Ab initio study on the thermolysis of β-hydroxyolefins in gas phase

Quíjano, Jairo; David, Jorge; Sánchez, Claudia; Rincón, Elizabeth; Guerra, Doris; León, Luis A.; Notario, Rafael; Abboud, José‐Luis M.

doi:10.1016/s0166-1280(01)00614-5

Cited by 12 publications

(12 citation statements)

References 3 publications

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“…Again, these values do not agree with the range of experimental determinations. Moreover, from comparisons between theoretical values of activation parameters for the case of β‐hydroxyalkenes 10 and β‐hydroxyalkynes 18, with β‐hydroxynitriles, we can observe that while concerned with a six‐membered cyclic transition structure for decomposition the predicted reactivity order (i.e., alkenes < alkynes < nitriles) agrees with experimental observations. The stronger argument against a six‐membered cyclic transition structure was before based on the small positive values for activation entropies (Δ S ≠ > 0), which were determined in Ref.…”

Section: Resultssupporting

confidence: 67%

“…It has been recently reported 1 that β‐hydroxynitriles decompose thermally to give a mixture of aldehydes or ketones and nitriles as depicted in Figure 1. This reaction seems to be similar to that thought to be involved in related thermal decompositions such as for β‐hydroxyketones 2–6, β‐hydroxyolefins 7–10, β‐hydroxyesters 4, 11–14, and β‐hydroxyalkynes 15–18. In these reactions, calculated activation energies ( E a ≈ 150–180 kJ mol −1 ) and activation entropies (Δ S ≠ ≈ −19 to −60 Jmol −1 K −1 ) have been used in support of reaction mechanisms via a six‐membered cyclic transition state (Fig.…”

Section: Introductionmentioning

confidence: 56%

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Theoretical study of the thermolysis reaction of β‐hydroxynitriles in the gas phase

Chamorro

Quíjano

Notario

et al. 2003

Int J of Quantum Chemistry

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ABSTRACT:The gas-phase thermal decomposition of 3-hydroxypropionitrile, 3-hydroxybutyronitrile, and 3-hydroxy-3-methylbutyronitrile has been studied at the MP2/6-31G(d) level of theory at 683.15 K and 0.06 atm. Results based both in energy and structure data seem to indicate a favorable route of decomposition via a six-membered cyclic transition state (similar to those suggested for thermal decomposition of other related compounds, such as ␤-hydroxyketones, ␤-hydroxyalkenes, and ␤-hydroxyalkynes) rather than a four-membered cyclic transition state or even a quasiheterolytic pathway. Wiley Periodicals, Inc. Int J Quantum Chem 91: 618 -625, 2003

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Section: Resultssupporting

confidence: 67%

Section: Introductionmentioning

confidence: 56%

Theoretical study of the thermolysis reaction of β‐hydroxynitriles in the gas phase

Chamorro

Quíjano

Notario

et al. 2003

Int J of Quantum Chemistry

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“…When pyrolyzed in the gas phase, these compounds decompose into olefins and carbonyl products, and in some cases dehydrate 13 . Ab initio theoretical calculations on the thermolysis of β ‐hydroxyolefins in the gas phase have corroborated the mechanism of reaction (1) and with the experimental results 14. In association with β ‐hydroxyolefins, the gas‐phase pyrolysis for a system where the alkene double bond is a part of an aromatic system, such as 2‐phenylethanol, was found to give mainly about 90% toluene and 10% styrene 15.…”

Section: Introductionsupporting

confidence: 60%

Theoretical calculations of the kinetics and mechanisms of the gas phase elimination of primary, secondary, and tertiary 2‐hydroxyalkylbenzenes

Mora

Lezama

Albornoz

et al. 2009

J of Physical Organic Chem

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Theoretical study of the elimination kinetics of 2-phenylethanol, 1-phenyl-2-propanol, and 2-methyl-1-phenyl-2propanol in the gas-phase has been carried out at the MP2/6-31G(d,p), B3LYP/6-31G(d,p), B3LYP/6-31RRG(d,p), MPW1PW91/6-31G(d,p), MPW1PW91/6-31RRG(d,p), PBEPBE/6-31G(d,p), and PBEPBE/6-31RRG(d,p) levels of theory. The three substrates undergo two parallel elimination reactions. The first elimination appears to proceed through a six-membered cyclic transition state to give toluene and the corresponding aldehyde or ketone. The second parallel elimination takes place through a four-membered cyclic transition state producing water and the corresponding unsaturated aromatic hydrocarbon. Results from MP2/6-31G(d,p) and MPW1PW91/6-31RRG(d,p) methods were found to be in good agreement with the experimental kinetic and thermodynamic parameters in the formation of toluene and the corresponding carbonyl compound. However, the results for PBEPBE/6-31G(d,p) were in better agreement with the experimental data for the second parallel reaction yielding water and the corresponding unsaturated aromatic hydrocarbon. The charge distribution differences in the TS related to the substitution by methyl groups in the substrates can account for the observed reaction rate coefficients. The synchronicity parameters imply semi-polar transition states for these elimination reactions.

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“…The thermolysis of b-hydroxy alkenes and ketones in the gas phase has been previously studied both experimentally [1][2][3][4][5] and theoretically [6]. Based on the results obtained, the corresponding mechanism has been proposed in which b-hydroxy alkenes decompose thermally to give a mixture of alkenes and carbonyl compounds, following a first-order homogeneous unimolecular reaction [3].…”

Section: Introductionmentioning

confidence: 99%

Correlations between hardness, electrostatic interactions, and thermodynamic parameters in the decomposition reactions of 3-buten-1-ol, 3-methoxy-1-propene, and ethoxyethene

et al. 2014

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Decomposition of the three isomeric compounds, 3-buten-1-ol (1), 3-methoxy-1-propene (2), and ethoxyethene (3), at two different (300 and 550 K) temperatures has been investigated by means of ab initio molecular orbital theory (MP2/6-311?G**//B3LYP/6-311?G**), hybrid-density functional theory (B3LYP/6-311?G**), the complete basis set, nuclear magnetic resonance analysis, and the electrostatic model associated with the dipole-dipole interactions. All three levels of theory showed that the calculated Gibbs free energy differences between the transition and ground state structures (DG = ) increase from compound 1 to compound 3. The variations of the calculated DG = values can not be justified by the decrease of the calculated global hardness (g) differences between the ground and transition states structures (i.e., D[g(GS)-g(TS)]). Based on the synchronicity indices, the transition state structures of compounds 1-3 involve synchronous aromatic transition structures, but there is no significant difference between their calculated synchronicity indices. The optimized geometries for the transition state structures of the decomposition reactions of compounds 1-3 consist in chair-like six-membered rings. The variation of the calculated activation entropy (DS = ) values can not be justified by the decrease of D[g(GS)-g(TS)] parameter from compound 1 to compound 3. On the other hand, dipole moment differences between the ground and transition state structures [D(l TS -l GS )] decrease from compound 1 to compound 3. Therefore, the electrostatic model associated with the dipole-dipole interactions justifies the increase of the calculated DG = values from compound 1 to compound 3. The correlations between DG = , D[g(GS)-g(TS)], (DS = ), k(T), electrostatic model, and structural parameters have been investigated.

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Ab initio study on the thermolysis of β-hydroxyolefins in gas phase

Cited by 12 publications

References 3 publications

Theoretical study of the thermolysis reaction of β‐hydroxynitriles in the gas phase

Theoretical study of the thermolysis reaction of β‐hydroxynitriles in the gas phase

Theoretical calculations of the kinetics and mechanisms of the gas phase elimination of primary, secondary, and tertiary 2‐hydroxyalkylbenzenes

Correlations between hardness, electrostatic interactions, and thermodynamic parameters in the decomposition reactions of 3-buten-1-ol, 3-methoxy-1-propene, and ethoxyethene

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