FLUORESCENCE-SPECTRA OF SALT-SOLUTIONS OF COUMARIN-CROWN ETHERS

The fluorescence spectra of the coumarin derivatives of crown ethers o btained from 7,8-dihydroxycoumarins were studied in the presence of so me alkali and alkaline earth cations in acetonitrile. The altered fluo rescence spectra were examined qualitatively from the point of enhance ment of fluorescent quantum yields as well as a resonance. Heavy metal effects were eliminated since there is no influence of the metal salt s on the spectra of the initial coumarin derivatives. However, both th e complexation-enhanced fluorescence and complexation-enhanced quenchi ng spectra is observed in the fluorescence emission and excitation spe ctra of macrocyclic ether-coumarin I metal salt systems. The origin of results are briefly discussed in terms of crown ether complexation. L n water solutions almost no such effects were observed.