Construction of three low dimensional Zn(II) complexes based on different organic-carboxylic acids

Three new Zn(II) complexes based on different organic-carboxylic acids, [Zn(mba)2(2,2′-bipy)] (1), [Zn(mpdaH)2(H2O)4] · 4H2O (2) and [Zn(cda)2(H2O)2]n (3) (Hmba = 4-methylbenzoic acid, H2mpda = 2,6-dimethylpyridine-3,5-dicarboxylic acid and H2cda = chelidonic acid) have been synthesized successfully under hydrothermal conditions. X-ray single crystal diffractions show that compounds 1 and 2 are the mononuclear and 3 is one-dimensional chain, in which the Zn(II) centers have different coordination geometries with octahedron for 1 and 2 and tetrahedron for 3. Through π–π stacking and/or hydrogen bonding (O–H⋯O and O–H⋯N) interactions, different supramolecular structures are assembled, namely, 2D supramolecular layer for 1 and 3D supramolecular networks for 2 and 3. Furthermore, the IR, TGA and luminescent properties are also investigated in this work.