LAUSR

Abstract In this study, preparation, characterization and catalytic application of a novel core-shell structured magnetic Ti-loaded phenylene-based nanoporous organosilica (Mag@Ti-NOS) nanocomposite are developed. The Mag@Ti-NOS was synthesized via cetyltrimethylammonium bromide (CTAB) directed co-condensation of tetramethoxysilane (TMOS), tetrabutyl orthotitanate (TBOT) and 1,4-bis(triethoxysilyl)benzene (BTEB) over Mag@SiO2 under alkaline conditions. This nanocomposite was characterized by using FT-IR, EDX, PXRD, VSM, SEM, TEM, XPS, ICP and TGA techniques. These analyses showed a core-shell structure with high chemical and thermal stability for the designed material. The Mag@Ti-NOS nanocomposite was employed as an effective, powerful and recyclable catalyst in the synthesis of tetrahydrobenzo[b]pyrans in H2O at 50 °C under ultrasonic conditions. This catalyst was recovered and reused several times without significant decrease in efficiency and stability. The recovered catalyst was analyzed by FT-IR, PXRD and SEM to study its stability during reaction process.