Gas-Phase Formation of Trioxy Acid via OH-Initiated Aldehyde Oxidation under Atmospheric Conditions

Abstract

The formation of a new carbonyl compound containing three linearly bonded oxygen atoms attached to the carbonyl carbon with a chemical formula of RC(O)O3H (trioxy acid) has been detected. The trioxy acid is formed in the reaction of benzaldehyde-derived acyl peroxy radicals and OH radicals under atmospherically relevant conditions. We employed flow reactor experiments with chemical ionization mass spectrometry, supported by quantum chemistry, to investigate the competitive reaction channels of acyl peroxy radicals formed during OH-initiated oxidation of aldehydes. While the role of trioxy acid in oxidation chemistry and cluster formation is not understood, this study provides insights in their formation and stability under atmospherically relevant conditions.