Direct evidence for a substantive reaction between the Criegee intermediate, CH2OO, and the water vapour dimer

Abstract

The C1 Criegee intermediate, CH₂OO, reaction with water vapour has been studied. The removal rate constant shows a quadratic dependence on [H₂O], implying reaction with the water dimer, (H₂O)₂. The rate constant, k_CH2OO+(H2O)2 = (4.0 ± 1.2) × 10⁻¹² cm³ molecule⁻¹ s⁻¹, is such that this is the major atmospheric sink for CH₂OO.