Three-dimensional two-fold interpenetrated CrIII–GdIII heterometallic framework as an attractive cryogenic magnetorefrigerant

Abstract

The hydrothermal reaction of CrO₃, Gd₂O₃ and iminodiacetic acid (H₂IDA) yields a three-dimensional (3D) two-fold interpenetrated complex [CrGd(IDA)₂(C₂O₄)]_∞ (1). The oxalate anions were generated in situ under hydrothermal conditions. Magnetic studies suggest the presence of weak antiferromagnetic coupling between Cr^III and Gd^III ions, and negligible Gd^III⋯Gd^III and Cr^III⋯Cr^III couplings. Complex 1 exhibits a large magnetocaloric effect with − ΔS^max_m = 39.86 J kg⁻¹ K⁻¹ (the mass aspect) and 93.69 mJ cm⁻³ K⁻¹ (the volumetric aspect), making it an attractive refrigerant for low-temperature applications.