Electronic structure of the members of the electron transfer series [NiL]z (z = 3+, 2+, 1+, 0) and [NiL(X)]n (X = Cl, CO, P(OCH3)3) species containing a tetradentate, redox-noninnocent, Schiff base macrocyclic ligand L: an experimental and density functional theoretical study

2010 ◽  
Vol 39 (8) ◽  
pp. 1996 ◽  
Author(s):  
Meenakshi Ghosh ◽  
Thomas Weyhermüller ◽  
Karl Wieghardt
Keyword(s):  
Electron Transfer ◽  
Electronic Structure ◽  
Schiff Base ◽  
Density Functional ◽  
Theoretical Study ◽  
Macrocyclic Ligand ◽  
Redox Noninnocent

Meso-alkynyl corroles and their cobalt(III), manganese(III) and gallium(III) complexes

2020 ◽  
Vol 24 (05n07) ◽  
pp. 737-749
Author(s):  
Michael Haas ◽  
Sabrina Gonglach ◽  
Wolfgang Schöfberger
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Theoretical Study ◽  
Lumo Energy ◽  
Functional Theory ◽  
Energy Gaps ◽  
Peak Broadening ◽  
Homo And Lumo ◽  
Homo Lumo

We report routes towards synthesis of novel [Formula: see text]-conjugated freebase cobalt, copper, gallium and manganese meso-alkynylcorroles. UV-vis spectra show that extensive peak broadening, red shifts, and changes in the oscillator strength of absorptions increase with the extension of [Formula: see text]-conjugation. Using density functional theory (DFT), we have carried out a first theoretical study of the electronic structure of these metallocorroles. Decreased energy gaps of about 0.3–0.4 eV between the HOMO and LUMO orbitals compared to the corresponding copper, gallium and manganese meso-5,10,15 triphenylcorrole are observed. In all cases, the HOMO energies are nearly unperturbed as the [Formula: see text]-conjugation is expanded. The contraction of the HOMO–LUMO energy gaps is attributed to the lowered LUMO energies.

Theoretical study on the electronic structure, mechanical property, and thermal expansion of yttrium oxysulfide

2015 ◽  
Vol 04 (01) ◽  
pp. 1550004
Author(s):  
Ruipeng Gao ◽  
Yefei Li
Keyword(s):  
Mechanical Property ◽  
Thermal Expansion ◽  
Electronic Structure ◽  
Bulk Modulus ◽  
Density Functional ◽  
Theoretical Study ◽  
Spherical Shape ◽  
Weak Anisotropy ◽  
Covalent Bonds ◽  
Very High

The electronic structure, mechanical property and thermal expansion of yttrium oxysulfide are calculated from first-principles using the theory of density functional. The calculated cohesive energy indicates its thermodynamic stable nature. From bond structure, the calculated bandgap is obtained as 2.7 eV; and strong covalent bonds exist between Y and O atoms intra 2D [ Y – O ] layer in material, while relatively weak covalent bonds also exist inter 2D [ Y – O ] layer and S atoms. From simulation, it is found that the bulk modulus is about 119.4 GPa for the elastic constants, and the bulk modulus shows weak anisotropy because the surface contours of them are close to a spherical shape. The calculated B/G clearly implies its ductile nature, and the Y 2 O 2 S phase can also be compressed easily. The temperature dependence of thermal expansions is mainly caused by the restoration of thermal energy due to lattice excitations at low temperature. When the temperature is very high, the thermal expansion coefficient increases linearly with temperature increasing. Meanwhile, the heat capacities are also calculated and discussed by thermal expansion and elasticity.

Theoretical Study of the Electronic Structures of Li-Doped ZnO

2012 ◽  
Vol 535-537 ◽  
pp. 214-218
Author(s):  
Qi Xin Wan ◽  
Jia Yi Chen ◽  
Zhi Hua Xiong ◽  
Dong Mei Li ◽  
Bi Lin Shao ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Formation Energy ◽  
Lattice Distortion ◽  
Theoretical Study ◽  
Functional Theory ◽  
Li Doping ◽  
The Density Functional Theory ◽  
Doped Zno ◽  
Good Agreement

The first-principles with pseudopotentials method based on the density functional theory was applied to calculate the geometric structure, the formation energy of impurities and the electronic structure of Li-doped ZnO. In the system of Li-doped ZnO, LiZn can not result in lattice distortion. In contrast with that case, LiO and Lii result in lattice distortion after Li doping in ZnO. In Li-doped ZnO, LiO is the most unstable than the other cases. Simultaneously, Lii is more stable than LiZn according to that Lii has smaller formation energy. Furthermore, the electronic structure of Li-doped ZnO indicates that that LiZn behaves as acceptor, while Lii behaves as donor. In conclusion, in Li-doped ZnO, Lii is always in the system to compensate the acceptor. Singly doping Li in ZnO is difficult to gain p-ZnO for the self-compensation. The results are in good agreement with other calculated and experimental results.

Characterization and Electronic Structures of Five Members of the Electron Transfer Series [Re(benzene-1,2-dithiolato)3]z(z= 1+, 0, 1−, 2−, 3−): A Spectroscopic and Density Functional Theoretical Study

2009 ◽  
Vol 48 (23) ◽  
pp. 10926-10941 ◽  
Author(s):  
Stephen Sproules ◽  
Flávio Luiz Benedito ◽  
Eckhard Bill ◽  
Thomas Weyhermüller ◽  
Serena DeBeer George ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electronic Structures ◽  
Density Functional ◽  
Theoretical Study

scholarly journals Theoretical study on crystal polymorphism and electronic structure of lead(ii) phthalocyanine using model dimers

RSC Advances ◽  
2017 ◽  
Vol 7 (14) ◽  
pp. 8646-8653 ◽  
Author(s):  
Nobutsugu Hamamoto ◽  
Hiromitsu Sonoda ◽  
Michinori Sumimoto ◽  
Kenji Hori ◽  
Hitoshi Fujimoto
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Theoretical Study ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Crystal Polymorphism ◽  
Small Models

The polymorphism in lead(ii) phthalocyanine solids was discussed with the results of density functional theory calculations using small models.

scholarly journals Unified Mechanistic Understanding of CO2 Reduction to CO on Transition Metal and Single Atom Catalysts

2021 ◽  
Author(s):  
Sudarshan Vijay ◽  
Wen Ju ◽  
Sven Brückner ◽  
Peter Strasser ◽  
Karen Chan
Keyword(s):  
Electron Transfer ◽  
Electronic Structure ◽  
Transition Metal ◽  
Density Functional ◽  
Co2 Reduction ◽  
Electron Transfer Reaction ◽  
Dipole Field ◽  
Single Atom ◽  
Activity Measurements ◽  
Carbon Catalysts

<p>CO is the simplest product from CO<sub>2</sub> electroreduction (CO<sub>2</sub>R), but the identity and nature of its rate limiting step remains controversial. Here we investigate the activity of both transition metals (TMs) and metal-nitrogen doped carbon catalysts (MNCs), and a present unified mechanistic picture of CO<sub>2</sub>R to for both these classes of catalysts. By consideration of the electronic structure through a Newns-Andersen model, we find that on MNCs, like TMs, electron transfer to CO<sub>2</sub><sub> </sub>is facile, such that CO<sub>2</sub> (g) adsorption is driven by adsorbate dipole-field interactions. Using density functional theory with explicit consideration of the interfacial field, we find CO<sub>2</sub> * adsorption to generally be limiting on TMs, while MNCs can be limited by either CO<sub>2</sub>* adsorption or by the proton-electron transfer reaction to form COOH*. We evaluate these computed mechanisms against pH-dependent experimental activity measurements on CO<sub>2</sub>R to CO activity for Au, FeNC, and NiNC. We present a unified activity volcano that, in contrast to previous analyses, includes the decisive CO<sub>2</sub>*<sub> </sub>and COOH* binding strengths as well as the critical adsorbate dipole-field interactions. We furthermore show that MNC catalysts are tunable towards higher activity away from transition metal scaling, due to the stabilization of larger dipoles resulting from their discrete and narrow <i>d</i>-states. The analysis suggests two design principles for ideal catalysts: moderate CO<sub>2</sub>* and COOH* binding strengths as well as large dipoles on the CO<sub>2</sub>*<sub> </sub>intermediate. We suggest that these principles can be exploited in materials with similar electronic structure to MNCs, such as supported single-atom catalysts, molecules, and nanoclusters, 2D materials, and ionic compounds towards higher CO<sub>2</sub>R activity. This work captures the decisive impact of adsorbate dipole-field interactions in CO<sub>2</sub>R to CO and paves the way for computational-guided design of new catalysts for this reaction.</p>

scholarly journals New Cerium (III) Complex of Schiff Base (E)-N-Benzylidene-4-Methoxyaniline: Synthesis and Density Functional Theoretical Study of Vibrational Spectra

2016 ◽  
Vol 32 (2) ◽  
pp. 903-919
Author(s):  
Imanelakehal Imanelakehal ◽  
Farhihalamia Farhihalamia ◽  
Saoussenlakehal Saoussenlakehal ◽  
Abbas Boukhari ◽  
Abdelha Fiddjerourou
Keyword(s):  
Schiff Base ◽  
Vibrational Spectra ◽  
Density Functional ◽  
Theoretical Study

Density functional theoretical study of the electronic structure and vibrational spectra of a polynuclear [Mg2(MeOH)4Mo8O22(OMe)6]2− complex

2008 ◽  
Vol 18 (3) ◽  
pp. 128-130 ◽  
Author(s):  
Tatyana A. Savinykh ◽  
Alexander F. Shestakov ◽  
Nadezhda V. Bardina ◽  
Tamara A. Bazhenova ◽  
Yurii M. Shulga
Keyword(s):  
Electronic Structure ◽  
Vibrational Spectra ◽  
Density Functional ◽  
Theoretical Study
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