scholarly journals Rare “Janus”-faced single-molecule magnet exhibiting intramolecular ferromagnetic interactions

2019 ◽  
Vol 10 (6) ◽  
pp. 1626-1633 ◽  
Author(s):  
Dimitris I. Alexandropoulos ◽  
Kuduva R. Vignesh ◽  
Theocharis C. Stamatatos ◽  
Kim R. Dunbar
Keyword(s):  
Metal Ions ◽  
Single Molecule ◽  
Metal Cluster ◽  
Single Molecule Magnet ◽  
Ferromagnetic Interactions

The unusual ferromagnetically coupled compound was prepared by the use of Me3SiN3 with the metal ions being exclusively bridged by end-on N3−. Th cationic molecule is a rare example of a 3d-metal cluster exhibiting a “Janus”-faced SMM behavior for the dried and wet forms.

Regulation of magnetic relaxation behavior by replacing 3d transition metal ions in [M2Dy2] complexes containing two different organic chelating ligands

2019 ◽  
Vol 48 (27) ◽  
pp. 10011-10022 ◽  
Author(s):  
Hui-Sheng Wang ◽  
Cheng-Ling Yin ◽  
Zhao-Bo Hu ◽  
Yong Chen ◽  
Zhi-Quan Pan ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Transition Metal Ions ◽  
Relaxation Behavior ◽  
Organic Ligands ◽  
Chelating Ligands ◽  
Single Molecule Magnet

Two [MIII2DyIII2] complexes (M = Fe for 1 and Co for 2) with mixed organic ligands were obtained. Complex 2 exhibits single molecule magnet behavior with Ueff = 64.0(9) K.

scholarly journals A New {Dy5} Single-Molecule Magnet Bearing the Schiff Base Ligand N-Naphthalidene-2-amino-5-chlorophenol

2018 ◽  
Vol 4 (4) ◽  
pp. 48
Author(s):  
Dimitris Alexandropoulos ◽  
Alysha Alaimo ◽  
Di Sun ◽  
Theocharis Stamatatos
Keyword(s):  
Magnetic Susceptibility ◽  
Schiff Base ◽  
Single Molecule ◽  
Schiff Base Ligand ◽  
Metal Cluster ◽  
Relaxation Times ◽  
Exchange Interactions ◽  
Common Vertex ◽  
Cluster Compound ◽  
Single Molecule Magnet

A new {Dy5} cluster compound has been synthesized and structurally characterized from the initial use of the Schiff base ligand N-naphthalidene-2-amino-5-chlorophenol (nacpH2) in coordination chemistry. The 1:1 reaction between Dy(hpd)3∙2H2O and nacpH2, in a solvent mixture comprising CH2Cl2 and MeOH, afforded orange crystals of [Dy5(OH)2(hpd)3(nacp)5(MeOH)5] (1) in 70% yield, where hpd− is the anion of 3,5-heptadione. The {Dy5} complex can be described as two vertical {Dy3(μ3-OH)}8+ triangles sharing a common vertex; such a metal topology is unprecedented in 4f-metal cluster chemistry. Direct current (dc) magnetic susceptibility studies revealed the presence of some weak ferromagnetic exchange interactions between the five DyIII ions at low temperatures. Alternating current (ac) magnetic susceptibility measurements at zero applied dc field showed that complex 1∙3MeOH∙CH2Cl2 exhibits temperature- and frequency-dependent out-of-phase signals below ~20 K, characteristics of a single-molecule magnet (SMM). The resulting relaxation times were used to construct an Arrhenius-type plot and determine an effective energy barrier, Ueff, of 100 K for the magnetization reversal. The application of a small dc field of 200 Oe resulted in the surpassing of the quantum tunneling process and subsequently the increase of the Ueff to a value of 170 K. The reported results are part of a long-term program aiming at the preparation of structurally and magnetically interesting lanthanide complexes bearing various Schiff base chelating/bridging ligands.

Suppression of Magnetic Quantum Tunneling in a Chiral Single-Molecule Magnet by Ferromagnetic Interactions

2017 ◽  
Vol 56 (24) ◽  
pp. 15119-15129 ◽  
Author(s):  
Kai-Alexander Lippert ◽  
Chandan Mukherjee ◽  
Jan-Philipp Broschinski ◽  
Yvonne Lippert ◽  
Stephan Walleck ◽  
...  
Keyword(s):  
Single Molecule ◽  
Quantum Tunneling ◽  
Single Molecule Magnet ◽  
Ferromagnetic Interactions

Exchange-Biasing in a Dinuclear Dysprosium(III) Single-Molecule Magnet with a Large Energy Barrier for Magnetization Reversal

2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetization Reversal ◽  
Energy Barrier ◽  
Magnetic Hysteresis ◽  
Large Energy ◽  
Magnetic Studies ◽  
Bridging Ligands ◽  
Single Molecule Magnet ◽  
Exchange Biasing

A dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy<sub>2</sub>L<sub>2</sub>(<i>µ</i>-Cl)<sub>2</sub>(THF)<sub>2</sub>] has been made using a diamine-bis(phenolate) ligand, H<sub>2</sub>L. Magnetic studies show an energy barrier for magnetization reversal (<i>U</i><sub>eff</sub>) around 1000 K. Exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 4 K. <i>Ab</i> initio calculations exclude the possibility of pure dipolar origin of this effect leading to the conclusion that super-exchange <i>via</i> the chloride bridging ligands is important.

Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Single Molecule ◽  
Energy Barrier ◽  
Thermal Relaxation ◽  
Relaxation Mechanism ◽  
Blocking Temperature ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Key Parameter

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.

scholarly journals Solid‐State Near‐Infrared Circularly Polarized Luminescence from Chiral YbIII‐Single‐Molecule Magnet

2021 ◽  
Author(s):  
Fabrice Pointillart ◽  
Bertrand Lefeuvre ◽  
Carlo Andrea Mattei ◽  
Jessica Flores Gonzalez ◽  
Frédéric Gendron ◽  
...  
Keyword(s):  
Solid State ◽  
Single Molecule ◽  
Near Infrared ◽  
Circularly Polarized ◽  
Single Molecule Magnet ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence
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