Sub 1 nm Poly(acrylic acid)-Capped Copper Nanoparticles for the Synthesis of 1,2,3-Triazole Compounds.

The stable, water-soluble, and fluorescent sub 1 nm sized poly(acrylic acid)-capped copper nanoparticles (PAACC NPs) were synthesized using a high-intensity ultrasound sonication (30 KHz) method. The reduction of copper NPs from copper(II) salt by mild reducing agent l-ascorbic acid in an aqueous medium was achieved in the presence of poly(acrylic acid). The PAACC NPs were characterized by DRS UV-visible, XPS, PL, FESEM, and HRTEM techniques. The resulting PAACC NPs show orange fluorescence with a peaking center at 560 nm. The PAACC NPs serve as effective catalysts for the synthesis of 1,2,3-triazoles via click reaction in good yields under mild reaction conditions.