The reaction between the ground-state hydroxyl radical, OH(2Π), and ethylene, C2H4, 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-CH2CHOH (vinyl alcohol) + H, CH3CHO (acetaldehyde) + H, and H2CO (formaldehyde) + CH3 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-CH2CHOH + H product channels account for 38% (in similar amounts) of the addition mechanism yield, the H2CO + CH3 channel for ∼58%, while the CH3CHO + H channel is formed in negligible amount (<4%). The implications for combustion and astrochemical environments are discussed.

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