Organometallic osmium and iridium complexes as phosphorescent dye in barometric sensitive coatings

Pressure sensitive paints (PSP) that measure changes in barometric pressure through oxygen quenching are an important analytical tool in wind tunnel and other research. PSPs are often used during the development phase of new aircraft, cars, and trucks where the performance of the proposed vehicle is researched. Previously, many PSPs have been based upon charged phosphorescent metal complex salts that may have poor solubility in the oxygen permeable host material. Charge neutral phosphorescent dyes should have better solubility, and to demonstrate this, neutral osmium and iridium complexes are presented in this report. X-ray structures are measured and DFT calculations are used to explain many of their properties. The complexes are dissolved into poly(1,1,1,3,3,3-hexafluoroisopropylmethacrylate-co-1H,1H-dihydroperfluorobutyl-methacrylate) (FIB), an oxygen permeable host polymer. The complexes exhibit good solubility and compatibility with the FIB polymer. The photo-degradation, temperature sensitivity, and Stern–Volmer curves of PSPs based on these complexes are presented. The complexes show great promise for use in PSPs.