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

The hydrothermal reaction of Zn2+ ions with a mixture of two ligands, Hcptpy and H3 btc (Hcptpy=4-(4-carboxyphenyl)-2,2':4',4''-terpyridine; H3 btc=1,3,5-benzenetricarboxylic acid), led to the formation of a 3D metal-organic framework (MOF) with 1D channels, [Zn2 (cptpy)(btc)(H2 O)]n (1), which was structurally characterized by using single-crystal X-ray diffraction (SXRD). In MOF 1, two independent Zn2+ ions were interconnected by btc3- ligands to form a 1D chain, whilst adjacent Zn2+ 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 Fe3+ ions in aqueous solution.