Extensive electron-nuclear angular momentum exchange in vibrational autoionization of np and nf Rydberg states of NO.

Vibrational autoionization of individual rotational levels of np (n ­ 1) and nf (n ­ 1) Rydberg states of nitric oxide (NO) with 11 # n # 15 have been studied employing two-color double-resonance excitation via the NO A S1 (ni ­ 1) state. The rotational state distributions of the resulting NO X S1 (n ­ 0) ion have been determined by time-of-flight photoelectron spectroscopy. These measurements show the occurrence of angular momentum exchange between the outgoing electron and the molecular-ion core, a process that has been commonly neglected in theoretical treatments of vibrational autoionization.