Abstract
The reaction between the ground-state hydroxyl radical, OH((2)Π), and ethylene, C(2)H(4), has been investigated under single-collision conditions by the crossed molecular beam scattering technique with mass-spectrometric detection and time-of-flight analysis at the collision energy of 50.4 kJ/mol. Electronic structure calculations of the underlying potential energy surface (PES) and statistical Rice-Ramsperger-Kassel-Marcus (RRKM) calculations of product branching fractions on the derived PES for the addition pathway have been performed. The theoretical results indicate a temperature-dependent competition between the anti-/syn-CH(2)CHOH (vinyl alcohol) + H, CH(3)CHO (acetaldehyde) + H, and H(2)CO (formaldehyde) + CH(3) product channels. The yield of the H-abstraction channel could not be quantified with the employed methods. The RRKM results predict that under our experimental conditions, the anti- and syn-CH(2)CHOH + H product channels account for 38% (in similar amounts) of the addition mechanism yield, the H(2)CO + CH(3) channel for ∼58%, while the CH(3)CHO + H channel is formed in negligible amount (<4%). The implications for combustion and astrochemical environments are discussed.