Green Fabrication of Cobalt NPs using Aqueous Extract of Antioxidant Rich Zingiber and Their Catalytic Applications for the Synthesis of Pyrano[2,3-c]pyrazoles.

AIM AND OBJECTIVE

In this study, biological synthesis of cobalt nanoparticles was developed in the presence of ginger extract as the reducing and capping agent through the simple and convenient co-precipitation method.

MATERIALS AND METHODS

The as-synthesized cobalt nanoparticles were characterized by X-ray diffraction (XRD), scanning Electron Microscopy (SEM), spectra energy dispersive analysis of Xray (EDS), Fourier transform infrared (FT-IR), and vibrating sample magnetometer (VSM) techniques. According to the vibrating sample magnetometer, cobalt nanoparticles show paramagnetic behaviour at room temperature. Furthermore, the effect of ginger extract concentration on the UV-Vis absorbance of Co nanoparticles was investigated. Based on the UVVis absorbance spectra, increasing ginger extract concentration causes particle size to decrease. In addition, the catalytic performance of the synthesized cobalt nanoparticles was investigated in the preparation of pyrano[2,3-c]pyrazoles via one-pot four-component reactions of aryl aldehydes, hydrazine hydrate, malononitrile and diethyl acetylenedicarboxylate.

RESULT AND CONCLUSION

The prepared pyrano[2,3-c]pyrazole derivatives were obtained in high yields within short reaction times and the nanocatalyst was easily separated using an external magnet and reused for several times with no significant loss of its activity.