Inhomogeneous Broadening of the Electronic Spectra of Laurdan

The excitation spectra and dependence of the luminescence spectra on the energy of excitation quanta were investigated for a laurdan molecule in glycerin. The most appreciable displacement of the emission spectra has been recorded for the most longwave luminescence band with a maximum in the region 500–510 nm. The relationship between the luminescence components of two emission bands with maxima at 425 and 500 nm depends strongly on the excitation energy. The dependences obtained are explained by the simultaneous existence of LE (localexcited) and TICT (twisted internal charge transfer) states and by the influence of the properties of the solvation sheath of laurdan, which invariably causes inhomogeneous broadening of the spectra of the polar solution molecules.