scholarly journals The dynamics of benzene on Cu(111): a combined helium spin echo and dispersion-corrected DFT study into the diffusion of physisorbed aromatics on metal surfaces

2017 ◽  
Vol 204 ◽  
pp. 471-485 ◽  
Author(s):  
M. Sacchi ◽  
P. Singh ◽  
D. M. Chisnall ◽  
D. J. Ward ◽  
A. P. Jardine ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Spin Echo ◽  
Metallic Surface ◽  
Bravais Lattice ◽  
Binding Interaction ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Lattice Density ◽  
Shed Light

We use helium spin-echo spectroscopy (HeSE) to investigate the dynamics of the diffusion of benzene adsorbed on Cu(111). The results of these measurements show that benzene moves on the surface through an activated jump-diffusion process between the adsorption sites on a Bravais lattice. Density Functional Theory (DFT) calculations with van der Waals (vdW) corrections help us understand that the molecule diffuses by jumping through non-degenerate hollow sites. The results of the calculations shed light on the nature of the binding interaction between this prototypical aromatic molecule and the metallic surface. The highly accurate HeSE experimental data provide a quantitatively stringent benchmark for the vdW correction schemes applied to the DFT calculations and we compare the performances of several dispersion interaction schemes.

Ti-coated BC2N nanotubes as hydrogen storage materials

2013 ◽  
Vol 91 (7) ◽  
pp. 598-604 ◽  
Author(s):  
Seifollah Jalili ◽  
Farzad Molani ◽  
Jeremy Schofield
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Molecular Form ◽  
Hydrogen Storage Materials ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Bc2n Nanotubes

Density functional theory (DFT) calculations have been performed to investigate Ti adsorption on BC2N nanotubes and the hydrogen adsorption capacity of Ti-coated structures. Different adsorption sites have been examined for the Ti adatom, and it is found that the most stable structure has a configuration with alternating columns of carbon and boron–nitrogen hexagons. The DFT calculations indicate that an adsorbed Ti atom on a carbon hexagon can bind four hydrogen molecules in molecular form, while Ti atoms on boron–nitride hexagons can adsorb three hydrogen molecules and two hydrogen atoms. Based on the calculations, the gravimetric efficiency corresponding to decoration of 67% of six carbon rings with Ti adatoms is estimated to be 8 wt %. Computation of the charge transfer reveals that the Ti atom on BC2N is in a cationic state. In addition, Ti adsorption has a significant influence on the electronic structure of the nanotubes and allows for the conversion of nanotubes from semiconductors in the pristine state to conductors upon doping. The interactions between the nanotubes, the Ti atom and hydrogen molecules have also been analyzed using Dewar coordination and Kubas interactions.

scholarly journals Study of the Effect of Absorbed Cu Species on the Surface of Specularite (0 0 1) by the DFT Calculations

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 930
Author(s):  
Mingzhu Huangfu ◽  
Jiaxin Li ◽  
Xi Zhang ◽  
Yiming Hu ◽  
Jiushuai Deng ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Activation Mechanism ◽  
Partial Density ◽  
Adsorption Model ◽  
Activation Effect ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Fe Complexes ◽  
Species Being

Cu2+ exhibited a good activation effect on specularite. However, its microscopic activation mechanism needs further study. Additionally, Cu2+ was mainly present in the flotation solution as Cu2+, Cu(OH)+, and Cu(OH)2 at pH = 7. Therefore, density functional theory (DFT) calculations were used to investigate the effect of Cu species such as Cu2+, Cu(OH)+, and Cu(OH)2 adsorbed on the crystal structure and properties of the specularite (0 0 1) surface. The adsorption mechanism of different Cu components on the surface was also further clarified by the analyses of the adsorption model, adsorption energy, partial density of states (PDOS), charge transfer, and bond properties. In addition, the obtained results are discussed. Based on the obtained results, it can be concluded that the geometric structure and electronic properties on the surface changed after adsorbing Cu components and that the O3–Fe1–O1 structure was more susceptible to the adsorbates. The adsorption engines results show that Cu components could be spontaneously adsorbed onto the specularite (0 0 1) surface with adsorption energies of −0.76, −0.85, and −1.78 eV, corresponding to Cu2+, CuOH+, and Cu(OH)2, respectively. Therefore, the adsorption stability of the Cu species on the specularite surface increased in the order of Cu2+ < Cu(OH)+ < Cu(OH)2. Additionally, the adsorption sites for Cu species on the surface were different. Cu2+ interacted mainly with O atoms on the surface, forming Cu–O complexes, while Cu(OH)+ and Cu(OH)2 acted mainly through the O atom of –OH, interacting with Fe atoms to form Cu–O–Fe complexes. The formation of Cu–O and Cu–O–Fe complexes increased the adsorption sites for sodium oleate, with more hydrophobic species being generated to improve the floatability of specularite.

scholarly journals NMR spectroscopy and ion pairing: Measuring and understanding how ions interact

2009 ◽  
Vol 81 (4) ◽  
pp. 615-633 ◽  
Author(s):  
Paul S. Pregosin
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Density Functional ◽  
Spin Echo ◽  
Ion Pairing ◽  
Functional Theory ◽  
Nmr Data ◽  
Insight Into ◽  
Qualitative Estimation

Pulsed gradient spin-echo (PGSE) diffusion and Overhauser NMR data together with density functional theory (DFT) calculations afford a qualitative estimation of the amount of ion pairing, as well as insight into the structures of a variety of inorganic, organic, and organometallic salts.

γ-Valerolactone-Introduced Controlled-Isomerization of Glucose for Lactic Acid Production over Sn-Beta Catalyst

2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lactic Acid ◽  
Dft Calculations ◽  
Acid Production ◽  
Density Functional ◽  
Lactic Acid Production ◽  
Hydrothermal Conversion ◽  
Functional Theory ◽  
Environment Friendly

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...

Mechanistic understanding of the Cu(i)-catalyzed domino reaction constructing 1-aryl-1,2,3-triazole from electron-rich aryl bromide, alkyne, and sodium azide: a DFT study

2021 ◽  
Author(s):  
Hanlin Gan ◽  
Liang Peng ◽  
Feng Long Gu
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Sodium Azide ◽  
Density Functional ◽  
Dft Study ◽  
Domino Reaction ◽  
Aryl Bromide ◽  
Functional Theory ◽  
Mechanistic Understanding

The mechanism of the Cu(i)-catalyzed domino reaction furnishing 1-aryl-1,2,3-triazole assisted by CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is explored with density functional theory (DFT) calculations.

Graph theory-based reaction pathway searches and DFT calculations for the mechanism studies of free radical-initiated peptide sequencing mass spectrometry (FRIPS MS): a model gas-phase reaction of GGR tri-peptide

2020 ◽  
Vol 22 (9) ◽  
pp. 5057-5069 ◽  
Author(s):  
Jae-ung Lee ◽  
Yeonjoon Kim ◽  
Woo Youn Kim ◽  
Han Bin Oh
Keyword(s):  
Graph Theory ◽  
Dft Calculations ◽  
Gas Phase ◽  
Density Functional ◽  
Reaction Pathway ◽  
Peptide Sequencing ◽  
Phase Reaction ◽  
Functional Theory ◽  
Fragmentation Mechanisms ◽  
Gas Phase Fragmentation

A new approach for elucidating gas-phase fragmentation mechanisms is proposed: graph theory-based reaction pathway searches (ACE-Reaction program) and density functional theory (DFT) calculations.

scholarly journals Density functional theory (DFT) calculations of VI/V reduction potentials of uranyl coordination complexes in non-aqueous solutions

2019 ◽  
Vol 21 (6) ◽  
pp. 3227-3241 ◽  
Author(s):  
Krishnamoorthy Arumugam ◽  
Neil A. Burton
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Aqueous Solutions ◽  
Density Functional ◽  
Coordination Complexes ◽  
Dft Study ◽  
Redox Behavior ◽  
Functional Theory ◽  
Reduction Potentials ◽  
Uranium Complexes

Of particular interest within the +6 uranium complexes is the linear uranyl(vi) cation and it forms numerous coordination complexes in solution and exhibits incongruent redox behavior depending on coordinating ligands. This DFT study predicts VI/V reduction potentials of a range of uranyl(vi) complexes in non-aqueous solutions within ∼0.10−0.20 eV of experiment.

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.

Synthesis, characterization, crystal structure and density functional theory (DFT) calculations of dioxomolybdenum (VI) complexes of an ONS donor ligand derived from benzoylacetone and S-benzyl dithiocarbazate

Polyhedron ◽  
2013 ◽  
Vol 50 (1) ◽  
pp. 602-611 ◽  
Author(s):  
Manashi Chakraborty ◽  
Sathi Roychowdhury ◽  
Nikhil Ranjan Pramanik ◽  
Tapas Kumar Raychaudhuri ◽  
Tapan Kumar Mondal ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Functional Theory ◽  
Donor Ligand

The Pivotal Alkyne Group in the Mutual Size-Conversion of Au9 with Au10 Nanoclusters

2021 ◽  
Author(s):  
Xiaohang Wu ◽  
Ying Lv ◽  
Yuyuan Bai ◽  
Haizhu Yu ◽  
Manzhou Zhu
Keyword(s):  
Density Functional Theory ◽  
Theoretical Model ◽  
Dft Calculations ◽  
Density Functional ◽  
Single Atom ◽  
Functional Theory

Herein, density functional theory (DFT) calculations were performed to elucidate the mechanism of the reversible single atom size conversion between [Au10(DMPP)4(C6H11C≡C)]3+ and [Au9(DMPP)4]3+ (DMPP is 2,2’-bis-(dimethylphosphino)-1,1’-biphenyl, the simplified, theoretical model...

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