Metal-organic frameworks based on 1,3,5-triazine-2,4,6-triyltrithio-triacetate: structures, topologies, photoluminescence and photocatalytic properties

Using a hemi-rigid multitopic ligand, 1,3,5-triazine-2,4,6-triyltrithio-triacetic acid (H3L), three metal(II)-complexes formulated as Pb2L(ox)(1/2)(H2O) (H(2)ox = oxalic acid) (1), Pb3L2(H2O)(2) (2) and Ni6L4(PEP)(6)(H2O)(12)center dot 7H(2)O (PEP = 4-(2-(pyridin-4-yl)ethyl)pyridine) (3) have been hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 features a novel 4-nodal (3, 4, 5, 6)-connected 3D framework with an unusual (4(2).6(3).8)(4(2).6(8))(2)(4(2).6)(2)(4(3).6(11).8)(2) topology and complex 2 presents a 3-nodal (5, 6, 8)-connected 3D framework with a novel (3.4(4).5(3).6(2))(3(3).4(12).5(5).6(8))(3(5).4(7).5(3)) topology. Complexes 1 and 2 are hybrid Pb oxides, in which a 2D Pb-O-Pb layer is observed. Complex 3 shows a 3-nodal (3, 4)-connected 3D framework with a novel (6.7(2))(2)(6(4).7.8)(2)(7(4).8.10) topology. L3- displays different coordination modes in the three complexes. Complexes 1 and 2 show different UV absorptions, emission spectra, photoluminescence lifetimes and they are photocatalytically active for the decomposition of methyl orange (MO) under UV light irradiation.