Proton‐Addition Complexes of Aromatic Hydrocarbons

Abstract

Abstract The structures of proton‐addition complexes of aromatic hydrocarbons were hitherto known only with respect to their stoichiometric compositions but can now be clarified by ultraviolet, infrared, and NMR spectroscopic methods. For example, it has been possible to prove by NMR soectroscopy that the expected addition of protons into 9,10‐dimethyl‐[a] benzanthracene actually does take place. Two isomeric proton adducts of toluene have been found by means of infrared spectra. On addition of protons, the ultraviolet spectra of aromatics change considerably; excellent agreement is sometimes observed between the band maxima calculated by quantum mechanics and those found by experiment.