文摘
Three Cu(II) complexes, [Cu(H2L)(ClO4)2] (1), [Cu(H2L)0.5(µ-SO4)(H2O)]·H2O (2) and [{Cu(H2L)(H2O)}{Cu(H2L)(Cl)]Cl3·4H2O (3), with a flexible ligand 1,2-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl)ethane (H2L) were synthesized from various Cu(II) salts. X-ray crystal structure analysis reveals that the H2L ligand demonstrates different coordination modes in each of these complexes. Complex 1 shows a mononuclear structure with ClO4− anions weakly coordinated to the metal center, which is further extended into a 1-D assembly through hydrogen bonds. Complex 2 is a polymeric species in which the dinuclear units [Cu2(H2L)(H2O)2] are linked through SO42− anions to form 1-D chains, which are further associated into a 2-D assembly through a self-assembled decameric water cluster. Complex 3 features an interesting 3-D coordination architecture assembled through extensive hydrogen interactions between chloride anions and water molecules. Notably, a unique discrete water–chloride cluster [(H2O)10(Cl)8]8− built around a chair-like water–chloride octameric core is identified in the crystal matrix of complex 3. The choice of counteranion plays a key role in the diverse structures of these complexes. The spectroscopic properties of the complexes have also been investigated.
