Synthesis and characterization of an unprecedented 3D lanthanide coordination polymer assembled by cubane-like clusters and a flexible V-shaped dicarboxylate ligand

• The (sfdb)2 − ligand adopts four different coordination modes.
• Four TbIII ions are bridged by four μ3-OH− groups to form a [Tb4(μ3-OH)4]8 + tetranuclear cluster.
• The 3D terbium coordination polymer is constructed by tetranuclear clusters.

A lanthanide coordination polymer based on H2sfdb ligand, namely [Tb4(sdbc)4(phen)2(μ3-OH)4]n ∙ 1.5nH2O (1) (H2sfdb = 4,4′-sulfonyldibenzoic acid, phen = 1,10-phenanthroline) has been hydrothermal synthesized and characterized. Compound 1 exhibits an unprecedented three-dimensional framework that comprised new cubane-like hydroxo clusters [Tb4(μ3-OH)4]8 + as the nodes and flexible (sfdb)2 − ligands as the linkers. In 1, (sfdb)2 − ligands display completely different four kinds of coordination modes. Interestingly, not only the carboxylate groups but also one oxygen atom of sulfonyl group of (sfdb)2 − ligand are coordinated with TbIII ions in 1, which is first found in the compounds based on H2sfdb ligand. The luminescence experiments show that TbIII compound exhibits the typical TbIII-centered luminescence.

Graphical AbstractFour terbium(III) ions are bridged by four µ3-OH- groups to form a [Tb4(µ3-OH)4]8+ tetranuclear cluster, which is connected to the other eight terbium clusters though (sfdb)2- ligands to generate a novel 3D framework.Figure optionsDownload as PowerPoint slide