Car-Parrinello Density Functional Calculations of the Bond Rupture Process of Thiolate on Gold in AFM Measurements: Progress and First Results

2001 ◽  
pp. 257-272
Author(s):  
Daniel Krüger ◽  
Roger Rousseau ◽  
Dominik Marx ◽  
Harald Fuchs ◽  
Michele Parrinello
Keyword(s):  
Density Functional Calculations ◽  
Density Functional ◽  
Rupture Process ◽  
Bond Rupture ◽  
First Results

Density Functional Calculations of EPR Parameter g Tensors of Some Transition Metal Complexes

2011 ◽  
Vol 2 (2) ◽  
pp. 139-141
Author(s):  
Vinita Prajapati ◽  
◽  
P.L.Verma P.L.Verma ◽  
Dhirendra Prajapati ◽  
B.K.Gupta B.K.Gupta
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Density Functional Calculations ◽  
Density Functional

scholarly journals On the Effects of Doping on the Catalytic Performance of (La,Sr)CoO3. A DFT Study of CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Antonella Glisenti ◽  
Andrea Vittadini
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Formation Energy ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Energy Profiles ◽  
High Concentrations ◽  
3D Impurities

The effects of modifying the composition of LaCoO3 on the catalytic activity are predicted by density functional calculations. Partially replacing La by Sr ions has benefical effects, causing a lowering of the formation energy of O vacancies. In contrast to that, doping at the Co site is less effective, as only 3d impurities heavier than Co are able to stabilize vacancies at high concentrations. The comparison of the energy profiles for CO oxidation of undoped and of Ni-, Cu-m and Zn-doped (La,Sr)CoO3(100) surface shows that Cu is most effective. However, the effects are less spectacular than in the SrTiO3 case, due to the different energetics for the formation of oxygen vacancies in the two hosts.

On tungstates of divalent cations (III) – Pb5O2[WO6]

2020 ◽  
Vol 235 (8-9) ◽  
pp. 311-317
Author(s):  
Stephan G. Jantz ◽  
Florian Pielnhofer ◽  
Henning A. Höppe
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Quantum Chemical ◽  
Density Functional ◽  
Divalent Cations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
First Results ◽  
Electrostatic Calculations

Abstract${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ was discovered as a frequently observed side phase during our investigation on lead tungstates. Its crystal structure was solved by single-crystal X-ray diffraction ($P{2}_{1}/n$, $a=7.4379\left(2\right)$ Å, $b=12.1115\left(4\right)$ Å, $c=10.6171\left(3\right)$ Å, $\beta =90.6847\left(8\right)$°, $Z=4$, ${R}_{\text{int}}=0.038$, ${R}_{1}=0.020$, $\omega {R}_{2}=0.029$, 4188 data, 128 param.) and is isotypic with ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{Te}}_{6}\right]$. ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ comprises a layered structure built up by non-condensed [WO6]${}^{6-}$ octahedra and ${\left[{\text{O}}_{4}{\text{Pb}}_{10}\right]}^{12+}$ oligomers. The compound was characterised by spectroscopic measurements (Infrared (IR), Raman and Ultraviolet–visible (UV/Vis) spectra) as well as quantum chemical and electrostatic calculations (density functional theory (DFT), MAPLE) yielding a band gap of 2.9 eV fitting well with the optical one of 2.8 eV. An estimation of the refractive index based on the Gladstone-Dale relationship yielded $n\approx 2.31$. Furthermore first results of the thermal analysis are presented.

scholarly journals Iron(II) complexes of dimethyltriazacyclophane

2018 ◽  
Vol 74 (12) ◽  
pp. 1641-1649
Author(s):  
Wei-Tsung Lee ◽  
Matthias Zeller ◽  
David Upp ◽  
Yuliya Politanska ◽  
Doug Steinman ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Dft Calculations ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Coordination Mode ◽  
Functional Theory ◽  
Metal Centers ◽  
Bonding Interaction

Treatment of the ortho-triazacyclophane 1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-triene [(C6H5)3(NH)(NCH3)2, L1] with Fe[N(SiMe3)2]2 yields the dimeric iron(II) complex bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)bis[(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)iron(II)], [Fe(C20H18N3)4] or Fe2(L1)4 (9). Dissolution of 9 in tetrahydrofuran (THF) results in solvation by two THF ligands and the formation of a simpler monoiron complex, namely bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido-κN 7)bis(tetrahydrofuran-κO)iron(II), [Fe(C20H18N3)2(C4H8O)2] or (L1)2Fe(THF)2 (10). The reaction is reversible and 10 reverts in vacuo to diiron complex 9. In the structures of both 9 and 10, the monoanionic triazacyclophane ligand L1− is observed in only the less-symmetric saddle conformation. No bowl-shaped crown conformers are observed in the solid state, thus preventing chelating κ3-coordination to the metal as had been proposed earlier based on density functional theory (DFT) calculations. Instead, the L1− ligands are bound in either a η2-chelating fashion through the amide and one amine donor (for one of the four ligands of 9), or solely through their amide N atoms in an even simpler monodentate η1-coordination mode. Density functional calculations on dimer 9 revealed nearly full cationic charges on each Fe atom and no bonding interaction between the two metal centers, consistent with the relatively long Fe...Fe distance of 2.912 (1) Å observed in the solid state.

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