A novel dinuclear zirconium (IV) complex derived from [Zr(acac)4] and a pentadentate Schiff base ligand: Synthesis, characterization and catalytic performance in synthesis of indole derivatives

[Zr(acac)4] underwent ligand exchanges with pentadentate Schiff base ligand of N,N′-bis(3-salicylidenaminopropyl)amine. Full characterization of this complex was accomplished with elemental analyses, spectroscopic studies (1H NMR, 13C NMR, FT-IR, UV–vis) and X-ray structure analysis. X-ray crystallography indicated that this complex had a dinuclear structure in which each seven coordinated zirconium atom adopted a distorted pentagonal bipyramid geometry that was joined to the second zirconium by a μ-oxo bridge. The catalytic activity of the prepared complex was investigated in the synthesis of indole derivatives under mild conditions. The results revealed that although in this complex Zr (IV) was surrounded by seven other atoms, it could still catalyze indole condensation reaction and lead to plausible yields of products.