Magnetic g-C sub(3)N sub(4-)SO sub(3)H composite by mechanochemical grinding: A sustainable approach to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes synthesis

Abstract

A magnetically separable g-C sub(3)N sub(4) composite functionalized with SO sub(3)H groups was synthesized by polymerizing melamine, followed by sulfonation and ball-milling with Fe sub(3)O sub(4). The obtained magnetic composite was characterized by various analytical techniques, such as CHNS, IR, XPS, Raman spectroscopy and powder XRD. Thermal stability was evaluated using TGA analysis. Surface area and porosity were determined using nitrogen adsorption-desorption via BET analysis. Magnetism was measured using VSM. Acidity was measured using pH determination by back titration. Surface morphology was evaluated using SEM-EDS and HRTEM analysis. Catalytic activity was evaluated for the synthesis of 14-Aryl/alkyl-14H-dibenzo[a,j]xanthenes under solvent-free conditions. The prepared catalyst exhibited excellent activity with an appreciable yield (82-99 percent) in a short duration (25-80 min). The catalyst was recovered using an external magnetic field and reused for eight consecutive cycles without any appreciable loss in its catalytic activity.