Tuning structural topologies of two coordination polymers via alter N-donor auxiliary ligand

• Two new Ni(II) coordination polymers have been hydrothermally synthesized.
• Complex 1 exhibited a 3D 4-fold interpenetrating typical diamondoid framework.
• Complexes 1 and 2 both displayed antiferromagnetic properties.

Based on the N-donor auxiliary ligand effect, two new Ni(II) coordination polymers [Ni2(HL)2(bpe)2] (1) and [Ni(HL)(bipy)(H2O)2] (2) [H3L = 2-(4′-carboxyphenyl)terephthalic acid; bpe = 1,2-bis(4-pyridyl)ethane; bipy = 4,4′-bipyridine] have been successfully synthesized and characterized by single-crystal X-ray diffraction study, elemental analysis, IR spectra, TGA and powder X-ray diffraction (PXRD). This work presents a comparative study on the tuning of structural topologies by using two N-donor ligands with different lengths as auxiliary ligands. The structural determination reveals that complex 1, incorporating bpe ligands, features a three-dimensional (3D) 4-connected 4-fold dia interpenetrating architecture with the point symbol of 66, while 2, containing bipy ligands, exhibits a two-dimensional (2D) sql layer structure with a 4-connected (44·62) topology. Moreover, the magnetic properties for 1 and 2 were also measured and compared on account of their different structures.

Two new CPs based on an unsymmetrical tricarboxylic acid and bpe or bipy have been successfully synthesized and characterized under the identical conditions. The results indicated that the flexibility and length of the N-donor auxiliary ligands play the significant roles in adjusting the coordination architecture and characters of the CPs.Figure optionsDownload as PowerPoint slide