Metal(II) complexes based on 1,4-bis(3-pyridylaminomethyl)benzene: structures, photoluminescence and photocatalytic properties

Using a novel ditopic N-donor ligand, 1,4-bis(3-pyridylaminomethyl)benzene (L), four metal(II)-complexes formulated as CdL(SO4)(H2O)(2) (1), CdL(1,3-bdc) (1,3-H(2)bdc = 1,3-benzene dicarboxylic acid) (2), PbL(1,3-bdc) (3) and ZnL1/2(2,5-tdc) (2,5-H(2)tdc = 2,5-thiophene dicarboxylic acid) (4) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes 1 and 3 feature uninodal 4-connected non-interpenetrated sql/Shubnikov tetragonal plane nets with {4(4).6(2)} topology. Complex 2 exhibits a 2-nodal (3,4)-connected 2D V2O5-type net with (4(2).6(3).8) (4(2).6) topology. Complex 4 exhibits a uninodal 6-connected hxl/Shubnikov plane net (3,6) with {3(6).4(6).5(3)} topology. The hemi-rigid L ligand possesses similar conformation in complexes 1, 3 and 4: the two pyridine rings of L are parallel, and the phenyl moiety is almost perpendicular to the two terminal pyridine rings. Complexes 1-4 show different thermal stabilities, UV-vis absorption, emission spectra, photoluminescence lifetimes and they are photocatalytically active for the decomposition of methyl orange under UV light irradiation.