scholarly journals Tetranuclear dysprosium single-molecule magnets: tunable magnetic interactions and magnetization dynamics through modifying coordination number

2019 ◽  
Vol 48 (6) ◽  
pp. 2135-2141 ◽  
Author(s):  
Kun Zhang ◽  
Gao-Peng Li ◽  
Vincent Montigaud ◽  
Olivier Cador ◽  
Boris Le Guennic ◽  
...  

The magnetic interactions and relaxation dynamics are modulated in two polynuclear dysprosium(iii) SMMs through a fine control of the coordination environment on the changeable coordination sites.

2019 ◽  
Vol 48 (37) ◽  
pp. 14062-14068 ◽  
Author(s):  
Jingjing Lu ◽  
Xiao-Lei Li ◽  
Zhenhua Zhu ◽  
Shuting Liu ◽  
Qianqian Yang ◽  
...  

Structural modification of the Dy6 cores of [Dy6L3(SCN)6(DMF)8]·4DMF (1) and [Dy6L3(NO3)6(DMF)4(H2O)2]·8DMF (2) results in the transition of magnetic relaxation behavior from single relaxation to multiple relaxation.


2015 ◽  
Vol 21 (40) ◽  
pp. 14099-14106 ◽  
Author(s):  
Shufang Xue ◽  
Yun‐Nan Guo ◽  
Liviu Ungur ◽  
Jinkui Tang ◽  
Liviu F. Chibotaru

2019 ◽  
Vol 48 (17) ◽  
pp. 5793-5799 ◽  
Author(s):  
Kun Zhang ◽  
Gao-Peng Li ◽  
Cheng Zhang ◽  
Yao-Yu Wang

Two-step relaxation processes are modulated in two Dy(iii)4 SMMs through modifying the auxiliary ligands on the changeable coordination sites.


2016 ◽  
Vol 45 (22) ◽  
pp. 9320-9327 ◽  
Author(s):  
Rebecca J. Holmberg ◽  
Marina A. Polovkova ◽  
Alexander G. Martynov ◽  
Yulia G. Gorbunova ◽  
Muralee Murugesu

Homonuclear and novel heteronuclear TbIII/YIII triple-decker heteroleptic crownphthalocyaninate complexes have been synthesized and studied for their SMM properties.


2021 ◽  
Author(s):  
Daniel Reta ◽  
Jon G. C. Kragskow ◽  
Nicholas Chilton

<p>Organometallic molecules based on [Dy(Cp<sup>R</sup>)<sub>2</sub>]<sup>+</sup> cations have emerged as clear front-runners in the search for high-temperature single-molecule magnets. However, despite a growing family of structurally-similar molecules, these molecules show significant variations in their magnetic properties, demonstrating the importance of understanding magneto-structural relationships towards developing more efficient design strategies. Here we refine our <i>ab initio</i> spin dynamics methodology and show that it is capable of quantitative prediction of relative relaxation rates in the Orbach region. Applying it to all reported [Dy(Cp<sup>R</sup>)<sub>2</sub>]<sup>+</sup> cations allows us to tease out differences in their relaxation dynamics, highlighting that the main discriminant is the magnitude of the crystal field splitting. We subsequently employ the method to predict relaxation rates for a series of hypothetical organometallic sandwich compounds, revealing an upper limit to the effective barrier to magnetic relaxation of around 2200 K, which has been reached. However, we show that further improvements to single-molecule magnets can be made by moving vibrational modes off-resonance with electronic excitations.</p>


2020 ◽  
Vol 26 (35) ◽  
pp. 7774-7778 ◽  
Author(s):  
Vijay S. Parmar ◽  
Fabrizio Ortu ◽  
Xiaozhou Ma ◽  
Nicholas F. Chilton ◽  
Rodolphe Clérac ◽  
...  

2020 ◽  
Author(s):  
Katie L. M. Harriman ◽  
Jesse Murillo ◽  
Elizaveta A. Suturina ◽  
Skye Fortier ◽  
Muralee Murugesu

<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>


2014 ◽  
Vol 70 (a1) ◽  
pp. C903-C903
Author(s):  
Christopher Woodall ◽  
Francisco Jose Martinez Lillo ◽  
Martin Míšek ◽  
Alessandro Prescimone ◽  
Dave Allan ◽  
...  

Since the discovery of Single-Molecule Magnets (SMMs) in 1993 there has been extensive interest in understanding, developing and tuning the nature of magnetic interactions within SMMs with the intention of gaining greater insight into the nature of these interactions.[1] Typically this is done synthetically using variations in ligand geometry and co-ordination environment to vary magnetic behaviour. More recently it has been demonstrated that high hydrostatic pressure are also an effective mechanism for "tuning" properties such as magnetic susceptibility in a variety of SMMs.[2] The number of studies utilising high hydrostatic pressure to investigate molecular magnetism is extremely limited due to their inherent difficulty however we report a new study investigating the pressure tunabilty of Re(IV) based SMMs. 4d and 5d metal ions such as Re are of interest due their enhanced magnetic exchanges relative to their 3d analogues and Re(IV) based complexes are of particular interest. Previous studies into [ReX6]2-(X = Cl, Br and I) anions demonstrate significant antiferromagnetic coupling, not transmitted through chemical interactions but rather through weak Re-X...X interactions in the solid state which may be easily perturbed at high pressure. [3] Therefore we report an investigation into the tunability of magnetic susceptibility in a variety of [ReX4] based compounds using high pressure magnetic susceptibility measurements and correlate the results with structure observations taken from high pressure single crystal X-ray diffraction experiments. The effects of the removal of solvent trapped in the lattice using temperature and vacuum and the corresponding effect on magnetic behaviour and chemical structure are also reported.


2019 ◽  
Vol 5 (4) ◽  
pp. 65 ◽  
Author(s):  
Tetsu Sato ◽  
Satoshi Matsuzawa ◽  
Keiichi Katoh ◽  
Brian K. Breedlove ◽  
Masahiro Yamashita

When using single molecule magnets (SMMs) in spintronics devices, controlling the quantum tunneling of the magnetization (QTM) and spin-lattice interactions is important. To improve the functionality of SMMs, researchers have explored the effects of changing the coordination geometry of SMMs and the magnetic interactions between them. Here, we report on the effects of the octa-coordination geometry on the magnetic relaxation processes of dinuclear dysprosium(III) complexes in the low-temperature region. Mixed ligand dinuclear Dy3+ triple-decker complexes [(TPP)Dy(Pc)Dy(TPP)] (1), which have crystallographically equivalent Dy3+ ions, and [(Pc)Dy(Pc)Dy(TPP)] (2), which have non-equivalent Dy3+ ions, (Pc2− = phthalocyaninato; TPP2− = tetraphenylporphyrinato), undergo dual magnetic relaxation processes. This is due to the differences in the ground states due to the twist angle (φ) between the ligands. The relationship between the off-diagonal terms and the dual magnetic relaxation processes that appears due to a deviation from D4h symmetry is discussed.


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