A Bifunctional Luminescent Metal–Organic Framework for the Sensing of Paraquat and Fe³⁺ Ions in Water

Abstract

Abstract The hydrothermal reaction of Zn 2+ ions with a mixture of two ligands, Hcptpy and H 3 btc (Hcptpy=4‐(4‐carboxyphenyl)‐2,2′:4′,4′′‐terpyridine; H 3 btc=1,3,5‐benzenetricarboxylic acid), led to the formation of a 3D metal–organic framework (MOF) with 1D channels, [Zn 2 (cptpy)(btc)(H 2 O)] n ( 1 ), which was structurally characterized by using single‐crystal X‐ray diffraction (SXRD). In MOF 1 , two independent Zn 2+ ions were interconnected by btc 3− ligands to form a 1D chain, whilst adjacent Zn 2+ ions were alternately bridged by cptpy − ligands to generate a 2D sheet, which was further linked by 1D chains to form a 3D framework with a new (3,3,4,4)‐connected topology. Furthermore, compound 1 also exhibited excellent stability towards air and water and, more importantly, luminescence experiments indicated that it could serve as a probe for the sensitive detection of paraquat (PAQ) and Fe 3+ ions in aqueous solution.