Detection of 'ended' NO recoil in the 355 nm NO_2 photodissociation mechanism

摘要

Circularly polarized 1 + 1' REMPI with ion imaging detection was used to probe #mu#-v-j angular correlations of the NO (X ~2#PI#_(1/2,3/2), #upsilon# = 0) photoproduct from linearly polarized 355 nm photodissociation of NO_2 in a molecular beam. Rotational angular momentum orientation was measured for the NO product, with the sense and magnitude of the orientation depending upon the direction of the NO recoil velocity with respect to the polarization vector of the photolysis light. The rotational orientation is shown to originate from the directionality of the torque responsible for NO rotational motion. The experimentally observed sense of rotation in the plane of the NO_2 parent molecule is consistent with an effective recoil impulse force applied to the N end of the NO product. A preliminary measure of the bipolar moment associated with this orientation for the j = 21.5 and j = 36.5 rotational levels gives a value of approximately #beta#_0~2(21) = 0.2.