scholarly journals Switching the Local Symmetry from D5h to D4h for Single-Molecule Magnets by Non-Coordinating Solvents

Inorganics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 64
Author(s):  
Xia-Li Ding ◽  
Qian-Cheng Luo ◽  
Yuan-Qi Zhai ◽  
Qian Zhang ◽  
Lei Tian ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Local Symmetry ◽  
Structure Change ◽  
Blocking Temperature ◽  
Magnetic Studies ◽  
Single Molecule Magnets ◽  
Magnetic Anisotropy Energy ◽  
Local Coordination ◽  
Symmetry Effect

A solvent effect towards the performance of two single-molecule magnets (SMMs) was observed. The tetrahydrofuran and toluene solvents can switch the equatorial coordinated 4-Phenylpyridine (4-PhPy) molecules from five to four, respectively, in [Dy(OtBu)2(4-PhPy)5]BPh41 and Na{[Dy(OtBu)2(4-PhPy)4][BPh4]2}∙2thf∙hex 2. This alternation significantly changes the local coordination symmetry of the Dy(III) center from D5h to D4h for 1 and 2, seperately. Magnetic studies show that the magnetic anisotropy energy barrier of 2 is higher than that of 1, while the relation of blocking temperature is just on the contrary due to the symmetry effect. The calculations of the electrostatic potential successfully explained the driving force of solvents for the molecular structure change, confirming the feasibility of adjusting the performance of SMMs via diverse solvents.

Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Single Molecule ◽  
Energy Barrier ◽  
Thermal Relaxation ◽  
Relaxation Mechanism ◽  
Blocking Temperature ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Key Parameter

We report a six coordinate DyIII single-molecule magnet<br>(SMM) with an energy barrier of 1110 K for thermal relaxation of<br>magnetization. The sample shows no retention of magnetization<br>even at 2 K and this led us to find a good correlation between the<br>blocking temperature and the Raman relaxation regime for SMMs.<br>The key parameter is the relaxation time (𝜏<sub>switch</sub>) at the point where<br>the Raman relaxation mechanism becomes more important than<br>Orbach.

D4h Local Symmetric dysprosium(III) Single-Molecule Magnet with Energy Barrier Exceeding 2000 K

2020 ◽  
Author(s):  
Xia-Li Ding ◽  
Yuan-Qi Zhai ◽  
Tian Han ◽  
Wei-Peng Chen ◽  
You-Song Ding ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Local Symmetry ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
The Third ◽  
Type Symmetry

<p><a></a><a></a><a><b>Three six-coordinate Dy(III) single-molecule magnets (SMMs) [Dy(O<sup>t</sup>Bu)<sub>2</sub>(L)<sub>4</sub>]<sup>+</sup> with <i>D</i><sub>4h</sub> local symmetry are obtained by optimising the equatorial ligands. Compound 1 where L = 4-phenylpyridine shows an energy barrier (<i>U</i><sub>eff</sub>) of 2075(11) K, which is the third largest <i>U</i><sub>eff</sub>, and the first <i>U</i><sub>eff</sub> > 2000 K for SMMs with axial-type symmetry so far.</b></a></p>

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>

Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Single Molecule ◽  
Energy Barrier ◽  
Thermal Relaxation ◽  
Relaxation Mechanism ◽  
Blocking Temperature ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Key Parameter

We report a six coordinate DyIII single-molecule magnet<br>(SMM) with an energy barrier of 1110 K for thermal relaxation of<br>magnetization. The sample shows no retention of magnetization<br>even at 2 K and this led us to find a good correlation between the<br>blocking temperature and the Raman relaxation regime for SMMs.<br>The key parameter is the relaxation time (𝜏<sub>switch</sub>) at the point where<br>the Raman relaxation mechanism becomes more important than<br>Orbach.

scholarly journals D4h Local Symmetric dysprosium(III) Single-Molecule Magnet with Energy Barrier Exceeding 2000 K

2020 ◽  
Author(s):  
Xia-Li Ding ◽  
Yuan-Qi Zhai ◽  
Tian Han ◽  
Wei-Peng Chen ◽  
You-Song Ding ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Local Symmetry ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
The Third ◽  
Type Symmetry

<p><a></a><a></a><a><b>Three six-coordinate Dy(III) single-molecule magnets (SMMs) [Dy(O<sup>t</sup>Bu)<sub>2</sub>(L)<sub>4</sub>]<sup>+</sup> with <i>D</i><sub>4h</sub> local symmetry are obtained by optimising the equatorial ligands. Compound 1 where L = 4-phenylpyridine shows an energy barrier (<i>U</i><sub>eff</sub>) of 2075(11) K, which is the third largest <i>U</i><sub>eff</sub>, and the first <i>U</i><sub>eff</sub> > 2000 K for SMMs with axial-type symmetry so far.</b></a></p>

Symmetry strategies for high performance lanthanide-based single-molecule magnets

2018 ◽  
Vol 47 (7) ◽  
pp. 2431-2453 ◽  
Author(s):  
Jun-Liang Liu ◽  
Yan-Cong Chen ◽  
Ming-Liang Tong
Keyword(s):  
Field Theory ◽  
Crystal Field ◽  
Single Molecule ◽  
High Performance ◽  
Local Symmetry ◽  
Design Strategies ◽  
Magnetic Studies ◽  
Single Molecule Magnets ◽  
Crystal Field Theory

Based on crystal-field theory, design strategies in consideration of local symmetry are highlighted for lanthanide-based single-molecule magnets, accompanied by practical concerns about magnetic studies and representative cases.

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>

Metallocyclic Ni4Ln2M2 single-molecule magnets

2017 ◽  
Vol 46 (20) ◽  
pp. 6544-6552 ◽  
Author(s):  
Mei-Jiao Liu ◽  
Kong-Qiu Hu ◽  
Cai-Ming Liu ◽  
Ai-Li Cui ◽  
Hui-Zhong Kou
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Studies ◽  
Single Molecule Magnets ◽  
Fe Complexes

Magnetic studies on nine new octanuclear cyclic heterotrimetallic complexes reveal that in comparison with analogous octanuclear complexes [Ni4Dy2M2] (M3+ = Fe, W and Co), the [Ni4Dy2Cr2] species show the highest energy barrier and the [Ni4Tb2M2] (M = Cr or Fe) complexes display single-molecule magnetic properties.

Exchange-Biasing in a Dinuclear Dysprosium(III) Single-Molecule Magnet with a Large Energy Barrier for Magnetization Reversal

2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetization Reversal ◽  
Energy Barrier ◽  
Magnetic Hysteresis ◽  
Large Energy ◽  
Magnetic Studies ◽  
Bridging Ligands ◽  
Single Molecule Magnet ◽  
Exchange Biasing

A dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy<sub>2</sub>L<sub>2</sub>(<i>µ</i>-Cl)<sub>2</sub>(THF)<sub>2</sub>] has been made using a diamine-bis(phenolate) ligand, H<sub>2</sub>L. Magnetic studies show an energy barrier for magnetization reversal (<i>U</i><sub>eff</sub>) around 1000 K. Exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 4 K. <i>Ab</i> initio calculations exclude the possibility of pure dipolar origin of this effect leading to the conclusion that super-exchange <i>via</i> the chloride bridging ligands is important.

Structural anisotropy of cyanido-bridged {CoII9WV6} single-molecule magnets induced by bidentate ligands: towards the rational enhancement of an energy barrier

2016 ◽  
Vol 52 (26) ◽  
pp. 4772-4775 ◽  
Author(s):  
Szymon Chorazy ◽  
Michał Rams ◽  
Anna Hoczek ◽  
Bernard Czarnecki ◽  
Barbara Sieklucka ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Relaxation ◽  
Bidentate Ligands ◽  
Single Molecule Magnets ◽  
Structural Anisotropy ◽  
Slow Magnetic Relaxation

{CoII9[WV(CN)8]6} clusters capped by odd and even number of bidentate ligands reveal the improved slow magnetic relaxation due to the significant structural anisotropy.

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