The reaction energies of ethylene, CO, and N 2 with proton, hydrogen atom, and hydride ion

It is shown by quantum chemical simulation (MP2/aug-cc-pVTZ) that the energy of addition of H +, H ̇, and H - decreases in the order ethylene, CO, and N 2. The energies of additions of CF 4, dimethyl ether, and BF 3 to the ions and radicals formed were calculated. Unlike the CH 3CH 2 - ion, the HCO - ion can add exothermically not one, but two BF 3 molecules. © 2011 Springer-Verlag

Mechanism of oxygen transfer from the vanadium(V) complexes with ligands O2 2- and O3 2-

The oxygen transfer from the vanadium(V) complexes containing peroxo, oxo, and ozonide ligands to electron-donating substrates (ethylene and vinyl methyl ether) was studied in the framework of the DFT with the M06 hybrid functional. The O atom of the ozonide fragment in the O3VO(η-O2)- complex is transferred to the electron-donating substrates with lower energy expenses than the O atom of the peroxo group of the isomeric triperoxo complex, in spite of the fact that the presence of the peroxo group in the ozonide complexes stabilizes it favoring the formation of the V-Oc bond according to the data of topological analysis of the electron density in terms of the theory of atoms in molecules (AIM). The calculation results are in agreement with the experimental kinetic data indicating somewhat lower reactivity of triperoxovanadate compared to the isomeric oxygenyl complexes. © 2014 Springer Science+Business Media New York

Special features of ethylene epoxidation by peroxyacetic acid

The B3LYP/6-31G(d, p) method of density functional theory was used to study the influence of carboxylic acid and water molecules on parallel ethylene oxidation reactions (epoxidation and hydroxylation) by peroxyacetic acid with the formation of various products. It was shown that carboxylic acid in the nondissociated form always present in the reaction mixture for several reasons had a catalytic action on this reaction and therefore contributed to an increase in its selectivity. We also found that the water molecule and its dimer facilitated epoxide formation. The suggestion was made that, if the reaction was performed in an aqueous medium, where the acid dissociated, the situation could radically change, and the hydroxylation reaction with the formation of glycol and/or its ester of the corresponding carboxylic acid would become predominant. © 2010 Pleiades Publishing, Ltd

The reaction energies of ethylene, CO, and N 2 with proton, hydrogen atom, and hydride ion

It is shown by quantum chemical simulation (MP2/aug-cc-pVTZ) that the energy of addition of H +, H ̇, and H - decreases in the order ethylene, CO, and N 2. The energies of additions of CF 4, dimethyl ether, and BF 3 to the ions and radicals formed were calculated. Unlike the CH 3CH 2 - ion, the HCO - ion can add exothermically not one, but two BF 3 molecules. © 2011 Springer-Verlag

A quantum-chemical study of the oxidation of ethylene by peroxyacetic acid derivatives

Density functional theory (B3LYP/6-31G(d, p)) and the Möller-Plesset perturbation theory (MP2/6-31G(d, p)) were used to study the electronic and geometric structure and relative stability of possible peroxyacetic acid and its trifluorinated derivative tautomers (including conformers), R-C(=O)(-OOH), R = CH3, CF3. Four types of stable tautomers of both compounds were found, and the energy characteristics of transitions between them were determined. The results of quantum-chemical modeling were used to study some special features of the oxidation of ethylene with the participation of all the tautomeric forms of both peroxy acids. For the acyclic form (ground state) of both peroxy acids and its conformers, two reactions are possible, namely, epoxidation with the formation of ethylene oxide (plus acid) and hydroxylation with the formation of ethanediol acetate ester and/or its isomer acetaldehyde semiacetal. At the same time, the oxidation of ethylene with the participation of all the other tautomeric forms (dioxirane and tautomers of the type of carbonyl and water oxides) only results in ethylene epoxidation. © Pleiades Publishing, Ltd., 2010

Mechanism of oxygen transfer from the vanadium(V) complexes with ligands O2 2- and O3 2-

The oxygen transfer from the vanadium(V) complexes containing peroxo, oxo, and ozonide ligands to electron-donating substrates (ethylene and vinyl methyl ether) was studied in the framework of the DFT with the M06 hybrid functional. The O atom of the ozonide fragment in the O3VO(η-O2)- complex is transferred to the electron-donating substrates with lower energy expenses than the O atom of the peroxo group of the isomeric triperoxo complex, in spite of the fact that the presence of the peroxo group in the ozonide complexes stabilizes it favoring the formation of the V-Oc bond according to the data of topological analysis of the electron density in terms of the theory of atoms in molecules (AIM). The calculation results are in agreement with the experimental kinetic data indicating somewhat lower reactivity of triperoxovanadate compared to the isomeric oxygenyl complexes. © 2014 Springer Science+Business Media New York

Special features of ethylene epoxidation by peroxyacetic acid

The B3LYP/6-31G(d, p) method of density functional theory was used to study the influence of carboxylic acid and water molecules on parallel ethylene oxidation reactions (epoxidation and hydroxylation) by peroxyacetic acid with the formation of various products. It was shown that carboxylic acid in the nondissociated form always present in the reaction mixture for several reasons had a catalytic action on this reaction and therefore contributed to an increase in its selectivity. We also found that the water molecule and its dimer facilitated epoxide formation. The suggestion was made that, if the reaction was performed in an aqueous medium, where the acid dissociated, the situation could radically change, and the hydroxylation reaction with the formation of glycol and/or its ester of the corresponding carboxylic acid would become predominant. © 2010 Pleiades Publishing, Ltd

A quantum-chemical study of the oxidation of ethylene by peroxyacetic acid derivatives

Density functional theory (B3LYP/6-31G(d, p)) and the Möller-Plesset perturbation theory (MP2/6-31G(d, p)) were used to study the electronic and geometric structure and relative stability of possible peroxyacetic acid and its trifluorinated derivative tautomers (including conformers), R-C(=O)(-OOH), R = CH3, CF3. Four types of stable tautomers of both compounds were found, and the energy characteristics of transitions between them were determined. The results of quantum-chemical modeling were used to study some special features of the oxidation of ethylene with the participation of all the tautomeric forms of both peroxy acids. For the acyclic form (ground state) of both peroxy acids and its conformers, two reactions are possible, namely, epoxidation with the formation of ethylene oxide (plus acid) and hydroxylation with the formation of ethanediol acetate ester and/or its isomer acetaldehyde semiacetal. At the same time, the oxidation of ethylene with the participation of all the other tautomeric forms (dioxirane and tautomers of the type of carbonyl and water oxides) only results in ethylene epoxidation. © Pleiades Publishing, Ltd., 2010