RT Journal Article
T1 An integrated protocol to study hydrogen abstraction reactions by atomic hydrogen in flexible molecules: Application to the butanol isomers
A1 Ferro Costas, David
A1 Cordeiro, Natalia D. S.
A1 Fernández Ramos, Antonio
K1 Hydrogen abstraction reactions
K1 Butanol isomers
K1 Atomic hydrogen
K1 Reactions
AB This work presents a protocol designed to study hydrogen abstraction reactions by atomic hydrogen in molecules with multiple conformations. The protocol starts with the search and location of the conformers of the equilibrium structures using the TorsiFlex program. By a simple modification of the starting geometry of reactants, a Python script generates the input for the hydrogen abstraction transition states. Initially, the search of the stationary points (reactants and transition states) is carried out at a low-level employing firstly a preconditioned search and secondly a random search. The low-level conformers were reoptimized using a higher level electronic structure method. This information allows the evaluation of the multistructural harmonic-oscillator partition functions, which are corrected for zero-point energy anharmonicity by the hybrid degeneracy-corrected second-order vibrational perturbation theory and for torsional anharmonicity by the multistructural torsional method, as implemented in the MsTor program. The structural information of the stationary points is used by Pilgrim to evaluate the multipath canonical variational transition state theory thermal rate constants with multidimensional small-curvature corrections for tunneling. Therefore, the thermal rate constants include variational (recrossing) and tunneling effects in addition to the effect of multiple conformations on the thermal rate constants. These features grant the applicability of the method to a wide range of temperatures. The method was applied to each of the hydrogen abstraction sites of the four isomers of butanol. The methodology employed allowed us to calculate the thermal rate constants in the temperature range of 250–2500 K and to accurately fit them to analytical expressions. The variety of abstraction sites shows that the protocol is robust and that it can be employed to study hydrogen abstraction reactions in molecules containing carbon and oxygen as heavy atoms
PB Royal Society of Chemistry
YR 2021
FD 2021-12-20
LK https://hdl.handle.net/10347/45168
UL https://hdl.handle.net/10347/45168
LA eng
NO Ferro-Costas, D., Cordeiro, M. N. D. S., and Fernández-Ramos, A. An integrated protocol to study hydrogen abstraction reactions by atomic hydrogen in flexible molecules: application to butanol isomers. Phys. Chem. Chem. Phys., 2022,24, 3043-3058
NO The authors thank “Centro de Supercomputación de Galicia” (CESGA) for the use of their computational facilities. This work was partially supported by the Consellería de Cultura, Educación e Ordenación Universitaria (Centro singular de investigación de Galicia acreditación 2019–2022, ED431G 2019/03 and Grupo de referencia competitiva ED431C 2021/40) and the European Regional Development Fund (ERDF), and the Ministerio de Ciencia Inovación through Grant PID2019-107307RB-I00. M. N. D. S. C. received financial support from FCT – Fundação para a Ciência e Tecnologia, through funding for the project PTDC/QUI-QIN/30649/2017. M. N. D. S. C. would like to also thank the FCT support to LAQV-REQUIMTE (UID/QUI/50006/2020). D. F.-C. thanks Xunta de Galicia for financial support through a postdoctoral grant (modalidade A, 2017)
DS Minerva
RD 25 abr 2026