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)] center dot (0.5bpe)(H2O)}(n) (1), {[Cu(C4H4O6)(bipy)] center dot 5H(2)O}(n) (2) and {[Cu(C4H4O5)(bpa)] center dot 2.5H(2)O}(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 pi-pi stacking interactions, generating a zipper-like doublestranded chain in 2. Compound 3 shows 2D 6(3) topology framework with a rectangle-like grid. (C) 2007 Elsevier B. V. All rights reserved.