Photocatalytic and magnetic properties of two Ni(II) metal–organic complexes based on 6,6′-di(benzimidazol-2-yl)-2,2′-bipyridine

Abstract

Two Ni(II)-based monomeric complexes with the formulas of [Ni(dbb)(H2O)2] (1) and [Ni2(H2dbb)2(xda)(H2O)2] (2) (H2dbb = 6,6′-di(benzimidazol-2-yl)-2,2′-bipyridine, H4xda = 5,5′-(1,4-xylylenediamino) diisophthalic acid) have been successfully synthesized under solvothermal conditions. Structural analysis revealed that the discrete monomers of 1 and 2 extend into high-dimensional networks through intermolecular hydrogen bonds, π···π stacking interactions and weak intermolecular interactions. As novel photocatalyst materials, 1 and 2 exhibited active performance towards the degradation of methyl violet (MV) under UV irradiation. Besides, the cyclic experiments indicated that 2 was stable and reusable, enabling it to be potential candidates for dye-containing wastewater treatment. The possible mechanism of the photocatalytic performance was also investigated in detail. Moreover, the magnetic susceptibility measurements of 1 and 2 demonstrated that week antiferromagnetic interactions were operative between the Ni(II) ions.