OXYGEN-SENSITIVE LUMINESCENT MATERIALS BASED ON SILICONE-SOLUBLE RUTHENIUM DIIMINE COMPLEXES

New oxygen-sensitive luminescent materials were obtained by physically immobilizing luminescent ruthenium(II) diimine complexes in silicone rubber. The dyes were made silicone-soluble by converting them into th e respective ion pairs with organic anions. Acetic acid-releasing one- component RTV silicones were found to provide the best matrix for sens or membranes. The dyed silicone prepolymers were spread onto planar so lid supports, cured, and characterized in terms of quenching by oxygen , response time, interferences, storage stability, and photostability. Strong evidence is presented from quenching experiments that the lumi nescent ion pairs are present in both a monomolecular and an aggregate d form, the respective quenching constants being highly different, Thi s results in nonlinear Stern-Volmer graphs. The new oxygen-sensitive m aterials are considered to present a major improvement over existing s ensor materials in terms of response time, luminescence intensity, and longterm stability, They not only may be applied as planar films but also as very thin coatings on various binds of waveguides, We also des cribe several novel materials for use as light-tight optical isolation s, They are spread onto the oxygen-sensitive films in order to minimiz e interferences by (a) ambient light and (b) potentially interfering s ample properties such as color, turbidity, fluorescence, and varying r efractive index.