Hydrothermal syntheses and structural characterization of four complexes with in situ formation of 1,2,3-triazole-4-carboxylate ligand

Four new complexes constructed by 1,2,3-triazole-4-carboxylate and bipyridyl-like ligands, namely [Cu(ta)(bipy)·H2O]n (1), [Mn2(ta)2(bipy)2(H2O)2·2H2O]n (2), [Zn(ta)(phen)2·5H2O]n (3), [Ni(ta)(phen)2·8H2O]n (4), (ta = 1,2,3-triazole-4-carboxylate, bipy = 2,2′-bipyridine, phen = 1,10-phen) were prepared under hydrothermal conditions and characterized by IR, elemental analyses and single-crystal X-ray analyses. Where the ta ligand is formed in situ by the decarboxylation of 1H-1,2,3-triazole-4,5-dicarboxylic acid. In the complex 1, the Cu (II) ions are bridged by ta ligand into a one-dimensional zigzag chain coordination polymer motif. Binuclear [Mn2(ta)2(bipy)2(H2O)2] units bridged by ta ligands are linked into a two-dimensional layered structure via interdimeric hydrogen bonds within the structure of 2. Compounds 3 and 4 are mononuclear complexes. Most interestingly, the crystal-lattice water molecules in complexes 3 and 4 are connected via intermolecular OH···O hydrogen bonds into 1D tapes and 2D layers, respectively.