Search

The pentagonal bipyramidal single-ion magnets (SIMs) are among the most attractive prototypes of high-performance single-molecule magnets (SMMs). Here, a fluorescence-active phosphine oxide ligand CyPh2PO (=cyclohexyl(diphenyl)phosphine oxide) was introduced into [Dy(CyPh2PO)2(H2O)5]Br3⋅2 (CyPh2PO)⋅EtOH⋅3 H2O, and combined dynamic magnetic measurement, optical characterization, ab initio calculation, and magneto-optical correlation of this high-performance pseudo- D5 h DyIII SIM with large Ueff (508(2) K) and high magnetic hysteresis temperature (19 K) were performed. This work provides a deeper insight into the rational design of promising molecular magnets. [ABSTRACT FROM AUTHOR]

An extremely rare non-Kramers holmium(III) single-ion magnet (SIM) is reported to be stabilized in the pentagonal-bipyramidal geometry by a phosphine oxide with a high energy barrier of 237(4) cm−1. The suppression of the quantum tunneling of magnetization (QTM) at zero field and the hyperfine structures originating from field-induced QTMs can be observed even from the field-dependent alternating-current magnetic susceptibility in addition to single-crystal hysteresis loops. These dramatic dynamics were attributed to the combination of the favorable crystal-field environment and the hyperfine interactions arising from 165Ho ( I=7/2) with a natural abundance of 100 %. [ABSTRACT FROM AUTHOR]

The pentagonal bipyramidal single‐ion magnets (SIMs) are among the most attractive prototypes of high performance single‐molecule magnets (SMMs). A fluorescence‐active phosphine oxide ligand is introduced, and by combining dynamic magnetic measurements, optical characterization, and ab initio calculations, the magneto‐optical correlation of a high‐performance pseudo‐D5h DyIII SIM with large Ueff = 508(2) K and high magnetic hysteresis temperature of 19 K, [Dy(CyPh2PO)2(H2O)5]Br3⋅2 (CyPh2PO)⋅EtOH⋅3 H2O (CyPh2PO=cyclohexyl(diphenyl)phosphine oxide) was studied. This work provides a deeper insight into the rational design of promising molecular magnets. More information can be found in the Full Paper by M.‐L. Tong, J.‐L. Liu, et al. on page 5708 ff. [ABSTRACT FROM AUTHOR]

Abstraction of a chloride ligand from the dysprosium metallocene [(Cpttt)2DyCl] ( 1Dy Cpttt=1,2,4-tri( tert-butyl)cyclopentadienide) by the triethylsilylium cation produces the first base-free rare-earth metallocenium cation [(Cpttt)2Dy]+ ( 2Dy) as a salt of the non-coordinating [B(C6F5)4]− anion. Magnetic measurements reveal that [ 2Dy][B(C6F5)4] is an SMM with a record anisotropy barrier up to 1277 cm−1 (1837 K) in zero field and a record magnetic blocking temperature of 60 K, including hysteresis with coercivity. The exceptional magnetic axiality of 2Dy is further highlighted by computational studies, which reveal this system to be the first lanthanide SMM in which all low-lying Kramers doublets correspond to a well-defined MJ value, with no significant mixing even in the higher doublets. [ABSTRACT FROM AUTHOR]

Here we reported the deuteration of the metal‐binding equatorial water molecules in a reported HoIII single‐molecule magnet (SMM) with pentagonal‐bipyramidal geometry, from [Ho(CyPh2PO)2(H2O)5]3+ to [Ho(CyPh2PO)2(D2O)5]3+. The hyperfine structures originating from the nuclear spin of 165HoIII can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope‐isomorphic complexes—respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the ab initio calculated tunnel splitting and the involvement of the super‐hyperfine interaction related to the difference in the nuclear spin number of protium (1H, I=1/2) and deuterium (2H, I=1). [ABSTRACT FROM AUTHOR]

Here we reported the deuteration of the metal‐binding equatorial water molecules in a reported HoIII single‐molecule magnet (SMM) with pentagonal‐bipyramidal geometry, from [Ho(CyPh2PO)2(H2O)5]3+ to [Ho(CyPh2PO)2(D2O)5]3+. The hyperfine structures originating from the nuclear spin of 165HoIII can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope‐isomorphic complexes—respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the ab initio calculated tunnel splitting and the involvement of the super‐hyperfine interaction related to the difference in the nuclear spin number of protium (1H, I=1/2) and deuterium (2H, I=1). [ABSTRACT FROM AUTHOR]

A series of heterometallic [LnIII xCuII 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 xCu y] 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 [Dy9Cu8] complexes, local magnetic properties of the DyIII centers have been determined by using the CASSCF+RASSI method. [ABSTRACT FROM AUTHOR]

Hyperfine interaction, isotope effect, magnetization dynamics, single-molecule magnets, super-hyperfine interaction Inside Cover: Magnetization Dynamics on Isotope-Isomorphic Holmium Single-Molecule Magnets (Angew. Keywords: hyperfine interaction; isotope effect; magnetization dynamics; single-molecule magnets; super-hyperfine interaction EN hyperfine interaction isotope effect magnetization dynamics single-molecule magnets super-hyperfine interaction 26870 26870 1 12/15/21 20211220 NES 211220 B Nuclear-spin driven relaxation b collaborating with the ligands in lanthanide single molecule magnets (SMMs) remains ambiguous. [Extracted from the article]

Keywords: hyperfine interaction; isotope effect; magnetization dynamics; single-molecule magnets; super-hyperfine interaction EN hyperfine interaction isotope effect magnetization dynamics single-molecule magnets super-hyperfine interaction 27074 27074 1 12/15/21 20211220 NES 211220 B Das Zusammenwirken b von kernspingetriebener Relaxation und den Liganden in Lanthanoid-Einzelmolekülmagneten (SMMs) ist nicht vollständig geklärt. Hyperfine interaction, isotope effect, magnetization dynamics, single-molecule magnets, super-hyperfine interaction Innentitelbild: Magnetization Dynamics on Isotope-Isomorphic Holmium Single-Molecule Magnets (Angew. [Extracted from the article]

Dances with carbonyl! CuII and LnIII react in situ with picolinaldehyde or acetylpyridine, which contain a nucleophilic carbonyl group, by Cannizzaro reaction, aldol reaction, or oxidation reaction. This strategy leads to a series of fascinating [LnxCuy] complexes that either exhibit a magnetocaloric effect or behave as single‐molecule magnets. Calculations have been performed to investigate the magnetic properties. For more details, see the Full Paper by E. Ruiz, M.‐L. Tong et al. on page 17567 ff. [ABSTRACT FROM AUTHOR]