Theoretical Study on the Continuous Reaction Mechanism of OUCH + With CS 2

ABSTRACT Understanding the reaction mechanisms of the atypical uranium species OUCH + provides insight into the intrinsic reactivity of uranium ions in the gas phase. Based on thermodynamic and kinetic calculations, this study investigates the continuous reactions of OUCH + with CS 2 , including the three processes: OUCH + + CS 2 → OUS + , OUS + + O 2 → UO 2 + and OUS + + H 2 O → UO 2 + . The reaction mechanisms between OUCH + and CS 2 , OUS + and O 2 , H 2 O were explored by using density functional theory. Reaction pathways were proposed from the calculated potential energy profiles, and the competitive mechanisms for the reactions of OUS + with O 2 and H 2 O were analyzed. Additionally, reaction rate constants were calculated by using variational transition state theory including one‐dimensional tunneling effects, and the concentration evolution of the continuous reaction was simulated. The results provide an important theoretical basis for advancing research on the chemistry of actinide elements.