Tribromide immobilized on surface of magnetic nanoparticles modified tris(triazine-triamine): A versatile and highly active catalyst for oxidation of sulfides and oxidative coupling of thiols

In this article, we show that tribromide heterogenized on the surface of silica-coated magnetic nanoparticles modified with N²,N4,N⁶-tris(aminomethyl)-1,3,5-triazine-2,4,6-triamine [Fe₃O₄@SiO₂-tris(triazine-triamine)-Br₃] is a novel and efficient reusable nanocatalyst for the oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides using hydrogen peroxide as green oxidant. The structure of the as-fabricated Fe₃O₄@SiO₂-tris(triazine-triamine)-Br₃ was characterized by a series of spectroscopic techniques including FT-IR spectroscopy, SEM, TEM, EDX, VSM, XRD and TGA techniques. TEM and SEM analysis confirmed that the typical silica shell thickness was assessed to be around 20 nm. Recycling studies revealed that the Fe₃O₄@SiO₂-tris(triazine-triamine)-Br₃ could be easily recovered by a simple magnetic separation and recycled at least 6 times without deterioration in catalytic activity.