Transient triplet–triplet absorption spectra of xanthone were obtained in several solvents
through picosecond pump probe experiments. Shape and wavelength maximum of the
absorption spectrum depended on the polarity. The evolution of the wavelength maximum
was analyzed in terms of the dielectric continuum theory (Onsager function), the Dimroth
empirical parameter ET (30) and the Kamlet and Taft solvent parameters. In nonpolar
solvents transient absorption spectra showed two bands, ascribed to transitions originating …