Supramolecular copper(II) complexes of novel Schiff bases derived from β-amino acid and salicylaldehyde: Syntheses, crystal structure, and magnetic property

•β-Amino-acid coordination compounds are less explored than the α-amino acids ones.•Two Cu(II) compounds have been synthesized based on β-amino-acid-based Schiff base.•Compounds 1 and 2 exhibit diverse supramolecular architectures (2D and discrete).•There exist antiferromagnetic interactions in 1 and 2.

Two new ternary mixed-ligand complexes [Cu2(L1)2(bipy)(EtOH)2] (1) (H2L1 = β-phenylal-anine, N-[1-(2-hydroxyphenyl)propylidene], bipy = 4,4′-bipyridine, EtOH = ethanol) and [CuL2(imi)] (2) (H2L2 = β-(2-chlorophenylal)anine, N-[1-(2-hydroxyphenyl)propylidene], imi = imidazole) have been synthesized and characterized by X-ray diffraction. In 1, the coordination geometry around the copper is square-pyramidal. The Schiff base ligand L1 coordinates to the Cu(II) ion in a tridentate mode, while the bipyridine ligand coordinates in bidentate bridging mode linking two adjacent Cu(II) ions. The binuclear unit are further linked by hydrogen bond to form a 2D wave-like supramolecular architecture. In 2, the coordination geometry around the copper is distorted square-planar. In the solid state, the imidazole ring is hydrogen-bonded to the carboxyl group, thus linked the two adjacent CuL2(imi) units together with a Cu–Cu distance of 3.515 Å. Magnetic behaviors of complex 1 and 2 exhibit antiferromagnetic interactions within the Cu(II) dimer fitted by the spin Hamiltonian H = −JS1S2.

Graphical abstractTwo new ternary mixed-ligand copper complexes with β-amino-acid-based Schiff bases have been synthesized and characterized, which display 1D, and 2D supramolecular network regulated by hydrogen bond. Their thermal and magnetic properties have also been studied.Figure optionsDownload full-size imageDownload as PowerPoint slide