The cations and anions of cyclobutanetetraone poly(phenylhydrazones) Original Research Article

Six cyclobutanetetraone poly(arylhydrazones) have been treated with acids and bases, and the structures of the resulting anions and cations studied by UV–Vis absorption and NMR spectroscopy. In acid media, all the hydrazones studied formed cations, which exhibited bathochromic shifts due to the extension of their resonance systems. However, in bases, only some (those which could enolize) formed anions that exhibited hypsochromic shifts; the others were unaltered.