Theoretical Determination of Enthalpies of Formation of Benzyloxy, Benzylperoxy, Hydroxyphenyl Radicals and Related Species in the Reaction of Toluene with the Hydroxyl Radical

2018 ◽  
Author(s):  
Oscar Ventura ◽  
Martina Kieninger ◽  
Zoi Salta ◽  
Agnie M. Kosmas
Keyword(s):  
Related Species ◽  
Theoretical Data ◽  
Closed Shell ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
Phenyl Radical ◽  
Theoretical Determination ◽  
Isodesmic Reactions ◽  
Benzyl Radical

<p>Reaction of toluene (T) with HO<sup>●</sup> produces addition products and the benzyl radical (TR). TR can react with HO<sup>●</sup> or O<sub>2</sub> to produce oxygenated species, for many of which there is no experimental information. We present here theoretically determined heats of formation (HFs) of 17 such species using non-isodesmic reactions of TR+O<sub>2</sub> and T+HO<sup>●</sup>+O<sub>2</sub>. For experimentally known HFs, we obtained a reasonable correlation between experimental and theoretical data for G4 (r2=0.999) and M06/cc-pVQZ (r2=0.997) results. Previously unknown HFs of other radicals (benzyloxy, spiro [1,2-dioxetane benzyl], hydroxyphenyl, and benzylperoxy) and closed shell species (salicylic alcohol, benzo[b]oxetane and p-hydroxy cyclohexa-2,5-dienone) were calculated using these methods. The species studied and the enthalpies of formation obtained were: salycilic alcohol, -69.7 ± 3.4 kcal/mol; benzyloxy radical, 28.4 ± 3.4 kcal/mol; hydroxyphenyl radical, 37.3 ± 3.4 kcal/mol; benzo[b]oxetane, 23.7 ± 3.4 kcal/mol; spiro [1,2-oxoetane phenyl] radical, 57.3 ± 3.4 kcal/mol; p-hydroxy cyclohexan-2,5-dienone, -42.1 ± 3.4 kcal/mol; and benzylperoxy radical, 28.5 ± 3.2 kcal/mol.</p>

Enthalpies of formation of the benzyloxyl, benzylperoxyl, hydroxyphenyl radicals and related species on the potential energy surface for the reaction of toluene with the hydroxyl radical

2019 ◽  
Author(s):  
Oscar Ventura ◽  
Martina Kieninger ◽  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Vincenzo Barone
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Hydroxyl Radical ◽  
Related Species ◽  
Energy Surface ◽  
Closed Shell ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
Isodesmic Reactions ◽  
Benzyl Radical

<p></p><p>The reaction of toluene (T) with OH<sup>●</sup> produces addition products as well as the benzyl radical (TR). TR can react with OH<sup>●</sup> or O<sub>2</sub> to produce oxygenated species, for many of which there is no experimental information available. We present here theoretically determined heats of formation (HFs) of 17 such species using the non-isodesmic reactions on the potential energy surface (PES) of TR+O<sub>2</sub> and T+OH<sup>●</sup>+O<sub>2</sub>. For those species the experimental HFs of which are known, we obtained a good correlation between experimental and theoretical values at the G4 (r<sup>2</sup>=0.999) and M06/cc-pVQZ (r<sup>2</sup>=0.997) levels, thus showing the goodness of the methods used. Previously unknown HFs of other radicals (benzyloxyl, spiro [1,2-dioxetane benzyl], hydroxyphenyl, and benzylperoxyl) and closed shell species (salicylic alcohol, benzo[b]oxetane and p-hydroxy cyclohexa-2,5-dienone) were later determined using those methods.<b></b></p><br><p></p>

scholarly journals Enthalpies of formation of the benzyloxyl, benzylperoxyl, hydroxyphenyl radicals and related species on the potential energy surface for the reaction of toluene with the hydroxyl radical

2019 ◽  
Author(s):  
Oscar Ventura ◽  
Martina Kieninger ◽  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Vincenzo Barone
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Hydroxyl Radical ◽  
Related Species ◽  
Energy Surface ◽  
Closed Shell ◽  
Experimental Information ◽  
Enthalpies Of Formation ◽  
Isodesmic Reactions ◽  
Benzyl Radical

<p></p><p>The reaction of toluene (T) with OH<sup>●</sup> produces addition products as well as the benzyl radical (TR). TR can react with OH<sup>●</sup> or O<sub>2</sub> to produce oxygenated species, for many of which there is no experimental information available. We present here theoretically determined heats of formation (HFs) of 17 such species using the non-isodesmic reactions on the potential energy surface (PES) of TR+O<sub>2</sub> and T+OH<sup>●</sup>+O<sub>2</sub>. For those species the experimental HFs of which are known, we obtained a good correlation between experimental and theoretical values at the G4 (r<sup>2</sup>=0.999) and M06/cc-pVQZ (r<sup>2</sup>=0.997) levels, thus showing the goodness of the methods used. Previously unknown HFs of other radicals (benzyloxyl, spiro [1,2-dioxetane benzyl], hydroxyphenyl, and benzylperoxyl) and closed shell species (salicylic alcohol, benzo[b]oxetane and p-hydroxy cyclohexa-2,5-dienone) were later determined using those methods.<b></b></p><br><p></p>

DIRECT DENSITY FUNCTIONAL THEORY DYNAMICS STUDY FOR THE CH3OCF2CF2OCH3 + OH REACTION

2011 ◽  
Vol 10 (02) ◽  
pp. 231-244 ◽  
Author(s):  
HONG-BO YU ◽  
FENG-CHAO CUI ◽  
YONG-XIA WANG ◽  
HONG-XIA LIU ◽  
JING-YAO LIU
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Data ◽  
State Theory ◽  
Stationary Points ◽  
Enthalpies Of Formation ◽  
Oh Radicals ◽  
Isodesmic Reactions ◽  
Functional Theory ◽  
Barrier Heights

The mechanism and kinetics of the reaction of CH3OCF2CF2OCH3 with OH radicals have been studied theoretically by a direct density functional theory dynamics method. All possible H -abstraction channels and displacement processes taking place on two different conformers of CH3OCF2CF2OCH3 have been taken into consideration. The potential energy surface information including the optimized geometries and harmonic vibrational frequencies of all the stationary points and barrier heights involved in these channels were obtained at the BB1K/6-31+G(d,p) level of theory. The rate constants were calculated using improved canonical variational transition state theory (ICVT) with the small-curvature tunneling correction (SCT) over the temperature range of 200–2000 K. The overall rate constant for the title reaction, which was obtained by considering the weight factor of each conformer from the Boltzman distribution function, is in reasonable agreement with the available experimental value. Three-term Arrhenius expression is fitted to be k T = 1.56 × 10-20 T 2.47 exp (-124.64/ T ) cm 3 molecule-1 s-1 (200–2000 K). Also, the enthalpies of formation of the reactant CH3OCF2CF2OCH3 and product radicals CH3OCF2CF2OCH2 and CH3OCF2CF2O , which lack experimental or theoretical data, were evaluated via applying isodesmic reactions.

Theoretical progress in the H2+ molecular ion: towards electron to proton mass ratio determinationThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 103-107 ◽  
Author(s):  
J.-Ph. Karr ◽  
L. Hilico ◽  
V. I. Korobov
Keyword(s):  
High Resolution ◽  
Mass Ratio ◽  
Theoretical Determination ◽  
Atomic Systems ◽  
The Road ◽  
Theoretical Progress ◽  
Proton Mass ◽  
Accuracy Level ◽  
Ratio Determination

High resolution ro-vibrational spectroscopy of H 2+ or HD+ can lead to a significantly improved determination of the electron to proton mass ratio me/mp if the theoretical determination of transition frequencies becomes sufficiently accurate. We report on recent theoretical progress in the description of the hyperfine structure of H 2+ , as well as first steps in the evaluation of radiative corrections at order mα7. Completion of the latter calculation should allow us to reach the projected 10−10 accuracy level and open the road to mass ratio determination.

Combined Experimentaland Theoretical Determination of the Atomic Structure of the (310) Twin in NB

1991 ◽  
Vol 238 ◽  
Author(s):  
Geoffrey H. Campbells ◽  
Wayne E. King ◽  
Stephen M. Foiles ◽  
Peter Gumbsch ◽  
Manfred Rühle
Keyword(s):  
High Resolution ◽  
Theoretical Models ◽  
High Resolution Electron Microscopy ◽  
Interatomic Potentials ◽  
Image Simulation ◽  
Theoretical Determination ◽  
Atomic Structures ◽  
Resolution Electron ◽  
High Resolution Images

ABSTRACTA (310) twin boundary in Nb has been fabricated by diffusion bonding oriented single crystals and characterized using high resolution electron microscopy. Atomic structures for the boundary have been predicted using different interatomic potentials. Comparison of the theoretical models to the high resolution images has been performed through image simulation. On the basis of this comparison, one of the low energy structures predicted by theory can be ruled out.

Thermochemistry of Organic and Heteroorganic Species. Part IX. Photoionization Studies of Isomerization and Fragmentation of Polysubstituted Cyclopropenes: Phenyl-Substituted Cyclopropenes

2000 ◽  
Vol 6 (1) ◽  
pp. 53-64 ◽  
Author(s):  
V.V. Takhistov ◽  
I.N. Domnin ◽  
D.A. Ponomarev
Keyword(s):  
Mass Spectrometry ◽  
Enthalpy Of Formation ◽  
Good Alternative ◽  
Enthalpies Of Formation ◽  
Isodesmic Reactions ◽  
Ion Structure ◽  
Photoionization Mass Spectrometry ◽  
General Methodology ◽  
Fragment Ions ◽  
The Enthalpy Of Formation

Ionization and appearance energies of some fragment ions from 1,2,3-trimethy1-3-phenyl-, 3-methyl-1,2,3-triphenyl-, 1,2-diphenyl-3-methoxycarbonyl-, 1,2,3-triphenyl-3-methoxycarbonyl- and 1,3,3-triphenyl-2-methoxycarbonyl-cyclopropenes were measured by photoionization mass spectrometry. It was shown that in none of these compounds did the fragment ions possess the expected stable substituted cyclopropenium ion structure. Accordingly, possible schemes of molecular ion isomerization are given. The enthalpies of formation of nearly 50 substituted cyclopropenium ions, and ions of related structure, were estimated using series of isodesmic reactions. This publication, together with the previous works of the authors in this Journal, demonstrates the general methodology for estimation of the enthalpy of formation for even-electron ions. It is suggested that the present methodology can provide a good alternative to other estimation or computation procedures applied to the thermochemistry of ions.

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

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