spectroscopy (STS) to oxide surfaces has allowed issues of image formation mechanism and spatial resolution limitations to be addressed. As the STM analyses of oxide surfaces continues, it is becoming clear that the geometric and electronic structures of these surfaces are intrinsically complex. Since STM requires conductivity, the oxides in question are transition metal oxides that accommodate aliovalent dopants or nonstoichiometry to produce mobile carriers. To date, considerable effort has been directed toward probing the structures and reactivities of ZnO polar and nonpolar surfaces, TiO2 (110) and (001) surfaces and the SrTiO3 (001) surface, with a view towards integrating these results with the vast amount of previous surface analysis (LEED and photoemission) to build a more complete understanding of these surfaces. However, the spatial localization of the STM/STS provides a level of detail that leads to conclusions somewhat different from those made earlier.

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