A Series of Lanthanide Compounds Constructed from Ln₈ Rings Exhibiting Large Magnetocaloric Effect and Interesting Luminescence

A series of lanthanide compounds, [Ln₈­(CH₂OH­CH₂OH)₈­(SO₄)₁₂]·​<i>m</i>(C₂H₇N)·​<i>n</i>H₂O (Ln = Gd (<b>1</b>), Sm (<b>2</b>), Tb (<b>3</b>), La (<b>5</b>), <i>m</i> = 2, <i>n</i> = 2; Ln = Eu (<b>4</b>), <i>m</i> = 0, <i>n</i> = 8), which contain Ln₈ rings by sulfate and glycol as the ligand have been synthesized and characterized. Besides, small organic amine and l-tartaric acid act as dual templating roles during the synthetic process. Magnetic investigation of compound <b>1</b> reveals the existence of weak antiferromagnetic interactions between Gd^III ions and the data of magnetic entropy change (−Δ<i>S</i>_m) is 36.86 J K^–1 kg^–1 (108.55 mJ cm^–3 K^–1) for Δ<i>H</i> = 7 T at 2.0 K, which is comparatively large among Gd^III based compounds. Additionally, because of the excellent luminescence properties of Sm^III, Tb^III, and Eu^III, compounds <b>2</b>–<b>4</b> were investigated