A novel eight-connected metal–organic replica of CsCl based on heptanuclear zinc clusters

A novel eight-connected metal–organic framework, ZnII7(btc-NO2)4(bpp)2(μ3-OH)2(H2O)2 (H3btc-NO2 = 5-nitro-1,2,3-benzenetricarboxylate and bpp = 1,3-bi(4-pyridyl)propane, 1), has been hydrothermally synthesized and characterized by elemental analyses, FTIR, and X-ray diffraction. A rare U-shaped [Zn7O4(O2C)12N4] secondary building unit was found in 1, together with double parallel btc-NO2 anions and bpp flexibility ligands as links, resulting in an eight-connected heptanuclear-based uninodal 3D framework with 424.64 topology. Moreover, the thermal stability and luminescent property of 1 have been investigated as well.