Two novel 3D self-threading coordination polymers with CdSO4 topology: Syntheses, structures and properties

•Compounds 1 and 2 exhibit the novel 3D self-threading framework.•1 and 2 can be simplified to a CdSO4 net, which is really rare in self-threading system.•Entangled coordination networks constructed from H3L ligand remain largely unexplored.

Two new isostructural metal-organic frameworks, namely [Co(HL)(bpp)] · 0.5H2O (1) and [Zn(HL)(bpp)] · 3H2O (2) (H3L = 5-(2′-carboxy-biphenyl-4-ylmethoxy)-isophthalic acid, bpp = 1,3-bis(4-pyridyl)propane), have been hydrothermally synthesized and further characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analyses, IR spectra and TG analyses. Compounds 1 and 2 exhibit interesting 3D frameworks of (65.8)-CdSO4 topology with dangling arm (i.e. the uncoordinated 2′-carboxy-biphenyl-4-ylmethoxy group of HL ligand). The remarkable feature of these two compounds is that each dangling arm threads into two 6-membered rings belonging to the 3D net itself, displaying the self-threading character. The magnetic properties of 1 and photoluminescence of 2 have also been investigated.

Graphical abstractTwo novel 3D self-threading metal-organic frameworks with CdSO4 topology, which add new members to the newborn self-threading family, are reported.Figure optionsDownload full-size imageDownload as PowerPoint slide