Construction of visible luminescent lanthanide coordination compounds with different stacking modes based on a carboxylate substituted terpyridyl derivative ligand

Abstract

Five new binuclear lanthanide coordination compounds, namely, Eu2(L)6(H2O)2·2(HL) (1), Ln2(L)6(H2O)2·5H2O (Ln = Sm (2), Eu (3), Gd (4), Tb (5)) (HL = 4′-(2-carboxyphenyl)-2,2′:6′,2″-terpyridine) were prepared under hydrothermal methods. Compounds 1–5 exhibit binuclear structures, and further packed by the hydrogen bonding interactions to form different supramolecular structures. These lanthanide compounds present typical visible luminescence and good thermal stabilities. The difference of luminescent intensity in 1-Eu and 3-Eu is caused by the rigidity of compounds.