Large magnetic entropy changes in three GdIII coordination polymers containing GdIII chains

Abstract

Three chain-based Gd^III coordination polymers, namely [Gd₂(SO₄)₃(phen)₂(H₂O)₂]_n (1), [Gd₂(oda)₂(ox)(H₂O)₆]_n (2) and {[Gd₂(glu)₃(H₂O)₂]·4H₂O}_n (3) (phen = 1,10-phenanthroline, H₂oda = oxydiacetic acid, H₂ox = oxalic acid and H₂glu = glutaric acid), have been successfully constructed by using multidentate O ligands under hydro/solvothermal conditions. Complex 1 has a one-dimensional (1D) chain bridged by inorganic sulfate, and complex 2 exhibits a 1D double-chain ladder-shaped structure connected by oxalate. While, complex 3 is a three-dimensional (3D) metal–organic framework composed of 1D chains. All of them display good thermal stabilities and large magnetic entropy changes with −ΔS^max_m > 31 J kg⁻¹ K⁻¹ (7 T), suggesting them to be good candidates for use as cryogenic magnetic refrigerants.