Relaxation dynamics in see-saw shaped Dy(iii) single-molecule magnets

2020 ◽  
Vol 7 (24) ◽  
pp. 4805-4812 ◽  
Author(s):  
Katie L. M. Harriman ◽  
Jesse Murillo ◽  
Elizaveta A. Suturina ◽  
Skye Fortier ◽  
Muralee Murugesu
Keyword(s):  
Single Molecule ◽  
Zero Field ◽  
Effective Energy ◽  
Relaxation Dynamics ◽  
Energy Barriers ◽  
Single Molecule Magnets

Unusual see-saw shaped Dy(iii) single-molecule magnets, [K(DME)n][LArDy(X)2] (LAr = {C6H4[(2,6-iPrC6H3)NC6H4]2}2−), X = Cl (1) and X = I (2) were synthesized and display high effective energy barriers (Ueff = 1278–1334 K) in zero field.

See-Saw Shaped Dy(III) Single-Molecule Magnets with High Anisotropy Barriers

2020 ◽  
Author(s):  
Katie L. M. Harriman ◽  
Jesse Murillo ◽  
Elizaveta A. Suturina ◽  
Skye Fortier ◽  
Muralee Murugesu
Keyword(s):  
Magnetic Susceptibility ◽  
Single Molecule ◽  
Molecular Geometry ◽  
High Energy ◽  
Zero Field ◽  
Relaxation Dynamics ◽  
Single Molecule Magnets ◽  
Ancillary Ligands ◽  
Spin Reversal ◽  
Magnetic Spin

<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>

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.

See-Saw Shaped Dy(III) Single-Molecule Magnets with High Anisotropy Barriers

2020 ◽  
Author(s):  
Katie L. M. Harriman ◽  
Jesse Murillo ◽  
Elizaveta A. Suturina ◽  
Skye Fortier ◽  
Muralee Murugesu
Keyword(s):  
Magnetic Susceptibility ◽  
Single Molecule ◽  
Molecular Geometry ◽  
High Energy ◽  
Zero Field ◽  
Relaxation Dynamics ◽  
Single Molecule Magnets ◽  
Ancillary Ligands ◽  
Spin Reversal ◽  
Magnetic Spin

<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>

Rare CH3O−/CH3CH2O−-bridged nine-coordinated binuclear DyIII single-molecule magnets (SMMs) significantly regulate and enhance the effective energy barriers

CrystEngComm ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1712-1724 ◽  
Author(s):  
Sheng Zhang ◽  
Nan Shen ◽  
Sha Liu ◽  
Rong Ma ◽  
Yi-Quan Zhang ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Single Molecule ◽  
Effective Energy ◽  
Energy Barriers ◽  
Single Molecule Magnets ◽  
Efficient Approach

This work presents an efficient approach to regulating and enhancing the magnetic anisotropy barriers through using bridged CH3O− anion or CH3CH2O− anion and constructing triple bridges.

scholarly journals New Silver(I) Coordination Polymer with Fe4 Single-Molecule Magnets as Long Spacer

2018 ◽  
Vol 4 (4) ◽  
pp. 43 ◽  
Author(s):  
Luca Rigamonti ◽  
Manuela Vaccari ◽  
Fabrizio Roncaglia ◽  
Carlo Baschieri ◽  
Alessandra Forni
Keyword(s):  
Coordination Polymer ◽  
Single Molecule ◽  
Building Blocks ◽  
Zero Field ◽  
Single Molecule Magnets ◽  
Long Distance ◽  
Linear Arrangement ◽  
Thermally Activated ◽  
Supramolecular Architectures ◽  
Donor Nitrogen

In continuation of our work on supramolecular architectures of single-molecule magnets (SMMs) as a promising strategy in developing their magnetic performance, in this paper we report the synthesis and single crystal X-ray structure of the centered triangular tetrairon(III) SMM, [Fe4(PhpPy)2(dpm)6], Fe4 (Hdpm = dipivaloylmethane, H3PhpPy = 2-(hydroxymethyl)-2-(4-(pyridine-4-yl)phenyl)propane-1,3-diol), and its assembly in the coordination polymer {[Fe4(PhpPy)2(dpm)6Ag](ClO4)}n, Fe4Ag, upon reaction with silver(I) perchlorate. Thanks to the presence of the pyridyl rings on the two tripodal ligands, Fe4 behaves as divergent ditopic linker, and due to the Fe4:AgClO4 1:1 ratio, Fe4Ag probably possesses a linear arrangement in which silver(I) ions are linearly coordinated by two nitrogen atoms, forming 1D chains whose positive charge is balanced by the perchlorate anions. The stabilization of such a polymeric structure can be ascribed to the long distance between the two donor nitrogen atoms (23.4 Å) and their donor power. Fe4Ag shows slow relaxation of the magnetization which follows a thermally activated process with Ueff/kB = 11.17(18) K, τ0 = 2.24(17) 10−7 s in zero field, and Ueff/kB = 14.49(5) K, τ0 = 3.88(8) 10−7 s in 1-kOe applied field, in line with what reported for tetrairon(III) SMMs acting as building blocks in polymeric structures.

scholarly journals Vibrational Coherences in Manganese Single-molecule Magnets after Ultrafast Photoexcitation

2018 ◽  
Author(s):  
Florian Liedy ◽  
Robbie McNab ◽  
Julien Eng ◽  
Ross Inglis ◽  
Thomas Penfold ◽  
...  
Keyword(s):  
Data Storage ◽  
Single Molecule ◽  
Optical Data Storage ◽  
Transient Absorption Spectroscopy ◽  
Optical Data ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Single Molecule Magnets ◽  
Teller Distortion ◽  
Jahn Teller

<p>Single-Molecule Magnets (SMMs) are metal complexes with two degenerate magnetic ground states arising from a non-zero spin ground state and a zero-field splitting. SMMs are promising for future applications in data storage, however, to date the ability to manipulate the spins using optical stimulus is lacking. Here, we have explored the ultrafast dynamics occurring after photoexcitation of two structurally related Mn(III)-based SMMs, whose magnetic anisotropy is closely related to the Jahn-Teller distortion, and demonstrate coherent modulation of the axial anisotropy on a femtosecond timescale. Ultrafast transient absorption spectroscopy in solution reveals oscillations superimposed on the decay traces with corresponding energies around 200 cm<sup>−1</sup>, coinciding with a vibrational mode along the Jahn-Teller axis. Our results provide a non-thermal, coherent mechanism to dynamically control the magnetisation in SMMs and open up new molecular design challenges to enhance the change in anisotropy in the excited state, which is essential for future ultrafast magneto-optical data storage devices.</p>

Enhanced energy barriers triggered by magnetic anisotropy modulation via tuning the functional groups on the bridging ligands in Dy2 single-molecule magnets

2018 ◽  
Vol 47 (42) ◽  
pp. 15197-15205 ◽  
Author(s):  
Yaru Qin ◽  
Yu Jing ◽  
Yu Ge ◽  
Wei Liu ◽  
Yahong Li ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Functional Groups ◽  
Single Molecule ◽  
Energy Barrier ◽  
Energy Barriers ◽  
Single Molecule Magnets ◽  
Bridging Ligands

Two dinuclear dysprosium complexes of 1 and 2 have been synthesized and both of them exhibit SMM behavior. The energy barrier is enhanced ca. 35 K by elaborately tuning the backbones of the ligands.

scholarly journals Single-molecule magnet properties of a monometallic dysprosium pentalene complex

2018 ◽  
Vol 54 (51) ◽  
pp. 7085-7088 ◽  
Author(s):  
Alexander F. R. Kilpatrick ◽  
Fu-Sheng Guo ◽  
Benjamin M. Day ◽  
Akseli Mansikkamäki ◽  
Richard A. Layfield ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barriers ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Dysprosium Complex

The pentalene-ligated dysprosium complex [(η8-Pn†)Dy(Cp*)] (1Dy) (Pn† = [1,4-(iPr3Si)2C8H4]2−) and its magnetically dilute analogue are single-molecule magnets, with energy barriers of 245 cm−1.

scholarly journals Ab Initio Prediction of High-Temperature Magnetic Relaxation Rates in Single-Molecule Magnets

2021 ◽  
Author(s):  
Daniel Reta ◽  
Jon G. C. Kragskow ◽  
Nicholas Chilton
Keyword(s):  
High Temperature ◽  
Ab Initio ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Quantitative Prediction ◽  
Relaxation Dynamics ◽  
Efficient Design ◽  
Relaxation Rates ◽  
Design Strategies ◽  
Single Molecule Magnets

<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>

Sign in / Sign up

Export Citation Format

Share Document