Fluorescence behavior of powders and high-pressure compacts of silica containing silyl-functionalized benzazole dyes

Four silyl-functionalized benzazole dyes were covalently bonded in the silica network by sol–gel technique using tetramethyl orthosilicate (TMOS) as inorganic precursor. High-pressure technique was used to produce fluorescent and transparent compacts of grafted silica at 6.0 GPa and room temperature. The excited state intramolecular proton transfer (ESIPT) mechanism of the benzazole dyes in the grafted silica powders and compacts was investigated by steady-state fluorescence spectroscopy.