Temperature-Induced Syntheses, Iodine Elimination, Enantiomers Resolution, and Single-Crystal-to-Single-Crystal Transformation of Imidazole-Co(II) Coordination Polymers with Amino-isophthalic Acid as Co-Ligand

On the basis of a temperature-induced effect, the solvothermal reaction of Co(Ac) 2 ·4H 2 O, 5-amino-2,4,6-triiodoisophthalic acid (H 2 atibdc), and 1,4-bis(2-methyl-imidazol-1-yl)butane (bib) at 80 °C gave a new coordination polymer [Co(bib)(atibdc)] ( 1 ), which shows a two-dimensional (2D) network with left- and right-handed helical chains. By raising the reaction temperature to 130 °C, a pair of homochiral enantiomers [Co(bib)(atibdc)]·2H 2 O ( 2, 2M, and 2P ) were successfully obtained, displaying a three-dimensional (3D) framework with three kinds of unique helical chains. Keeping the temperature of the reaction system to 150 °C, excited, an in situ iodine elimination reaction occurred, and a new linker 5-aminoisophthalic acid (H 2 aipa) was generated, which then cooperated with the bib ligand to construct a coordination polymer [Co(bib)(aipa)] ( 3 ), showing a 3D 3-fold interpenetrating architecture. The comparison of final solid structures exhibits an exclusive temperature-induced effect on the construction of the coordination polymer. Furthermore, via a single-crystal-to-single-crystal (SCSC) transformation, the 2D network of 1 can be derived from the 3D framework of 2, which presents a rare type of temperature-solvent induced SCSC transformation. In addition, the magnetic properties of 1 – 3 have been investigated as well.