Unusual fluorescence anisotropy spectra of three-component donor–mediator–acceptor systems in uniaxially stretched polymer films in the presence of energy transfer

Energy transfer was studied for donor–mediator–acceptor systems in uniaxially stretched polymer films. The systems differ in the ability of mediator transition moment to orientate in the matrix. It was found that acceptor fluorescence remains polarized in the stretched matrix irrespectively of mediator. This means that information on the orientation of electric vector of the exciting light was conserved after energy transfer. In disordered system sensibilized fluorescence of mediator and acceptor is strongly depolarized. The effect of transition moments correlation on 〈κ2〉 in the stretched matrix is presented using Monte-Carlo simulation.