Synthesis, structure and luminescent recognition properties of cerium(IV) coordination polymers based on pyridine-2,6-dicarboxylic acid

•The complexes possess three-dimensional frameworks which are assembled through hydrogen bonds and π–π interactions.•{[Ce2(PDA)2(H2O)5SO4]·2H2O}n presents one-dimensional nanosized cavities, where the guest water dwelled.•Luminescence of the complexes in methanol display selectivities to Zn2+, Hg+, Pb2+ Mn2+ and Cd2+ or Cu2+ ions.

3D coordination polymers of {[Ce2(PDA)3(H2O)3]*0.25(H2O)}n and {[Ce2(PDA)(HPDA)(H2O)5SO4]*2H2O}n, (H2PDA = pyridine-2,6-dicarboxylic acid,) have been prepared under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, thermal analyses and single crystal X-ray diffraction. In the dihydrate polymer the SO42−- anions serve as bridges between 1D wavelike chains and the adjacent parallel pyridine rings are connected through π–π interactions. The striking feature of the dihydrate polymer is that 1D nanosized cavities are observed, which house guest water molecules. Weak interaction exists between Ce(IV) center and S atom(Ce…S) due to the connection of chelate SO42− anion. A magnetic study of the dihydrate polymer confirms that it presents antiferromagnetism. Thermogravimetric and differential thermogravimetric analyses reveal that both polyers are stable at high temperature. Luminescent emissions of complexes demonstrate that they display selectivities towards Zn2+, Hg+, Pb2+ Mn2+ and Cd2+ or Cu2+ ions.

Graphical abstractThe coordination polymer is connected between the adjacent building block of [Ce2(PDA)2(H2O)5SO4]·2H2O through carboxylate bridges (O–C–O). An infinite 1D (Ce–O2–Ce–OCO–Ce–O2–Ce)∞ wavelike chain motif along the a   axis is formed through the bridges of carboxylate (O–C–O) and double oxygen alternately. Furthermore, the adjacent 1D chains are jointed through SO42− anions from both above and below to construct a highly ordered 2D layer along the c axis. Considering the sum of the van der Waals radii of Ce and S atoms, it is reasonable to assume that there is certain interaction between Ce and S atoms.Figure optionsDownload full-size imageDownload as PowerPoint slide