Self-Assembly of 2D Lanthanide-Metal Coordination Polymers Based on 5-Nitroisophthalic Acid Linker: Synthesis, Structures, and Luminescence

Three 2D novel lanthanide-based metallic coordination frameworks involving the 5-nitroisophthalic acid ligand were characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction, namely, [Er(NIPH)2(H2O)2](H2O)2(1), [Eu4(NIPH)6(H2O)8](H2O)5(2), and [Eu4(NIPH)6(H2O)6](H2O)4(3), synthesized under hydrothermal conditions, self-assemble through Ln2[NIPH]2 building blocks to give a 2D coordination layer structure. The adjacent layers stack to form a 3D supramolecular framework through weak interactions, such as hydrogen bonding, π–π interactions, and lone pair-π interactions. However, in 1 and 2 formed 2D 4-connected (4,4) topological network. In addition, in this work the photoluminescent property of the compound 3 has been studied.