THE NO(A (4)PI) STATE - FIRST GAS-PHASE KINETIC MEASUREMENTS

Observation of the temporal evolution of NO(B (2) Pi-X (2) Pi) emissio n following one-photon excitation of the NO(a (4) Pi) state is used to study NO(a) kinetics. Loss rate coefficients are determined for the u psilon = 11 level, using NO and He as colliders. The loss rate coeffic ient for NO is (1.44 +/- 0.29) X 10(-10) cm(3) s(-1), and that for He is (1.23 +/- 0.16) X 10(-12) cm(3) s(-1); comparisons are made with th e approximately isoenergetic upsilon = 2 level of the B (2) Pi state. Details of the a --> B electronic energy transfer process are investig ated. Transfer to the nearest B (2) Pi level, upsilon = 2, occurs rela tively rapidly, whereas population of the upsilon = 0 level requires v ibrational cascading within the quartets.