Autoionizing-resonance enhanced preferential photodissociation of CO2 in superexcited states

Publisher Website
Google Scholar
Abstract
Fluorescence excitation spectra of CO2+(Ã 2Πu→X̃ 2Πg), (B̃ 2∑u+→X̃ 2Πg), and CO(A 1Π→X 1Σ) emissions produced in the photoionization and neutral photodissociation of CO2 have been obtained in the 30–92 nm region. A strong competition between autoionization and neutral dissociation observed in the region near the ionization thresholds to form CO2+(Ã 2Πu) and CO2+(B̃ 2Σu+) states clearly shows the preferential enhancement of the neutral dissociation, which is explained mainly by the intrinsic autoionization rate of the individual superexcited Rydberg states. A drastic step‐down decrease in a fluorescence excitation spectrum in the vacuum ultraviolet region at the thresholds has been ascribed to a dramatic density dilution of the superexcited states into the continuum.