The two paths of the oxidation of acetylene (C₂H₂) with hydroxyl radical (OH·) and oxygen (O₂), an important atmospheric reaction studied by Glowacki et al., are depicted. Initially the C₂H₂-OH· radical forms with a high degree of internal vibrational energy, and the cis and trans forms interconv... Show moreThe two paths of the oxidation of acetylene (C₂H₂) with hydroxyl radical (OH·) and oxygen (O₂), an important atmospheric reaction studied by Glowacki et al., are depicted. Initially the C₂H₂-OH· radical forms with a high degree of internal vibrational energy, and the cis and trans forms interconvert. If the reaction with O₂ occurs when this internal energy is present, roughly equal amounts of the two sets of products are formed. However, if collisions cool the intermediate sufficiently, the more stable cis form and the glyoxal pathway (that reforms OH·) is favored. Show less
