Oxygen Sensors Based on Luminescence Quenching: Interactions of Tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) Chloride and Pyrene with Polymer Supports

Abstract

Oxygen quenching of [Ru(Ph₂phen)₃]Cl₂ (Ph₂phen = 4,7-diphenyl-1,10-phenanthroline) and pyrene has been studied in a series of polymer networks of Gp-163 (a methacryloxy functional polydimethylsiloxane) co-polymerized with one of several co-monomers: styrene, trimethylsilyl-methylmethacrylate (T3642), vinyl-tris(2-methoxy-ethoxy)silane, or vinyl-tris(trimethylsiloxy)silane. Sensor performance was studied as a function of the polymer composition in order to delineate the important features for satisfactory O₂ sensor supports. Quenching behavior was examined as a function of polymer structure, including amount and type of co-monomer. This work shows that the earlier two-domain model is too simplistic. The relative affinities of the different domains for the [Ru(Ph₂phen)₃]Cl₂ and pyrene and the efficacy of the domains for O₂ quenching are important; however, subtle changes in microstructure within domains can also strongly affect behavior. In particular, T3642 exhibits excellent structural and good quenching properties with [Ru(Ph₂phen)₃]Cl₂.