Sol‐Gel Organic‐Inorganic Hybrid Materials Containing Lanthanide Complexes with Polydentate Acyclic and Cyclic Ligands: Synthesis and Spectral‐Luminescent Properties

In this work we report the results of the study on luminescent lanthanide-containing silica-based hybrid materials. The preparation of organic–inorganic hybrids was realized in several stages. At first, the prior modification of the organic ligand (ethylenediaminetetraacetic (EDTA), diethylenetriaminepentaacetic (DTPA) acids, or p-tert-butyl-calix[4]arene (TBC)) with triethoxysylil group was carried out. Then the obtained precursors were reacted with an equimolar amount of lanthanide salt. At last, a sol-gel process was held and organic–inorganic hybrid materials were synthesized. All samples were characterized by elemental analysis, IR-, NMR-spectroscopy, and SEM. Under UV-excitation typical 4f-luminescence was observed in Ln-EDTA-APTMS/SiO2, Ln-DTPA-APTMS/SiO2 and Ln-TBC-TESPIC/SiO2 (Ln = Nd(III), Eu(III), Tb(III), and Yb(III)). The factors determining luminescence efficiency in studied systems are discussed.