Double-stranded helicates of Ni(II), Co(II), Fe(II) and Zn(II) with oligo-α-naphthyridylamino ligand: Synthesis, structure and properties

Using tetranaphthyridyltriamine ligand, N2-(2-(1,8-naphthyridin-7-ylamino)-1,8-naphthyridin-7-yl)-N7-(1,8-naphthyridin-2-yl)-1,8-naphthyridine-2,7-diamine (H3tentra), double-stranded dinuclear helical compounds [M2(H3tentra)2(ClO4)4] [M = NiII (1), CoII (2), FeII (3), ZnII (4)] have been synthesized and structurally characterized. The geometry about the metal (II) ions was described as distorted tetrahedral, with both ligands acting as bisbidentate N4 donors. Strong π–π interactions were observed for all synthesized double stranded helicates of H3tentra ligand.