Coordination polymers of lanthanide complexes with benzene dicarboxylato ligands

Abstract

Three kinds of coordination polymers of lanthanide complexes with benzene dicarboxylato ligands, [Ln(L¹)_1.5(H₂O)₂]·H₂O (H₂L¹ = 2,5-dibenzoylterephthalic acid; Ln = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7)), [Ln(L²)(phen)(OH)] (H₂L² = 4,6-dibenzoylisophthalic acid; phen = 1,10-phenanthroline; Ln = Sm (8), Eu (9), Tb (10), Dy (11), Er (12), Yb (13)) and [Ln(L¹)_0.5(L²)(H₂O)₂] (Ln = Er (14), Ho (15)), were synthesized under hydrothermal conditions. They were characterized by elemental analysis, IR spectroscopy and thermogravimetric analysis. Their solid-state structures were determined by single-crystal X-ray diffraction. Complexes 1–7 are isostructural, each featuring the L¹ connected dinuclear unit of Ln₂O₂(CO₂)₆ to produce a 6-connected 3D network with (4¹²·6³) topology. Isostructural complexes 8–13 possess 2D layer structures consisting of left- and right-handed helical chains that are further assembled into 3D supramolecular architectures through C–H⋯O, C–H⋯π and π⋯π interactions. Complexes 14 and 15 display 2D layer structures, and are further linked into 3D supramolecular architectures through C–H⋯O and π⋯π interactions. The luminescence properties of 3, 4 and 6–11 were investigated.