Influence of conformational effects on spectroscopic properties of 2-dimethylamino-9(4'-dimethylamino) phenyl-9-fluorenol.

Absorption and fluorescence spectra of 2-dimethylamino-9(4'-dimethylamino)phenyl-9-fluorenol have been studied in different solvents. The fluorescence spectra at various temperatures show the excitation wavelength dependence. The spectroscopic data are compared with the results of the quantum chemical calculation obtained using PM3 and INDO/S methods. The fluorescence decay curves of the molecule under study can be only satisfactorily fitted by a biexponential function. The steady state and time resolved spectroscopy studies as well as the theoretical calculation confirm that in methylcyclohexane and ethyl acetate solutions always two absorbing and emitting species exist, namely rotamers alpha and beta in the ground and excited states.