Preparation and luminescent properties of lanthanide (Eu 3+ and Tb 3+ ) complexes grafted to 3-aminopropyltriethoxysilane by covalent bonds

•Aromatic acids/bridged polysilsesquioxanes have been synthesized by sol–gel method.•As-prepared compounds in sol condition were coated on quartz plates to form a layer of thin film.•The obtained materials enhanced thermal stability, mechanical resistances, waterproofness as well as machining properties.