Synthesis, Sructure and Thermal Stability of One-dimensional Calcium Coordination Polymer [Ca( μ-p-HPO)_2(NO_3)_2]_n Constructed by p-pyridone Ligand

A novel one-dimensional coordination polymer, [Ca( μ-p-HPO)2(NO3)2]n, ( p-HPO=p-pyridone) was synthesized and characterized by the element analysis, IR, TG and X-ray single crystal diffraction. It crystallizes in the monoclinic space group C2/c with unit cell parameters: a=1.992 1(4) nm, b=0.374 96(7) nm, c=1.930 3(4) nm, β=109.21(3)°. V=1.361 6(5) nm3, Z=4, R=0.034 9, wR=0.084 4. The Ca atom is eight-coordinated by four O atoms from different p-pyridone ligands and four O atoms from two chelating nitrate anions, and displays a distorted square pyramidal coordination geometry. Each p-pyridone ligand bridges two adjacent Ca atoms, forming a infinite chain along the b direction. The Ca...Ca distance is 0.374 96(7) nm. A layer structure is further constructed by intermolecular hydrogen bonds and π-π interactions. The result of TG analysis shows that the title complex is stable under 185 ℃. CCDC: 241576.