A highly stable indium phosphonocarboxylate framework as a multifunctional sensor for Cu2+ and methylviologen ions

Abstract

An indium phosphonocarboxylate framework, {H₃O[In(pbpdc)]·3H₂O}_n (InPCF-1) (pbpdc = 4′-phosphonobiphenyl-3,5-dicarboxylate), was hydrothermally synthesized. The structure of InPCF-1 features the inorganic chains as rod-shaped second building units. The rod-packing arrangement results in a three-dimensional (3-D) framework with a novel (3,4,5)-connected net. Studies of the gas adsorption, and thermal and chemical stability of InPCF-1 demonstrated its adsorption capacity for CO₂, selective separation of CO₂ over O₂ and N₂, high thermal stability, and a remarkable chemical resistance to boiling water, ethyl alcohol, and methylbenzene. Importantly, InPCF-1 shows a selective and sensitive response to Cu²⁺ ions. It also serves as a sensor for methylviologen.