| Abstract: | A study has been made of the instantaneous fluorescence spectra of 4,4′-bis-dimethylaminobenzophenone (Michler’s ketone, MK), 4,4′-bis-diethylaminobenzophenone (DEAB), and 4-dimethylaminobenzophenone (DMAB) in various solvents, at room temperature. It has been shown that an increase of the solvent polarity leads to an increase of fluorescence intensity and a shift of the fluorescence band maximum toward longer wavelengths. The presence of traces of water in the solutions increases the fluorescence intensity and gives a red shift of the maximum. From the relationships found between the position of the fluorescence maximum and the polarity of the solvent, estimates have been made of the dipole moment of the luminescent state, which is 1.6·10−27 C·m for the MK, 2.1·10−27 C·m for the DEAB, and 0.8·10−27 C·m for the DMAB. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of the Ukraine, 31 Nauka Prospect, 252039 Kiev, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 1, pp. 36–40, January–February, 1997. |
