Fluoride‐Bridged {GdIII3MIII2} (M=Cr,Fe, Ga) Molecular Magnetic Refrigerants |
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| Authors: | Kasper S Pedersen Dr Giulia Lorusso Juan José Morales Dr Thomas Weyhermüller Dr Stergios Piligkos Saurabh Kumar Singh Dennis Larsen Magnus Schau‐Magnussen Dr Gopalan Rajaraman Dr Marco Evangelisti Prof?Dr Jesper Bendix |
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| Affiliation: | 1. Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen (Denmark);2. Instituto de Ciencia de Materiales de Aragón, Departamento de Física de la Materia Condensada, CSIC‐Universidad de Zaragoza, 50009 Zaragoza (Spain);3. Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr (Germany);4. Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai (India) |
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| Abstract: | The reaction of fac‐MIIIF3(Me3tacn)]?x H2O with Gd(NO3)3?5H2O affords a series of fluoride‐bridged, trigonal bipyramidal {GdIII3MIII2} (M=Cr ( 1 ), Fe ( 2 ), Ga ( 3 )) complexes without signs of concomitant GdF3 formation, thereby demonstrating the applicability even of labile fluoride‐complexes as precursors for 3d–4f systems. Molecular geometry enforces weak exchange interactions, which is rationalized computationally. This, in conjunction with a lightweight ligand sphere, gives rise to large magnetic entropy changes of 38.3 J kg?1 K?1 ( 1 ) and 33.1 J kg?1 K?1 ( 2 ) for the field change 7 T→0 T. Interestingly, the entropy change, and the magnetocaloric effect, are smaller in 2 than in 1 despite the larger spin ground state of the former secured by intramolecular Fe–Gd ferromagnetic interactions. This observation underlines the necessity of controlling not only the ground state but also close‐lying excited states for successful design of molecular refrigerants. |
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| Keywords: | density functional calculations fluoride ligands lanthanides magnetic properties magnetic refrigeration |
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