An enantiopure FeIII4 single-molecule magnet

Abstract

A pair of enantiopure star-shaped Fe(III)(4) clusters were constructed from simple chiral ligands. AC field frequency dependence and a hysteresis loop, which are very important features of SMMs, were observed. Circular dichroism (CD) spectra demonstrated that the chirality was successfully transferred from the ligand to the coordination environment of Fe(3+) ions.

Propeller‐Shaped Fe4 and Fe3M Molecular Nanomagnets: A Journey from Crystals to Addressable Single Molecules

“…Homoleptic tetrairon(III) propellers have formula [Fe 4 L 6 ], where H 2 L is a polydentate ligand containing a chelating pocket for the peripheral ions and an alkoxido or phenoxido bridging group . They normally crystallize as 1:1 mixtures of Λ and Δ propeller isomers (but see ref .…”

“…They normally crystallize as 1:1 mixtures of Λ and Δ propeller isomers (but see ref . for an interesting case of spontaneous resolution) and their isolation in enantiopure form requires homochiral H 2 L ligands . Very recently a structurally similar mixed‐valence derivative was reported, with a central Fe 3+ ion linked to three peripheral Fe 2+ centers via phenoxido bridges …”

A Pair of Enantiopure Cubane‐Type CuII4O4 Clusters: Synthesis, Structure, Chirality and Magnetism

“…To the best of our knowledge, only one example was reported by Plass et al in 2008 by using a d-glucose derived ligand. Since 2011, we have reported a series of enantiopure star-shaped Fe III 4 single-molecule magnets [15] and Co II Co III 3 single-ion magnets [16] from a class of very simple Schiff base ligands. [11,12] Chiral magnets have opened up a new field of research on molecular materials which possess both magnetic and optical properties.…”

Evolvement of molecular nanomagnets in China

“…A suitable choice of organic ligand and bridging ligand between the metal centres is also crucial to the final products. In this way, a lot of SMMs with only 3d metal centres, such as the Co 4 , Fe 4 , Co 5 , Co 7 , Co 12 , Mn 15 and Mn 22 compounds, were reported by groups in China [18][19][20][21][22][23]. Although these compounds are indeed SMMs with interesting structures and magnetic properties, the systematicness of these compounds and the control of the products are generally poor.…”

“…However, a fast relaxation process, resulting most probably from QTM for many 4f-based SMMs, occurs for both compounds below around 3 K. The magnetic coupling between the Dy 3+ centres was found to be weak FO for the oxalate-bridged compound. In 2011, Tang and co-workers [50] reported an asymmetric Dy 2 compound, Dy 2 ovph 2 Cl 2 (MeOH) 3 ](MeCN) (19), where the Dy 3+ centres were linked by the alkoxido groups of two ovph 2− ligands (H 2 ovph = pyridine-2-carboxylic acid [(2-hydroxy-3-methoxyphenyl)methylene] hydrazide) and were ferromagnetically coupled. In the high-temperature regime, blockage of the magnetization occurs at individual Dy 3+ sites owing to the individual single-ion anisotropy, and two relaxation processes were observed.…”