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

Three new 1D chain coordination polymers (CPs) [M(FDC)(2)(H2O)(2)](n) [M = Zn (1), Cd (2)], [Cd(FDC)(2)(bpy)(H2O)](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, Cd2+ 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 Cd2+ ions are linked by N atoms of bpy ligands. 1-3 are further extended to 3D supramolecular structures by O-H center dot center dot center dot O hydrogen bonds and pi center dot center dot center dot pi 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 Fe3+ with a low detection limit of 1.0 x 10(-6) M, indicating that 1 and 3 could be used as efficient fluorescent sensors with high sensitivity and selectivity for Fe3+. (C) 2019 Elsevier B.V. All rights reserved.