Synthesis, structure and high thermal stability of a novel threedimensional Zinc(II) complex with an unsymmetrical rigid-flexible ligand

A novel metal-organic framework, [Zn(C₁₀H₈O ₅)]_n (1) (C₁₀H₈O₅ = 2-(4-carboxylatophenoxy)propionate), was synthesized and characterized by elemental analysis, IR spectroscopy, X-ray crystallography and thermogravimetric analysis. The crystal structure study reveals that each zinc atom is coordinated by four oxygen atoms from four different ligands to obtain a distorted tetrahedron. The rigid carboxyl group bridges two adjacent zinc atoms to form a dimer of eightmembered rings, whereas the flexible carboxyl group bridges two adjacent dimers to form ID chains along the a axis. Two adjacent ID chains are interconnected by the ligands to produce 2D layers. These layers are further stabilized by intermolecular hydrogen bonds to construct a 3D framework showing high thermal stability (445 °C).