SPECTROSCOPIC PROPERTIES OF 9-ACETOXY-2,3-DIMETHOXY AND ACETOXY-3-METHOXY-10-(4'-HALOGENOPHENYL)ANTHRACENE DERIVATIVES

The absorption and fluorescence spectra, fluorescence quantum yields a nd decay times were measured for the first time for six 9-acetoxy-10-h alogenophenylanthracene derivatives. It is found that the rate constan ts of radiative (k(F)) and non-radiative (k(D)) processes do not depen d on the Z value of the halogen atom substituted in the 4' position of the phenyl ring. However, they strongly depend on the acetoxy and met hoxy groups substituted in the 2 and 3 positions of the anthracene rin g: k(D)>k(F). The shape of the absorption spectrum is similar to that of anthracene, but the mirror symmetry between the absorption and emis sion spectra is lost.