CuII-GdIII Cryogenic Magnetic Refrigerants and Cu8Dy9 Single-Molecule Magnet Generated by In Situ Reactions of Picolinaldehyde and Acetylpyridine: Experimental and Theoretical Study
Keywords: density functional calculations, magnetocaloric effect, single-molecule magnets, 3d–4f complexes, CASSCF calculations
Abstract
A series of heterometallic [LnIII xCu II y] complexes, [Gd2Cu2]n (1), [Gd4Cu8] (2), [Ln9Cu8] (Ln=Gd, 3×Gd; Ln=Dy, 3×Dy), were successfully synthesized by a one-pot route at room temperature with three kinds of in situ carbonyl-related reactions: Cannizzaro reaction, aldol reaction, and oxidation. This strategy led to dysprosium analogues that behaved as single-molecule magnets (SMMs) and gadolinium analogues that showed significant magnetocaloric effect (MCE). In this study a numerical DFT approach is proposed by using pseudopotentials to calculate the exchange coupling constants in three polynuclear [Gd xCuy] complexes; with these values exact diagonalization or quantum Monte Carlo simulations have been performed to calculate the variation of the magnetic entropy involved in the MCE. For the [Dy 9Cu8] complexes, local magnetic properties of the Dy III centers have been determined by using the CASSCF+RASSI method. Metal bands: A series of heterometallic [LnIII xCu II y] complexes (Ln=Gd, Dy; see scheme) were synthesized under one-pot conditions at room temperature with four kinds of carbonyl in situ reactions. This strategy led to dysprosium analogues that behave as single-molecule magnets and the gadolinium analogues that show significant magnetocaloric effect. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Más información
Título según SCOPUS: | CuII - GdIII cryogenic magnetic refrigerants and Cu8Dy9 single-molecule magnet generated by in situ reactions of picolinaldehyde and acetylpyridine: Experimental and theoretical study |
Título de la Revista: | CHEMISTRY-A EUROPEAN JOURNAL |
Volumen: | 19 |
Número: | 51 |
Editorial: | WILEY-V C H VERLAG GMBH |
Fecha de publicación: | 2013 |
Página de inicio: | 17567 |
Página final: | 17577 |
Idioma: | English |
DOI: |
10.1002/chem.201303275 |
Notas: | SCOPUS |