Photodissociation of atmospheric positive ions. II. 3500–8600 Å

Abstract

Using a drift tube mass spectrometer, photodissociation cross sections have been measured for many positive atmospheric cluster ions at ion laser and dye laser wavelengths between 3500 and 8600 Å. Structureless cross sections were observed for the dimer ions O+4, NONO+, N+4, and CO2CO2+, and for cluster ions of O2+. The nature of the electronic states involved is discussed. Evidence of a second dissociative state for O4+ and O2+⋅H2O in the ultraviolet is presented. Upper limits on the cross sections of COCO+ and cluster ions of NO+ and H3O+ below 1×10−19 cm2 were established at many wavelengths.