Metal–organic coordination architectures of bis(N-imidazolyl) pyridazine: Syntheses, structures, emission and photocatalytic properties

Abstract

In efforts to explore the effects of metal ions, counter anions on the structures and properties of metal–organic complexes, seven new complexes [ZnL4(OH)2] (1), {[ZnL(AcO)2](CH3CH2OH)}∞ (2), {[ZnL(H2O)4](SO4)}∞ (3), [CdL4(OH)2] (4), {[CdL(AcO)2](CH3CH2OH)}∞ (5), {[CdL(H2O)4](SiF6)}∞ (6) and {[Cu2L2(SO4)2(H2O)2](H2O)}∞ (7) [L=3,6-bis(N-imidazolyl) pyridazine] were synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. Complexes 1 and 4 have similar mononuclear structures. Complexes 2, 3 and 6 have 1-D chain structures, while 5 reveals 2-D neutral infinite sheet structure. One 1-D chain and one 2-D sheet form complicated structure of complex 7. The ligands L adopt didentate bridging mode to coordinate to the metal ions in complexes 2, 3, and 5–7. Obviously, the structural differences among them are attributable to the differences of metal ions, counter anions and coordination modes of ligand. The fluorescent property of complexes 1–6 have been investigated and discussed. In addition, complexes 1–5 exhibit photocatalytic activity and selectivity for dye degradation under UV light.