Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes
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MDPI
Materia
Transition metal ions Lanthanide(III) metal ions Molecular magnetism Magneto-caloric effect
Date
2021Referencia bibliográfica
Oyarzabal, I.; Echenique-Errandonea, E.; San Sebastián, E.; Rodríguez-Diéguez, A.; Seco, J.M.; Colacio, E. Synthesis, Structural Features and Physical Properties of a Family of Triply Bridged Dinuclear 3d-4f Complexes. Magnetochemistry 2021, 7, 22. https://doi.org/10.3390/magnetochemistry7020022
Patrocinador
Junta de Andalucía (FQM-195 and the projects of excellence P11-FQM-7756 and A-FQM-172-UGR18); MINECO of Spain (Projects CTQ2014-56312-P and PGC2018-102052-B-C21); University of Granada; University of The Basque Country UPV/EHU (Project GIU14/01)Résumé
New dinuclear MII-LnIII complexes of general formulas [Cu(µ-L)(µ-OAc)Ln(NO3
)2
]·CH3CN·
H2O (LnIII = Gd (1), Tb (2), Dy (3) and Er (4)), [Ni(CH3CN)(µ-L)(µ-OAc)Ln(NO3
)2
]·CH3CN (LnIII =
Nd (5), Gd (6), Tb (7), Dy (8), Er (9) and Y (10)) and [Co(CH3CN)(µ-L)(µ-OAc)Ln(NO3
)2
]·CH3CN
(LnIII = Gd (11), Tb (12), Dy (13), Er (14) and Y (15)) were prepared from the compartmental ligand
N,N0
-dimethyl-N,N0
-bis(2-hydroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L). In all these
complexes, the transition metal ions occupy the internal N2O2 coordination site of the ligand, whereas
the LnIII ions lie in the O4 external site. Both metallic ions are connected by an acetate bridge, giving
rise to triple mixed diphenoxido/acetate bridged MIILnIII compounds. Direct current (dc) magnetic
measurements allow the study of the magnetic exchange interactions between the 3d and 4f metal
ions, which is supported by density functional theory (DFT) theoretical calculations for the GdIII
-
based counterparts. Due to the weak ferromagnetic exchange coupling constants obtained both
experimentally and theoretically, the magneto-thermal properties of the less anisotropic systems
(compounds 1 and 6) are also studied. Alternating current (ac)magnetic measurements reveal the
occurrence of slight frequency dependency of the out-of-phase signal for complexes 8, 9 and 13, while
complex 15 displays well-defined maximums below ~6 K.