Delicate modulated assembly of a new kind of trinuclear copper(ii) motif governed by N-containing agents

Abstract

A new kind of trinuclear copper(II) motif [Cu₃L] was prepared in situ by adopting a multidentate ligand, N′²,N′^2′-bis(2-hydroxybenzoyl)biphenyl-2,2′-dicarbohydrazide (H₆L), in the presence of a series N-containing agents. Featuring five different assembly styles, [Cu₃L(DMF)_2.5(hmta)]·3H₂O (1), [Cu₃L(DMA)(H₂O)(Hmor)] (2), [Cu₃L(py)₂]·DMF (3), [Cu₃L(DMF)(H₂O)]·2DMF (4), and [Cu₃L(DMA)(H₂O)]·0.5DMA (5) (hmta = hexamethylenetetramine, Hmor = morphiline, py = pyridine) were obtained. In these assemblies, the [Cu₃L] units are connected with each other into one-dimensional chains via bridging of N-containing agents or via sharing an oxygen atom of L⁶⁻ to fuse together. Furthermore, the connecting styles are found to be governed by the character of the N-containing agents used, which is discussed in detail. Thermal gravimetric analysis and magnetic measurement of some complexes were performed.