Self-assembly and structures of new lanthanide coordination polymers with 1,3-phenylenebis(oxy)diacetic acid

Seven Ln(III) coordination polymers, namely [Ln(PODA)(FA)(H2O)]n [Ln = La(1), Ce(2), Pr(3), Nd(4), Eu(5)] and [Ln(PODA)1.5(phen)]n [Ln = La(6), Pr(7)] (H2PODA = 1,3-phenylenebis(oxy)diacetic acid, HFA = formic acid, phen = 1,10-phenanthroline) have been synthesized under hydrothermal conditions and characterized by IR spectroscopy, elemental analysis, single crystal X-ray crystallography, UV–Vis spectroscopy and powder X-ray diffraction analysis (PXRD). Structural analysis reveals that 1–5 are isostructural and exhibit 3-D frameworks with a (32.42.52)2(38.420.524.614) topology, which comprise single- and quadruple-strand helical chains; while 6 and 7 show similar layer structures with a (44.62) topology, however, they only consist of one kind of single-strand helical chain. In addition, the thermal stabilities of complexes 3 and 7 and the luminescent properties of complex 5 have been briefly investigated.

Seven new lanthanide coordination polymers with 1,3-phenylenebis(oxy)diacetic acid, formic acid or 1,10-phenanthroline, of which five complexes own single- and quadruple-stranded helical chains, have been synthesized and characterized. The single crystal X-ray diffraction results demonstrate that PODA2− ligand, with two carboxylate groups at a suitable angle, is apt to construct helical structures with lanthanide ions, and formic acid, with multi-dentate bridging coordination modes, as a co-ligand helps to construct multi-stranded helical and higher-dimensional structures.Figure optionsDownload as PowerPoint slide