Self-assembly, structures and properties of three new Ni(II) coordination polymers derived from two different bis-pyridyl-bis-amide ligands and two aromatic polycarboxylates

Abstract

Three new Ni(II) coordination polymers exhibiting different 1D and 2D framework structures have been hydrothermally synthesized: [Ni(L 1)(1,3-BDC)(H 2O) 3] ⋅H 2O (1), [Ni(L 1)(1,3,5-HBTC)(H 2O) 3] (2), [Ni 3(L 2)3(1,3,5-BTC) 2(H 2O) 8] ⋅12H 2O (3) [L 1= N,N ′-bis(pyridin-3-yl)cyclohexane-1,4-dicarboxamide, L 2= N,N ′-bis(3-pyridyl)octandiamide, 1,3-H 2BDC = 1,3-benzenedicarboxylic acid, 1,3,5-H 3BTC = 1,3,5-benzenetricarboxylic acid]. X-ray single crystal diffraction analyses revealed that polymer 1 is a 2D interlaced layer based on the 1D [Ni(L 1)(1,3-BDC)(H 2O) 3] meso-helical chains. Polymer 2 is a 1D wave-shaped chain derived from the 1D [Ni(L 1)] n chain and monodentate coordinated 1,3,5-HBTC anions. Polymer 3 possesses an interesting 2D layer containing the trinuclear [Ni 3(1,3,5-BTC) 2] substructural unit and 1D zigzag [Ni(L 2)] n chain, representing a 3,4-connected {6 ⋅8 2} 2 {62⋅82⋅10⋅12} topology. Finally, the adjacent 1D chains or the 2D layers are connected through hydrogen bonding interactions to construct 3D supramolecular networks. Further, the thermal stability, solid state fluorescent property and photocatalytic activity of 1–3 have been investigated. Three new Ni(II) coordination polymers have been hydrothermally synthesized by self-assembly of two bis-pyridyl-bis-amide ligands (L1, L2) and two aromatic polycarboxylates (1,3-H2BDC, 1,3,5-H3BTC). The thermal stability, fluorescent properties and the photocatalytic activities of polymers 1–3 have been studied.