Hydrothermal synthesis, crystal structures, and luminescent properties of a series of new lanthanide oxalatophosphonates with a layer architecture

Abstract

Eleven new lanthanide oxalatophosphonate hybrids with a 2D layered structures, namely, [Ln(H₃L)(C₂O₄)]·2H₂O (Ln = La–Dy, Er and Y, H₄L = C₆H₅CH₂N(CH₂PO₃H₂)₂), have been synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Compounds 1–11 are isomorphous and they exhibit a 2D framework structure. Two {LnO₈} polyhedra and four {CPO₃} tetrahedra are interconnected into a unit via corner-sharing, and the so-built units are bridged by the oxalate anions into a layer. The result of connections in this manner is the formation of a 24-atom window. The thermal stabilities and guest desorption–sorption properties of compounds 1–11 have been investigated. The luminescent properties of compounds 5, 6, 8 and 9 have also been studied.