Metal coordination architectures of N-acyl-salicylhydrazides: The effect of metal ions and steric repulsion of ligands to their structures of polynuclear metal complexes

Three polynuclear transition metal complexes [Mn8(DMF)8(L1)8] · 4DMF (1), [Mn6(DMF)6(L2)6] · [Mn6(DMF)4(H2O)2(L2)6] · 2DMF (2), [Cu3(L3)2(py)2] (3) of the pentadentate ligands N-acyl-salicylhydrazides were synthesized and characterized, their crystal structures were investigated. The oxidation state and properties of the central metal ions are important in crystal structure formation, trivalent Mn(III) ion which easily form stable octahedral coordination metallamacrocycle complexes, metallacrowns 1 and 2 were obtained; while bivalent Cu(II) ion is easier to form square planar, trinuclear complexes 3 was obtained. The steric effect of the N-acyl side chains also plays an important role in the structures of these polynuclear complexes. The magnetic property of 1 was also investigated.

Graphical abstractThe chelating modes of ligands around the metal centers are the same, but the different connectivities of them lead to the formation of metallacrowns or trinuclear complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide