Energy transfer dynamics in the A(0u+) state of Bi2

Laser induced fluorescence, pulsed and CW, techniques have been used to study energy transfer within the A(0(u)(+)) state of Bi-2. In particular, electronic quenching in the vibrational levels near predissociation, v'=18-25, have been examined for rare gas and nitrogen collision partners. The quenching from non-predissociated levels is independent of vibrational state and are rather rapid, 2.3 - 8.5 x 10(-11) cm(3)/molecule-s for v'=22. The quenching from the first significantly predissociated level, v'=23, is even faster with rate coefficients ranging from 7.4 - 15.7 x 10(-11) cm(3)/molecule-s. Heterogeneous predissociation is very rapid for 21less than or equal to v' less than or equal to39, with rates, Gamma = k(pd)(v') J (J+1), of k(pd) as large as 1.5 x 10(5) s(-1). Vibrational-to-translational energy transfer probabilities for the lowest vibrational levels, v'=0-4, range from 0.75 - 1.75% per collision, considerably lower than would be anticipated for these highly non-adiabatic collisions. Spectrally resolved emissions from collisionally populated rotational levels of Bi-2(A,v'=1) were observed for helium, neon and argon collision partners after laser excitation of the high rotational levels J'=171, 201, and 231. Total rotational removal rates from the initially prepared state range from 2.8 - 8.9 x 10(-10) cm(3)/molecule-s. Collisional population of rotational states with \DeltaJ\ less than or equal to 56 was observed at pressures of 0.09 - 1.4 torr. The state-to-state rates are adequately modeled by the energy based statistical power gap law.