THE SELF-RELAXATION OF VIBRATIONALLY EXCITED FLUOROSULFATE RADICALS

The vibrational relaxation of ground state FSO3 radicals in self-colli sions has been studied by using ArF laser photolysis of F2S2O6-FSO3-N2 (or He) equilibrium mixtures to generate the radicals and time-resolv ed absorption detection to monitor the decay of the populations. The s elf-relaxation rate constant for the ensemble of vibrationally excited FSO3 Was found to be (4.2 +/- 0.4) x 10(9) M-1 s-1 over the temperatu re range 379-406 K. Near-resonant intermolecular vibrational-to-vibrat ional energy transfer pathways may play a dominant role. The rate cons tant for the quenching by the F2S2O6 collision partner, (4.0 +/- 0.4) x 10(8) M-1 s-1, has been determined at 295 K for the fast component o f the decay. This value is 4.2 times greater than that determined prev iously for the slow component.