Self-assembly in dinuclear, cyclic homotetranuclear and cyclic heterotetranuclear complexes with a picolylhydrazone ligand

Reactions among Cu(ClO4)2 · 6H2O, Cu(acac)2/VO(acac)2 and 3-methoxysalicylaldehyde Picoloylhydrazone in different solvents give three complexes, [Cu2L(acac)(H2O)2]ClO4 (1), [Cu4L2(acac)2(py)2](ClO4)2 (2) and (VO2)2L2Cu2(acac)2 (3) (acac = acetyl acetonate and py = pyridine). There is an extended 2D structure in complex 1 constructed by hydrogen bonds between the binuclear complex cation and the ClO4− anion, and an extended 1D structure in complex 2 constructed by weak π⋯π stacking interactions between neighboring cyclic tetranuclear complex molecules. Complex 3 is the first oxovanadium–copper complex with a bridging oxo oxygen atom between the V atom and the Cu atom. The solid-state photoluminescent properties of the three title complexes have been studied. There is an antiferromagnetic interaction in 1.

Graphical abstractReactions among Cu(ClO4)2 · 6H2O, Cu(acac)2/VO(acac)2 and 3-methoxysalicylaldehyde Picoloylhydrazone in different solvents give three complexes [Cu2L(acac)(H2O)2]ClO4 (1), [Cu4L2(acac)2(py)2](ClO4)2 (2) and [Cu2L2(acac)2(VO2)2] (3) (acac = acetylacetonate and py = pyridine). There is an extended Cu4 structure by hydrogen bonds in 1 and a cyclic tetranuclear structure in 2. Complex 3 is an unusual cyclic heterotetranuclear complex. The solid-state photoluminescence of the four title complexes were studied. There is an antiferromagnetic interaction in 1.Figure optionsDownload full-size imageDownload as PowerPoint slide