Syntheses, topologies, and luminescence of four Ln–organic polymers constructed from aromatic tetracarboxylic acids†‡
Abstract
Four new coordination polymers (CPs), {[H2N(CH3)2]2[Ln2(BPT)(ox)2]}n (Ln = Er for 1, Yb for 2, and Sm for 3; H2ox = oxalic acid) and {[Gd(HDCP)(H2O)]·H2O}n (4), have been constructed from Ln ions and two aromatic tetracarboxylate acids (H4BPT = 3,3′,5,5′-biphenyltetracarboxylic acid, H4DPT = 4,5-di(4′-carboxylphenyl)phthalic acid) under solvothermal reactions through the linker extension strategy. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complexes 1–3 are isomorphous and exhibit an unprecedented (6,8)-connected 3D architecture with a point symbol of (33·410·57·62·76)(33·46·56)2, which is built up from right- and left-handed [Ln(ox)]n helixes. Complex 4 shows a 3D (4,8)-connected flu net with (412·612·84)(46)2 topology based on 1D [Gd(COO)2]n ladder chains. Moreover, their luminescence properties have been investigated.