Hydrothermal Synthesis and Crystal Structure of a 2D Zinc(Ⅱ) Coordination Polymer with 5-Hydroxynicotinic Acid

The title compound,[Zn(5-hydroxynicotinate) 2 2H 2 O] n,has been synthesized by reacting zinc sulfate vitriol with 5-hydroxynicotinic acid under hydrothermal conditions,and its structure was determined by X-ray crystallography with the following data:monoclinic,space group C2/c,C 12 H 12 N 2 O 8 Zn,M r=377.61,a=10.223(3),b=10.319(3),c=13.613(4),β=105.922(6)°,Z=4,V=1380.9(8)3,F(000)=768,D c=1.816 g/cm 3,μ(MoKα)=1.826 mm-1,the final R=0.0401 and wR=0.1380 for 1157 observed reflections (I > 2σ(I)).In the structure of the title compound,the Zn II ion located in an inversion center lies in a distorted tetrahedral environment at a N 2 O 2 coordination mode,and the 5-hydroxynicotinic acid ligand links symmetry-related Zn II ions at a μ 2-N,O bridging way forming a two-dimensional covalent structure.In the crystal,solvent water molecules form intermolecular O-H O hydrogen bonds and pyridine rings of adjacent layers form π-π stacking (3.346),which connect adjacent two-dimensional sheets into a three-dimensional supramolecular network.