Photoenergetics of molecular forms of acridine dyes in polymer matrices

The spectral and luminescence properties of acridine yellow and acridine orange in polyvinyl alcohol matrices were studied. The concentration dependences of the relative quantum yield of fluorescence show that in the systems studied the dye molecules form dimers and more complex associates. The quantwn yield of fluorescence from acridine yellow dimers is higher than that from monomers. The quantum yields and fluorescence decay times of various acridine molecular forms were determined, and the patterns of excitation energy transfer between these forms were studied. The critical radii of nonradiative energy transfer were calculated. The kinetic data show that excited monomeric acridines undergo rotational relaxation while excited associates do not.