Two CoII coordination polymers with mixed ligands of carboxylate and flexible 1,3-bis(4-pyridyl)propane

Two new mixed ligand CoII coordination polymers, [Co(TP)(bpp)(H2O)]n (1) and {[Co4(μ3-OH)2(BTC)2(bpp)2(H2O)2]·bpp}n (2) (TP = terephthalate, BTC = 1,2,3-benzenetricarboxylate, bpp = 1,3-bis(4-pyridyl)propane), have been synthesized by hydrothermal reactions of Co(NO3)2·6H2O with bpp and TP2− or BTC3− ligands. They were characterized by single-crystal X-ray diffraction, Thermogravimetric Analysis (TGA), Elemental Analysis (EA) and IR. Single-crystal X-ray diffractions reveal that two complexes feature various metal-carboxylate subunits extended further by bpp ligands to form one-dimensional (1D) to 3D polycatenation or 3D network, respectively. 1 contains a type of 1D zigzag ladders which are further interlocked with the other two vertically identical ones, resulting in a 3D entangled architecture. 2 exhibits a 3D porous and magnetic framework containing the chair-like tetranuclear clusters, and the framework of 2 can be simplified as in 412·63 topology with 6-connected [Co4(μ3–OH)2]6+ cluster as node. TGA for 1 and 2, magnetic properties for 2 are also discussed.