| Abstract: Two new metal-organic coordination polymers[Cu4(4-nph)(L)6]n (1) and {[Cu2(bda)2(bib)2(H2O)4]·4H2O}n (2) were prepared under hydrothermal conditions by employing 4-nitrophthalic acid (4-H2nph)/2, 2'-bipyridine-4, 4'-dicarboxylic acid (H2bda) as the primary ligand and 3-(2-pyridyl)pyrazole (HL)/1, 4-bis(imidazol-1-yl)-butane (bib) as the ancillary ligand. They were characterized by elemental analysis, infrared spectroscopy, thermogravimetry, X-ray single crystal diffractometer, and X-ray powder diffractometer. The results show that complex 1 belongs to monoclinic system, C2/c space group with cell parameters:a=1.956 16(8) nm, b=1.290 68(8) nm, c=2.160 34(12) nm, β=97.073(2)°, V=5.412 9(5) nm3, Z=4; and complex 2 crystallizes in triclinic system, P1 space group with cell parameters:a=0.962 22(15) nm, b=1.102 90(17) nm, c=1.404 3(2) nm, α=72.752(4)°, β=79.271(4)°, γ=67.065(3)°, V=1.306 6(4) nm3, Z=1. In complex 1, the carboxyl ligand 4-nph2- bridges the metal centers via monodentate modes. The metal centers are coordinated by 4-nph2- to form a 1D structure. In complex 2, the flexible bib linked metal centers to form a dinuclear structure with a 26-member ring. In addition, the quantum-chemical calculations were accomplished on "molecular fragments" extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in the Gaussian 16 program. The calculation values denoted the distinct covalent interaction between the coordinated atoms and Cu(Ⅱ) ion. |
