Investigation of the formation of acid rain based on the sulfur tetroxide (SO4 (C2v)) and OH radical reaction

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

Herein, theoretical studies were performed on the atmospheric oxidation of sulfurous acid (H₂SO₃) and sulfite ions (HSO₃⁻) by ozone (O₃) to produce sulfuric acid and hydrosulfate ions. The most favorable path for the H₂SO₃ + O₃ reaction has been found to be initiated from concerted H-abstraction and oxygen addition, with an overall energy barrier of 18.3 kcal mol⁻¹. On the other hand, the most favorable path for the HSO₃⁻ + O₃ reaction is initiated from oxygen addition, with an overall energy barrier of only 0.3 kcal mol⁻¹. Kinetic simulations were performed to estimate the significance of these reactions in the formation of atmospheric sulfate and destruction of the ozone layer. The results provide new insight into the missing source of atmospheric sulfate and particulate matter.

Herein, theoretical studies were performed on the atmospheric oxidation of sulfurous acid (H₂SO₃) and sulfite ions (HSO₃⁻) by ozone (O₃) to produce sulfuric acid and hydrosulfate ions.

Theoretical study on the properties and stabilities of complexes formed between SO4(C2v) and isostructure species of CO2, CS2, and SCO

In this work ab initio calculations at MP2 level in conjugation with aug-cc-pVXZ (X=D and T) basis set were performed in order to examine complexes formed between SO4 and each of linear molecules of CO2, CS2, and SCO. The results have been discussed on real minima located on singlet potential energy surface (PES). Single-point energy calculations at the MP2/aug-cc-pVTZ level uphold results obtained at the MP2/aug-cc-pVDZ level. The atom in molecules theory (AIM) was utilized to analyze the nature of intermolecular interactions. Also, natural bond orbital (NBO) analysis has been used in order to get charge transfer quota in complexes. The results show that the atmospheric role of SO4-CS2 system is more important than those followed by SO4-SCO and SO4-CO2, respectively.