CuII-GdIII Cryogenic Magnetic Refrigerants and Cu8Dy9 Single-Molecule Magnet Generated by In Situ Reactions of Picolinaldehyde and Acetylpyridine: Experimental and Theoretical Study

Lin, Wei-Quan; Chen, Yan-Cong; Gómez-Coca, Silvia; Aravena, Daniel; Ruiz, Eliseo; Leng, Ji-Dong; Tong, Ming-Liang

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