4,4′-Trimethyl­enedipiperidiniumbenzene-1,4-dicarboxyl­ate

The hydro­thermal reaction of benzene-1,4-dicarboxylic acid and 4,4′-trimethyl­ene dipiperidine leads to the formation of the title compound, C13H28N2 2+·C8H4O4 2−. The anion is located on a center of inversion whereas the cation is positioned on a twofold rotation axis. In the crystal structure, the anions and cations are linked by N—H⋯O and N—H⋯(O,O) hydrogen bonds

Synthesis, Structures and Electrochemical Properties of Lithium 1,3,5-Benzenetricarboxylate Complexes

Four lithium coordination polymers, [Li3(BTC)(H2O)6] (1), [Li3(BTC)(H2O)5] (2), [Li3(BTC)(μ2-H2O)] (3), and [Li(H2BTC)(H2O)] (4) (H3BTC = 1,3,5-benzenetricarboxylatic acid), have been synthesized and characterized. All the structures have been determined using single crystal X-ray diffraction studies. Complexes 1 and 2 have two-dimensional (2-D) sheets, whereas complex 3 has three-dimensional (3-D) frameworks and complex 4 has one-dimensional (1-D) tubular chains. The crystal-to-crystal transformation was observed in 1–3 upon removal of water molecules, which accompanied the changes in structures and ligand bridging modes. Furthermore, the electrochemical properties of complexes 3 and 4 have been studied to evaluate these compounds as electrode materials in lithium ion batteries with the discharge capacities of 120 and 257 mAhg−1 in the first thirty cycles, respectively