Absorption Spectra and Photochemical Rearrangements in Phenylalkene Cations in Solid Argon

Article abstract of DOI:10.1021/ja00411a026

Matrix photoionization experiments with phenylalkenes produced and trapped the parent molecular cations in solid argon at 20 K.In the substituted styrene cation cases, structure was resolved in red and ultraviolet absorption bands and assigned to Ph-C stretching and Ph-C=C bending modes.Molecular ion rearrangements were observed during sample formation and upon the photolysis of the cold sample; allylbenzene cation rearranged to β-methylstyrene cation and indan cation with 290 nm irradiation.The matrix absorption bands were substantially sharper than photodissociati on spectra, which suggests that excess internal energy may contribute substantially to the bandwidth of gaseous molecular ions produced by electron impact.