Two-photon dissociation of sulfur dioxide at 248 and 308 nm

摘要: Abstract The photodissociation of SO2 after two-photon excitation at 248 and 308 nm has been studied by means photofragment translational spectroscopy (PTS). With excitation, the time-of-flight distributions SO photofragments exhibit high kinetic-energy thresholds which are assigned to formation SO(X 3Σ−) +O (3P), (1D), SO(a 1Δ) (3P). A weak vibrational structure indicates production molecules in states up least ν=8. After nm, nine different primary processes clearly identified leading SO+O as well S+O2 fragments various electronic states. All observed kinetic energy conform a dissociation Do=543 kJ/mol (45400 cm−1) for reaction SO2→SO+O Do= 569 (47600 SO2→S+O2. Evidence was found higher region 28000–31000 cm−1, particular previously not (A″ 3Σ+) state possesses term To close 30000 cm−1. Furthermore, PTS method, providing direct way determine each individual fragment pair, revealed that spin is conserved dissociation.