Auxiliary ligand-triggered assembly of two dinuclear Cu(II) compounds with a pyridylhydrazone derivative: Synthesis, crystal structure and magnetic property

•Two new Cu(II)-based dimers have been fabricated with pyridylhydrazone ligand and different carboxylate coligands.•Isomeric compounds 1 and 2 exhibit entirely different structural characteristics.•The bimetallic units in 1 and 2 perform antiferromagnetic and ferromagnetic coupling, respectively.

Employing different benzendicarboxylic acids as co-ligands, two new compounds, [Cu2(bpad)2(Hp)2]n (1) and [Cu2(bpad)2(Hip)2]n (2) (Hbpad = N3-benzoylpyridine-2-carboxamidrazone, H2p = phthalic acid, H2ip = isophthalic acid), have been synthesized. The structures and magnetic properties of title compounds have been systematically characterized. The two dinuclear Cu(II) compounds are isomers in which the metal ions adopt distinguishably penta-coordinated geometries. Cu(II) ions with square pyramidal structure are bridged by carboxylate oxygen atoms in 1, while the Cu(II) centers with trigonal bipyramid model are linked by carbamoyl oxygen atoms in 2. Magnetic measurements illustrate that the short contacts causing antiferromagnetic intra-dimer interactions consist in compound 1, whereas ferromagnetic intra-dimer interactions are performed on compound 2.

Graphical abstractTwo new dinuclear Cu(II) compounds based on pyridylhydrazone derivative are synthesized and characterized. The structure and magnetism of two compounds are mediated by different benzendicarboxylic acids as co-ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide