Fabrication of polypyrrole/Cu(ii) nanocomposite through liquid/liquid interfacial polymerization: a novel catalyst for synthesis of NH-1,2,3-triazoles in PEG-400

Abstract

In the present paper, we have reported the synthesis and application of a polypyrrole (PPy)/Cu(II) nanocomposite as an efficient heterogeneous catalyst for the synthesis of 4-aryl-NH-1,2,3-triazoles. The nanocomposite was prepared via liquid/liquid interfacial polymerization where copper and initiator (FeCl₃) were dispersed in the aqueous phase and the monomer was dissolved in the organic phase. The synthesized sample was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Spectroscopic analyses showed the successful incorporation of Cu in the polymer matrix and the decoration of copper nanoparticles within the PPy matrix was observed from the morphological analysis. Herein, we have developed a simple one-pot, multicomponent system using a PPy/Cu catalyst for the synthesis of NH-triazoles. Keeping in view the principles of green chemistry, the reactions were performed in the low-cost and environmentally friendly solvent polyethylene glycol 400 (PEG 400). A very low loading of copper (0.01 mol%) catalyzed the reaction very efficiently with an excellent yield of the desired product. Furthermore, the catalytic system can be recovered and recycled up to 5th subsequent cycle, maintaining its catalytic activity with excellent yields of triazoles. To the best of our knowledge no previous work has been reported for the synthesis of 4-aryl-NH-1,2,3-triazoles using this efficient novel catalyst.