Base-Resistant Ionic Metal-Organic Framework as a Porous Ion-Exchange Sorbent

Abstract

A systematic approach has been employed to obtain a hydrolytically stable cationic metal-organic framework (MOF). The synthesized two-dimensional Ni(II)-centered cationic MOF, having its backbone built from purely neutral N-donor ligand, is found to exhibit uncommon resistance over wide pH range, particularly even under highly alkaline conditions. This report presents a rare case of a porous MOF retaining structural integrity under basic conditions, and an even rarer case of a porous cationic MOF. The features of stability and porosity in this ionic MOF have been harnessed for the function of charge- and size-selective capture of small organic dye through ion-exchange process across a wide pH range.