We report a novel technology for fabricating sol-gel derived nano-scale molecular hybrid materials that contain NHC( O)NH groups anchored to a silica network. The modified 2-amino pyridine is grafted by 3-(triethoxysilyl)-propyl isocyanate and applied to coordinate to RE3+ (Eu3+, Tb3+) through nitrogen atoms of the heterocycle of pyridine group and further formed Si O backbones after hydrolysis and polycondensation processes. For analogy and luminescence efficiency purpose, we added 1,10-phenanthroline to the above hybrids in order to increase the conjugating effects and sensitize rare earth ions emissions. IR, ultraviolet absorption and luminescence spectra were utilized to characterize the structure and photophysical properties of the obtained hybrid material and the above spectroscopic data reveal that the triplet energy of 1,10-phenanthroline in this favorable hybrid system matches with the emissive energy level of RE3+.

Covalently bonded silicate/modified aromatic acid luminescent composites have been prepared from 3-(triethoxysilyl)-propyl isocyanate (TEPIC) grafted salicylic acid and central metal ions (Tb, Zn). The existence of covalent linkages between TEPIC and silica matrices were realized by 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 triplet energy of modified salicylic acid in this favorable hybrid system matches with the emissive energy level of Tb3+. In addition, Zn containing hybrids exhibit a broad band around 420 nm which may be beneficial to fabricate blue emission materials.

The syntheses of modified nicotinic and picolinic acid by (3-aminopropyl)triethoxysilane and the preparation of their corresponding organic-inorganic molecular-based hybrid materials with the two components equipped with covalent bonds are described. The organic part is a derivative of heterocyclic compounds which is used to coordinate to Tb3+ and further introduced into silica matrixes by Si-O bonds after hydrolysis and polycondensation processes. According to the Judd-Ofelt theory, covalency increases with the increasing reciprocal energy difference between the 4fN and 4fN-15d1 configurations. Infrared, ultraviolet absorption, phosphorescence spectra, and luminescence spectra were applied to characterize the photophysical properties of the obtained hybrid material, and the above spectroscopic data revealed that the triplet energy of modified heterocyclic acid especially the modified nicotinic acid matched the emissive energy level of Tb3+. In this way, an intramolecular energy transfer process took place within these molecular-based hybrids and strong green emission of Tb3+ was achieved.

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 Si O 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.

Maleic anhydride was grafted by long chain alcohol 1-eicosanol to a novel sort of corresponding monoester, mono-eicosyl cis-butene dicarboxylate. Then the four novel ternary lanthanide (Eu3+, Tb3+, Dy3+, Gd3+) complexes with the as-derived long chain monoester and a second ligand 1,10-phenanthroline were synthesized and characterized by elemental analysis, IR spectra. The photophysical properties of these complexes were studied in detail with ultraviolet absorption spectra, low temperature phosphorescent spectra, fluorescent spectra and luminescent lifetimes, indicating that the intramolecular energy transfer mechanism runs smoothly within these ternary complexes in terms of sensitized functions of 1,10-phenanthroline and strong characteristic green, red or blue emissions of Tb3+, Eu3+ or Dy3+have been achieved.