THE SINGLE CRYSTAL PHOSPHORESCENCE OF ADENINE AT 77 K

Abstract— The low temperature phosphorescence spectra of large single crystals of adenine salts (adenine sulphate, adenine hemisulphate monohydrate, adenine hydrobromide hemihydrate) were compared with the spectra of polyadenylic acid in polydlcoholic glasses compiled from literature. The results show that adenine single crystals may serve as a convenient molecular system for modeling energy levels of polyadenylic acid and energy transfer between adenine molecules, at least in the case of triplet states. The main advantage of such a model system is that their periodic molecular arrangement and the site of protonation are exactly known from the X-ray diffraction studies.