Zheng, Yan-Zhen Evangelisti, Marco Tuna, Floriana E. P. Winpenny, Richard Co–Ln Mixed-Metal Phosphonate Grids and Cages as Molecular Magnetic Refrigerants The synthesis, structures, and magnetic properties of six families of cobalt–lanthanide mixed-metal phosphonate complexes are reported in this Article. These six families can be divided into two structural types: grids, where the metal centers lie in a single plane, and cages. The grids include [4 × 3] {Co<sub>8</sub>Ln<sub>4</sub>}, [3 × 3] {Co<sub>4</sub>Ln<sub>6</sub>}, and [2 × 2] {Co<sub>4</sub>Ln<sub>2</sub>} families and a [4 × 4] {Co<sub>8</sub>Ln<sub>8</sub>} family where the central 2 × 2 square is rotated with respect to the external square. The cages include {Co<sub>6</sub>Ln<sub>8</sub>} and {Co<sub>8</sub>Ln<sub>2</sub>} families. Magnetic studies have been performed for these compounds, and for each family, the maximum magnetocaloric effect (MCE) has been observed for the Ln = Gd derivative, with a smaller MCE for the compounds containing magnetically anisotropic 4f-ions. The resulting entropy changes of the gadolinium derivatives are (for 3 K and 7 T) 11.8 J kg<sup>–1</sup> K<sup>–1</sup> for {Co<sub>8</sub>Gd<sub>2</sub>}; 20.0 J kg<sup>–1</sup> K<sup>–1</sup> for {Co<sub>4</sub>Gd<sub>2</sub>}; 21.1 J kg<sup>–1</sup> K<sup>–1</sup> for {Co<sub>8</sub>Gd<sub>4</sub>}; 21.4 J kg<sup>–1</sup> K<sup>–1</sup> for {Co<sub>8</sub>Gd<sub>8</sub>}; 23.6 J kg<sup>–1</sup> K<sup>–1</sup> for {Co<sub>4</sub>Gd<sub>6</sub>}; and 28.6 J kg<sup>–1</sup> K<sup>–1</sup> for {Co<sub>6</sub>Gd<sub>8</sub>}, from which we can see these values are proportional to the percentage of the gadolinium in the core. Co 8Ln families;Co 6Ln;Co 4Ln families;7 T;magnetocaloric effect;3 K;Magnetic studies;metal centers;Co 4Ln;RefrigerantsThe synthesis;gadolinium derivatives;Co 4Gd;entropy changes;kg;MCE;Co 8Ln family;Co 6Gd 2016-02-22
    https://acs.figshare.com/articles/dataset/Co_Ln_Mixed_Metal_Phosphonate_Grids_and_Cages_as_Molecular_Magnetic_Refrigerants/2558458
10.1021/ja208367k.s017