Preparation of water-soluble imidazole-functionalized pillar[5]arenes: The activities of antibacterial and antioxidant, catalytic reduction of 4-nitrophenol

Macrocyclic supramolecular materials such as pillar[n]arenes play a prominent role in enhancing antibacterial activity through host-guest interactions. Herein, the water-soluble pillar[5]arene imidazole-1 and pillar[5]arene imidazole-2 were prepared, and their structure and chemical compositions were analyzed through multiple characterization methods. Afterward, the prepared imidazole-functionalized pillar[5]arenes were examined for antibacterial activity against Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, and Salmonella typhimurium bacteria. Also, the antioxidant activities of the prepared imidazole-functionalized pillar[5]arenes were investigated using 2,2-Diphenyl-1-picrylhydrazyl. In addition, the catalytic activities of pillar[5]arene imidazole-1 and pillar[5]arene imidazole-2 by reduction of 4-nitrophenol were studied, indicating the catalytic reduction of 4-nitrophenol was 93.0 % for the pillar[5]arene imidazole-1 catalyst at 18 min. Comparison of the reactivity of pillar[5]arene imidazole-1 with that of pillar[5]arene imidazole-2 shows an increase in antibacterial and catalytic activity. This study summarized that using suitable catalysts, catalytic reduction aims to convert the most harmful and toxic organic compound 4-nitrophenol into non-toxic 4-aminophenol and popularize it in industry.