Butterfly M₂^IIIEr₂ (M^III = Fe and Al) SMMs: Synthesis, Characterization, and Magnetic Properties

Abstract

The reaction of N -(2-pyridylmethyl)iminodiethanol (H 2 L, pmide), FeCl 2 ·4H 2 O or AlCl 3 ·6H 2 O with ErCl 3 ·6H 2 O and p -Me-PhCO 2 H in the ratio of 2:1:1:4 in the presence of Et 3 N in MeOH and MeCN yielded compounds [Fe 2 Er 2 (μ 3 -OH) 2 (pmide) 2 ( p -Me-PhCO 2 ) 6 ]·2MeCN ( 1 ) and [Al 2 Er 2 (μ 3 -OH) 2 (pmide) 2 ( p -Me-PhCO 2 ) 6 ]·2MeCN ( 2 ). These two complexes are isostructural, possessing a planar butterfly motif with the Er III ions in the wingtip positions. Both compounds show single molecule magnet (SMM) behavior. For the [Al 2 Er 2 ] compound, the slow relaxation of the magnetization under zero applied direct current (dc) field does not show maxima, but the relaxation processes could be analyzed using an applied dc field of 1000 Oe. In-depth alternating current measurements under different dc fields on the [Fe 2 Er 2 ] compound reveals that the Fe–Fe and Fe–Er interactions speed up the relaxation and decrease the energy barrier height of the SMM in comparison with the [Al 2 Er 2 ] case.

From the {FeIII2Ln2} Butterfly's Perspective: the Magnetic Benefits and Challenges of Cooperativity within 3 d–4 f Based Coordination Clusters

“…The selected isostructural analogues of [M III 2 Er 2 (μ 3 ‐OH) 2 (pmide) 2 ( p ‐Me−PhCO 2 ) 6 ] (M=Fe 19 a and Al 21 a ) were also synthesised and their magnetic behaviour investigated. [21] Both compounds show field‐induced single molecule magnet (SMM) behaviour. The results reinforce the widely held belief that Dy III containing 3 d–4 f compounds generally “perform” better as SMMs than those with other Kramers ions (in this case Er III ).…”

“…The selected isostructural analogues of [M III 2 Er 2 (μ 3 ‐OH) 2 (pmide) 2 ( p ‐Me−PhCO 2 ) 6 ] (M=Fe 19 a and Al 21 a ) were also synthesised and their magnetic behaviour investigated [21] . Both compounds show field‐induced single molecule magnet (SMM) behaviour.…”

Self-Assembly of Lanthanide–Aluminum Cluster-Organic Frameworks with Magnetocaloric Effect and Luminescence

“…Therefore, the assembly of the lanthanide–aluminum-based cluster-organic frameworks is vital in cluster chemistry and photochemistry. However, the Ln–Al clusters are rare, and the Ln–Al cluster-organic frameworks have been unexplored hitherto, as the presented Ln–Al clusters are isolated due to the hydrophobic ligands at the edge of the cores, such as LnAl 4 , Ln 2 Al 2 , and Ln 2 Al 3 . , If these isolated Ln–Al clusters can be extended to high-dimensional frameworks, the unique features of the clusters can be transferred to the framework, leading to exquisite conformations and remarkable properties. , …”

Synthesis, structures, and magnetic properties of butterfly-shaped hexanuclear [FeIII4LnIII2] single-molecule magnets

“…In recent decades, research on heterometallic complexes containing 3d-4f metal ions has attracted increasing attention from scientists. [1][2][3][4][5] Since 4f metal ions have different coordination modes and coordination abilities from 3d metal ions, 3d-4f coordination compounds show a variety of topological diversity. [6][7][8] Furthermore, transitions, transfers, and synergies between 3d and 4f metal ions and quantum size effects endow such compounds with unique physical and chemical properties.…”