MoO42−-templated Ln20Ni21 heterometallic clusters with large low-field magnetic entropy

Abstract

The anionic template method is an effective strategy for synthesizing high-nuclearity transition-lanthanide (3d–4f) heterometallic clusters. Herein, two lanthanide clusters with formulas [Gd₂₀Ni₂₁(μ₃-OH)₂₁(CO₃)₆(IDA)₂₁(C₂H₄NO₂)₆(C₂O₄)₃(MoO₄)_1.5(μ₂-OH)_1.5(H₂O)₉]Cl_10.5·79H₂O (1) and [Tb₂₀Ni₂₁(μ₃-OH)₂₁(CO₃)₆(IDA)₂₁(C₂H₄NO₂)₆(C₂O₄)₃(MoO₄)(μ₂-OH)₂(H₂O)₁₀]Cl₁₁·32H₂O (2) were synthesized by introducing MoO₄²⁻ anions as templates. Structural analysis indicates that compounds 1 and 2 are isomorphic, featuring a fascinating triangular-shaped metal framework. Magnetic property investigations illuminate the fact that compound 1 exhibits a large −ΔS_m of 37.83 J kg⁻¹ K⁻¹ at 3 K for ΔH = 7 T. In particular, it is worth mentioning that compound 1 has an excellent low-field magnetic entropy (−ΔS_m = 23.85 J kg⁻¹ K⁻¹ at 2 K, 2 T).