Shreyas Pansambal - S. N. Arts, D. J. Malpani Commerce & B. N. Sarda Science College, Sangamner, Maharashtra, India.
Suresh Ghotekar - Department of Chemistry, Sanjivani Arts, Commerce and Science College, Kopargaon, Maharashtra, India.
Sunil Shewale - Ahmednagar College, Ahmednagar, Maharashtra, India.
Keshav Deshmukh - S. N. Arts, D. J. Malpani Commerce & B. N. Sarda Science College, Sangamner, Maharashtra, India.

Magnetically separable silica-coated cobalt ferrite (CoFe2O4@SiO2) magnetic nanoparticles (MNPs) were synthesized by sol-gel auto combustion method. Silica matrix was employed to minimize the agglomeration and coarsening of the MNPs. The structural and morphological properties of the as-prepared nanocatalyst were investigated using XRD, EDX, TEM-SAED, FTIR, XPS and VSM techniques. Furthermore, these nanoparticles were used as an efficient nanocatalyst for simple, swift and one-pot synthesis of 5-aryl-1,2,4-triazolidine-3-thione derivatives. The reaction steps include imine formation, cyclization, condensation and aromatization without use of any oxidizing or reducing reagents. The present methodology offers remarkable merits like shorter reaction time, mild reaction conditions, excellent yield, simplicity, safer reaction pathway, easy workup and recyclable catalyst without any significant loss in catalytic activity and can be used for large scale synthesis. Hence, the present study describing the synthesis of CoFe2O4@SiO2 nanoparticles by efficient sol-gel auto combustion method followed by the investigation of potent catalytic activities may be useful for nanochemistry research opening a new arena in this field.

Magnetic nanoparticles, CoFe2O4@SiO2, nanocatalyst, Recyclable catalyst, Magnetic separation