Three new two-dimensional metal-organic coordination polymers derived from bis(pyridinecarboxamide)-1,4-benzene ligands and 1,3-benzenedicarboxylate: Syntheses and electrochemical property

Three new metal-organic coordination polymers, [Co(3-bpcb)(1,3-BDC)]·H2O (1), [Co(4-bpcb)(1,3-BDC)]·2H2O (2) and [Cu(4-bpcb)(1,3-BDC)]2·0.5(4-bpcb) (3), have been hydrothermally synthesized using N,N′-bis(3-pyridinecarboxamide)-1,4-benzene (3-bpcb) or N,N′-bis(4-pyridinecarboxamide)-1,4-benzene (4-bpcb) and 1,3-benzenedicarboxylate (1,3-H2BDC) mixed ligands and characterized by elemental analyses, IR, TG, XRPD and single-crystal X-ray diffraction. Complexes 1–2 exhibit the similar two-dimensional (2D) network with different undulation degrees and dimensions, owing to different N positions from the 3-bpcb and 4-bpcb ligands. 1,3-BDC ligand in complexes 1 and 2 shows two coordination modes. The adjacent 2D layers for 1–2 are further linked by hydrogen bonding interactions to form a three-dimensional (3D) supramolecular network. Complex 3 possesses infinite 3-fold interpenetrating 2D network composed of three kinds of Cu-4-bpcb one-dimensional (1D) chains and 1,3-BDC ligands, in which 1,3-BDC only shows one coordination mode. The 2D network is further extended into 3D supramolecular framework by hydrogen bonding interactions. The non-coordinated 4-bpcb ligands existing in the 2D network connect with adjacent 2D layers through the hydrogen bonding interactions. In addition, the electrochemical behaviors and the fluorescence property of complexes 1–3 have been reported.

Graphical abstractThree new metal-organic coordination polymers, namely, [Co(3-bpcb)(1,3-BDC)]·H2O (1), [Co(4-bpcb)(1,3-BDC)]·2H2O (2) and [Cu(4-bpcb)(1,3-BDC)]2·0.5(4-bpcb) (3), [3-bpcb = N,N′-bis(3-pyridinecarboxamide)-1,4-benzene, 4-bpcb = N,N′-bis(4-pyridinecarboxamide)-1,4-benzene and 1,3-H2BDC = 1,3-benzenedicarboxylate] have been synthesized under the hydrothermal conditions. Complexes 1–3 all possess infinite two-dimensional layer structures. Specially, complex 3 shows the 3-fold interpenetrating 2D network. Moreover, the electrochemical behaviors and the fluorescence property of 1–3 are also reported.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► 3-bpcb or 4-bpcb and polycarboxylate are selected as the mixed ligands. ► 1–2 exhibit the 2D network, 3 possesses 3-fold interpenetrating 2D network. ► The electrochemical behaviors and the fluorescence property of 1–3 have been reported.