PHOTOPHYSICAL PROPERTIES OF RUTHENIUM POLYPYRIDYL PHOTONIC SIO2 GELS

The photophysical properties of Ru(bpy)3(PF6)2 and cis-Ru(bpy)2(CN)2 ( where bpy = 2,2-bipyridine) doped into monolithic SiO2 aquo and alco g els prepared by sol-gel processing techniques is described. The excite d-state properties of the dopants are dramatically altered by the gel matrix. The photoluminescence emission energy and quantum yield of the dopants increase through the sol-to-gel transition. Steady-state fluo rescence polarization measurements reveal significant anisotropy. Time -resolved fluorescence decays observed from these photonic materials a re complex. Evidence for a bimodal distribution of dopant sites is obt ained from modeling the emission decays and from application of the ex ponential series method. Implications of these results for molecular p hotonic applications are discussed.