Novel hybrid materials with covalent bonding and rare earth ions-induced enhancing luminescence of bridged 9-amino acridine

Covalently bonded silicate/modified acridine luminescent composites have been prepared from 3-(triethoxysilyl)-propyl isocyanate (TEPIC) grafted 9-amino acridine and central metal ions. The existence of covalent linkages between TEPIC and silica matrices was introduced after hydrolysis and polycondensation processes of ethoxysilyl groups. Luminescence spectra were utilized to characterize the photophysical properties of the obtained hybrid material and the above spectroscopic data reveal that the lanthanide ions and such covalent bonds trigger the increasing blue emission intensities (4-10 times) of modified acridine. Scanning electron micrographs inferred that the hybrids were quite homogeneous and free from phase separation.