Adsorption Forms of Water Molecules on Gas-Phase Platinum Clusters Pt3+ Studied by Vibrational Photodissociation Spectroscopy

2019 ◽  
Vol 233 (6) ◽  
pp. 881-894 ◽  
Author(s):  
Fumitaka Mafuné ◽  
Manami Abe ◽  
Satoshi Kudoh
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Gas Phase ◽  
Vibrational Spectra ◽  
Density Functional ◽  
Molecular Form ◽  
Vibrational Excitation ◽  
Water Molecules ◽  
Functional Theory ◽  
Platinum Clusters

Abstract The vibrational spectra of Pt3(H2O)m+ (m = 1–4) cluster were measured in the 3000–3800 cm−1 range via infrared photodissociation (IRPD) spectroscopy. The IRPD spectra were recorded through the photodissociation of Pt3(H2O)m+-Ar (m = 1–3) complexes and Pt3(H2O)4+ cations upon vibrational excitation. The spectra were compared to the vibrational spectra of several stable isomers obtained by density functional theory (DFT) calculations and the adsorption forms of the water molecules were subsequently discussed. The IRPD spectra of all the studied Pt3(H2O)m+ cations exhibited intense peaks at ∼3600 and 3700 cm−1. This suggested that the water molecules mainly adsorb onto the Pt clusters in molecular form and that each molecule binds directly to a Pt atom via its O atom side. For the water-rich Pt3(H2O)4+ cations, all four water molecules were directly bound to the Pt atoms; however, according to the DFT calculations, the fourth H2O molecule could bind to a first-layer water molecule through hydrogen bonding.

A density functional theory study of the hydration of calcium ions confined in the interlayer space of montmorillonites

2014 ◽  
Vol 13 (04) ◽  
pp. 1450028 ◽  
Author(s):  
Zhaoyang Lou ◽  
Houbin Liu ◽  
Yao Zhang ◽  
Yingfeng Meng ◽  
Qun Zeng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Interlayer Space ◽  
Negative Charge ◽  
Internal Surface ◽  
Water Molecules ◽  
Surrounding Water ◽  
Functional Theory ◽  
Internal Surfaces

The structures of Ca2+hydrates in the interlayer space of montmorillonites (MMT) were studied by periodic density functional theory (DFT) calculations under the GGA/PBE approximation. Affected by the internal surfaces, which are rich of negative charge, the Ca2+hydration exhibits different behaviors from that in gas phase. The Ca2+is located at the six-oxygen-ring (SOR) on the internal surface in dry MMT, while the incoming water molecules bind with the Ca2+, the O atoms on surface, and/or with each other. The water molecules have a tendency of forming a hydrogen bond (HB) network that connects the upper and lower surfaces. Attracted by surrounding water molecules, the Ca2+gradually moves outward with increasing number of water molecules. Moreover, the hydration energy (EH) of Ca2+is determined not only by the interaction between Ca2+and H2O , but also by that among Ca2+, H2O and the surfaces. As a result, the EHhas only small changes for additional incoming water molecules, in contrast to the great and monotonic decrease in gas phase.

scholarly journals Inducing molecular isomerization assisted by water

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Dongsheng Wang ◽  
Lei Zhao ◽  
Haiquan Zhao ◽  
Jiazun Wu ◽  
Manfred Wagner ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Water Vapor ◽  
Dft Calculations ◽  
Information Hiding ◽  
Density Functional ◽  
Water Molecules ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Color Switching

Abstract Light is not the only stimulus that can induce linear-to-cyclic isomerization of donor-acceptor Stenhouse adducts (DASAs). Here we demonstrate the water-induced linear-to-cyclic isomerization of DASAs. The mechanism of the water-induced linear-to-cyclic isomerization of DASAs is investigated by density functional theory (DFT) calculations. Water molecules coordinate with DASAs and stabilize the intermediates and cyclic isomers, which favors cyclization thermodynamically. Moreover, the linear-to-cyclic isomerization is reversible. Heating removes the coordinated H2O molecules, which further triggers cyclic-to-linear isomerization. DASAs have been applied in information hiding/displaying and color switching under water vapor and heating control.

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.

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