Synthesis, crystal structures, and properties of two novel cadmium(II)–organic frameworks based on asymmetric dicarboxylate and N-donor ligands

•Two cadmium(II) complexes with asymmetric dicarboxylate and N-donor ligands.•The synthesis shows that N-donor ligand plays the key role.•1 Displays a double zigzag chain structure.•2 Shows a 2-fold interpenetrated 3D α-Po structural topology.

Two novel cadmium(II)–organic frameworks with asymmetric dicarboxylate and N-donor ligands, namely [Cd(cpa)(phen)]n (1) and {[Cd2(cpa)2(bpy)1.5]·0.5H2O}n (2) (H2cpa = 3-(4-benzoic)propionic acid, phen = 1,10-phenanthroline, bpy = 4,4′-bipyridine) have been hydrothermally synthesized and characterized by elemental analyses, FT-IR spectra, single-crystal X-ray diffraction analyses, TGA, powder XRD and fluorescent measurements. 1 displays a double zigzag chain structure containing 8-number and 22-number circles. 2 Shows a 6-connected 3D polymer network based on tetranuclear cadmium cluster units. The most striking feature of 2 is that a pair of identical 3D networks are interlocked with each other to the form a 2-fold interpenetrated 3D α-Po structural topology. The diverse structures of two complexes indicate that the skeleton of N-donor ligands plays a great role in the assembly of such different frameworks. In addition, the thermal stabilities, XRD and photoluminescence properties of 1–2 were also studied.

Graphical abstractTwo novel cadmium coordination polymers have been synthesized and characterized. 1 is a double zigzag chain structure. 2 Displays a 2-fold interpenetration 3D α-Po structural topology. The thermal stabilities and luminescence properties were also studied.Figure optionsDownload full-size imageDownload as PowerPoint slide