A bonding evolution theory study on the catalytic Noyori hydrogenation reaction

Munárriz, J. (Universidad de Zaragoza) ; Laplaza, R. ; Polo, V. (Universidad de Zaragoza)

Resumen: The electronic rearrangements involved in Noyori hydrogenation reactions with double bonds (ethene and formaldehyde) are analysed using the bonding evolution theory. The study and analysis of the changes on the electron localisation function topology along a given reaction path reveals fluxes of electron density, allowing to unambiguously identify the main chemical events happening along the chemical reactions. This analysis shows that the first hydrogen transfer (with hydride character) occurs before the transition state (TS), while the second hydrogen transfer (with proton character) takes places after having reached the TS. The lower energy barrier found for formaldehyde over ethene is explained by two reasons. First, the hydride transfer is favoured for the C = O bond over C = C due to the electrophilic character of the carbon atom. Second, a negatively charged CH3–X (X = CH2, O) hidden intermediate is formed in the proximities of the TS region. The oxygen atom is able to stabilise this negatively charged species more effectively than the CH2 group due to its higher electronegativity and the presence of V(O) lone pairs. The obtained analysis explains and rationalises catalyst chemoselectivity (C = O vs. C = C). Finally, a curly arrow representation diagram accounting for the electronic rearrangements is proposed on the basis of BET results.

Idioma: Inglés

DOI: 10.1080/00268976.2018.1542168

Año: 2018

Publicado en: MOLECULAR PHYSICS 117, 9-12 (2018), 1315 - 1324
ISSN: 0026-8976

Factor impacto JCR: 1.571 (2018)

Categ. JCR: PHYSICS, ATOMIC, MOLECULAR & CHEMICAL rank: 28 / 36 = 0.778 (2018) - Q4 - T3
Categ. JCR: CHEMISTRY, PHYSICAL rank: 114 / 147 = 0.776 (2018) - Q4 - T3

Factor impacto SCIMAGO: 0.635 - Biophysics (Q2) - Physical and Theoretical Chemistry (Q2) - Molecular Biology (Q2) - Condensed Matter Physics (Q2)

Financiación: info:eu-repo/grantAgreement/ES/MEC/FPU14-06003
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2015-67366-P

Tipo y forma: Artículo (PostPrint)

Área (Departamento): Área Química Física (Dpto. Química Física)