Synthesis of SBA-15@3,4,5-tri Hydroxyphenyl Acetic@ Tb for the Facile Synthesis of 5-Substituted 1 H-tetrazoles

New organic-inorganic mesoporous hybrid materials containing terbium complexes covalently attached to mesoporous silica SBA-15 have been successfully prepared. The mesoporous silica SBA-15 was modified with 3,4,5-tri hydroxyphenyl acetic acid ligand and then used to fabricate the lanthanide-based mesoporous material SBA-15@3,4,5-tri hydroxyphenyl acetic@ Tb. The mesoporous material was characterized by Fourier transforms infrared (FTIR) spectra, powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results show that the 3,4,5-tri hydroxyphenyl acetic acid ligand and Tb ions are attached to the SBA-15 host. The catalysts were tested in the synthesis of 5-substituted 1H-tetrazoles. This catalyst is an efficient catalyst for [3 + 2] cycloaddition with NaN₃ to prepare 5-substituted 1H-tetrazoles. The catalyst was recycled for up to six cycles without significant loss of activity.