Photodissociation of positive and negative ions formed in O2

摘要

The tandem quadrupole photodissociation mass spectrometer has been used to study photodissociation reactions of O2+, O3+, O4+, O2minus;, and O3minus;formed in O2at pressures between 0.01ndash;1 torr. At low pressures O2+photodissociation was observed using 600 nm radiation, and pressure studies indicate that an excited state of O2+is involved, which is collisionally relaxed with a rate constant of approximately 2times;10minus;11cm3/sec. Photodissociation of O3+was found to occur at sim;600 nm primarily by the reaction O3+rarr;O++O2with a large cross section (10minus;17cm2).