Syntheses, structures and characteristic of three copper(II) coordination polymers with flexible ligand 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene

In order to investigate the influence of the flexibility of the ligand molecule, the counter anion and solvent system on the architecture of coordination polymers, three new copper(II) coordination polymers [Cu(bbtz)(H2O)2(NO3)2] (1), [Cu(bbtz)2(CH3CN)2](ClO4)2(H2O)2 (2) and [Cu(bbtz)2(H2O)2](ClO4)2(DMF)3 (3) were synthesized using flexible ligand 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (bbtz) and corresponding copper(II) salts and characterized by IR and thermogravimetric analysis. The X-ray diffraction analysis shows that 1 has one-dimensional chain structure, while 2 and 3 have similar double-stranded chain structures. A conformational analysis of the ligand molecule demonstrates that the flexibility of bbtz and the rotational freedom of the triazole rings are responsible for the diversity of the structures of the complexes.