Journal of Chemical Physics, Vol.116, No.7, 2776-2782, 2002
Rotationally resolved photoionization dynamics of hot CO fragmented from OCS
The photoionization dynamics of rotationally hot CO, photodissociated from OCS, have been studied using laser photoelectron spectroscopy via the intermediate B (1)Sigma(+) Rydberg state leading to the X (2)Sigma(+) of the ion. The photodissociation of OCS near 230 nm produces rotationally hot, but vibrationally cold CO (X (1)Sigma(+),N-',v(')=0,1) fragments along with S (D-1) atoms. These high rotational levels show photoelectron spectra with a very strong DeltaN=0 transition and weaker DeltaN=+/-1, +/-2, and +/-3 transitions. Agreement between measured and calculated spectra is good and suggests that there is significant angular momentum coupling in the photoelectron orbital. In the ionization step not only Deltav=0, but also off-diagonal, non-Franck-Condon (Deltavnot equal0) transitions are observed. The intensities of these transitions vary strongly within the region studied and can be explained by the excitation of superexcited Rydberg states with an A (2)Pi core.