Journal of Chemical Physics, Vol.110, No.4, 2029-2041, 1999
Probing the alignment of NO(X-2 Pi) by [2+1] resonance-enhanced multiphoton ionization via the C-2 Pi state: A test of semiclassical theory in 355 nm photodissociation of NO2
A theoretical method to analyze the two-and three-dimensional imaging data of photofragments with polarized angular momentum was tested by comparing with the experimental data on NO from 355 nm photodissociation of NO2. The alignment of NO(X (2)Pi) was detected by [2+1] resonance-enhanced multiphoton ionization via the C (2)Pi state. The data were analyzed by assuming the mu-nu-J triple vector correlation described by semiclassical multipole moments in the velocity-fixed frame. The geometrical factors for the two-photon absorption were derived rigorously for the intermediate coupling between Hund's cases (a) and (b). It was also shown, however, that the geometrical factors for high J are independent of the coupling case and can be approximated by simple formulas. Excellent agreement between the simulation and the experimental data proved the validity of the semiclassical treatment.
Keywords:LASER TECHNIQUES;PHOTOFRAGMENT VELOCITY;ROTATIONAL ALIGNMENT;VECTOR CORRELATIONS;REACTION-PRODUCTS;TOP MOLECULES;2-PHOTON;SPECTROSCOPY;ABSORPTION;DYNAMICS