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.

Two 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 as PowerPoint slide