scholarly journals Low-Coordinate Dinuclear Dysprosium(III) Single Molecule Magnets Utilizing LiCl as Bridging Moieties and tris(amido)amine as Blocking Ligands

2021 ◽  
Vol 7 (9) ◽  
pp. 125
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Mikolaj Zychowicz ◽  
Dawid Pinkowicz

A low-coordinate dinuclear dysprosium complex {[Dy(N3N)(THF)][LiCl(THF)]}2 (Dy2) with a double bridging ‘LiCl’ moiety and tris(amido)amine (N3N)3- anions as a blocking ligand is synthesized and characterized structurally and magnetically. Thanks to the use of the chelating blocking ligand (N3N)3− equipped with large steric –SiMe3 groups, the coordination sphere of both DyIII ions is restricted to only six donor atoms. The three amido nitrogen atoms determine the orientation of the easy magnetization axes of both DyIII centers. Consequently, Dy2 shows slow magnetic relaxation typical for single molecule magnets (SMMs). However, the effective energy barrier for magnetization reversal determined from the AC magnetic susceptibility measurements is much lower than the separation between the ground and the first excited Kramers doublet based on the CASSCF ab initio calculations. In order to better understand the possible influence of the anticipated intramolecular magnetic interactions in this dinuclear molecule, its GdIII-analog {[Gd(N3N)(THF)][LiCl(THF)]}2 (Gd2) is also synthesized and studied magnetically. Detailed magnetic measurements reveal very weak antiferromagnetic interactions in Gd2. This in turn suggests similar antiferromagnetic interactions in Dy2, which might be responsible for its peculiar SMM behavior and the absence of the magnetic hysteresis loop.

2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikołaj Zychowicz ◽  
Dawid Pinkowicz

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>


2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikołaj Zychowicz ◽  
Dawid Pinkowicz

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>


Inorganics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 66
Author(s):  
Mamo Gebrezgiabher ◽  
Yosef Bayeh ◽  
Tesfay Gebretsadik ◽  
Gebrehiwot Gebreslassie ◽  
Fikre Elemo ◽  
...  

The breakthrough in Ln(III)-based SMMs with Schiff base ligands have been occurred for the last decade on account of their magnetic behavior, anisotropy and relaxation pathways. Herein, we review the synthetic strategy, from a structural point of view and magnetic properties of mono, di, tri and polynuclear Ln(III)-based single-molecule magnets mainly with Schiff bases of Salicylaldehyde origin. Special attention has been given to some important breakthroughs that are changing the perspective of this field with a special emphasis on slow magnetic relaxation. An overview of 50 Ln(III)-Schiff base complexes with SMM behavior, covering the period 2008–2020, which have been critical in understanding the magnetic interactions between the Ln(III)-centers, are presented and discussed in detail.


2019 ◽  
Author(s):  
Guo-Zhang Huang ◽  
Ze-Yu Ruan ◽  
Jie-Yu Zheng ◽  
Yan-Cong Chen ◽  
Si-Guo Wu ◽  
...  

<p><a></a>Controlling molecular magnetic anisotropy via structural engineering is delicate and fascinating, especially for single-molecule magnets (SMMs). Herein a family of dysprosium single-ion magnets (SIMs) sitting in pentagonal bipyramid geometry have been synthesized with the variable-size terminal ligands and counter anions, through which the subtle coordination geometry of Dy(III) can be finely tuned based on the size effect. The effective energy barrier (Ueff) successfully increases from 439 K to 632 K and the magnetic hysteresis temperature (under a 200 Oe/s sweep rate) raises from 11 K to 24 K. Based on the crystal-field theory, a semi-quantitative magneto-structural correlation deducing experimentally for the first time is revealed that the Ueff is linearly proportional to the structural-related value S2<sup>0</sup> corresponding to the axial coordination bond lengths and the bond angles. Through the evaluation of the remanent magnetization from hysteresis, quantum tunneling of magnetization (QTM) is found to exhibit negative correlation with the structural-related value S<sub>tun</sub> corresponding to the axial coordination bond angles.<br></p>


2015 ◽  
Vol 44 (29) ◽  
pp. 13242-13249 ◽  
Author(s):  
Malay Dolai ◽  
Mahammad Ali ◽  
Ján Titiš ◽  
Roman Boča

Two CuII–DyIII and CoIII–DyIII dinuclear complexes of a Schiff base ligand (H3L) exhibit single-molecule magnetic behaviour with multiple slow magnetic relaxation processes for the former.


2016 ◽  
Vol 52 (26) ◽  
pp. 4772-4775 ◽  
Author(s):  
Szymon Chorazy ◽  
Michał Rams ◽  
Anna Hoczek ◽  
Bernard Czarnecki ◽  
Barbara Sieklucka ◽  
...  

{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.


2017 ◽  
Vol 46 (25) ◽  
pp. 8259-8268 ◽  
Author(s):  
Wan-Ying Zhang ◽  
Yong-Mei Tian ◽  
Hong-Feng Li ◽  
Peng Chen ◽  
Yi-Quan Zhang ◽  
...  

A series of linear trinuclear complexes Ln2M(OQ)8 [Ln(iii) = Dy and Er, M(ii) = Ca and Mg] were structurally and magnetically investigated.


2014 ◽  
Vol 67 (11) ◽  
pp. 1542 ◽  
Author(s):  
Michele Vonci ◽  
Colette Boskovic

Polyoxometalates are robust and versatile multidentate oxygen-donor ligands, eminently suitable for coordination to trivalent lanthanoid ions. To date, 10 very different structural families of such complexes have been found to exhibit slow magnetic relaxation due to single-molecule magnet (SMM) behaviour associated with the lanthanoid ions. These families encompass complexes with between one and four of the later lanthanoid ions: Tb, Dy, Ho, Er, and Yb. The lanthanoid coordination numbers vary between six and eleven and a range of coordination geometries are evident. The highest energy barrier to magnetisation reversal measured to date for a lanthanoid–polyoxometalate SMM is Ueff/kB = 73 K for the heterodinuclear Dy–Eu compound (Bu4N)8H4[DyEu(OH)2(γ-SiW10O36)2].


2020 ◽  
Vol 49 (35) ◽  
pp. 12458-12465 ◽  
Author(s):  
Hanhan Chen ◽  
Lin Sun ◽  
Jinpeng Zhang ◽  
Zikang Xiao ◽  
Pengtao Ma ◽  
...  

Triangular {Er3} cluster containing POM exhibits field-induced two thermally activated relaxation processes. Whereas, the diamagnetic dilution sample indicates slow magnetic relaxation with the QTM being partially suppressed.


2019 ◽  
Vol 7 (14) ◽  
pp. 4164-4172 ◽  
Author(s):  
Szymon Chorazy ◽  
Jakub J. Zakrzewski ◽  
Mateusz Reczyński ◽  
Koji Nakabayashi ◽  
Shin-ichi Ohkoshi ◽  
...  

Functional materials incorporating cyanido-bridged DyIIICoIII molecules combine visible photoluminescence and slow magnetic relaxation, both switchable by the level of humidity within the reversible room temperature dehydration process.


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