Two 2D grid-based Co(II) amino acid Schiff base complexes with left- and right-handed helical chains: Structures and magnetism

•Two rare 2D layered Co(II) amino acid Schiff base complexes were synthesized.•Both the frameworks consist of 1D left- and right-handed helical chains.•Magnetic studies reveal the dominant antiferromagnetic exchange interactions.

Two layered Co(II) amino acid Schiff base complexes, [Co(napala)(tbpe)0.5]n (1) and [Co(napgly)(tbpe)0.5]n (2) [H2napala = N-(2-hydroxy-1-naphthylmethylidene)-d/l-alanine, H2napgly = N-(2-hydroxy-1-naphthylmethylidene)-glycine and tbpe = trans-1,2-bis(4-pyridyl)ethylene], have been synthesized by solvothermal methods and characterized using single-crystal X-ray diffraction. The bridging of Schiff base ligands napala2 − or napgly2 − with Co(II) forms one-dimensional (1D) left- and right-handed helical chains which are further pillared by tbpe to build a two-dimensional (2D) grid-based hcb-type framework. Moreover, both complexes show high thermal stability and exhibit antiferromagnetic coupling between the Co(II) centers mediated by the syn–anti-COO−-bridges.

Graphical abstractTwo new Co(II) amino acid Schiff base complexes exhibit 2D grid-based layers. The 2D structures contain left- and right-handed helical chains and trans-1,2-bis(4-pyridyl)ethylene bridges. The magnetic properties of the complexes were studied in details.Figure optionsDownload full-size imageDownload as PowerPoint slide