| Abstract: | On the Luminescence of 9-Fluorenone The fluorescence of 9-fluorenone has been measured in various solvents. At room temperature and for non-hydrogen bonding solvents an emission with 19.3 ? \documentclass{article}\pagestyle{empty}\begin{document}$ \widetilde\nu $\end{document} max ? 21.4 · 103 cm?1 is found, whereas the fluorescence for hydrogen bonding solvents is broad and strongly red shifted, 16.7 ? \documentclass{article}\pagestyle{empty}\begin{document}$ \widetilde\nu $\end{document} max ? 17.5 · 103 cm?1. For these solvents also a strong temperature dependence of the emission characteristics is observed. The effects are attributed to hydrogen bonding of excited singlet fluorenone. Further, the phosphorescence of 9-fluorenone is detected for ethanol and EPA (diethyl ether/2-methyl-butane/ethanol (99.5%) 5:5:2) solutions, locating the lowest triplet ππ* state at 17,600 cm?1. |
