Ferromagnetic [Mn3] Single-Molecule Magnets and Their Supramolecular Networks

2009 ◽  
Vol 62 (9) ◽  
pp. 1108 ◽  
Author(s):  
Ross Inglis ◽  
Giannis S. Papaefstathiou ◽  
Wolfgang Wernsdorfer ◽  
Euan K. Brechin
Keyword(s):  
Single Molecule ◽  
Quantum Physics ◽  
Three Dimensional ◽  
Exchange Interactions ◽  
Molecular Magnets ◽  
Single Molecule Magnets ◽  
Spin Networks ◽  
Quantum Tunnelling ◽  
Field Bias ◽  
Supramolecular Networks

The complexes [MnIII3O(Et-sao)3(O2CPh(Cl)2)(MeOH)3(H2O)] (1), [MnIII3O(Et-sao)3(ClO4)(MeOH)3] (2), [MnIII3O(Et-sao)3(O2Ph(CF3)2)(EtOH)(H2O)3] (3), and [MnIII3O(Ph-sao)3(O2C-anthra)(MeOH)4]·Ph-saoH2 (4·Ph-saoH2) display dominant ferromagnetic exchange interactions leading to molecules with S = 6 ground states. The molecules are single molecule magnets (SMM) displaying large effective energy barriers for magnetization reversal. In each case their crystal structures reveal multiple intermolecular H-bonding interactions. Single crystal hysteresis loop measurements demonstrate that these interactions are strong enough to cause a clear field bias, but too weak to transform the spin networks into classical antiferromagnets. These three-dimensional networks of exchange coupled SMMs demonstrate that quantum tunnelling magnetization can be controlled using exchange interactions, suggesting supramolecular chemistry can be exploited to modulate the quantum physics of molecular magnets.

Strictly linear trinuclear Dy–Ca/Mg–Dy single-molecule magnets: the impact of long-range f–f ferromagnetic interactions on suppressing quantum tunnelling of magnetization leading to slow magnetic relaxation

2017 ◽  
Vol 46 (25) ◽  
pp. 8259-8268 ◽  
Author(s):  
Wan-Ying Zhang ◽  
Yong-Mei Tian ◽  
Hong-Feng Li ◽  
Peng Chen ◽  
Yi-Quan Zhang ◽  
...  
Keyword(s):  
Long Range ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Single Molecule Magnets ◽  
Quantum Tunnelling ◽  
Trinuclear Complexes ◽  
Slow Magnetic Relaxation ◽  
Ferromagnetic Interactions ◽  
The Impact

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

scholarly journals Cover Feature: Photoluminescent Lanthanide(III) Single‐Molecule Magnets in Three‐Dimensional Polycyanidocuprate(I)‐Based Frameworks (Chem. Eur. J. 51/2019)

2019 ◽  
Vol 25 (51) ◽  
pp. 11795-11795
Author(s):  
Jakub J. Zakrzewski ◽  
Szymon Chorazy ◽  
Koji Nakabayashi ◽  
Shin‐ichi Ohkoshi ◽  
Barbara Sieklucka
Keyword(s):  
Single Molecule ◽  
Three Dimensional ◽  
Single Molecule Magnets ◽  
J 51

The Application Research of Single-Molecule Magnets and Molecular Spin Electronics Materials

2012 ◽  
Vol 485 ◽  
pp. 522-525
Author(s):  
Hai Mei Xiao ◽  
Li Chun Shi
Keyword(s):  
Single Molecule ◽  
Degrees Of Freedom ◽  
Organic Ligand ◽  
Chemical Properties ◽  
Molecular Magnets ◽  
Single Molecule Magnets ◽  
Spin Electronics ◽  
Molecular Spin ◽  
Basic And Applied Research ◽  
Physical And Chemical

In the basic and applied research, the electronics and spin degrees of freedom is a very promising field of research and development over the past decade, spintronics from fundamental physics to technical devices already have a great deal of progress. This study made an overview of the synthesis, structure and properties of single molecular magnets and their applications in molecular spin combined with the latest research on this study sphere. Single molecular magnets are made of inner magnetic nuclei and peripheral organic molecule lamella, which can improve physical and chemical properties by means of adorn radical of organic ligand and exchange internal magnetic ions. And this paper also analyzes the molecular spin of the electron spin and charge electronic devices at the molecular level.

scholarly journals Studies of hysteresis and quantum tunnelling of the magnetisation in dysprosium(iii) single molecule magnets

2019 ◽  
Vol 48 (24) ◽  
pp. 8541-8545 ◽  
Author(s):  
Fabrizio Ortu ◽  
Daniel Reta ◽  
You-Song Ding ◽  
Conrad A. P. Goodwin ◽  
Matthew P. Gregson ◽  
...  
Keyword(s):  
Single Molecule ◽  
Quantum Tunneling ◽  
Single Molecule Magnets ◽  
Quantum Tunnelling

We report a study of quantum tunneling of the magnetisation in three Dy(iii) single-molecule magnets.

Mixed valency in polynuclear Mn II /Mn III , Mn III /Mn IV and Mn II /Mn III /Mn IV clusters: a foundation for high-spin molecules and single-molecule magnets

2007 ◽  
Vol 366 (1862) ◽  
pp. 113-125 ◽  
Author(s):  
Theocharis C Stamatatos ◽  
George Christou
Keyword(s):  
Single Molecule ◽  
Exchange Interactions ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Single Molecule Magnets ◽  
Zero Field Splitting Parameter ◽  
Jahn Teller ◽  
Splitting Parameter ◽  
Molecular Spin ◽  
Molecular Compounds

Mixed-valent Mn/O dinuclear and polynuclear molecular compounds containing Mn III are almost without exception trapped valence. Large differences between the strengths of the exchange interactions within Mn II Mn III , Mn III Mn III and Mn III Mn IV pairs lead to situations where Mn III Mn IV interactions, the strongest of the three mentioned and antiferromagnetic in nature, dominate the intramolecular spin alignments in trinuclear and higher nuclearity mixed-valent complexes and often result in molecules that have large, and sometimes abnormally large, values of molecular spin ( S ). When coupled to a large molecular magnetoanisotropy of the easy-axis-type (negative zero-field splitting parameter, D ), also primarily resulting from individual Jahn–Teller distorted Mn III centres, such molecules will function as single-molecule magnets (molecular nanomagnets). Dissection of the structures and exchange interactions within a variety of mixed-valent Mn x cluster molecules with metal nuclearities of Mn 4 , Mn 12 and Mn 25 allows a ready rationalization of the observed S , D and overall magnetic properties in terms of competing antiferromagnetic exchange interactions within triangular subunits, resulting spin alignments and relative orientation of Mn III JT axes. Such an understanding has provided a stepping stone to the identification of a ‘magnetically soft’ Mn 25 cluster whose groundstate spin S value can be significantly altered by relatively minor structural perturbations. Such ‘spin tweaking’ has allowed this cluster to be obtained in three different forms with three different groundstate S values.

Recent Advances in Molecular Magnetic Materials

2009 ◽  
Vol 62 (9) ◽  
pp. 1081 ◽  
Author(s):  
Keith S. Murray
Keyword(s):  
Magnetic Materials ◽  
Single Molecule ◽  
Three Dimensional ◽  
Single Molecule Magnets ◽  
Coupled Clusters ◽  
Framework Materials ◽  
Range Magnetic Order ◽  
Molecular Magnetic Materials ◽  
Long Range Magnetic Order ◽  
Molecular Computers

This review describes advances made in three areas of molecular magnetic materials of the types A: extended frameworks (coordination polymers) showing long-range magnetic order, B: spin-coupled clusters with emphasis on single molecule magnets and (n × n) grid species, C: polynuclear spin-switching (spin crossover) compounds of FeII with emphasis on dinuclear compounds and one-dimensional (1D) and three-dimensional (3D) (framework) materials, including porous ‘hybrid’ systems. The work of the author and his group is largely used to provide examples, together with results from other groups and collaborators that are included for comparison and completeness. Supramolecular aspects such as cluster–cluster and chain–chain interactions are discussed where relevant. A brief discussion is also given of the recent studies, carried out elsewhere, dealing with aspects of spintronics and the possible future relevance to molecular computers (type B materials) and with memory and other device possibilities (type C materials)

Dalton technical issue “Lanthanide and transition metal complexes as molecular magnets Single-molecule magnets within polyoxometalate-based frameworks

2021 ◽  
Author(s):  
Malihe Babaei Zarch ◽  
Masoud Mirzaei ◽  
Maryam Bazargan ◽  
Sandeep K Gupta ◽  
Franc Meyer ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Molecular Magnets ◽  
Technical Issue ◽  
Hydrothermal Conditions ◽  
Single Molecule Magnets ◽  
Design And Synthesis

As an extension of our interest in polyoxometalates (POMs) and lanthanoids, we report the design and synthesis of two polyoxometalate-based frameworks under hydrothermal conditions; [Ho4(PDA)4(H2O)11][(SiO4)@W12O36]·8H2O (1) and [Tb4(PDA)4(H2O)12][(SiO4)@W12O36]·4H2O (2) (H2PDA...

Zero-Field Quantum Tunneling of the Magnetization in a Series of High Energy-Barrier Dysprosium (III) Single-Molecule Magnets

2018 ◽  
Author(s):  
Fabrizio Ortu ◽  
Daniel Reta ◽  
You-Song Ding ◽  
Conrad A. P. Goodwin ◽  
Matthew P. Gregson ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetic Hysteresis ◽  
High Energy ◽  
Exact Nature ◽  
Zero Field ◽  
Vibrational Modes ◽  
Single Molecule Magnets ◽  
Quantum Tunnelling ◽  
Intermediate Energies ◽  
High Energy Barrier

<p>Energy barriers to magnetisation reversal (U<sub>eff</sub>) in single-molecule magnets (SMMs) have vastly increased recently, but only for the dysprosocenium SMM [Dy(Cp<sup>ttt</sup>)<sub>2</sub>][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] (Cp<sup>ttt</sup> = C<sub>5</sub>H<sub>2</sub><sup>t</sup>Bu<sub>3</sub>-1,2,4) has this translated into a considerable increase in magnetic hysteresis temperatures. The lack of concomitant increases in hysteresis temperatures with U<sub>eff</sub> values is due to efficient magnetic relaxation at zero-field, referred to as quantum tunnelling of the magnetisation (QTM); however, the exact nature of this phenomenon is unknown. Recent hypotheses suggest that both transverse dipolar magnetic fields and hyperfine coupling play a significant role in this process for Dy(III) SMMs. Here, by studying the compounds [Dy(<sup>t</sup>BuO)Cl(THF)<sub>5</sub>][BPh<sub>4</sub>] (<b>1</b>), [K(18-crown-6-ether)(THF)<sub>2</sub>][Dy(BIPM)<sub>2</sub>] (<b>2</b>, BIPM = C{PPh<sub>2</sub>NSiMe<sub>3</sub>}<sub>2</sub>), and [Dy(Cp<sup>ttt</sup>)<sub>2</sub>][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] (<b>3</b>), we show conclusively that neither of these processes are the main contributor to zero-field QTM for Dy(III) SMMs, and suggest that its origin instead owes to molecular flexibility. By analysing the vibrational modes of the three molecules, we show that the modes that most impact the magnetic ion occur at the lowest energies for <b>1</b>, at intermediate energies for <b>2</b> and at higher energies for <b>3</b>, in correlation with their ability to retain magnetisation. Therefore, we conclude that SMM performance could be improved by employing more rigid ligands with higher-energy metal-ligand vibrational modes.</p>

Quantum tunnelling of the magnetization in a monolayer of oriented single-molecule magnets

Nature ◽  
2010 ◽  
Vol 468 (7322) ◽  
pp. 417-421 ◽  
Author(s):  
M. Mannini ◽  
F. Pineider ◽  
C. Danieli ◽  
F. Totti ◽  
L. Sorace ◽  
...  
Keyword(s):  
Single Molecule ◽  
Single Molecule Magnets ◽  
Quantum Tunnelling

scholarly journals Asymmetric Dinuclear Lanthanide(III) Complexes from the Use of a Ligand Derived from 2-Acetylpyridine and Picolinoylhydrazide: Synthetic, Structural and Magnetic Studies

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3153
Author(s):  
Diamantoula Maniaki ◽  
Panagiota S. Perlepe ◽  
Evangelos Pilichos ◽  
Sotirios Christodoulou ◽  
Mathieu Rouzières ◽  
...  
Keyword(s):  
Single Molecule ◽  
Metal Ion ◽  
Ac Susceptibility ◽  
Solvent Molecule ◽  
Exchange Interactions ◽  
Experimental Fact ◽  
Anisotropy Axis ◽  
Magnetic Studies ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation

A family of four Ln(III) complexes has been synthesized with the general formula [Ln2(NO3)4(L)2(S)] (Ln = Gd, Tb, Er, and S = H2O; 1, 2 and 4, respectively/Ln = Dy, S = MeOH, complex 3), where HL is the flexible ditopic ligand N’-(1-(pyridin-2-yl)ethylidene)pyridine-2-carbohydrazide. The structures of isostructural MeOH/H2O solvates of these complexes were determined by single-crystal X-ray diffraction. The two LnIII ions are doubly bridged by the deprotonated oxygen atoms of two “head-to-head” 2.21011 (Harris notation) L¯ ligands, forming a central, nearly rhombic {LnIII2(μ-OR)2}4+ core. Two bidentate chelating nitrato groups complete a sphenocoronal 10-coordination at one metal ion, while two bidentate chelating nitrato groups and one solvent molecule (H2O or MeOH) complete a spherical capped square antiprismatic 9-coordination at the other. The structures are critically compared with those of other, previously reported metal complexes of HL or L¯. The IR spectra of 1–4 are discussed in terms of the coordination modes of the organic and inorganic ligands involved. The f-f transitions in the solid-state (diffuse reflectance) spectra of the Tb(III), Dy(III), and Er(III) complexes have been fully assigned in the UV/Vis and near-IR regions. Magnetic susceptibility studies in the 1.85–300 K range reveal the presence of weak, intramolecular GdIII∙∙∙GdIII antiferromagnetic exchange interactions in 1 [J/kB = −0.020(6) K based on the spin Hamiltonian Ĥ = −2J(ŜGd1∙ ŜGd2)] and probably weak antiferromagnetic LnIII∙∙∙LnIII exchange interactions in 2–4. Ac susceptibility measurements in zero dc field do not show frequency dependent out-of-phase signals, and this experimental fact is discussed for 3 in terms of the magnetic anisotropy axis for each DyIII center and the oblate electron density of this metal ion. Complexes 3 and 4 are Single-Molecule Magnets (SMMs) and this behavior is optimally observed under external dc fields of 600 and 1000 Oe, respectively. The magnetization relaxation pathways are discussed and a satisfactory fit of the temperature and field dependencies of the relaxation time τ was achieved considering a model that employs Raman, direct, and Orbach relaxation mechanisms.

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