Fine Tuning the Energy Barrier of Molecular Nanomagnets via Lattice Solvent Molecules

Abstract

Solvents play important roles in our lives, they are also of interest in molecular materials, especially for molecular magnets. The solvatomagnetic effect is generally used for trigger and/or regulation of magnetic properties in molecule-based systems, however, molecular nanomagnets showing solvatomagnetic effects are very difficult to obtain. Here we report four 3d-4f heterometallic cluster complexes containing ROH lattice solvent molecules, [Cu3Tb2(H3L)2(OAc)2(hfac)4]∙2ROH {H6L = 1,3-Bis[tris(hydroxymethyl)methylamino]propane, hfac− = hexafluoroacetylacetonate; R = CH3, 1; R = C2H5, 2; R = C3H7, 3; R = H, 4}. Single-molecule magnet (SMM) properties of these four complexes were observed to be dependent on the ROH lattice solvent molecule. There is an interesting magneto-structural correlation: the larger the R group, the higher the energy barrier. For the first time, the solvatomagnetic effect is used for the continuous fine adjustment of the energy barrier of 0D molecular nanomagnets. Additionally, [Cu3Dy2(H3L)2(OAc)2(hfac)4]∙2MeOH (5), an analogue of [Cu3Tb2(H3L)2(OAc)2(hfac)4]∙2MeOH (1), is also reported for comparison.

Asymmetric Assembly of Chiral Lanthanide(III) Tetranuclear Cluster Complexes Using Achiral Mixed Ligands: Single-molecule Magnet Behavior and Magnetic Entropy Change

“…The bis-tris propane ligand is a common polydentate ligand containing not only the N coordination site but also the O coordination site, which had been successfully used to assemble some 3d cluster complexes, , 3d-3d heteronuclear cluster complexes, , and 3d–4f heteronuclear cluster complexes. − We also recently used it to solvothermally react dysprosium acetate and lithium hydroxide in EtOH at 100 °C, yielding a dysprosium­(III) tetranuclear cluster SMM, [Dy 4 (H 3 L) 2 (OAc) 6 ]·2EtOH, which shows double magnetic relaxation behavior at the zero field . In this study, we used the bis-tris propane ligand to react with Ln­(F 6 acac) 2 Ac·2H 2 O (Ln = Dy and Gd) and lithium hydroxide in MeOH or (MeOH + CH 2 Cl 2 ) for several hours at room temperature, and then slowly evaporated the solvent to obtain lanthanide­(III) tetranuclear cluster compounds 1 and 2 .…”

Dehydration–Hydration Switching of Single-Molecule Magnet Behavior and Visible Photoluminescence in a Cyanido-Bridged DyIIICoIII Framework

“…For instance, Dy III demands an axial crystal field to achieve substantial magnetic anisotropy. − The help of organometallic chemistry was useful; however, the related SMMs are very air-sensitive. , It hampers the addition of other properties, which is crucial for multiresponsive molecular devices. , Multifunctional SMMs were attainable using lanthanide coordination complexes with organic ligands inducing chirality or electrical conductivity. − A special interest was devoted to luminescent SMMs, − which can be good candidates for dual magnetoluminescent sensing . Desolvation driven molecular switches based on lanthanide SMMs were also reported. − They showed a tuning of magnetic relaxation by exchange of solvent of crystallization. A similar effect was also found for d-block metal-based SMMs …”

Minute torsional reorganization elicited a large visible-range fluorescence gain in terphenyl-derived crystals

“…A slight modification in the crystalline state arrangement might result in an extensive gain in their optical output. [1][2][3][4][5][6][7][8][9][10] In recent years, reports on the influence of geometrical arrangements [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] leading to a dramatic augmentation of the fluorescence have attracted significant attention. In the case of diketopyrrolopyrrole (DPP)-based semiconductor solids, the effect of a-branching in structural modifications in the solid-state has been well addressed.…”