Lanthanide-centered Luminescent Covalent Hybrid Material Obtained By Sol-gel Method

Lanthanide ions always exhibit their excellent photophysical abilities when they are excited by the UV light because of their unique electron configurations. Covalently grafting the lanthanide complexes to the silica backbone via Si-C bonds can improve the materials' properties. The organic ligands can reinforce the energy absorption efficiency and the inorganic portions of the structure offer good mechanical properties. In this paper, the linkage for connecting organic compounds to inorganic solid supports, the chromophoric group and the sol-gel process are investigated thoroughly. And the properties of the received materials are also determined in this paper.Two ordinary organic groups are selected in this paper: sulfonic acid group and hydrosulfide group. They are modified by organosilanes respectively and derived multifunctional precursors are afterward submitted to complex with lanthanide ions. After sol-gel process, luminescent materials are received. Narrow-width green emissions are achieved for Tb³⁺ ions. Narrow-width red emissions are achieved for Eu³⁺ and Sm³⁺ ions. The investigations prove that these two kinds of linkage are feasible and can be expected to be conveniently applied to other hybrid systems.In this paper, three kinds of chromophoric group are selected: pyridine, calixarene andβ-diketone. They are modified by organosilanes respectively and derived multifunctional precursors are afterward submitted to complex with lanthanide ions. After sol-gel process, luminescent materials are received. The excellent emissions mean that the efficient intramolecular energy transfer process between carboxylic group and lanthanide ions took place within these molecular-based hybrids.The sol-gel process is also investigated in this paper. A new route to gelatine and hybrid microparticles is put forward, based on an o/w process and organosilane polycondensation. The results prove that the coordination between the ions and the ligands in the sol-gel process can impact on the organization in those amorphous systems. Although all the hybrid materials are amorphous, the organizations do exist and could be adjusted.