CONCENTRATION QUENCHING OF PHOTOLUMINESCENT RU(BPY)(3)(2-BIPYRIDINE PENDANT GROUPS IN DEPENDENCE OF MOLECULAR-DISTRIBUTION() DISPERSED IN APOLYSILOXANE FILM CONTAINING 2,2')

The photoluminescent Ru(bpy)(3)(2+) complex was dispersed in a polysil oxane film containing 2,2'-bipyridine (bpy) pendant groups. The unusua lly long photoluminescence lifetime of the Ru(bpy)(3)(2+) (1,94 mu s a t 25 degrees C) and the blue-shifted photoluminescent wavelength sugge st a rigid polymer matrix. The fluorescence yield becomes lower with h igher probe concentration, indicating concentration quenching. Accordi ng to the analysis based on Stern-Volmer plots, the quenching obeys a mechanism composed of both static and dynamic processes. A statistical intermolecular distance distribution between the probes was used to i nterpret the results in terms of static and dynamic quenching. It is s hown that in the present system the dispersed complexes diffuse slight ly during the excited state.