scholarly journals Correlating blocking temperatures with relaxation mechanisms in monometallic single-molecule magnets with high energy barriers (Ueff > 600 K)

2019 ◽  
Vol 55 (49) ◽  
pp. 7025-7028 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas K. Kostopoulos ◽  
David Collison ◽  
Richard E. P. Winpenny ◽  
Nicholas F. Chilton
Keyword(s):  
Single Molecule ◽  
High Energy ◽  
Energy Barriers ◽  
Single Molecule Magnets

Correlating blocking temperatures with relaxation mechanisms in single-molecule magnets.

Planar Dy3 + Dy3 clusters: design, structure and axial ligand perturbed magnetic dynamics

2015 ◽  
Vol 44 (47) ◽  
pp. 20316-20320 ◽  
Author(s):  
Xiao-Lei Li ◽  
Han Li ◽  
Di-Ming Chen ◽  
Chao Wang ◽  
Jianfeng Wu ◽  
...  
Keyword(s):  
Single Molecule ◽  
High Energy ◽  
Axial Ligand ◽  
Magnetic Behaviour ◽  
Energy Barriers ◽  
Magnetic Dynamics ◽  
Design Structure

Coupling Dy3 triangles results in two unique Dy6 complexes showing single-molecule magnetic behaviour with high energy barriers of 116 and 181 K for Dy6–NO3 and Dy6–SCN, respectively.

Enhanced energy barriers triggered by magnetic anisotropy modulation via tuning the functional groups on the bridging ligands in Dy2 single-molecule magnets

2018 ◽  
Vol 47 (42) ◽  
pp. 15197-15205 ◽  
Author(s):  
Yaru Qin ◽  
Yu Jing ◽  
Yu Ge ◽  
Wei Liu ◽  
Yahong Li ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Functional Groups ◽  
Single Molecule ◽  
Energy Barrier ◽  
Energy Barriers ◽  
Single Molecule Magnets ◽  
Bridging Ligands

Two dinuclear dysprosium complexes of 1 and 2 have been synthesized and both of them exhibit SMM behavior. The energy barrier is enhanced ca. 35 K by elaborately tuning the backbones of the ligands.

scholarly journals Single-molecule magnet properties of a monometallic dysprosium pentalene complex

2018 ◽  
Vol 54 (51) ◽  
pp. 7085-7088 ◽  
Author(s):  
Alexander F. R. Kilpatrick ◽  
Fu-Sheng Guo ◽  
Benjamin M. Day ◽  
Akseli Mansikkamäki ◽  
Richard A. Layfield ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barriers ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Dysprosium Complex

The pentalene-ligated dysprosium complex [(η8-Pn†)Dy(Cp*)] (1Dy) (Pn† = [1,4-(iPr3Si)2C8H4]2−) and its magnetically dilute analogue are single-molecule magnets, with energy barriers of 245 cm−1.

See-Saw Shaped Dy(III) Single-Molecule Magnets with High Anisotropy Barriers

2020 ◽  
Author(s):  
Katie L. M. Harriman ◽  
Jesse Murillo ◽  
Elizaveta A. Suturina ◽  
Skye Fortier ◽  
Muralee Murugesu
Keyword(s):  
Magnetic Susceptibility ◽  
Single Molecule ◽  
Molecular Geometry ◽  
High Energy ◽  
Zero Field ◽  
Relaxation Dynamics ◽  
Single Molecule Magnets ◽  
Ancillary Ligands ◽  
Spin Reversal ◽  
Magnetic Spin

<p>Utilizing a terphenyl bisanilide ligand, two Dy(III) complexes [K(DME)<sub>x</sub>][L<sup>Ar</sup>Dy(X)<sub>2</sub>] (L<sup>Ar</sup> = {C<sub>6</sub>H<sub>4</sub>[(2,6-<i><sup>i</sup></i>PrC<sub>6</sub>H<sub>3</sub>)NC<sub>6</sub>H<sub>4</sub>]<sub>2</sub>}<sup>2-</sup>), X = Cl (<b>1</b>) and X = I (<b>2</b>) were synthesized. The ligand imposes an unusual see-saw shaped molecular geometry leading to a coordinatively unsaturated complex with near-linear N-Dy-N (avg. 159.9° for<b>1</b> and avg. 160.3<sup>o</sup> for <b>2</b>) bond angles. These complexes exhibit Single-Molecule Magnet (SMM) behavior with significant uniaxial magnetic anisotropy as a result of the transverse coordination of the bisanlide ligand which yields high energy barriers to magnetic spin reversal of <i>U</i><sub>eff</sub> = 1334 K/ 927cm<sup>-1</sup> (<b>1</b>) and 1299 K/ 903 cm<sup>-1</sup> (<b>2</b>) in zero field. Magneto-structural correlations are discussed with the goal of finding a link between halide ancillary ligands in the structurally analogous complexes and the through barrier relaxation dynamics observed in the ac magnetic susceptibility, despite the similar dc magnetic susceptibility for compounds <b>1</b> and <b>2</b>. <i>Ab initio</i> calculations reveal that the dominant crystal field of the bisanilide ligand controls the orientation of the main magnetic axis which runs nearly parallel to the N-Dy-N bonds, and defines the height of the energy barrier. Thus, further validating the use of transverse ligands to enhance the SMM properties of Dy(III) ions.</p>

Tuneable energy barriers in tetrairon(III) single-molecule magnets

2004 ◽  
Vol 272-276 ◽  
pp. E749-E751 ◽  
Author(s):  
A Cornia ◽  
A.C Fabretti ◽  
P Garrisi ◽  
C Mortalò ◽  
D Bonacchi ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barriers ◽  
Single Molecule Magnets

Significant Enhancement of Energy Barriers in Dinuclear Dysprosium Single-Molecule Magnets Through Electron-Withdrawing Effects

2013 ◽  
Vol 135 (36) ◽  
pp. 13242-13245 ◽  
Author(s):  
Fatemah Habib ◽  
Gabriel Brunet ◽  
Veacheslav Vieru ◽  
Ilia Korobkov ◽  
Liviu F. Chibotaru ◽  
...  
Keyword(s):  
Single Molecule ◽  
Significant Enhancement ◽  
Energy Barriers ◽  
Single Molecule Magnets

Two C2v symmetry dysprosium(iii) single-molecule magnets with effective energy barriers over 600 K

2021 ◽  
Author(s):  
Xixi Meng ◽  
Mengmeng Wang ◽  
Xiaoshuang Gou ◽  
Wenlong Lan ◽  
Kexin Jia ◽  
...  
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Effective Energy ◽  
Magnetization Dynamics ◽  
Energy Barriers ◽  
Single Molecule Magnets

Two high-performance C2v symmetry dysprosium(iii) single-molecule magnets were synthesized. The mechanism of magnetization dynamics was studied in detail.

Zero-Field Quantum Tunneling of the Magnetization in a Series of High Energy-Barrier Dysprosium (III) Single-Molecule Magnets

2018 ◽  
Author(s):  
Fabrizio Ortu ◽  
Daniel Reta ◽  
You-Song Ding ◽  
Conrad A. P. Goodwin ◽  
Matthew P. Gregson ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetic Hysteresis ◽  
High Energy ◽  
Exact Nature ◽  
Zero Field ◽  
Vibrational Modes ◽  
Single Molecule Magnets ◽  
Quantum Tunnelling ◽  
Intermediate Energies ◽  
High Energy Barrier

<p>Energy barriers to magnetisation reversal (U<sub>eff</sub>) in single-molecule magnets (SMMs) have vastly increased recently, but only for the dysprosocenium SMM [Dy(Cp<sup>ttt</sup>)<sub>2</sub>][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] (Cp<sup>ttt</sup> = C<sub>5</sub>H<sub>2</sub><sup>t</sup>Bu<sub>3</sub>-1,2,4) has this translated into a considerable increase in magnetic hysteresis temperatures. The lack of concomitant increases in hysteresis temperatures with U<sub>eff</sub> values is due to efficient magnetic relaxation at zero-field, referred to as quantum tunnelling of the magnetisation (QTM); however, the exact nature of this phenomenon is unknown. Recent hypotheses suggest that both transverse dipolar magnetic fields and hyperfine coupling play a significant role in this process for Dy(III) SMMs. Here, by studying the compounds [Dy(<sup>t</sup>BuO)Cl(THF)<sub>5</sub>][BPh<sub>4</sub>] (<b>1</b>), [K(18-crown-6-ether)(THF)<sub>2</sub>][Dy(BIPM)<sub>2</sub>] (<b>2</b>, BIPM = C{PPh<sub>2</sub>NSiMe<sub>3</sub>}<sub>2</sub>), and [Dy(Cp<sup>ttt</sup>)<sub>2</sub>][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] (<b>3</b>), we show conclusively that neither of these processes are the main contributor to zero-field QTM for Dy(III) SMMs, and suggest that its origin instead owes to molecular flexibility. By analysing the vibrational modes of the three molecules, we show that the modes that most impact the magnetic ion occur at the lowest energies for <b>1</b>, at intermediate energies for <b>2</b> and at higher energies for <b>3</b>, in correlation with their ability to retain magnetisation. Therefore, we conclude that SMM performance could be improved by employing more rigid ligands with higher-energy metal-ligand vibrational modes.</p>

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