Functional Ionic Porous Frameworks Based on Triaminoguanidinium for CO2 Conversion and Combating Microbes

Abstract

Porous organic frameworks (POFs) with heteroatom rich ionic backbone have emerged as advanced materials for catalysis, charge-specific molecular separation and antibacterial activity. The loading of metal ions further enhances Lewis acidity augmenting the activity associated with the frameworks. Metal-loaded ionic POFs however often suffer from physicochemical instability, limiting their scope for diverse applications. Herein, we report the fabrication of triaminoguanidinium-based ionic POFs through Schiff base condensation in a cost-effective and scalable manner. The resultant N-rich ionic frameworks facilitate selective CO2 uptake and provide high metal (ZnO, 57.3  1.2%) loading capacity. The hierarchically mesoporous ZnO-rich metalated frameworks (Zn/POFs) show remarkable catalytic activity in the cycloaddition of CO2 and epoxides into cyclic organic carbonates under solvent-free condition with high catalyst recyclability. In addition, both ionic POFs and Zn/POFs exhibit robust antibacterial (Gram-positive, S. aureus and Gram-negative, E. coli) and antiviral activity targeting HIV and VSV-G enveloped lentiviral particles. The enhanced catalytic, as well as broad-spectrum antimicrobial activity, are likely due to the synergistic effect of triaminoguanidinium ions and ZnO infused with the frameworks. We thus establish triaminoguanidinium-based POFs and Zn/POFs as a new class of multifunctional materials for environmental remediation and biomedical applications.[a]MD.