Does Hydride Ion Transfer from Silanes to Carbenium Ions Proceed Via a Rate-Determining Formation of a Silicenium Ion or Via a Rate-Determining Electron Transfer? An Ab Initio Quantum Mechanical Study and a Curve-Crossing Analysis

The dehydrogenation of 1,4-dihydronaphthalene by tetrachloro-p-benzoquinone in phenetole solution has been investigated. The present work does not fully confirm earlier studies which report that the reaction follows second-order kinetics and that the hydride ion transfer is rate determining. In the investigations described in this paper second-order kinetics are only observed in the later stages of the reaction and a 1:1 stoichiometry of the reactants in the process is not obtained. Substitution of tritium in the 1,4-positions of the hydrocarbon appears to not significantly affect the reaction rate. The present results indicate that charge-transfer complexes are formed in the reaction and it is suggested that electron transfer within these complexes could be the rate-determining step in the dehydrogenation.

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Ab initio quantum-mechanical study of the effects of the inclusion of iron on thermoelastic and thermodynamic properties of periclase (MgO)

Physics and Chemistry of Minerals ◽

10.1007/s00269-012-0519-7 ◽

2012 ◽

Vol 39 (8) ◽

pp. 649-663 ◽

Cited By ~ 13

Author(s):

Isacco Scanavino ◽

Roman Belousov ◽

Mauro Prencipe

Keyword(s):

Thermodynamic Properties ◽

Ab Initio ◽

Quantum Mechanical ◽

Mechanical Study ◽

Quantum Mechanical Study

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Quantum-Mechanical Study of the Collision Dynamics of O2(3Σg−) + O2(3Σg−) on a New ab Initio Potential Energy Surface†

The Journal of Physical Chemistry A ◽

10.1021/jp905045b ◽

2009 ◽

Vol 113 (52) ◽

pp. 14952-14960 ◽

Cited By ~ 14

Author(s):

Jesús Pérez-Ríos ◽

Massimiliano Bartolomei ◽

José Campos-Martínez ◽

Marta I. Hernández ◽

Ramón Hernández-Lamoneda

Keyword(s):

Potential Energy ◽

Potential Energy Surface ◽

Ab Initio ◽

Energy Surface ◽

Quantum Mechanical ◽

Collision Dynamics ◽

Mechanical Study ◽

Quantum Mechanical Study

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Quantum-Mechanical Assessment of the Energetics of Silver Decahedron Nanoparticles

Nanomaterials ◽

10.3390/nano10040767 ◽

2020 ◽

Vol 10 (4) ◽

pp. 767 ◽

Cited By ~ 1

Author(s):

Svatava Polsterová ◽

Martin Friák ◽

Monika Všianská ◽

Mojmír Šob

Keyword(s):

Ab Initio ◽

Phenomenological Approach ◽

Excess Energy ◽

Quantum Mechanical ◽

Ab Initio Methods ◽

Surface Energies ◽

Mechanical Study ◽

Quantum Mechanical Study ◽

Total Energies ◽

Infinite Planar

We present a quantum-mechanical study of silver decahedral nanoclusters and nanoparticles containing from 1 to 181 atoms in their static atomic configurations corresponding to the minimum of the ab initio computed total energies. Our thermodynamic analysis compares T = 0 K excess energies (without any excitations) obtained from a phenomenological approach, which mostly uses bulk-related properties, with excess energies from ab initio calculations of actual nanoclusters/nanoparticles. The phenomenological thermodynamic modeling employs (i) the bulk reference energy, (ii) surface energies obtained for infinite planar (bulk-related) surfaces and (iii) the bulk atomic volume. We show that it can predict the excess energy (per atom) of nanoclusters/nanoparticles containing as few as 7 atoms with the error lower than 3%. The only information related to the nanoclusters/nanoparticles of interest, which enters the phenomenological modeling, is the number of atoms in the nanocluster/nanoparticle, the shape and the crystallographic orientation(s) of facets. The agreement between both approaches is conditioned by computing the bulk-related properties with the same computational parameters as in the case of the nanoclusters/nanoparticles but, importantly, the phenomenological approach is much less computationally demanding. Our work thus indicates that it is possible to substantially reduce computational demands when computing excess energies of nanoclusters and nanoparticles by ab initio methods.

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