Photochemical Rearrangements of o-and m-Dichlorobenzene Cation to p-Dichlorobenzene Cation in Solid Argon

Article abstract of DOI:10.1021/ja00290a015

Matrix photoionization experiments with o- and m-dichlorobenzene and 1,2,4-trichlorobenzene produced and isolated for spectroscopic study not only radical cations of the precursor compound but also rearranged cation products.It is postulated that a bridged chloronium ions is formed upon excitation to the lone pair hole state which serves as an intermediate in rearrangements among the excited-state di- and trichlorobenzene cation isomers.The chlorine lone pair hole excited state facilitates a "chloronium ion walk" around the aromatic ring.