Methan als Selektivitätsverstärker in der Lichtbogensynthese von endohedralen Fullerenen: selektive Synthese des Einzelmolekülmagneten Dy2TiC@C80 und dessen Kongener Dy2TiC2@C80

Junghans, Katrin; Schlesier, Christin; Kostanyan, Aram; Samoylova, Nataliya A.; Deng, Qingming; Rosenkranz, Marco; Schiemenz, Sandra; Westerström, Rasmus; Greber, Thomas; Büchner, B.; Popov, Alexey A.

doi:10.1002/ange.201505870

Cited by 11 publications

(3 citation statements)

References 45 publications

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“…The Dy 2 ScN@C 80 (Dy 2 TiC@C 80 ) endofullerenes were produced using an arc-discharge synthesis using graphite rods packed with a mixture of Sc (Ti), Dy, and graphite powder under He atmosphere with small amounts of NH 3 (CH 4 ) [13,21]. The x-ray absorption measurements were carried out at the X-Treme beamline [25] of the Swiss Light Source.…”

Section: Methodsmentioning

confidence: 99%

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Precise measurement of angles between two magnetic moments and their configurational stability in single-molecule magnets

et al. 2021

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A key parameter for the low-temperature magnetic coupling of in dinuclear lanthanide single-molecule magnets (SMMs) is the barrier U FA resulting from the exchange and dipole interactions between the two 4 f moments. Here we extend the pseudospin model previously used to describe the ground state of dinuclear endofullerenes to account for variations in the orientation of the single-ion anisotropy axes and apply it to the two SMMs Dy 2 ScN@C 80 and Dy 2 TiC@C 80 . While x-ray magnetic circular dichroism (XMCD) indicates the same J z = 15/2 Dy ground state in both molecules, the Dy-Dy coupling strength and the stability of magnetization is distinct. We demonstrate that both the magnitude of the barrier U FA and the angle between the two 4 f moments are determined directly from precise temperature-dependent magnetization data to an accuracy better than 1 • . The experimentally found angles between the 4 f moments are in excellent agreement with calculated angles between the quantization axes of the two Dy ions. Theory indicates a larger deviation of the orientation of the Dy magnetic moments from the Dy bond axes to the central ion in Dy 2 TiC@C 80 . This may explain the lower stability of the magnetization in Dy 2 TiC@C 80 , although it exhibits a ∼49% stronger exchange coupling than in Dy 2 ScN@C 80 .

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Section: Methodsmentioning

confidence: 99%

“…the isoelectronic and isospintronic didysprosium sister compound Dy 2 TiC@C 80 . However, Dy 2 TiC@C 80 is magnetically less stable compared to Dy 2 ScN@C 80 [21], as evident from the hysteresis in Fig. 1(c) where Dy 2 TiC@C 80 has a lower remanent magnetization and a significantly smaller coercive field.…”

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Precise measurement of angles between two magnetic moments and their configurational stability in single-molecule magnets

et al. 2021

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“…First magnetic studies were performed on Gd@C 82 [12], and it took 17 more years until SMM behavior in endohedral fullerenes was found with DySc 2 N@C 80 [13]. In the following many different C 80 mixed dysprosium-lanthanide nitride clusters have been synthesized and magnetically characterized [14][15][16]. As in other radical bridged lanthanide complexes [17] dysprosium ion pairs appear to form excellent SMMs [18].…”

Section: Introductionmentioning

confidence: 99%

Gadolinium as an accelerator for reaching thermal equilibrium and its influence on the ground state of Dy2GdN@C80 single-molecule magnets

et al. 2021

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Endohedral fullerenes are perfect nanolaboratories for the study of magnetism. The substitution of a diamagnetic scandium atom in Dy 2 ScN@C 80 with gadolinium decreases the stability of a given magnetization and demonstrates Gd to act as a single atom catalyst that accelerates the reaching of thermal equilibrium. X-ray magnetic circular dichroism at the M 4,5 edges of Gd and Dy shows that Gd affects the ground state. The Gd magnetic moment follows the sum of the external and the dipolar magnetic field of the two Dy ions and compared to Dy 2 ScN@C 80 a lower exchange barrier is found between the ferromagnetic and the antiferromagnetic Dy configuration. The Arrhenius equilibration barrier as obtained from superconducting quantum interference device magnetometry is more than one order of magnitude larger, though a much smaller prefactor imposes the faster equilibration in Dy 2 GdN@C 80 . This sheds light on the importance of angular momentum balance and symmetry in magnetic relaxation.

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Mononuclear Clusterfullerene Single‐Molecule Magnet Containing Strained Fused‐Pentagons Stabilized by a Nearly Linear Metal Cyanide Cluster

et al. 2017

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Fused-pentagons results in an increase of local steric strain according to the isolated pentagon rule (IPR), and for all reported non-IPR clusterfullerenes multiple (two or three) metals are required to stabilizet he strained fused-pentagons, making it difficult to access the single-atom properties.Herein, we report the syntheses and isolations of novel non-IPR mononuclear clusterfullerenes MNC@C 76 (M = Tb,Y ), in which one pair of strained fused-pentagon is stabilized by amononuclear cluster.The molecular structures of MNC@C 76 (M = Tb,Y)were determined unambiguously by single-crystal X-ray diffraction, featuring an on-IPR C 2v (19138)-C 76 cage entrapping an early linear MNC cluster,w hichi sr emarkably different from the triangular MNC cluster within the reported analogous clusterfullerenes based on IPR-obeying C 82 cages. The TbNC@C 76 molecule is found to be afield-induced singlemolecule magnet (SMM). Fullerenesareclosedcarboncageswithhollowinteriors,andsuch unique structures bring about intriguing physical and chemical properties.[1] Most fullerenes isolated during the past three decades are based on classical carbon cages composed of hexagons and pentagons only, [1,2] forw hich the stability is generally determined by the isolated pentagon rule (IPR) proposed by Kroto in the 1980s.[3] According to IPR, fusedpentagons result in an increase of local steric strain of ac arbon cage,t hus destabilizing the fullerene. [3,4] Stabilization of the strained fused-pentagon within an on-IPR fullerene cage has been fulfilled by either endohedral or exohedral derivatization.[4] In particular,f or endohedral fullerenes which are as pecial class of fullerene with an atom, ion, or cluster entrapped in the interior of carbon cage, [5] the strong coordination of the entrapped metal ion(s) with the fused-pentagon gives rise to an intramolecular electron transfer and consequently stabilization of the non-IPR endohedral fullerene. [4][5][6] Most of the non-IPR endohedral fullerenes reported to date are based on clusterfullerenes [7] owing to the feasibility of entrapping multiple metals in diverse forms of metal clusters,s uch as Sc 3 N@C 68 , [6a,b] Gd 3 N@C 2n (2n = 78, 82, 84), [6c-e] LaSc 2 N@C 80 , [6f] and Sc 2 S@C 72 .[6g] Noteworthy,f or these reported non-IPR clusterfullerenes,multiple (two or three) metal ions are required to stabilize simultaneously the charged metal clusters and the fused-pentagons.H ence,i ti sd esirable to synthesize novel non-IPR endohedral fullerenes containing mononuclear metal clusters.Clusterfullerenes have been recently recognized as single molecule magnets (SMMs) with potential applications in spintronics,q uantum computing,a nd high-density storage devices. [8,9] To date only af ew endohedral fullerene SMMs have been reported, including Ln x Sc 3Àx N@C 80 (Ln = Dy,H o, x = 1, 2) [9a-d] and Dy 2 TiC@C 80 , [9e] which are all based on an I h -C 80 cage entrapping multiple rare-earth-metal ions that are fixed as atriangle along with the central non-magnetic ion (N or C)...

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Methan als Selektivitätsverstärker in der Lichtbogensynthese von endohedralen Fullerenen: selektive Synthese des Einzelmolekülmagneten Dy₂TiC@C₈₀ und dessen Kongener Dy₂TiC₂@C₈₀

Cited by 11 publications

References 45 publications

Precise measurement of angles between two magnetic moments and their configurational stability in single-molecule magnets

Precise measurement of angles between two magnetic moments and their configurational stability in single-molecule magnets

Gadolinium as an accelerator for reaching thermal equilibrium and its influence on the ground state of Dy2GdN@C80 single-molecule magnets

Mononuclear Clusterfullerene Single‐Molecule Magnet Containing Strained Fused‐Pentagons Stabilized by a Nearly Linear Metal Cyanide Cluster

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