Context: In this discussion, we began building two model, S2O + CHCl•− and O3 + CHCl•−, using DFT-BHandHLYP method, to study their reactions mechanisms on singlet PES. For this purpose, we hope to explore the effects of the difference between sulfur and oxygen atoms on the CHCl•− anion. Experimentalists and computer scientists may utilize the collected data to generate a wide range of hypotheses for experimental phenomena and predictions, allowing them to realize their full potential.Methods: The ion-molecule reaction mechanism of CHCl•− with S2O and O3 was studied using the DFT-BHandHLYP level of theory with the aug-cc-pVDZ basis set. Our theoretical findings show that Path 6 is the favored reaction pathway for CHCl•− + O3 reaction as identified by the O-abstraction reaction pattern. Comparing to the direct H- and Cl-abstraction mechanisms, the reaction (CHCl•− + S2O) prefers the intramolecular SN2 reaction pattern. Moreover, the calculated results demonstrated that the CHCl•− + S2O reaction is thermodynamically more favorable than the CHCl•− + O3 reaction, which is kinetically more advantageous. As a result, if the required reaction condition in the atmospheric process is met, the O3 reaction will happen more effectively. In terms of kinetics and thermodynamics viewpoints, the CHCl•− anion was very effective in eliminating S2O and O3.Graphical Abstract: