Thionyl fluoride (SOF₂) poses significant environmental and health risks due to its toxicity and potential to form hazardous byproducts. A theoretical investigation is essential to understand its reactivity, stability, and decomposition pathways, which can aid in assessing its impact and guiding safer applications. In this study, we theoretically evaluated the characteristics of the complexes resulting from the interaction between SOF2 and HSX molecules (X = F, Cl, Br, and I) at the MP2/aug-cc-pVTZ computational level. The optimization results demonstrate that three conformations were obtained from the interaction between SOF2 and HSX (X = F, Cl, Br, and I). Complexes of conformation I with the nature of ChB-HB were stabilized through two H⋯O and S⋯X interactions. Meanwhile, conformation II and III complexes reached stability only through the linear interaction of S⋯O and X⋯O with the characteristics of ChB and XB, respectively. Also, the results obtained from the interaction energy demonstrate that conformation I complexes have significant stability in comparison with other conformations due to the presence of two simultaneous HB and ChB interactions. Furthermore, a complete series of complementary analyses, such as NBO (Natural bond orbital), AIM (Atom in molecule), MEPs (Molecular electrostatic potential map), NCI (Non-covalent interaction index) analyses, etc., have been used further to explore the electronic, orbital, and structural characteristics.
