New 3D Lanthanide Phosphonates: Syntheses, Crystal Structure, Thermal Stability, Luminescence, and Magnetism

Abstract

Hydrothermal reactions of lanthanide oxide or lanthanide chloride with 3-ammonium-1-hydroxy­propylidene-1,1-diphosphonic acid (+H3N­CH2CH2C­(OH)­(PO3H2)­(PO3H–), H4L) afforded seven new lanthanide phosphonates, namely, [Ln(HL)] (Ln = Eu (1), Tb (2), Sm (3), Gd (4), Er (5), Nd (6), and Pr (7)). Compounds 1–7 are characterized by single-crystal X-ray diffraction, powder XRD, elemental analysis, IR spectroscopy, and thermogravimetric analysis (TGA). Compounds 1–5 crystallize in the orthorhombic Pnma space group, whereas compounds 6 and 7 crystallize in the monoclinic P2(1)/c space group. Compounds 1–7 exhibit a similar 3D open framework with eight-membered ring channels, which are occupied by organic pendants of CH2CH2NH3. TGA and PXRD reveal that compound 1 is thermally stable up to 350 °C under an air atmosphere. It is interesting that compounds 1 and 2 display bright red and green luminescence, respectively, which can be further enhanced obviously upon cooling to 10 K. It is worth noting that the bright red emission of compound 1 can be preserved after heat-treatment at 350 °C under an air atmosphere. Compounds 6 and 7 can give off NIR luminescence and near UV emission, respectively. Furthermore, the magnetic properties of solids 1 and 3–6 have also been studied.

Chelating agents for radiolanthanides: Applications to imaging and therapy

“…46 The 166 Ho complex of pamidronic acid has been suggested for bone pain palliation therapy, 47 wherein good bone uptake was noted after 48 h, although at a level that was not superior to 166 Ho-EDTMP. Interestingly, the solid-state X-ray structural properties of Ln(III) complexes (Ln = Eu, Tb, Sm, Nd) of pamidronate were only recently reported 48 and show 3D open frameworks, which are presumably unlikely to be representative of the solution state speciation relevant to the radiolanthanide work. A recent DFT study also proposed that the pamidronate is likely to act as a tridentate ligand to Sm(III).…”

Use of highly stable phosphonate coordination polymers as adsorbents for wastewater

“…Due to these exceptional characteristics, CPs based on phosphonates opened great opportunities for new applications in various interdisciplinary domains as ion exchange, intercalation chemistry, proton conduction, catalysis, and others. [ 28,29 ]…”

Syntheses, Crystal structures, Magnetisms and Luminescences of two Series of Lanthanide Coordination Polymers Based on Tricarboxylic Ligand

“…Lanthanide coordination polymers (CPs) have attracted extensive attention due to their fascinating luminescent properties, which render themselves extensive applications, such as in light‐emitting materials, bioanalytical sensors, and optical communications, etc . A plethora of lanthanide coordination polymers have been synthesized, and most of them exhibit interesting photophysical and magnetic properties arisen from 4 f electrons .…”