Syntheses, Structures, and Characterization of a Series of Novel Cobalt(II) Complexes with Bi- and Mono- Triazole Ligands

Using the bi- and mono-triazole ligand, a series of novel cobalt(II) complexes [Co(L-1)(2)(NCS)(2)(H2O)(2)] (1), [Co-2(NCS)(4)(H2O)(6)]center dot 3L(2) (2) and [Co(L-3)(2)(NCS)(2)(H2O)(2)] (L-1 = 4-3-pyridine-1,2,4-triazole, L-2 = 1,4-bis(4H-1,2,4-triazol-4-yl)benzene, and L-3 = 2,6-di(1,2,4- triazol-4-yl)pyridine) have been synthesized. The crystal structures of 1-3 have been determined by single-crystal X-ray diffraction analysis. 1 and 3 has the mononuclear fundamental structure unit while 2 form the dinuclear structure unit. 1-3 were furthermore assembled into three-dimensional (3D) supramolecular complex via the intermolecular hydrogen bonds and aromatic pi-pi stacking interactions. The complexes 1-3 also have been characterized by elemental analysis, FT-IR, and TGA analysis. Variable temperature magnetic susceptibility measurement (2-300K) also reveals weak anti-ferromagnetic interactions in 2.