Two ZnII coordination complexes assembled by trithiocyanuric acid and two different N-donor auxiliary ligands

The dipyridyl-type building blocks 4-amino-3,5-bis(pyridin-3-yl)- 1,2,4-triazole (3-bpt) and 4,4'-bipyridine (bpy) have been used to assemble with Zn-II in the presence of trithiocyanuric acid (ttcH(3)) to afford two coordination compounds, namely bis[4-amino-3,5-bis(pyridin-3-yl)-1,2,4-triazole-kappa N-3]bis(tri-thiocyanurato- kappa N-2,S)zinc(II), [Zn(C3H2N3S3)(2)(C12H10N6)(2)]center dot-2H(2)O, (1), and catena-poly[[[bis(trithiocyanurato-kappa N-2, S)zinc(II)]- mu-4,4'-bipyridine-kappa N-2:N']4,4'-bipyridine monosolvate], {[Zn-2-(C3H2N3S3)(4)(C10H8N2)(3)]center dot C10H8N2}(n), (2). Single-crystal X-ray analysis indicates that complex (1) is a mononuclear structure, while complex (2) presents a one-dimensional chain coordination motif. In both complexes, the central Zn-II cation adopts an octahedral geometry, coordinated by four N- and two S-donor atoms. Notably, trithiocyanurate (ttcH(2)(-)) adopts the same bidentate chelating coordination mode in each complex and exists in the thione tautomeric form. The 3-bpt co-ligand in (1) adopts a monodentate coordination mode and serves as a terminal pendant ligand, whereas the 4,4'-bipyridine (bpy) ligand in (2) adopts a bidentate-bridging coordination mode. The different coordination characters of the different N-donor auxiliary ligands lead to structural diversity for complexes (1) and (2). Further analysis indicates that the resultant three-dimensional supramolecular networks for (1) and (2) arise through intermolecular N-H center dot center dot center dot S and N-H center dot center dot center dot N hydrogen bonds. Both complexes have been further characterized by FT-IR spectroscopy and elemental analyses.