[Fe15]: a frustrated, centred tetrakis hexahedron

The combination of two different FeIIIsalts in a solvothermal reaction with triethanolamine results in the formation of a high symmetry [Fe III 15] cluster whose structure conforms to a centred, tetrakis hexahedron. © The Royal Society of Chemistry 2021

Surface binding vs. sequestration; the uptake of benzohydroxamic acid at iron(III) oxide surfaces

Benzohydroxamic acid is shown to be an unexpectedly good ligand for iron(III) oxides, favouring surface attachment to the formation of trisbenzohydroxamato complexes, which are known to have very high thermodynamic stability in solution

Enhancing SMM properties via axial distortion of Mn-3(III) clusters

Replacement of carboxylate and solvent with facially capping tripodal ligands enhances the single-molecule magnet (SMM) properties of [Mn-3(III)] triangles

Bis-tris propane as a new multidentate ligand for nickel- and cobalt-based spin clusters

We describe the first use of Bis-tris propane {2,2′-(propane-1,3-diyldiimino)bis[2-(hydroxymethyl)propane-1,3-diol], H<sub>6</sub>L}, in nickel and cobalt chemistry and report the synthesis, structure and magnetic properties of [Ni<sub>4</sub>(H<sub>4</sub>L)(H<sub>3</sub>L)(acac)<sub>2</sub>]<sup>+</sup> (1) and [Co<sup>II</sup><sub>3</sub>Co<sup>III</sup><sub>2</sub>(H<sub>2</sub>L)<sub>2</sub>(acac)<sub>3</sub>(MeOH)]<sup>+</sup> (2)

Ferromagnetic [Mn-3] Single-Molecule Magnets and Their Supramolecular Networks

International audienceThe complexes [(Mn3O)-O-III(Et-sao)(3)(O2CPh(Cl)(2))(MeOH)(3)(H2O)] (1), [(Mn3O)-O-III(Et-sao)(3)(ClO4)(MeOH)(3)] (2), [(Mn3O)-O-III(Et-sao)(3)(O2Ph(CF)(2))(EtOH)(H2O)(3)] (3), and [(Mn3O)-O-III(Ph-sao)(3)(O2C-anthra)(MeOH)(4)]center dot Ph-saoH(2) (4 center dot Ph-saoH(2)) display dominant ferromagnetic exchange interactions leading to molecules with S = 6 ground states. The molecules are single molecule magnets (SMM) displaying large effective energy barriers for magnetization reversal. In each case their crystal structures reveal multiple intermolecular H-bonding interactions. Single crystal hysteresis loop measurements demonstrate that these interactions are strong enough to cause a clear field bias, but too weak to transform the spin networks into classical antiferromagnets. These three-dimensional networks of exchange coupled SMMs demonstrate that quantum tunnelling magnetization can be controlled using exchange interactions, suggesting supramolecular chemistry can be exploited to modulate the quantum physics of molecular magnets

New high-spin clusters featuring transition metals

Three possible routes to polynuclear transition metal complexes are discussed. The first route, oligomerization induced by desolvation of small cages, is exemplified by synthesis of a dodecanuclear cobalt cage, and by reactions which give octa– and dodecanuclear chromium cages. The second route involves linking cages through organic spacers, and is illustrated by use of phthalate to link together cobalt and nickel cages. For the nickel case a complex consisting of four cubanes and a sodium octahedron is found. The third route involves the use of water to introduce hydroxide bridges into cages. One method of introducing water is to use hydrated metal salts; the transformation of a Cu6Na cage into a Cu12La8 illustrates this approach. Alternatively, adventitious water within solvents can be used as a source, and this approach has led to a Co24 cage. The structures and magnetic properties of these various cages are discussed

Chiral single-molecule magnets: a partial Mn(III) supertetrahedron from achiral components

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