Barometric Sensitive Coatings Based upon Osmium Complexes Dissolved in a Fluoroacrylic Polymer

Pressure sensitive paints (PSP) that measure the changes in air pressure have proved to be useful in the design of aircraft and other vehicles. In this study we incorporate highly luminescent divalent osmium complexes into PSP. The divalent osmium complexes were heptafluorobutyrate salts of [Os(N−N)2(L−L)]2+ or [Os(L−L)2(N−N)]2+, where N−N is a derivative of 1,10-phenanthroline, and L−L is a diphosphine or diarsine ligand. The complexes were dissolved into poly(1,1,1,3,3,3-hexafluoroisopropylmethacrylate-co-1H,1H-dihydroperflurobutylmethacrylate) (FIB) at a concentration of 0.002 g of complex to 1.000 g of polymer. The luminescence of the coatings was tested for pressure sensitivity, temperature dependence, and photodegradation. The paints featured strong pressure response, and the temperature dependence of the luminescence was measured as low as −0.11% °C−1. Several of the complexes exhibited little photodegradation upon prolonged exposure to 400 nm light. These attributes make the complexes very desirable luminescent dyes for PSP.