Assembly, characterization and photocatalytic properties of four copper(II) coordination complexes functionalized by three flexible bis(pyridyl)-bis(amide) ligands

Four new Cu(II) coordination complexes with the formulae [Cu(3-bpyp)(1,4-NDC)(H2O)(2)] (n) (1), [Cu(3-bpyp)(2,5-TDC)(H2O)] (n) (2), [Cu(3-bpsa)(0.5)(2,5-TDC)(H2O)] (n) (3) and {[Cu(3-bpma)(5-NIP)(H2O)]center dot H2O} (n) (4) have been hydrothermally prepared from the corresponding flexible bis(pyridyl)-bis(amide) pro-ligands with different spacers 3-bpyp = N,N'-bis(3-pyridinecarboxamide)-1,3-propane, 3-bpsa = N,N'-bis(3-pyridyl)sebacicdiamide, 3-bpma = N,N'-bis(3-pyridyl)malonamide, together with three aromatic dicarboxylic acids as the co-ligands (1,4-H2NDC = 1,4-naphthalenedicarboxylic acid, 2,5-H2TDC = thiophene-2,5-dicarboxylic acid, 5-H2NIP = 5-nitroisophthalic acid). All four complexes have been characterized by X-ray crystallography. Complex 1 shows 1D "sinusoidal-like" chains constructed from 1,4-NDC and 3-bpyp ligands. Complex 2 exhibits a 1D tube-shaped structure derived from dinuclear [Cu-2(3-bpyp)(2)] (n) loops and 1D [Cu(2,5-TDC)] (n) wave-shaped chains. Complex 3 is a 2D layered polymer containing 1D [Cu(2,5-TDC)] (n) wavelike chains and [Cu(3-bpsa)] (n) zigzag chains. Complex 4 consists of a 1D undulated polymeric chain based on both 5-NIP and 3-bpma bridging ligands. In all four complexes, the adjacent 1D chains or 2D layers are extended into 3D supramolecular networks via hydrogen bonding interactions. The photocatalytic properties of these complexes toward the degradation of organic dyes have been studied. Four new Cu(II) coordination complexes functionalized by three flexible bis(pyridyl)-bis(amide) ligands have been hydrothermally synthesized. Complexes 1, 2 and 4 represent the different 1D polymeric chains constructed by the mixed ligands of aromatic dicarboxylic acids and flexible bis(pyridyl)-bis(amide) ligands. Complex 3 is a 2D layered polymer based on 1D [Cu(2,5-TDC)](n) wavelike chain and [Cu(3-bpsa)](n) zigzag chain. The photocatalytic properties of the complexes 1-4 toward the degradation of organic dyes have been studied.