Stabilized Cu₂O Nanoparticles on Macroporous Polystyrene Resins [Cu₂O@ARF]: Improved and Reusable Heterogeneous Catalyst for On-Water Synthesis of Triazoles via Click Reaction

Abstract

Amberlite resin formate (ARF) with a polyionic polar environment is successfully utilized as a unique support for immobilization of stabilized Cu2O nanoparticles (NPs). The composite [Cu2O@ARF] is characterized by FT–IR, XRD, XPS, HR–TEM, and ICP–AES analyses. The HR–TEM results confirm existence of fairly dispersed Cu2O NPs with average diameter (∼5–7 nm) onto the resin surface, while ICP–AES analyses show loading of copper (10.8 mg) per gram of the resin composite (1.08 wt % of Cu). The ionic resin with counteranions (HCOO–) could reduce precursor Cu(II) to Cu(I) and stabilize Cu2O NPs. The as-synthesized composite acts as a robust, efficient, and recyclable catalyst for efficient construction of a 1,2,3-triazole ring under aqueous and aerobic conditions. The TOF (219 h–1) is found significantly high as compared to that of some related existing catalysts (120 h–1). The prowess of the catalyst is further demonstrated in the synthesis of a triazole-bearing antitumor drug molecule.