Three new coordination polymers based on a fluorene derivative ligand for the highly luminescent sensitive detection of Fe3+

Abstract

Three new 1D chain coordination polymers (CPs) [M(FDC) 2 (H 2 O) 2 ] n [M = Zn ( 1 ), Cd ( 2 )], [Cd(FDC) 2 (bpy)(H 2 O)] n ( 3 ) (HFDC = 9-fluorenone-4-carboxylic acid, bpy = 4,4′-bipyridine) were prepared by reactions of the corresponding metal salt with the fluorene derivative ligands of HFDC. Compounds 1 – 3 have been characterized by elemental analysis, IR, TGA, PXRD and single crystal X-ray diffraction. 1 and 2 are isomorphous. In 2 , Cd 2+ ions are joined by O atoms from coordinating water molecules and FDC − ligands, generating a 1D coordination polymer along the a axis, and 3 features a 1D chain structure in which adjacent Cd 2+ ions are linked by N atoms of bpy ligands. 1 – 3 are further extended to 3D supramolecular structures by O–H⋯O hydrogen bonds and π···π interactions. To the best of our knowledge, the title compounds are the first example of CPs based on the HFDC ligand. Moreover, 1 and 3 are good chemosensors for the detection of Fe 3+ with a low detection limit of 1.0 × 10 −6 M, indicating that 1 and 3 could be used as efficient fluorescent sensors with high sensitivity and selectivity for Fe 3+ . 1 and 2 are isomorphous. In 2 , Cd 2+ ions are joined by O atoms from coordinating water molecules and FDC − ligands, generating a 1D coordination polymer along the a axis, and 3 features a 1D chain structure in which adjacent Cd 2+ ions are linked by N atoms of bpy ligands. 1 and 3 are good chemosensors for the detection of Fe 3+ with a low detection limit of 1.0 × 10 −6 M, indicating that 1 and 3 could be used as efficient fluorescent sensors with high sensitivity and selectivity for Fe 3+ . • Three new one-dimensional coordination polymers based on the HFDC ligand have been purposefully synthesized. • 1 and 3 can be fluorescent probes with excellent sensitivity and selective detection for Fe 3+ in the water system. • The TGA reveals that compounds 1 and 2 possess good thermal stability.