Investigation of dye-matrix interactions in sol-gel derived hybrid organic-inorganic nanocomposites

Several dyes such as a spiropyran, a spirooxazine and two tetraarylporphyrins have been incorporated inside hybrid organic-inorganic matrices synthesized through the acid hydrolysis of dimethyldiethoxysilane and zirconium n-propoxide. These matrices are nanocomposites with well defined hydrophilic (zirconium oxopolymer nodules) and hydrophobic (polydimthylsiloxane chains) domains. As a consequence, they are good candidates to investigate dye-matrix interactions in matrices containing transition metal. These interactions are shown to occur through hydrogen bonds, covalent bonds or Lewis acid-base type bonds. They strongly modify the optical response of the dyes (absorption-emission spectra, lifetime, kinetics..).