Exploring Mechanism and Kinetics of 1,4-Dioxane Oxidative Degradation by OH Radical: A Computational Quantum Chemistry Investigation

Abstract

This study aims to shed light on the mechanism and kinetics of 1,4-dioxane degradation by hydroxyl radical (OH) across various solvation conditions to evaluate electronic and structural properties at the MP2/aug-cc-pVTZ level. Transition states (TS) structures determined in the gas phase and SMD solvation model reveal similar hydrogen abstraction patterns. In contrast, the explicit solvation model (ES) introduces significant changes, suggesting a kinetic preference for axial pathways. The reaction rate constants, employing Deformed Transition State Theory (d-TST), are consistently higher for axial abstraction. The preference for axial hydrogen abstraction, solvation effects on transition states, and temperature-dependent rate constants are highlighted. Furthermore, the identification of carbon–carbon orbital distortion suggests potential bond breakage. This research provides valuable insights into the reaction between 1,4-dioxane and OH radical across different solvation models and enhances the understanding of the advanced oxidative process.