PHOSPHORESCENT COMPLEXES OF PORPHYRIN KETONES - OPTICAL-PROPERTIES AND APPLICATION TO OXYGEN SENSING

A new class of dyes, platinum(II) and palladium(II) complexes of the p orphyrin ketones (or ''oxochlorins''), exhibiting strong phosphorescen ce at room temperature is described. Several representative compounds were prepared and studied by spectral luminescence methods in solution . Compared to the related porphyrin and chlorin complexes, the new dye s display high photochemical stability, long wave spectral characteris tics, and good compatibility with semiconductor optoelectronics (e,g,, excitation by light-emitting diodes), These properties make the new d yes promising for a number of relevant applications, such as quenched phosphorescence sensing and phosphorescence probing (e.g., in binding assays). Analytical application of the porphyrin ketone complexes to p hosphorescence lifetime-based sensing of molecular oxygen is described . Platinum(II) octaethylporphine ketone was dissolved in a polystyrene layer to give an oxygen-sensitive film, Oxygen measurements were perf ormed with a prototype fiber-optic instrument based on solid-state com ponents, such as light-emitting diodes and photodiodes, The instrument measured phosphorescence lifetime via changes in phase shift, The pho sphorescence lifetime was determined to change from about 61.4 mu s at zero oxygen to 16.3 mu s in air (210 hPa of oxygen) at 22 degrees C, The analytically useful range of the sensor was 0-210 hPa of oxygen pa rtial pressure, with a detection limit of 1.5 hPa. The precision of th e device was 1.0 hPa at 210 hPa of oxygen and 0.5 hPa at zero oxygen.