Spectroscopic studies on carbonium ions derived from aromatic olefins. Part II. Acenaphthylene, N-vinylcarbazole, and tetraphenylethylene

Abstract

The ultraviolet and visible spectra of three new carbonium ions are reported. Acenaphthylene was protonated in acetic acid–sulphuric acid mixtures. N-Vinylcarbazole was protonated by excess of perchloric acid in methylene dichloride. Both olefins gave the expected classical secondary carbonium ions. The interaction of perchloric acid with tetraphenylethylene gave an electrically conducting species with an absorption spectrum which precludes its being the product of protonation at the double bond. We believe this ion to be formed from the olefin by para protonation of a phenyl group.