Red/Near-Infrared Light-Emitting Organic-Inorganic Hybrids Doped with Covalently Bound Boron Dipyrromethene (BODIPY) Dyes via Microwave-Assisted One-Pot Process

Red/near-infrared (NIR) light-emitting boron dipyrromethene (BODIPY) dyes bearing methacryloyl groups were synthesized, and these dyes were covalently bonded to poly(2-hydroxyethyl methacrylate) (PHEMA) silica hybrids. The preparation of their hybrids was performed by simultaneous sol gel reaction of trimethoxy(methyl)silane and radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with the dyes under microwave irradiation or conventional heating. Strong red/NIR light-emitting hybrids without discoloration of the dyes were successfully obtained under microwave irradiation, whereas the dyes lost luminescent properties in the hybrids prepared under conventional heating. Photostability test of the hybrids showed that covalent attachment of the dyes led to significant improvement in the photostability in comparison with the solution state. Further, elution amount of the dyes from the hybrids in organic solvents decreased relative to that from physical dye-admixing hybrids due to the covalent bond between PHEMA and the dyes.