Effect of three bis-pyridyl-bis-amide ligands with various spacers on the structural diversity of new multifunctional cobalt(II) coordination polymers

•Three multifunctional cobalt(II) complexes based on various bis-pyridyl-bis-amide ligands.•Complex 1 is a 3D coordination structure with 8-connected {420.68} topology.•Complex 2 is a 1D “cage+cage”-like chain.•Complex 3 is a 3D coordination network with a 6-connected {412.63} topology.•The fluorescent, electrochemical and magnetic properties of 1–3 were reported.

Three new cobalt(II) coordination polymers [Co2(1,4-NDC)2(3-bpye)(H2O)] (1), [Co(1,4-NDC)(3-bpfp)(H2O)] (2) and [Co(1,4-NDC)(3-bpcb)] (3) [3-bpye=N,N′-bis(3-pyridinecarboxamide)-1,2-ethane, 3-bpfp=bis(3-pyridylformyl)piperazine, 3-bpcb=N,N′-bis(3-pyridinecarboxamide)-1,4-benzene, and 1,4-H2NDC=1,4-naphthalenedicarboxylic acid] have been hydrothermally synthesized. The structures of complexes 1–3 have been determined by X-ray single crystal diffraction analyses and further characterized by infrared spectroscopy (IR), powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Complex 1 is a 3D coordination structure with 8-connected {420.68} topology constructed from 3D [Co2(1,4-NDC)2(H2O)]n framework and bidentate 3-bpye ligands. Complex 2 shows 1D “cage+cage”-like chain formed by 1D [Co2(1,4-NDC)2]n ribbon chains and [Co2(3-bpfp)2] loops, which are further linked by hydrogen bonding interactions to form a 3D supramolecular network. Complex 3 displays a 3D coordination network with a 6-connected {412.63} topology based on 2D [Co2(1,4-NDC)2]n layers and bidentate 3-bpcb bridging ligands. The influences of different bis-pyridyl-bis-amide ligands with various spacers on the structures of title complexes are studied. Moreover, the fluorescent properties, electrochemical behaviors and magnetic properties of complexes 1–3 have been investigated.

Graphical abstractThree multifunctional cobalt(II) complexes constructed from three bis-pyridyl-bis-amide and 1,4-naphthalenedicarboxylic acid have been hydrothermally synthesized and characterized. The fluorescent, electrochemical and magnetic properties of 1–3 have been investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide