Mono Dispersable Water-Soluble Iron Sulfide Nanoclusters: Synthesis, Characterization and Catalytic Application for Highly Efficient Synthesis of Xanthene Derivatives

In this manuscript, we have synthesized Iron sulfide nanoclusters (FeSNCs) by precipitation reaction between ferric chloride (FeCl3 · 6H2O) and thiourea with sodium borohydride (NaBH4) as a reducing agent at room temperature in water. These nanoclusters are synthesized within two minutes. The morphology and size of these synthesized FeSNCs were confirmed from transmission electron microscopy (TEM) and scanning electron microscopy (SEM). TEM and SEM data showed that the average diameters of these FeSNCs are around 70 nm. The Power X-ray diffraction (XRD) patten of the FeSNCs clearly showed the crystalline nature of these nanoclusters. Vibrating sample magnetometer (VSM) experiment showed that these nanoclusters are ferromagnetic in nature having high magnetization (20 emu/g). The nitrogen adsorption isotherm of FeSNCs confirmed the porous nature. These well characterized FeSNCs were further utilized as a catalyst for the synthesis of 9-aryl-1,8-dioxooctahydroxanthenes and 14-substituted-14H-dibenzo[a, j] xanthene derivatives. It is observed that the catalytic activities of FeSNCs are much better than the other reported heterogeneous and homogeneous catalysts. After completion of the reaction, FeSNCs are separated from the reaction mixture with the help bar magnet, washed and reused for the next catalytic reaction. Current method offers several advantages over other reported methods such as excellent yields, short reaction times, simple reaction procedure, and reusability of the catalyst upto five times without any significant loss in its activity.