fabrication of [fe₃o₄@sio₂@si-(ch₂)₃-bipyr][znₓclᵧ] as a novel magnetic catalyst, and its utility for construction of 𝐵𝑖𝑠-coumarins and 𝐵𝑖𝑠(pyrazolyl)methanes

Initially, a novel magnetic catalyst namely [fe3o4@sio2@si-(ch2)3-bipyr][znxcly] (fscbz) was fabricated, and its structure was corroborated using energy-dispersive x-ray spectroscopy (edx), field emission scanning electron microscopy (fe-sem), x-ray diffraction (xrd), fourier-transform infrared spectroscopy (ft-ir), thermogravimetric (tg), and vibrating-sample magnetometery (vsm) analyses. in continue, it was employed to catalyze the solvent-free construction of bis-coumarins (from aryl aldehydes and 4-hydroxycoumarin) and bis(pyrazolyl)methanes (from aryl aldehydes and 3-methyl-1-phenyl-1h-pyrazol-5(4h)-one). the coumarin and pyrazole derivatives were attained in short times (10-20 min) and high yields (89-98%). fscbz was reusable for two times with retaining its catalytic performance.