Assembly, structures and properties of four Cu(II) coordination polymers based on a semi-rigid bis-pyridyl-bis-amide ligand and different polycarboxylates

Four new Cu(II) coordination polymers, namely, [Cu(3-bpah)(1,4-NDC)(H2O)]·3H2O (1), [Cu2(3-bpah)(1,4-NDC)2]·(1,4-H2NDC)·3H2O (2), [Cu(3-bpah)(3-NIP)] (3), [Cu(3-bpah)(1,3,5-HBTC)]·2H2O (4), where 3-bpah = N,N′-bis(3-pyridinecarboxamide)-1,2-cyclohexane, 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid, 3-H2NIP = 3-nitrophthalic acid, 1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid, have been synthesized under hydrothermal conditions. The structures of 1–4 have been determined by single crystal X-ray diffraction and were further characterized by infrared spectroscopy (IR) and thermogravimetric analyses (TGA). Complex 1 displays a 1D double strand. Complex 2 shows a 3D α-Po framework with 1,4-H2NDC guest molecules inside the cages. Complex 3 reveals a 2D wave-like network. Complex 4 exhibits a 2D sql topology. The structural discrepancies of complexes 1–4 imply that the O-donor ancillary ligands play an important role in the formation of the resultant structures of the title coordination polymers. The fluorescent, electrochemical and photocatalytic properties of complexes 1–4 have been studied.