A {Gd12Na6} Molecular Quadruple-Wheel with a Record Magnetocaloric Effect at Low Magnetic Fields and Temperatures

Thomais G Tziotzi; David Gracia; Scott J Dalgarno; Jürgen Schnack; Marco Evangelisti; Euan K Brechin; Constantinos J Milios

doi:10.1021/jacs.3c01610

A {Gd₁₂Na₆} Molecular Quadruple-Wheel with a Record Magnetocaloric Effect at Low Magnetic Fields and Temperatures

J Am Chem Soc. 2023 Apr 12;145(14):7743-7747. doi: 10.1021/jacs.3c01610. Epub 2023 Apr 3.

Authors

Thomais G Tziotzi¹, David Gracia², Scott J Dalgarno³, Jürgen Schnack⁴, Marco Evangelisti², Euan K Brechin⁵, Constantinos J Milios¹

Affiliations

¹ Department of Chemistry, University of Crete, Voutes 71003, Herakleion, Greece.
² Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC & Universidad de Zaragoza, 50009 Zaragoza, Spain.
³ Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, U.K.
⁴ Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany.
⁵ EaStCHEM School of Chemistry, The University of Edinburgh, Edinburgh EH9 3FJ, Scotland, U.K.

Abstract

Reaction of Gd(OAc)₃·4H₂O, salicylaldehyde and CH₃ONa in MeCN/MeOH affords [Gd₁₂Na₆(OAc)₂₅(HCO₂)₅(CO₃)₆(H₂O)₁₂]·9H₂O.0.5MeCN (1·9H₂O.0.5MeCN), whose structure describes a quadruple-wheel consisting of two {Na₃} and two {Gd₆} rings. The magnetic properties of 1 reveal very weak antiferromagnetic interactions between the Gd^III ions, which give rise to a record magnetocaloric effect at low applied magnetic fields and low temperatures. The magnetic entropy change reaches -ΔS_m= 29.3 J kg^-1 K^-1 for full demagnetization from B = 1 T at T = 0.5 K.