Construction of lanthanide luminescent molecular-based hybrid material using modified functional bridge chemical bonded with silica

The study focuses on the syntheses of modified chloronictinic acid by (3-aminopropyl)triethoxysilane and the preparation of their corresponding organic-inorganic molecular-based hybrid material with the two components equipped with covalent bonds. The bridging unit is a derivative of 2-chloronictinic acid (ClNIC-Si) which is utilized to coordinate to Tb3+ or Eu3+ (abbreviated as RE3+) and further introduced into silica matrices by SiO bonds after hydrolysis and polycondensation processes. Ultraviolet absorption, phosphorescence spectra, and fluorescence spectra were applied to characterize the photophysical properties of the obtained hybrid material and the above spectroscopic data present that the triplet energy of modified chloronictinic acid efficiently initiates the antenna effect and matches with the emissive energy level of RE3+. Accordingly, the intramolecular energy transfer process completed within these molecular-based hybrids and strong green or red emissions of RE3+ have been obtained.