Efficient excitation energy transfer in a soluble polyimide

A novel polyimide containing both perylene units and fluorene units was designed and synthesized. The polyimide exhibited strong solid film fluorescence. When the polymer solution or films were irradiated by the UV light of 308 nm (the maximum absorption position of fluorene moieties and perylene moieties did not absorb light of this wavelength), only the emission light of perylene moieties was observed. These results indicate that the excitation energy of fluorene moieties completely transfer to perylene moieties.