COLLISIONAL DYNAMICS OF THE BRF B3-PI(O+) STATE .2. VIBRATIONAL-ENERGY TRANSFER

Pulsed, laser induced fluorescence techniques have been used to study vibrational energy transfer within the B 3-PI(0+) state of bromine monofluoride. Rate coefficients for state-to-state vibrational transfer were determined from the observed BrF(B-X) emission in the presence of He, Ne, Ar, Kr, Xe, and CF4. Vibrational states v'= 2, 5, and 6 were probed and time-resolved emission observed from states v'= 0-6. The vibrational relaxation is well described by the Montroll-Shuler model for harmonic oscillators. The fundamental rate coefficient for vibrational transfer from v' = 1 to v' = 0 ranged from 2.2 X 10(-13) to 3.9 X 10(-12) cm3/molecule s for the rare gases and was 4.1 +/- 1.0 X 10(-12) cm3/Molecule s for CF4. The scaling of the vibrational transfer rates with vibrational quantum number is consistent with the predictions of the Landau-Teller theory. Quantum-resolved vibrational transfer rates for BrF, IF, and BrCl are compared to the predictions of the Schwartz, Slawsky, and Herzfeld (SSH) theory.