A series of novel lanthanide carboxyphosphonates with a 3D framework structure: Synthesis, structure, and luminescent and magnetic properties

摘要

By introduction of 1,4-benzenedicarboxylic acid as the second organic ligand, a series of novel lanthanide carboxyphosphonates with a 3D framework structure, namely, [Ln _3(H _2L)(HL) _2(bdc) _2(H _2O)]·7H _2O (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8); H _3L = H _2O _3PCH _2NC _5H _9COOH; H _2bdc = HOOCC _6H _4COOH) have been synthesized under hydrothermal conditions. Compounds 1-8 are isostructural and feature a 3D framework in which Ln(iii) polyhedra are interconnected by bridging {CPO _3} tetrahedra into 2D inorganic layers parallel to the ab plane. The organic groups of H _2L ~- are grafted on the two sides of the layer. These layers are further cross-linked by the bdc ~(2-) ligands from one layer to the Ln atoms from the other into a pillared-layered architecture with one-dimensional channel system along the a axis. The thermal stability of compounds 1-8 has been investigated. Luminescent properties of compounds 5-8, and the magnetic properties of compound 8 have also been studied.