Studies on Aminoanthraquinone Compounds I—Absorption Spectra in Solution and in the Solid State

The ultraviolet and visible absorption spectra of six aminoanthraquinones have been determined in solution, on polymer films, and as solid deposits on quartz. The compounds were 1‐ and 2‐amino‐, 1:4‐ and 1:5‐diamino‐, 1:4:5‐triamino‐, and 1:4:5:8‐tetra‐amino‐anthraquinone. The solvents were ethyl and isopropyl alcohols, and transparent polymer films of nylon, N‐methoxymethylnylon, and secondary cellulose acetate were used. The effect of the solvent or substrate on the absorption spectrum and the problem of colour and chemical constitution in relation to the aminoanthraquinones have been discussed.