In situ hydrothermal syntheses, crystal structures and luminescent properties of two novel zinc(II) coordination polymers based on tetrapyridyl ligand

Two novel Zn(II) coordination polymers, [Zn(2-pytpy)(fum)](n)center dot nH(2)O (1) and [Zn-6(4-pytpy)(3)(mal)(4)](n)center dot 5n(H2O) (2), (2-pytpy = 4 '-(4-pyridyl)-2,2':6',2 ''-terpyridine, 4-pytpy = 4'-(4-pyridyl)-4,2':6',4 ''-terpyridine, H(2)fum = fumaric acid and H(2)mal = malic acid) have been hydrothermally synthesized and structurally characterized. Notably, in situ ligand reactions occur in the formation of complexes 1 and 2, in which maleic acid is converted into fumaric acid and malic acid, respectively. Complex 1 is a 1D infinite chain structure, which is extended into a supramolecular layer by intermolecular pi center dot center dot center dot pi stacking interactions. Complex 2 is a 3D network structure, in which the bidentate-bridging 4-pytpy ligands link the layers based on the tetranuclear Zn(II) subunits to form the (4,10)-connected network. The luminescent properties of 1 and 2 have been investigated with emission spectra and UV-Vis diffuse reflectance spectra in the solid state. Additionally, these two complexes possess great thermal stabilities. (C) 2010 Elsevier B.V. All rights reserved.