Water is the glue in bridging two [GdNi3] heterometallic fragments to form the new molecular cluster [Et4N][Gd 2Ni6(val)12(MeCN)6(H 2O)3][Gd(NO3)5](ClO 4)5 (1, val= valine anion, see figure), otherwise cemented by amino acid ligands. The shape of the complex cation of 1 resembles an ancient goblet, and its structure holds weak magnetic exchange pathways, as confirmed theoretically and experimentally; this confers the cluster ideal conditions to exhibit good magnetocaloric properties.

The authors thank the Generalitat de Catalunya for the prize ICREA Academia 2008 (G.A.) and Grant 2009SGR-1459 (E.C. and E.R.) and Spanish MCI through CTQ2009–06959 (G.A., L.B.), MAT2009-13977- C03 (M.E.), and CTQ2008–06670-C02–01 (E.C., ER). The advanced light source (S.J.T.) is supported by the U.S. Department of Energy (DE-AC02–05CH11231).

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