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

Abstract

Using a hemi-rigid multitopic ligand, 1,3,5-triazine-2,4,6-triyltrithio-triacetic acid (H₃3333L), three metal(II)-complexes formulated as Pb₂L(ox)_1/2(H₂O) (H₂ox = oxalic acid) (1), Pb₃L₂(H₂O)₂ (2) and Ni₆L₄(PEP)₆(H₂O)₁₂·7H₂O (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 (4².6³.8)(4².6⁸)₂(4².6)₂(4³.6¹¹.8)₂ topology and complex 2 presents a 3-nodal (5, 6, 8)-connected 3D framework with a novel (3.4⁴.5³.6²)(3³.4¹².5⁵.6⁸)(3⁵.4⁷.5³) 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 (6.7²)₂(6⁴.7.8)₂(7⁴.8.10) topology. L³⁻3− 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.