Syntheses, structures and properties of four 3D microporous lanthanide coordination polymers based on 3,5-pyrazoledicarboxylate and oxalate ligands

• Published in: Journal of solid state chemistry Vol. 212; pp. 185 - 190
• Main Authors: Song, Juan, Wang, Ji-Jiang, Hu, Huai-Ming, Wu, Qing-Ran, Xie, Juan, Dong, Fa-Xin, Yang, Meng-Lin, Xue, Gang-Lin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2014; Elsevier
• Subjects: Carboxylate ligands; Channels; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Coordination polymers; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; HYDRATION; HYDROTHERMAL SYNTHESIS; In situ reaction; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Lanthanide; Lanthanides; LIGANDS; LUMINESCENCE; Luminescence properties; Materials science; MONOCLINIC LATTICES; NITRATES; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Organic compounds; OXALATES; OXALIC ACID; Physics; Polyhedrons; POLYMERS; Porous materials; granular materials; RARE EARTHS; Solid state; SOLIDS; SPACE GROUPS; Specific materials; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Thermal expansion; thermomechanical effects and density; THERMAL GRAVIMETRIC ANALYSIS; Thermal properties of condensed matter; Thermal properties of crystalline solids; Three dimensional; X-RAY DIFFRACTION; Carboxylate ligands; Coordination polymers; Lanthanide; In situ reaction; Luminescence properties; Space groups; Molecular structure; Polychelate; Porous materials; Luminescence; Nitrates; Coordination polyhedron; Thermal stability; Europium additions; Rare earths; Optical properties; Supramolecular structure; Oxalates; Crystal structure; Zigzag structure; Monoclinic lattices; Thermal properties; Solid state; Microporosity; Hydrothermal synthesis; Oxalic acid; Ligands; Carboxylates
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2014.01.020

Four three-dimensional lanthanide coordination polymers with reversible structural interconversions, [Ln2(Hpdc)2(C2O4)(H2O)4]n·2nH2O [Ln=Sm (1), Eu (2), Tb (3) and Dy (4)], have been synthesized by hydrothermal reactions of lanthanide nitrates with 3,5-pyrazoledicarboxylic (H3pdc) and oxalic acids. It is noteworthy that there is an in situ reaction in 1, in which H3pdc was decomposed into (ox)2− with Cu(II)–Sm(III) synergistic effect under hydrothermal conditions. These compounds are isostructural and crystallized in the monoclinic P21/c space group. The Ln(III) ions are eight-coordinated with dodecahedron coordination geometry. These polyhedra are linked by oxalate groups to form 1D zigzag chain, which are further connected by 3,5-pyrazoledicarboxylate to extend similar 3D frameworks with channels along c-axis in 1–4. These coordination polymers display the characteristic emission bands of the Ln(III) ions in the solid state and possess good thermal stabilities. Four 3D microporous lanthanide coordination polymers with reversible structural interconversion have been synthesized. They exhibit characteristic emission bands of the lanthanide ions and possess great thermal stability. [Display omitted] •Four lanthanide coordination polymers have been hydrothermal synthesized.•There is an in situ reaction in 1 in which H3pdc was decomposed into (ox)2− with the Cu(II)–Sm(III) synergistic effect under hydrothermal conditions.•TGA and XRD studies reveal that upon hydration–dehydration, compounds 1–4 undergo a reversible structural interconversion process through a cooling-heating cycle.•Compounds 1–4 exhibit characteristic lanthanide-centered luminescence.