Journal of Physical Chemistry A, Vol.104, No.12, 2567-2572, 2000
Collisional energy transfer of NO D (2)Sigma(+) (upsilon '=0) and A (2)Sigma(+) (upsilon '=4) by O-2, N-2, Ar, and NO
Temporally and spectrally resolved fluorescence from NO D (2)Sigma(+) nu' = 0 and A (2)Sigma(+) nu' = 4 after two-photon excitation is studied in the presence of O-2, N-2, Ar, and NO colliders at room temperature. Quenching rate constants are determined for these gases. Nitrogen is found to efficiently quench these levels, with rate constants of (2.6 +/- 0.2) x 10(-10) cm(3) s(-1) and (2 +/- 0.15) x 10(-11) cm(3) s(-1), respectively. The large quenching rate for A (2)Sigma(+) nu' = 4 by N-2 compared to those of lower vibrational levels is explained by the onset of near resonant energy transfer into the N-2 A (3)Sigma(u)(+) metastable state, similar to the path known for quenching the C (2)Pi and D (2)Sigma(+) states.
Keywords:LASER-INDUCED FLUORESCENCE;NITRIC-OXIDE;RYDBERG STATES;QUENCHING RATES;RELAXATION;MOLECULES;2-SIGMA+;D2-SIGMA+;LIFETIME;GASES