Phosphorescence of nucleic acids and DNA components at 77 K.
The emission spectra of nucleic acids, pyrimidine and purine nucleotides, nucleosides and bases and a series of pyrimidine derivatives were obtained using UV light excitation in glasses (ethanol and 2:1 mixtures of ethylene glycol and water (EG-H2O); also partly in butyronitrile and 2-methyltetrahydrofuran) at 77 K. The quantum yields of fluorescence phi f and phosphorescence phi p of some 30 compounds are presented; for several substituted uracils they are reported for the first time. The values cover a range from phi f = 0.0002 and phi p = 0.001 for uracil in ethanol to phi f = 0.50 for guanosine in acidic ethanol and phi p = 0.095 for guanosine-5'-monophosphate in EG-H2O (pH 6-7). The phosphorescence lifetime tau p at 77 K ranges from about 0.3 s (uracil moiety) to 3 s (adenine moiety). The measured tau p, phi f and phi p values are compared with those available in the literature.
Görner
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Max-Planck-Institut für Strahlenchemie, Mülheim an der Ruhr, F.R.G.
D004247:DNA; D005453:Fluorescence; D005615:Freezing; D008163:Luminescent Measurements; D009705:Nucleosides; D009711:Nucleotides; D011131:Polyribonucleotides; D011687:Purines; D011743:Pyrimidines; D012997:Solvents
D009705:Nucleosides; D009711:Nucleotides; D011131:Polyribonucleotides; D011687:Purines; D011743:Pyrimidines; D012997:Solvents; D004247:DNA