Four Novel Coordination Polymers Based on Flexible 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene Ligand: Synthesis, Structure, Luminescence and Magnetic Properties

Four new metal-organic coordination polymers, [Co-5(btx)(2)(NDC)(4)((3)-OH)(2)(H2O)(2)]H2O}(n)(1), [Co(btx)(IP)](n)(2), [Mn(btx)(NIP)(H2O)](n)(3), {[Zn(btx)(2)(H2O)(2)]2NO(3)2H(2)O}(n)(4) (btx=1,4-bis(1,2,4-triazol-1-ylmethyl)benzene; H2NDC=1,4-naphthalenedicarboxylic acid; H2IP=5-hydroxyisophthalic acid; H2NIP=5-nitroisophthalic acid) were synthesized under hydrothermal conditions and characterized by techniques of single-crystal X-ray diffraction analysis, elemental analysis, infrared spectra (IR) and thermogravimetric analysis (TGA). The resulting MOFs analyses demonstrate that complex 1 displays a rare 3D 10-connected framework with the point symbol of {3(6)4(34)5(3)6(2)} based on pentanuclear [Co-5((3)-OH)(2)(COO)(8)] cluster. Complex 2 presents a 5- connected 2D layer structure with the point symbol of {4(8)6(2)}. Complex 3 features 4-connected threefold interpenetrating 3D network structure with the {6(5)8} point symbol. Complex 4 shows a 2D architecture. The variable-temperature magnetic susceptibility data show that the complex 1 exhibits antiferromagnetic interaction. Different to complex 1, the complex 2, 3 both show weak ferromagnetic interaction. Furthermore, the luminescence of complex 4 was also studied.