The Ratio of Quantum Yields of Fluorescence and Phosphorescence of Some N-Heterocyclic Compounds in Solutions at 77 K

  • Ivan Janić
Conference paper


Measurements were made of the ratio of quantum yields of fluorescence and phosphorescence (ɳf/ ɳp), the position of the 0–0 transition of the fluorescent and phosphorescent spectrum and the lifetime of phosphorescence in the molecules (free base) and cations (conjugate acid) of seven nitrogen containing heterocyclic compounds (5,6- and 7,8-henzoquinoline, 2-, 4- 6-, 7- and 8-methylquinoline) dissolved in n-hexane and ethanol at different concentrations at 77 K. The n-hexane and ethanol solutions of henzoquinoline have a ɳfp between 0.5 and 6; the cation, between 2.5 and 17. In pure hydrocarbon solvents at 77 K, methylquinolines show only phosphorescence (ɳfp < 0.01). In alcohol solvents at 77 K there occurs both fluorescence and phosphorescence (in ethanol ɳfp = 0.8 to 4.5).


Quantum Yield Luminescence Spectrum Free Base Electronic Ground State Conjugate Acid 
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Copyright information

© Plenum Press, New York 1973

Authors and Affiliations

  • Ivan Janić
    • 1
  1. 1.Institute of Physics and MathematicsUniversity of Novi SadNovi SadYugoslavia

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