The role of excited electronic states in ion fragmentation: C 6H 6+

Abstract

The present article presents a critical review of our understanding of the fragmentation behavior of the electronically excited C 6H 6 + system. This system produces a number of primary ionic fragments at low excitation energy. The determination of the structure of these fragments is discussed. The evidence for structural isomerization is reviewed, both for fragmenting and non- fragmenting C 6H 6 + ions. The energetics of various ionization and fragmentation processes is established and presented, leading to conclusions about the relative stability of various C 6H 6 + isomer states. The competition between fragmentation, internal conversion, and reradiation of electronic excitation energy is examined. Lastly, the methodology for estimating heats of formation of molecules and ions of unusual structure is briefly discussed.