Absorption Spectra and Photochemical Rearrangements of Xylene and Methylcycloheptatriene Cations in Solid Argon

Article abstract of DOI:10.1021/j100233a027

Matrix photoionization experiments have been performed for several p-dialkylbenzenes and alkylcycloheptatrienes.Broad absorptions at 23500 and 34700 cm^-1 following UV matrix two-photon ionization of p-xylene are assigned to the parent cation, in agreement with photodissociation spectra of gaseous cation.A broad absorption at 20240 cm^-1 following vacuum-UV matrix photoionization of 7-methylcycloheptatriene is assigned to the parent cation, in agreement with the difference between photoelectron bands.Mercury arc photolysis has been used to activate the extensive rearrangements of the p-xylene and 7-methylcycloheptatriene cations, which finally rearrange to a common conjugated triene cation identified as a substituted methylenecyclohexadiene cation.