Rhodamine-based field-induced single molecule magnets in Yb(iii) and Dy(iii) series

Abstract

Dye-based rhodamine derivatives have been utilized for the isolation of mononuclear lanthanide compounds characteristic of field-induced single molecule magnets.

Octanuclear Heterobimetallic {Ni4Ln4} Assemblies Possessing Ln4 Square Grid [2 × 2] Motifs: Synthesis, Structure, and Magnetism

“…This conclusion is further supported by a comparison of Cole-Cole plots of the Tb 3+ material's ac susceptibility data collected in non-zero dc-fields ( Figure 16). For µ 0 H DC = 0.59 T, isotherms in the χʹ-χʹʹ plane appear to form extended arcs that become more extended on cooling, as predicted by the modified Debye model, 32 whereas the behavior for µ 0 H DC = 0.1 T shows a temperature dependence that is incompatible with traditional SMM behavior. Figure 14).…”

“…Here each ion obeys χT = µ 0 N A µ eff 2 /(3k B ) where µ eff = g J (J (J + 1)) 1/2 µ B and g J is the Landé g-factor. 28 The room-temperature value of χT was found to be within A rapid drop in χT for Ni 4 Gd 4 occurs in the region of T < 10 K. Density functional theory calculations 29 predict that the Ni−Gd exchange interaction mediated through each of the three non-linear Ni-O-Gd bonds should be ferromagnetic and have J NiGd ≈ 2.3 K. The observed rapid decrease of χT on cooling can therefore be interpreted as due to a combination of the thermal depopulation of crystal-field split Ni 2+ ion energy levels, [30][31][32] and the onset of Gd−Gd interactions. The onset of a low-temperature plateau in the susceptibility is indicative of singleion anisotropy of the Ni 2+ ions.…”

“…This bears a strong resemblance to previously reported SMMs in which zero-field slow relaxation was suppressed by quantum tunneling of magnetization (QTM). 30,32,40 On applying the derived optimum field of µ 0 H DC = 0.14 T (Figure 13c, 13d and Figure S13); the frequency dependence of χ′ can be seen to become enhanced and be driven to higher temperatures with peaks occurring at the highest frequencies. This may be explained as due to the single-ion anisotropy of Dy 3+ .…”

Mononuclear Dysprosium Alkoxide and Aryloxide Single‐Molecule Magnets

“…Owing to the possibility of ferromagnetic exchange interactions, the vast majority of Yb III SMMs are either homometallic dimers or heterometallic 3d‐4f mixed multinuclear complexes, which have been discussed in detail elsewhere [142] . Mononuclear Yb III SMMs most commonly show CN8; the majority of them contain large multi‐dentate ligands [85, 103, 133, 142] . Sujita et al.…”

Crystal structure of (E)-2-(3,6-bis(ethylamino)-2,7-dimethyl-9H-xanthen-9-yl)-N′-((6-methylpyridin-2-yl)methylene)benzohydrazide – methanol (1/1), C34H37N5O3

“…Rhodamine derivatives have attracted great attention not only in the field of analytical chemistry [6][7][8] but also in the field of coordination chemistry [9,10], because of the excellent spectroscopic properties and coordination ability to transition metals and rare-earth metals. The asymmetric unit of the title compound contains a ring-closed 6-methyl-2-pyridinecarbaldehyde rhodamine 6G hydrazone molecule and one methanol solvent molecule.…”