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.

scholarly journals Revisiting the Zintl‒Klemm Concept for ALn2Ag3Te5-Type Alkaline-Metal (A) Lanthanide (Ln) Silver Tellurides

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 184 ◽  
Author(s):  
Katharina Eickmeier ◽  
Kai Fries ◽  
Fabian Gladisch ◽  
Richard Dronskowski ◽  
Simon Steinberg
Keyword(s):  
Electronic Structures ◽  
Valence Electron ◽  
Alkaline Metal ◽  
Mixed Metal ◽  
Population Analyses ◽  
Structural Preferences ◽  
Valence Electrons ◽  
First Time ◽  
Electron Transfers ◽  
Metal Bonds

Understanding the bonding nature of solids is decisive, as knowledge of the bonding situation for any given material provides valuable information about its structural preferences and physical properties. Although solid-state tellurides are at the forefront of several fields of research, the electronic structures, particularly their nature of bonding, are typically understood by applying the Zintl‒Klemm concept. However, certain tellurides comprise ionic as well as strong (polar) mixed-metal bonds, in obvious contrast to the full valence-electron transfers expected by Zintl‒Klemm’s reasoning. How are the valence-electrons really distributed in tellurides containing ionic as well as mixed-metal bonds? To answer this question, we carried out bonding and Mulliken as well as Löwdin population analyses for the series of ALn2Ag3Te5-type tellurides (A = alkaline-metal; Ln = lanthanide). In addition to the bonding analyses, we provide a brief description of the crystal structure of this particular type of telluride, using the examples of RbLn2Ag3Te5 (Ln = Ho, Er) and CsLn2Ag3Te5 (Ln = La, Ce), which have been determined for the first time.

Towards a Structure-Rsa Relationship for Non-Linear Optical Materials.

1994 ◽  
Vol 374 ◽  
Author(s):  
G. S. Bahra ◽  
J. Griffiths ◽  
W. Healy ◽  
V. Millar ◽  
S. J. Till ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Quantum Chemical ◽  
Optical Materials ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Non Linear ◽  
Chemical Techniques ◽  
Linear Optical ◽  
Semi Empirical

AbstractMeasurements on the reverse saturable absorption (RSA) properties of some polyene dyes are presented. For a series of linear dyes, a correlation is observed between the symmetry of a molecule and its ability to exhibit RSA. To our knowledge, this is the first structure-RSA relationship discovered to date.Certain of these materials have been studied with semi-empirical quantum chemical techniques and the observed structure-RSA relationship is rationalised in terms of the calculated electronic structures. In this paper, we report primarily on some studies we have carried out on the linear dye systems.

scholarly journals Bonding diversity in rock salt-type tellurides: examining the interdependence between chemical bonding and materials properties

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20679-20686
Author(s):  
Jasmin Simons ◽  
Jan Hempelmann ◽  
Kai S. Fries ◽  
Peter C. Müller ◽  
Richard Dronskowski ◽  
...  
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Rock Salt ◽  
Chemical Bonding ◽  
Electronic Structures ◽  
Proper Understanding ◽  
Materials Properties ◽  
Solid State Materials ◽  
Future Technologies

Future technologies are in need of solid-state materials showing the desired chemical and physical properties, and designing such materials requires a proper understanding of their electronic structures.

scholarly journals Revealing the Nature of Chemical Bonding in an ALn2Ag3Te5-Type Alkaline-Metal (A) Lanthanide (Ln) Silver Telluride

Inorganics ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 70 ◽  
Author(s):  
Kai C. Göbgen ◽  
Kai S. Fries ◽  
Fabian C. Gladisch ◽  
Richard Dronskowski ◽  
Simon Steinberg
Keyword(s):  
Crystal Structure ◽  
Electronic Structures ◽  
Quantum Chemical ◽  
Electron Distribution ◽  
Valence Electron ◽  
Alkaline Metal ◽  
Bonding Analysis ◽  
Silver Telluride ◽  
Electron Transfers ◽  
Silver Atoms

Although the electronic structures of several tellurides have been recognized by applying the Zintl-Klemm concept, there are also tellurides whose electronic structures cannot be understood by applications of the aforementioned idea. To probe the appropriateness of the valence-electron transfers as implied by Zintl-Klemm treatments of ALn2Ag3Te5-type tellurides (A = alkaline-metal; Ln = lanthanide), the electronic structure and, furthermore, the bonding situation was prototypically explored for RbPr2Ag3Te5. The crystal structure of that type of telluride is discussed for the examples of RbLn2Ag3Te5 (Ln = Pr, Nd), and it is composed of tunnels which are assembled by the tellurium atoms and enclose the rubidium, lanthanide, and silver atoms, respectively. Even though a Zintl-Klemm treatment of RbPr2Ag3Te5 results in an (electron-precise) valence-electron distribution of (Rb+)(Pr3+)2(Ag+)3(Te2−)5, the bonding analysis based on quantum-chemical means indicates that a full electron transfer as suggested by the Zintl-Klemm approach should be considered with concern.

Improved Sol-Gel Materials for Efficient Solid State Dye Lasers

1993 ◽  
Vol 329 ◽  
Author(s):  
Michael Canva ◽  
Patrick Georges ◽  
Jean-Fran^ois Perelgritz ◽  
Alain Brun ◽  
Fréddric Chaput ◽  
...  
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
Tunable Lasers ◽  
Optical Quality ◽  
Dye Lasers ◽  
Laser Dyes ◽  
Host Matrix ◽  
Host Matrices

AbstractPhotoresistant laser dyes were trapped in silica based xerogel host matrices to obtain solid state tunable lasers. For this purpose very dense xerogel samples with improved chemical and physical properties were prepared at room temperature by the sol-gel technology. The as-prepared materials were polished to obtain optical quality surfaces and were used as new lasing media.Lasing action of such different dyes as rhodamine, perylene and pyrromethene doping dense sol-gel matrices was demonstrated. Efficiencies of 30 % or lifetimes of more than 100,000 shots were achieved with different new ≤dye dopant/host matrix≥ couples. Their different performances are reviewed and discussed.

The Nature of Chemisorbed CO2 in Zeolite A

2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski
Keyword(s):  
Solid State ◽  
Ir Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Surface Coverage ◽  
Gas Mixtures ◽  
Mas Nmr ◽  
Significant Fraction ◽  
Zeolite A

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.

ESR, spectroscopic, and quantum-chemical studies on the electronic structures of complexes formed by Cu(I) with radicals

1986 ◽  
Vol 22 (1) ◽  
pp. 27-33
Author(s):  
N. P. Gritsan ◽  
O. M. Usov ◽  
N. V. Shokhirev ◽  
I. V. Khmelinskii ◽  
V. F. Plyusnin ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Quantum Chemical ◽  
Chemical Studies ◽  
Quantum Chemical Studies
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