Corredoira-Vázquez J, González-Barreira C, Fondo M, García-Deibe AM, Sanmartín-Matalobos J, Gómez-Coca S, Ruiz E, Colacio E. Dinuclear Fluoride Single-Bridged Lanthanoid Complexes as Molecule Magnets: Unprecedented Coupling Constant in a Fluoride-Bridged Gadolinium Compound.
Inorg Chem 2022;
61:9946-9959. [PMID:
35737854 PMCID:
PMC9275779 DOI:
10.1021/acs.inorgchem.2c00773]
[Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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A new synthetic method
allows isolating fluoride-bridged complexes
Bu4N{[M(3NO2,5Br-H3L1,1,4)]2(μ-F)} (M = Dy, 1; M = Ho, 2; M = Gd, 3) and Bu4N{[Dy(3Br,5Cl-H3L1,2,4)]2(μ-F)}·2H2O, 4·2H2O. The crystal structures of 1·5CH3C6H5,·2·2H2O·0.75THF, 3, and 4·2H2O·2THF show that all of them are
dinuclear compounds with linear single fluoride bridges and octacoordinated
metal centers. Magnetic susceptibility measurements in the temperature
range of 2–300 K reveal that the GdIII ions in 3 are weakly antiferromagnetically coupled, and this constitutes
the first crystallographically and magnetically analyzed gadolinium
complex with a fluoride bridge. Variable-temperature magnetization
demonstrates a poor magnetocaloric effect for 3. Alternating
current magnetic measurements for 1, 2,
and 4·2H2O bring to light that 4·2H2O is an SMM, 1 shows an
SMM-like behavior under a magnetic field of 600 Oe, while 2 does not show relaxation of the magnetization even under an applied
magnetic field. In spite of this, 2 is the first fluoride-bridged
holmium complex magnetically analyzed. DFT and ab initio calculations support the experimental magnetic results and show
that apparently small structural differences between 1 and 4·2H2O introduce important changes
in the dipolar interactions, from antiferromagnetic in 1 to ferromagnetic in 4·2H2O.
Dinuclear linear fluoride single-bridged
DyIII, HoIII, and GdIII complexes
are systematically
obtained from mononuclear aquo-complexes, with the DyIII ones showing slow relaxation of the magnetization and the GdIII one revealing a weak AF coupling through the Gd−F−Gd
bridge.
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