Solvothermal syntheses and structural characterization of a series of metal–hydroxycarboxylate coordination polymers

The combination of transition metal ions with mixed ligands resulted in the formation of three new coordination polymers, {[Co(C4H4O5)(bpe)(H2O)2] · (0.5bpe)(H2O)}n (1), {[Cu(C4H4O6)(bipy)] · 5H2O}n (2) and {[Cu(C4H4O5)(bpa)] · 2.5H2O}n (3) (C4H4O52-=malate dianion, C4H4O62-=tartrate dianion, bpe = 1,2-bis(4-pyridyl)ethene, bipy = 2,2′-bipyridine, bpa = 1,2-bis(4-pyridyl)ethane), which were prepared under solvothermal conditions and characterized by single-crystal X-ray diffraction. 1 and 2 feature 1D chain structures. Interestingly, each pair of chains recognizes each other through aromatic π–π stacking interactions, generating a zipper-like double-stranded chain in 2. Compound 3 shows 2D 63 topology framework with a rectangle-like grid.

Graphical abstractThe combination of metal ions with mixed ligands has resulted in the formation of three novel coordination polymers. 1 and 2 feature infinite chain structures, 3 represents a rectangular grid arrangement of copper(II) atoms bridged inversely by malate dianion, which show typical (6, 3) topology framework. The magnetic property of 1 was investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide