scholarly journals Tetraanionic Biphenyl Lanthanide Complexes as Single-Molecule Magnets

2015 ◽  
Vol 54 (5) ◽  
pp. 2374-2382 ◽  
Author(s):  
Wenliang Huang ◽  
Jennifer J. Le Roy ◽  
Saeed I. Khan ◽  
Liviu Ungur ◽  
Muralee Murugesu ◽  
...  
2020 ◽  
Vol 49 (23) ◽  
pp. 7774-7789 ◽  
Author(s):  
Elena A. Mikhalyova ◽  
Matthias Zeller ◽  
Jerry P. Jasinski ◽  
Raymond J. Butcher ◽  
Luca M. Carrella ◽  
...  

Mono-, di- & trinuclear ternary complexes of Dy3+ & Tb3+ with pyrazole & oligo-diketonates are both luminescent and single molecule magnets. Quantum yields & Ueff values decrease with higher nuclearity & reduced intramolecular Ln–Ln distance.


2019 ◽  
Vol 5 (2) ◽  
pp. 30 ◽  
Author(s):  
Ryuta Ishikawa ◽  
Shoichi Michiwaki ◽  
Takeshi Noda ◽  
Keiichi Katoh ◽  
Masahiro Yamashita ◽  
...  

A series of chloralilate-bridged dinuclear lanthanide complexes of formula [{LnIII(Tp)2}2(μ-Cl2An)]·2CH2Cl2, where Cl2An2− and Tp− represent the chloranilate and hydrotris (pyrazolyl)borate ligands, respectively, and Ln = Gd (1), Tb (2), Ho (3), Er (4), and Yb (5) was synthesized. All five complexes were characterized by an elemental analysis, infrared spectroscopy, single crystal X-ray diffraction, and SQUID measurements. The complexes 1–5 in the series were all isostructural. A comparison of the temperature dependence of the dc magnetic susceptibility data of these complexes revealed clear differences depending on the lanthanide center. Ac magnetic susceptibility measurements revealed that none of the five complexes exhibited a slow magnetic relaxation under a zero applied dc field. On the other hand, the Kramers systems (complexes 4 and 5) clearly displayed a slow magnetic relaxation under applied dc fields, suggesting field-induced single-molecule magnets that occur through Orbach and Raman relaxation processes.


2018 ◽  
Vol 47 (48) ◽  
pp. 17349-17356 ◽  
Author(s):  
Guo Peng ◽  
Ying-Ying Zhang ◽  
Bo Li ◽  
Xiao-Fan Sun ◽  
Hong-Ling Cai ◽  
...  

A family of mononuclear lanthanide complexes exhibiting slow magnetic relaxation is reported, providing the first examples of pure 4f sulfonate-based single molecule magnets.


Author(s):  
Zhuo Wu ◽  
Yong-Mei Tian ◽  
Peng Chen ◽  
Wenbin Sun ◽  
Bingwu Wang ◽  
...  

A series of mononuclear lanthanide complexes with formula [Hex4N][Ln(DBM)4] (1Ln) (Ln = Nd and Tb), [But4N][Dy(DBM)4] (2), [Et4N][Dy(DBM)4] (3), [PhCH2N(CH3)3][Dy(DBM)4] (4) and [Hex4N][Dy(TTA)4 (5) formed by four β-diketonate ligands (i.e....


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>


2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  

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.


2018 ◽  
Author(s):  
Shannon Houck ◽  
Nicholas Mayhall

<div>Many multiconfigurational systems, such as single-molecule magnets, are difficult to study using traditional computational methods due to the simultaneous existence of both spin and spatial degeneracies. In this work, a new approach termed n-spin-flip Ionization Potential/Electron Affinity (<i>n</i>SF-IP or <i>n</i>SF-EA) is introduced which combines the spin-flip method of Anna Krylov with particle-number changing IP/EA methods. We demonstrate the efficacy of the approach by applying it to the strongly-correlated N<sub>2</sub><sup>+</sup> as well as several double exchange systems. We also demonstrate that when these systems are well-described by a double exchange model Hamiltonian, only 1SF-IP/EA is required to extract the double exchange parameters and accurately predict energies for the low-spin states. This significantly reduces the computational effort for studying such systems. The effects of including additional excitations (using a RAS-<i>n</i>SF-IP/EA scheme) are also examined, with particular emphasis on hole and particle excitations.</div>


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