Details

Autor(en) / Beteiligte

• Fleming, Donald G
• Arseneau, Donald J
• Cottrell, Stephen P
• Peck, Jamie N T

Titel

Rate constants and kinetic isotope effects for H-atom abstraction reactions by muonium in the Mu + propane and Mu + n-butane reactions from 300 K to 435 K: challenges for theory

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2020-03, Vol.22 (11), p.6326-6334

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This paper reports measurements of the temperature dependence of the rate constants for H-atom abstraction reactions from propane and n-butane by the light isotopic H-atom muonium (Mu), k (T), over temperatures in the range 300 K to 435 K. Simple Arrhenius fits to these data yield activation energies, E, that are some 2-4 times lower than E found from corresponding fits for the H + propane and H + n-butane reactions studied elsewhere, both experimentally and theoretically, and fit over a similar temperature range. These activation energies E are also much lower than estimated from zero-point-energy corrected vibrationally adiabatic potential barriers, both results suggesting that quantum tunneling plays an important role in determining k (T) and for the Mu + propane reaction in particular. The results are expected to pose a considerable challenge to reaction rate theory for isotopic H-atom reactions in alkane systems.