Emerging Trends on Designing High-Performance Dysprosium(III) Single-Molecule Magnets

2022 ◽  
pp. 307-319
Author(s):  
Tesfay G. Ashebr ◽  
Hui Li ◽  
Xu Ying ◽  
Xiao-Lei Li ◽  
Chen Zhao ◽  
...  
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Single Molecule Magnets ◽  
Emerging Trends

High performance single-molecule magnets, Orbach or Raman relaxation suppression?

2020 ◽  
Vol 7 (13) ◽  
pp. 2478-2486 ◽  
Author(s):  
Alejandro Castro-Alvarez ◽  
Yolimar Gil ◽  
Leonel Llanos ◽  
Daniel Aravena
Keyword(s):  
Ab Initio ◽  
Single Molecule ◽  
High Performance ◽  
Blocking Temperature ◽  
Single Molecule Magnets

Relaxation mechanisms limiting the blocking temperature for high-performance single molecule magnets (SMMs) are investigated. Best SMMs are limited by the exponential regime. Current ab initio methods can yield accurate estimations for this limit.

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.

scholarly journals Pseudo-Tetrahedral vs Pseudo-Octahedral ErIII Single Molecule Magnets and the 'Disruptive' Role of Coordinated TEMPO Radicals

2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikołaj Zychowicz ◽  
Dawid Pinkowicz
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Relaxation Mechanism ◽  
Magnetic Memory ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation ◽  
Tempo Radical

Erbium(III) complexes are the most interesting candidates for high-performance single molecule magnets (SMMs) just after dysprosium(III). Herein, we thoroughly explore the underrepresented class of neutral pseudo-tetrahedral erbium(III) SMMs and demonstrate their exceptional slow magnetization dynamics controlled by the Raman relaxation mechanism and the molecular magnetic memory effect in the form of a waist-restricted magnetic hysteresis loop. The influence of the coordinated TEMPO radical on the slow magnetization relaxation performance is also demonstrated and discussed.<br>

scholarly journals Dysprosiacarboranes: A New Type of Organometallic Single-Molecule Magnets

2019 ◽  
Author(s):  
Peng-Bo Jin ◽  
Yuan-Qi Zhai ◽  
Ke-Xin Yu ◽  
Richard E. P. Winpenny ◽  
Yan-Zhen Zheng
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
High Performance ◽  
Blocking Temperature ◽  
Effective Energy ◽  
Single Molecule Magnets ◽  
Linear Complex ◽  
Substitution Pattern ◽  
New Type

Dicarbollide ion, nido-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub><sup>2-</sup> is isoelectronic with cyclopentadienyl. Here we make dysprosiacarboranes, namely [(C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>)<sub>2</sub>Ln(THF)<sub>2</sub>][Na(THF)<sub>5</sub>] (Ln = Dy, <b>1Dy</b>) and [(THF)<sub>3</sub>(μ-H)<sub>3</sub>Li]<sub>2</sub>[{η<sup>5</sup>-C<sub>6</sub>H<sub>4</sub>(CH<sub>2</sub>)<sub>2</sub>C<sub>2</sub>B<sub>9</sub>H<sub>9</sub>}Dy{η<sup>2</sup>:η<sup>5</sup>-C<sub>6</sub>H<sub>4</sub>(CH<sub>2</sub>)<sub>2</sub>C<sub>2</sub>B<sub>9</sub>H<sub>9</sub>}<sub>2</sub>Li] <b>3</b> and show that dicarbollide ligands impose strong magnetic axiality on the central Dy(III) ion. The effective energy barrier (Ueff) for loss of magnetisation can be varied by the substitution pattern on the dicarbollide. This is demonstrated by comparing complexes of nido-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub><sup>2-</sup> and nido-[o-xylylene-C<sub>2</sub>B<sub>9</sub>H<sub>9</sub>]<sup>2-</sup> which show Ueff of 430(5) K and 804(7) K, respectively. The blocking temperature defined by the open hysteresis temperature of 3 reaches 6.8 K. Moreover, the linear complex [Dy(C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>)<sub>2</sub>]<sup>-</sup> is predicted to have comparable SMM properties with linear [Dy(CpMe<sub>3</sub>)<sub>2</sub>]<sup>+</sup> complex. As such, carboranyl ligands and its derivatives may open a new type of organometallic ligands for high-performance SMM design. <br>

Magnetism in Ln molecular systems with 4f/valence-shell interplay (FV-magnetism)

2019 ◽  
Vol 55 (93) ◽  
pp. 13963-13966 ◽  
Author(s):  
Vasilii Dubrovin ◽  
Alexey A. Popov ◽  
Stanislav Avdoshenko
Keyword(s):  
High Temperatures ◽  
Single Molecule ◽  
First Principles ◽  
High Performance ◽  
Valence Shell ◽  
Single Molecule Magnets ◽  
Molecular Systems ◽  
Very High

The hunt for high-performance single-molecule magnets (SMM) revealed that lanthanide systems combining 4f- and valence-shells show magnetic bistability up to very high temperatures. We rationalize magnetism in such systems from first principles.

Pseudo-tetrahedral vs pseudo-octahedral ErIII single molecule magnets and the disruptive role of coordinated TEMPO radicals

2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikolaj Zychowicz ◽  
Dawid Pinkowicz
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Single Molecule Magnets

ErIII complexes are potential candidates for high-performance single molecule magnets (SMMs) just after DyIII. Herein, we thoroughly explore the under-represented class of neutral pseudo-tetrahedral ErIII SMMs and demonstrate their exceptional...

scholarly journals Pseudo-Tetrahedral vs Pseudo-Octahedral ErIII Single Molecule Magnets and the 'Disruptive' Role of Coordinated TEMPO Radicals

2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikołaj Zychowicz ◽  
Dawid Pinkowicz
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Relaxation Mechanism ◽  
Magnetic Memory ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation ◽  
Tempo Radical

Erbium(III) complexes are the most interesting candidates for high-performance single molecule magnets (SMMs) just after dysprosium(III). Herein, we thoroughly explore the underrepresented class of neutral pseudo-tetrahedral erbium(III) SMMs and demonstrate their exceptional slow magnetization dynamics controlled by the Raman relaxation mechanism and the molecular magnetic memory effect in the form of a waist-restricted magnetic hysteresis loop. The influence of the coordinated TEMPO radical on the slow magnetization relaxation performance is also demonstrated and discussed.<br>

scholarly journals Dysprosiacarboranes: A New Type of Organometallic Single-Molecule Magnets

2019 ◽  
Author(s):  
Peng-Bo Jin ◽  
Yuan-Qi Zhai ◽  
Ke-Xin Yu ◽  
Richard E. P. Winpenny ◽  
Yan-Zhen Zheng
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
High Performance ◽  
Blocking Temperature ◽  
Effective Energy ◽  
Single Molecule Magnets ◽  
Linear Complex ◽  
Substitution Pattern ◽  
New Type

Dicarbollide ion, nido-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub><sup>2-</sup> is isoelectronic with cyclopentadienyl. Here we make dysprosiacarboranes, namely [(C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>)<sub>2</sub>Ln(THF)<sub>2</sub>][Na(THF)<sub>5</sub>] (Ln = Dy, <b>1Dy</b>) and [(THF)<sub>3</sub>(μ-H)<sub>3</sub>Li]<sub>2</sub>[{η<sup>5</sup>-C<sub>6</sub>H<sub>4</sub>(CH<sub>2</sub>)<sub>2</sub>C<sub>2</sub>B<sub>9</sub>H<sub>9</sub>}Dy{η<sup>2</sup>:η<sup>5</sup>-C<sub>6</sub>H<sub>4</sub>(CH<sub>2</sub>)<sub>2</sub>C<sub>2</sub>B<sub>9</sub>H<sub>9</sub>}<sub>2</sub>Li] <b>3</b> and show that dicarbollide ligands impose strong magnetic axiality on the central Dy(III) ion. The effective energy barrier (Ueff) for loss of magnetisation can be varied by the substitution pattern on the dicarbollide. This is demonstrated by comparing complexes of nido-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub><sup>2-</sup> and nido-[o-xylylene-C<sub>2</sub>B<sub>9</sub>H<sub>9</sub>]<sup>2-</sup> which show Ueff of 430(5) K and 804(7) K, respectively. The blocking temperature defined by the open hysteresis temperature of 3 reaches 6.8 K. Moreover, the linear complex [Dy(C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>)<sub>2</sub>]<sup>-</sup> is predicted to have comparable SMM properties with linear [Dy(CpMe<sub>3</sub>)<sub>2</sub>]<sup>+</sup> complex. As such, carboranyl ligands and its derivatives may open a new type of organometallic ligands for high-performance SMM design. <br>

scholarly journals Air-Stable Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets with Nearly Perfect D6h Local Symmetry

2019 ◽  
Author(s):  
Zi-Han Li ◽  
Yuan-Qi Zhai ◽  
Wei-Peng Chen ◽  
You-Song Ding ◽  
Yan-Zhen Zheng
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Local Symmetry ◽  
Fine Tuning ◽  
Magnetic Reversal ◽  
Single Molecule Magnets ◽  
Experimental Realization ◽  
High Coordination Number ◽  
Macrocyclic Schiff Base ◽  
High Coordination

Local eight-coordination of the Dy(III) with D<sub>6h</sub> symmetry receives much expectation for high-performance single-molecule magnets (SMMs) due to the simultaneous fulfillment of the magnetic axiality and high coordination number (a requisite for the air stability). But the experimental realization is challenging due to the required restriction of six coordination atoms in the equatorial plane of the hexagonal-bipyramid, which is usually too crowded for the central Dy(III) ion. Here we show by using the hexaaza macrocyclic Schiff base ligand and fine-tuning the axial alkoxide/phenol type ligands, a family of hexagonal-bipyramidal Dy(III) complexes, namely [Dy<sup>III</sup>(L)(Cl)<sub>2</sub>(H<sub>2</sub>O/CH<sub>3</sub>OH)]Cl <b>1</b>, [Dy<sup>III</sup>(L)(C<sub>6</sub>F<sub>5</sub>O)<sub>2</sub>(H<sub>2</sub>O)](BPh<sub>4</sub>)·<b>2</b>, [Dy<sup>III</sup>(L)(PhO)<sub>2</sub>](BPh<sub>4</sub>) <b>3</b>, [Dy<sup>III</sup>(L)(4-MeO-PhO)<sub>2</sub>](BPh<sub>4</sub>) <b>4</b>, [Dy<sup>III</sup>(L)(naPhO)<sub>2</sub>](BPh<sub>4</sub>) <b>5 </b>and [Dy<sup>III</sup>(L)(Ph<sub>3</sub>SiO)<sub>2</sub>](BPh<sub>4</sub>) <b>6</b><b> </b>, can be isolated. Among them, complexes <b>3</b>, <b>4</b> and <b>5</b> possess nearly perfect D<sub>6h</sub> local symmetry. Complex <b>4</b> shows the highest effective magnetic reversal barrier 1338 K and an open hysteresis temperature 6 K at the field sweeping rate of 1.2 mT/s, which represents a new record for D<sub>6h</sub> SMMs.

scholarly journals Uncertainty Estimates for Magnetic Relaxation Times and Magnetic Relaxation Parameters

2019 ◽  
Author(s):  
Daniel Reta ◽  
Nicholas Chilton
Keyword(s):  
Single Molecule ◽  
Magnetic Relaxation ◽  
High Performance ◽  
Ac Susceptibility ◽  
Relaxation Times ◽  
Model Parameters ◽  
Single Molecule Magnets ◽  
Relaxation Parameters ◽  
Uncertainty Estimates ◽  
Crystallographic Disorder

We describe a method for obtaining uncertainties in magnetic relaxation times from AC susceptibility experiments. We provide a program for fitting AC data and the resulting magnetic relaxation times accounting for the uncertainties correctly, to give magnetic relaxation parameters with accurate uncertainties. We show that the implicit distributions in the magnetic relaxation times have large consequences for the uncertainties in the model parameters, and that the magnitude of these uncertainties appear to correlate with crystallographic disorder in three families of high-performance Dy(III) single-molecule magnets.

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