NOVEL METAL-ORGANIC RUTHENIUM(II) DIIMINE COMPLEXES FOR USE AS LONGWAVE EXCITABLE LUMINESCENT OXYGEN PROBES

New ruthenium(II) diimine complexes are presented which are useful as luminescent oxygen probes. Because their luminescence excitation maxim a are between 535 and 570 nm, they can be photo-excited by green LEDs which are much brighter than the blue LEDs used so far for existing Ru diimines. The spectral and photophysical properties as well as the so lubility properties of the new probes are investigated and discussed i n terms of quenching, photostability, and lifetimes. The probes were i ncorporated into organic polymers by three different methods, to obtai n oxygen-sensitive materials for use in optical oxygen sensing. The me mbranes were characterized with respect to oxygen sensitivity, lumines cence intensity, response times, and stability. Notwithstanding the po or luminescence of the new ruthenium(II) probes, their stability, LED compatibility and efficient quenching by oxygen makes them an interest ing alternative to existing luminescent oxygen probes.