Molecular spectra and dissociation dynamics of SO2F2 under external electric fields

Abstract

AbstractSulfuryl fluoride (SO2F2) is a powerful greenhouse gas that threatens human health. It is essential to study the dissociation mechanism of SO2F2 under external electric fields (EEFs). Based on M06‐2X/6‐311G(d, p) level, the stepwise and concerted dissociation properties of SO2F2 have been investigated under EEFs, including the dipole moment, bond lengths, total energy, orbital energy level distribution, and infrared spectrum. With increasing external‐electric‐field intensity, the 1S–4F and 1S–5F bonds become longer, the total energy decreases, and the energy gap decreases. Infrared spectroscopy shows that the vibration frequencies of the 1S–4F and 1S–5F bonds decrease as the electric‐field intensity increases, and a significant red shift occurs. Time‐dependent density functional theory was used to calculate the ultraviolet‐visible absorption spectrum. Additionally, the potential‐energy curves along the 1S–4F and 1S–5F bonds under electric fields were calculated. The results show that stepwise dissociation of the 1S–4F and 1S–5F bonds occur when F = 0.08 and 0.06 a.u., respectively. Corrected dissociation occurs when F = 0.95 a.u. The spectrum and dissociation mechanism of SO2F2 under EEFs provide a basic understanding of the molecular structure and degradation kinetics of SO2F2, and it provides insight into decomposition of SO2F2.