| Summary: | Two structurally dissimilar 3d-4f cages having the formulae [(Co<sup>III</sup>)<sub>3</sub>Gd<sub>4</sub>(μ<sub>3</sub>-OH)<sub>2</sub>(CO<sub>3</sub>) (O<sub>2</sub>C<sup>t</sup>Bu)<sub>11</sub>(teaH)<sub>3</sub>]·5H<sub>2</sub>O (<b>1</b>) and [(Co<sup>III</sup>)<sub>3</sub>Dy<sub>3</sub>(μ<sub>3</sub>-OH)<sub>4</sub>(O<sub>2</sub>C<sup>t</sup>Bu)<sub>6</sub>(teaH)<sub>3</sub>]·(NO<sub>3</sub>)<sub>2</sub>·H<sub>2</sub>O (<b>2</b>) have been isolated under similar reaction conditions and stoichiometry of the reactants. The most important factor for structural diversity seems to be the incorporation of one μ<sub>3</sub>-carbonate anion in <b>1</b> and not in <b>2</b>. Co atoms are in a +3 oxidation state in both complexes, as shown by the Bond Valence Sum (BVS) calculations and bond lengths, and as further supported by magnetic measurements. Co<sub>3</sub>Gd<sub>4</sub> displays a significant magnetocaloric effect (−∆S<sub>m</sub> = 25.67 J kg<sup>−1</sup> K<sup>−1</sup>), and Co<sub>3</sub>Dy<sub>3</sub> shows a single molecule magnet (SMM) behavior.
|
|---|