Synthesis, Structure, Thermostability and DFT Calculations of a Cobalt(II) Coordination Compound Comstructed by Oxybis(benzoic acid) and Pyridyl-triazole

A new coordination polymer, [Co(oba)(3,4'-Hbpt)]center dot H2O (H(2)oba=4,4'-oxybis (benzoic acid) and 3,4'-Hbpt=3-(3-pyridyl)-5-(4'-pyridyl)-1-H-1,2,4-triazole), was prepared in the presence of V-shaped ligand H(2)oba, rigid ligand 3,4'-Hbpt and cobalt acetate by hydrothermal reactions. The title complex was characterized by single-crystal X-ray diffraction, thermogravimetric analyses, elemental analysis and IR spectroscopy. It belongs to monoclinic system, space group P2(1)/c. In the complex, the Co(II) ions are linked by two carboxylate groups from protonated V-shaped oba(2-) to form an 8-membered ring. Then, oba(2-), 3,4'-Hbpt connect adjacent Co(I) ions to form a 25-membered ring. Furthermore, the adjacent eight-membered and 25-membered rings are connected by oba(2-) pillars to form a 2D layer-hole in the structure. In addition, theoretical calculation based on density functional theory (DFT) at B3LYP/6-31*G (d) and 6-31**G (d,p) level is also employed to explicate the most optimized conformation, and investigate stability, frontier orbitals and the optimal configuration of H(2)oba, which is corresponded with experimental conformation. CCDC: 930887.