Cobalt(II), silver(I), and lead(II) tetrabromoterephthalates exhibiting the 1-D linear chain, 2-D CdCl2-type layer, and 3-D penta-nodal mixed-connecting coordination frameworks

Reaction of tetrabromoterephthalic acid (H2TBTA) with Co(OAc)2, AgNO3, or Pb(OAc)2 under similar conditions affords three new coordination polymers {[Co(TBTA)(DMF)2(H2O)2](DMF)2}n (1), [Ag(TBTA)0.5]n (2), and [Pb2(TBTA)1.5(OH)(DMF)]n (3). All these complexes have been characterized by elemental analysis, IR, powder X-ray diffraction, and TG-DTA techniques. Single-crystal X-ray diffraction reveals that complex 1 has a 1-D neutral coordination array in which the adjacent CoII centers are bridged by the TBTA spacers, whereas 2 displays a binodal CdCl2-type coordination layer in which the AgI ions and TBTA ligands function as 3- and 6-connected nodes, respectively. In the structure of 3, two types of PbII ions are interconnected via the μ4- and μ5-TBTA ligands as well as the μ3-hydroxyl ions to generate a complicated 3-D penta-nodal coordination framework with (3,4,5)-connectivity. These results clearly suggest that the metal centers with distinct binding tendencies are responsible for the remarkable structural diversity of such crystalline materials.

Graphical abstractThis work presents the metal-regulated assembly of three novel coordination polymers of CoII, AgI, and PbII with tetrabromoterephthalate, which show distinct coordination frameworks such as the 1-D linear chain, 2-D CdCl2-type layer, and 3-D penta-nodal network.Figure optionsDownload full-size imageDownload as PowerPoint slide