Rate coefficient and mechanism of the OH-initiated degradation of cyclobutanol: A combined experimental and theoretical study

Understanding the active role of water in laboratory chamber studies of reactions of the OH radical with alcohols of atmospheric relevance

“…A good agreement is observed between k d determined in this work and previously reported values. 14,24,25 The dependence of k obs on [H 2 O] determined for the cROHs shows that the water effect is at play, although the underlying mechanism must differ from that operating for the linear alcohols, for which k obs exhibits a quadratic dependence on [H 2 O]. 8,9 Electronic structure calculations were performed to evaluate the effect of one water molecule on the activation barriers for the reaction between cButOH and OH radical in the gas phase.…”

“…where [cROH] 17 The experimental setup was described in detail in previous works. 8,9,14 The reactions were carried out in a 60 L collapsible bag, which was filled to its maximum capacity at atmospheric pressure. The bag was surrounded by six germicide lamps (Phillips 30 W), providing UV radiation with l max around 254 nm to produce OH radicals by the UV photolysis of H 2 O 2 .…”

“…18 Computational Electronic structure calculations were performed to evaluate the effect of the water molecule on the activation barriers of the wet versus dry reaction of cButOH and the OH radical. Calculations were carried out using the most stable cButOH conformer, 14 with uCCSD(T)//uBHandHLYP/aug-cc-PVDZ as implemented in the Gaussian16 software package. 19 The selected methodology was previously shown to render satisfactory results for the modelling of oxidation reactions of volatile organic compounds, [20][21][22] and was also tested in previous work by our group.…”

“…19 The selected methodology was previously shown to render satisfactory results for the modelling of oxidation reactions of volatile organic compounds, [20][21][22] and was also tested in previous work by our group. 14,23…”

“…We have determined the reaction rate coefficients for the series of cyclic alcohols (cROHs) cyclobutanol (cButOH), cyclopentanol (cPenOH) and cyclohexanol (cHexOH) with the OH radical at different RH values. These cROHs are emitted into the troposphere from biogenic (cButOH) 13,14 and anthropogenic sources (cPenOH and cHexOH). 15,16…”