Comment on "Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature" by W. Siebrand, Z. Smedarchina, E. Martínez-Núñez and A. Fernández-Ramos, Phys. Chem. Chem. Phys., 2016, 18, 22712

R.J. Shannon (1, 2) , J.C. Gómez Martín (1, 2) , R.L. Caravan (1, 2) , M.A. Blitz (1, 2) , J.M.C. Plane (2, 1) , D.E. Heard (1, 2) , M. Antiñolo (3) , M. Agundez (4) , E. Jiménez (3) , B. Ballesteros (3) , André Canosa (5) , G. El Dib (5) , J. Albaladejo (1) , J. Cernicharo (4)

1 University of Leeds
2 School of Chemistry [Leeds]
3 Facultad de Ciencias y Tecnologias Quimicas
4 ICMM - Instituto de Ciencia de Materiales de Madrid
5 IPR - Institut de Physique de Rennes

The article "Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature" proposes a dimer mediated mechanism in order to explain the large low temperature rate coefficients for the OH + methanol reaction measured by several groups. It is demonstrated here theoretically that under the conditions of these low temperature experiments, there are insufficient dimers formed for the proposed new mechanism to apply. Experimental evidence is also presented to show that dimerization of the methanol reagent does not influence the rate coefficients reported under the conditions of methanol concentration used for the kinetics studies. It is also emphasised that the low temperature experiments have been performed using both the Laval nozzle expansion and flow-tube methods, with good agreement found for the rate coefficients measured using these two distinct techniques.

Mots clés: Molecular physics; CRESU

Domaines: Chimie théorique et/ou physique; Chimie-Physique [physics.chem-ph]

R.J. Shannon, J.C. Gómez Martín, R.L. Caravan, M.A. Blitz, J.M.C. Plane, et al.. Comment on "Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature" by W. Siebrand, Z. Smedarchina, E. Martínez-Núñez and A. Fernández-Ramos, Phys. Chem. Chem. Phys., 2016, 18, 22712. Physical Chemistry Chemical Physics, 2018, 20 (12), pp.8349-8354. ⟨10.1039/c7cp04561a⟩. ⟨hal-01774215⟩