Unusually large hyperfine structure of the electron spin levels in an endohedral dimetallofullerene and its spin coherent properties

Abstract

We report the synthesis, ESR spectroscopic and spin coherent properties of the dimetallofullerene Sc2@C80(CH2Ph). The single-electron metal-metal bond of the Sc2 dimer inside the fullerene’s cage is stabilized with the...

Robust Single Molecule Magnet Monolayers on Graphene and Graphite with Magnetic Hysteresis up to 28 K

“…The method should lend itself well to larger scale manufacturing techniques, like ink‐jet printing and the use of nanospotters, and is compatible with graphene electronics and spintronics, [ 16 ] opening the way toward patterned devices with hybrid graphene‐SMM interfaces. Furthermore, while {Tb 2 } is an excellent SMM, its non‐4f analogs {Y 2 } and especially {Sc 2 } have recently been shown to be promising qubit candidates, [ 17 ] and the functionalization and deposition methods presented here might be a way of addressing them on a single molecule level. Finally, the linker molecule presented in this work is but the first option tested, and other approaches to hybrids of fullerenes with graphene and 2D materials can be applied to create assemblies with required properties.…”

Electrophilic Trifluoromethylation of Dimetallofullerene Anions en Route to Air-Stable Single-Molecule Magnets with High Blocking Temperature of Magnetization

“…To address this problem, we developed a thermal reaction of EMF anions in DMF with benzyl bromide, which gives neutral benzyl monoadducts of di-EMFs as a result of nucleophilic substitution with bromide ion as a leaving group . This approach allowed successful isolation of a series of M 2 @C 80 (CH 2 Ph) compounds (M = Sc, Y, Gd – Er) with very unusual magnetic properties, stemming from the single-electron lanthanide–lanthanide bond and the unprecedentedly strong exchange coupling between lanthanide ions mediated by the valence electron spin. ,, In particular, Tb 2 @C 80 (CH 2 Ph) was found to be a single-molecule magnet (SMM, see refs − for recent reviews) with extremely broad magnetic hysteresis and blocking temperature of magnetization near 30 K, , which made it one of the strongest SMMs second to only some Dy and Tb lanthanocenes. − Furthermore, Tb 2 @C 80 (CH 2 Ph) and its pyrrolidine cycloadduct show the highest hysteresis temperature and the longest relaxation times among air-stable SMMs − and self-assembled monolayers of Tb 2 @C 80 (CH 2 Ph) derivative on graphene and graphite exhibit magnetic hysteresis up to 28 K . Despite this success, the benzylation route revealed some drawbacks, making it far from being optimal when the upscale of the di-EMF production is required.…”

“…Even slight overheating changes its mechanism from nucleophilic substitution to radical polyaddition, which produces intractable mixtures of EMF­(CH 2 Ph) n multiadducts. As di-EMFs with single-electron lanthanide–lanthanide bond are very robust SMMs and qubit candidates, ,,,− development of a streamlined approach to their synthesis and separation would be very beneficial.…”

Metamagnetic transition and a loss of magnetic hysteresis caused by electron trapping in monolayers of single-molecule magnet Tb2@C79N

“…16 These molecules gained particular interest during last years because of their interesting magnetic properties. [17][18][19][20][21][22][23][24][25][26][27][28][29] Delocalization of a valence electron between two lanthanide ions results in giant magnetic coupling in the endohedral metal dimer with a formal [M 3+ -e-M 3+ ] configuration. For metal ions exhibiting axial single-ion magnetic anisotropy in these settings, like Dy and Tb, strong coupling results in robust single-molecule magnetism with enhanced blocking temperature of magnetization and very broad magnetic hysteresis.…”