Search

A lanthanide coordination polymer based on H 2 sfdb ligand, namely [Tb 4 (sdbc) 4 (phen) 2 (μ 3 -OH) 4 ] n ∙ 1.5 n H 2 O ( 1 ) (H 2 sfdb = 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 [Tb 4 (μ 3 -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 Tb III ions in 1 , which is first found in the compounds based on H 2 sfdb ligand. The luminescence experiments show that Tb III compound exhibits the typical Tb III -centered luminescence. [ABSTRACT FROM AUTHOR]

Abstract: Four new mixed-ligand complexes, namely [Zn2(pam)2(2,2′-bpy)2] (1), [Cd(pam)(2,2′-bpy)2] n (2), [Zn(pam)(phen)] n (3) and [Cd (pam)(phen)] n ·0.5n CH3CH2OH·0.5nH2O (4) (H2pam=pamoic acid, 2,2′-bpy=2,2′-bipyridine, phen=1,10-phenanthroline) have been synthesized under hydro(solvo)thermal conditions. Complex 1 possesses a discrete dinuclear metallamacrocyclic structure. Complex 2 is a 1D homochiral helical coordination polymer that is built from achiral components, whereas 3 displays a 1D helical chain structure. 4 is an unusual 2D double-layered structure generated by π⋯π interactions of two 2D networks. The structural differences of these complexes are mainly due to the differences of the size of the rigid aromatic chelate ligands and d10 metal ions. It appears that the chelate ligands and metal ions of the larger size favor the formation of high-dimensional structures, whereas those of the smaller size favor the formation of low-dimensional structures in the present system. The photoluminescence and thermal stability of these complexes were investigated. [Copyright &y& Elsevier]