Syntheses and Crystal Structures of Co(II) and Cu(II) Complexes Based on 3,5-Bis(3-pyridyl)-4-amino-1,2,4-triazole Ligand

Two new metal complexes of {[CoL(H2O)(4)SO4 center dot H2O}(n) (1) and [Cu (hfac)(2)L-2] (2, hfac = hexafluoroacetylacetonate) based on 3,5-bis(3-pyridyl)-4-amino-1,2,4-triazole (L) have been synthesized and characterized by infrared spectrum (IR), elemental analysis (EA), and X-ray single crystal diffraction. For 1, ligand L adopts a cis-conformation and acts as a bidentate spacer to bind Co(II) centers to form a one-dimensional (1D) sinusoidal chain. These sinusoidal chains are linked with each other and give a three-dimensional (3D) framework through O-H center dot center dot center dot O and O-H center dot center dot center dot N hydrogen bonds of neighboring chains. H2O guest molecules and SO42- anions are bound on the framework through hydrogen bonding system. For 2, while the ligand L also adopts a cis-conformation, it acts as a monodentate spacer to bind Cu(II) centers to form a discrete mononuclear complex, which is also linked into a three-dimensional (3D) framework through hydrogen bonds. CCDC: 1568579, 1; 1568580, 2.