A novel method for preparation of 8-hydroxyquinoline functionalized mesoporous silica: Aluminum complexes and photoluminescence studies

8-Hydroxyquinoline (8-HQ) was attached to mesoporous silica by sulfonamide bond formation between 8-hydroxyquinoline-5-sulfonyl chloride (8-HQ-SO2Cl) and aminopropyl functionalized SBA-15 (designated as SBA-SPS-Q) and then aluminum complexes of 8-HQ was covalently bonded to SBA-SPS-Q using coordinating ability of grafted 8-HQ.The prepared materials were characterized by powder X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FT-IR), thermal analysis (TGA-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analysis and fluorescence spectra. The environmental effects on the emission spectra of grafted 8-HQ and its complexes were studied and discussed in details.

Research highlights► Design a new method for grafting 8-HQ ligand to the surface of SBA-15 via a stable sulfonamide bond. ► Synthesis of 8-HQ aluminum complex containing of this new 8-HQ functionalized SBA-15 material. ► Different fluorescence behaviors of grafted 8-HQ ligand in comparison with 8-HQ molecules in a aqueous solution. ► Tuning the emission of grafted 8-HQ aluminum complexes through the ligand exchange reaction using appropriate substitution on coordinated 8-HQ.