Six complexes based on bis(imidazole/benzimidazole-1-yl)pyridazine ligands: Syntheses, structures and properties

•Six complexes based on bis(imidazole/benzimidazole-1-yl)pyridazine.•Structural analysis of all complexes.•Fluorescent properties of complex 6.

Herein we reported six new Ni(II)/Cu(II)/Zn(II) complexes, namely, [Ni(L1)4(OH)2] (1), [Cu(L1)4(OH)2] (2), [Cu(L1)2(SiF6)]n (3), {[Cu(L2)(HCOO)2]·H2O·CH3OH}n (4), [Ni(L2)2(NO3)2]n (5) and {[Zn(L2)Cl2]·DMF}n (6) (L1 = 3,6-bis(imidazole-1-yl)pyridazine, L2 = 3,6-bis(benzimidazole-1-yl)pyridazine), which were characterized by single-crystal X-ray diffraction, elemental analysis, IR, PXRD. These complexes have been successfully constructed under interface diffusion process, heating reflux or hydrothermal conditions. The structures of 1 and 2 are mononuclear complexes. Complex 3 exhibits a 6-connected 3D topology network with the Schläfli symbol of (412·63). In complex 4, two Cu(II) were connected through two HCOO− anions to form dinuclear structure unit, which is arranged into a 1D ladder-like structure by μ2-L2 ligands. Complexes 5 and 6 are 1D zigzag chains connected by L2 ligands, but the Ni(II) ion is six-coordinated in 5 and the Zn(II) ion is four-coordinated in 6. Moreover, the solid-state luminescence property and UV–vis diffuse reflection spectrum of complex 6 have been investigated and discussed.

Graphical abstractSix new Ni(II)/Cu(II)/Zn(II) complexes with bis(imidazole/benzimidazole-1-yl)pyridazine have been successfully constructed and characterized by single-crystal X-ray diffraction, elemental analysis, IR, PXRD. The structures of 1 and 2 are zero dimensional coordination complexes. Complex 3 has a 3D network structure. Complexes 4, 5 and 6 have an infinite 1D chain structure. Moreover, the solid-state luminescence properties and UV–vis diffuse reflection spectrumin of complex 6 have been investigated and discussed.Figure optionsDownload full-size imageDownload as PowerPoint slide