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), [Eu-4(NIPH)(6)(H2O)(8)](H2O)(5) (2), and [Eu-4(NIPH)(6)(H2O)(6)](H2O)(4) (3), synthesized under hydrothermal conditions, self-assemble through Ln(2)[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, pi-pi interactions, and lone pair-pi 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.