Identification of the early intermediates formed in ozonolysis of cis-2-butene and limonene: a theoretical and matrix isolation study

Abstract

This study combined quantum chemical calculations and the matrix isolation technique to identify the formation of primary intermediates from the ozonolysis of cis-2-butene and limonene. Quantum chemical calculations were conducted under the framework of density functional theory (DFT) at M06-2x/6-311+(d, p) level of theory to predict the possible mechanism as well as the new absorption bands. New bands whose intensity increased with annealing, were observed in twin jet deposition, which indicated the formation of primary ozonides, CI and secondary ozonides in the investigated systems. Isotopic labeling (¹⁸O) experiments further supported the assignment of observed bands. The results and findings in this study would enrich the understanding of the reaction mechanism of alkene ozonolysis.