Two Schiff-base complexes of cadmium and manganese on modified MCM-41 as practical, recyclable and selective nanocatalysts for the synthesis of sulfoxides

In this work, 2-Hydroxy-5-nitrobenzaldehyde Schiff-base complexes of cadmium and manganese on MCM-41 (Cd-5NSA-MCM-41 and Mn-5NSA-MCM-41) have been investigated as stable, efficient, environment friendly, reusable, and chemoselective nanocatalysts. These catalysts were characterized by various techniques such as X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), Fourier transform-infrared spectroscopy (FT-IR) and atomic absorption spectroscopy (AAS). Sulfoxide derivatives were synthesized in the presence of Cd-5NSA-MCM-41 and Mn-5NSA-MCM-41 through mild and selective oxidation of sulfides and all sulfoxide products were obtained in good yields within acceptable times. In order to synthesis of sulfoxides, hydrogen peroxide (H2O2) was used as an environmentally friendly, non-toxic, available and inexpensive oxidant. These catalysts can recovered and reused for several times without significant loss in catalytic activities. In addition the recovered catalysts was characterized with several techniques such as XRD diffraction, AAS analysis and FT-IR spectroscopy, which are shown a good agreement to fresh catalysts. Comparison of reused and un-reused catalysts were confirmed the heterogeneous nature and good stability of these catalysts.

Automated summary

In this study, 2-Hydroxy-5-nitrobenzaldehyde Schiff-base complexes of cadmium and manganese on MCM-41 were investigated as stable, efficient, environment friendly, reusable, and chemoselective nanocatalysts. The catalysts were characterized by various techniques and were found to be capable of selectively oxidizing sulfides to sulfoxide derivatives using hydrogen peroxide as an oxidant. The catalysts exhibited good recovery and reuse properties, with the recovered catalysts showing similar characteristics to the fresh catalysts, confirming their heterogeneous nature and stability.