Synthesis, Structures, and Properties of 3D Lanthanide (III) Coordination Polymers Based on 5-Nitroisophthalic Acid

Abstract

A three lanthanide-based coordination compounds of [Sm₄(NIPH)₅(ox)(H₂O)₅](H₂O)₄ (1), [Eu₄(NIPH)₅(oba)(H₂O)₅](H₂O) (2) and [Eu₂(NIPH)₃(H₂O)₁₄](H₂NIPH)(H₂O)₆ (3) (H₂NIPH = 5-nitroisophthalic acid, ox = oxalic acid, H₂oba = 4,4′-oxydibenzoic acid) were synthesized by hydrothermal reaction and characterized by single-crystal X-ray diffraction. These compounds contain an -Ln-O-C-O-Ln- zigzag chain, which connect to each other through the oxygen atoms of the H₂NIPH ligands to form a wave-like layer. These layers are bridged by oxalate or H₂NIPH ligands to generate three-dimensional coordination framework. Within these compounds, porous structure with one-dimensional channels which were filled with isolated organic ligands or lattice water molecules are also observed. Fascinatingly, these lattice water molecules display unprecedented water morphology and play important roles in the stabilizing the whole network. In addition, these compounds show strong photoluminescence at room temperature, respectively, and may be good candidates for potential luminescence materials.

Keywords:

• Fluorescence
• water cluster
• 5-nitroisophthalic acid

Acknowledgments

This work was supported by the NSF of Guangxi Province (No. 2012GXNSFAA053031), Guangxi Department of Education (201203YB071), the Innovation Project of Guangxi University for Nationalities (No.gxun-chx2013096) and the open fund of Key Laboratory of Guangxi Key laboratory of Chemistry and Engineering of Forest Products (No. GXFC 13-08).