Enhancing the energy barrier of dysprosium(iii) single-molecule magnets by tuning the magnetic interactions through different N-oxide bridging ligands

CrystEngComm ◽  
2019 ◽  
Vol 21 (41) ◽  
pp. 6219-6225 ◽  
Author(s):  
Juan Wang ◽  
Mingfang Yang ◽  
Juan Sun ◽  
Hui Li ◽  
Jinjin Liu ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Interactions ◽  
Single Molecule Magnets ◽  
Bridging Ligands

The synergistic effect of strengthened Dy-Dy magnetic interactions and slightly enhanced symmetry of DyIII ions results in a great Ueff enhancement from 11.79 K to 226.73 K.

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.

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.

Structural anisotropy of cyanido-bridged {CoII9WV6} single-molecule magnets induced by bidentate ligands: towards the rational enhancement of an energy barrier

2016 ◽  
Vol 52 (26) ◽  
pp. 4772-4775 ◽  
Author(s):  
Szymon Chorazy ◽  
Michał Rams ◽  
Anna Hoczek ◽  
Bernard Czarnecki ◽  
Barbara Sieklucka ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Relaxation ◽  
Bidentate Ligands ◽  
Single Molecule Magnets ◽  
Structural Anisotropy ◽  
Slow Magnetic Relaxation

{CoII9[WV(CN)8]6} clusters capped by odd and even number of bidentate ligands reveal the improved slow magnetic relaxation due to the significant structural anisotropy.

Polyoxometalate-Supported Lanthanoid Single-Molecule Magnets

2014 ◽  
Vol 67 (11) ◽  
pp. 1542 ◽  
Author(s):  
Michele Vonci ◽  
Colette Boskovic
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Relaxation ◽  
Donor Ligands ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Coordination Numbers ◽  
Oxygen Donor ◽  
Slow Magnetic Relaxation

Polyoxometalates are robust and versatile multidentate oxygen-donor ligands, eminently suitable for coordination to trivalent lanthanoid ions. To date, 10 very different structural families of such complexes have been found to exhibit slow magnetic relaxation due to single-molecule magnet (SMM) behaviour associated with the lanthanoid ions. These families encompass complexes with between one and four of the later lanthanoid ions: Tb, Dy, Ho, Er, and Yb. The lanthanoid coordination numbers vary between six and eleven and a range of coordination geometries are evident. The highest energy barrier to magnetisation reversal measured to date for a lanthanoid–polyoxometalate SMM is Ueff/kB = 73 K for the heterodinuclear Dy–Eu compound (Bu4N)8H4[DyEu(OH)2(γ-SiW10O36)2].

scholarly journals Energy-Barrier Enhancement by Ligand Substitution in Tetrairon(III) Single-Molecule Magnets

2004 ◽  
Vol 116 (9) ◽  
pp. 1156-1159 ◽  
Author(s):  
Andrea Cornia ◽  
Antonio C. Fabretti ◽  
Pierfrancesco Garrisi ◽  
Cecilia Mortalò ◽  
Daniele Bonacchi ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Ligand Substitution ◽  
Single Molecule Magnets

Magnetic Exchange Effects in {CrIII2DyIII2} Single Molecule Magnets Containing Alcoholamine Ligands

2014 ◽  
Vol 67 (11) ◽  
pp. 1581 ◽  
Author(s):  
Stuart K. Langley ◽  
Daniel P. Wielechowski ◽  
Boujemaa Moubaraki ◽  
Brendan F. Abrahams ◽  
Keith S. Murray
Keyword(s):  
Single Molecule ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Studies ◽  
Single Molecule Magnets ◽  
Magnetic Exchange ◽  
Bridging Ligands ◽  
Metallic Core ◽  
Ligand Coordination ◽  
Magnetic Hysteresis Loops

The synthesis and magnetic characterisation of four new heterometallic {CrIII2DyIII2} complexes 2–5 are described. The present work follows on from a recently isolated complex [CrIII2DyIII2(OMe)2(O2CPh)4(mdea)2(NO3)2] (1) (mdeaH2 = N-methyldiethanolamine), which displayed impressive single molecule magnet (SMM) properties, notably highly coercive magnetic hysteresis loops below 3.5 K. Compounds 1–5 all display a planar butterfly type metallic core arrangement, with the DyIII ions occupying the central body positions and the CrIII ion the outer wing positions. The core is stabilized by the amine–diolate, and carboxylate bridging ligands. Variation of the amine–diolate ligand resulted in several structural analogues which maintain the same metallic core, but differ from the parent 1 in the outer ligand coordination environment. Magnetic studies reveal complexes 2–5 also display SMM behaviour, unambiguously confirmed via low temperature magnetic hysteresis loops, each displaying wide coercive fields, a rare occurrence for lanthanoid-based SMMs.

D4h Local Symmetric dysprosium(III) Single-Molecule Magnet with Energy Barrier Exceeding 2000 K

2020 ◽  
Author(s):  
Xia-Li Ding ◽  
Yuan-Qi Zhai ◽  
Tian Han ◽  
Wei-Peng Chen ◽  
You-Song Ding ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Local Symmetry ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
The Third ◽  
Type Symmetry

<p><a></a><a></a><a><b>Three six-coordinate Dy(III) single-molecule magnets (SMMs) [Dy(O<sup>t</sup>Bu)<sub>2</sub>(L)<sub>4</sub>]<sup>+</sup> with <i>D</i><sub>4h</sub> local symmetry are obtained by optimising the equatorial ligands. Compound 1 where L = 4-phenylpyridine shows an energy barrier (<i>U</i><sub>eff</sub>) of 2075(11) K, which is the third largest <i>U</i><sub>eff</sub>, and the first <i>U</i><sub>eff</sub> > 2000 K for SMMs with axial-type symmetry so far.</b></a></p>

scholarly journals Pressure tunablity in ReX4based SMMs; A magnetostructural study

2014 ◽  
Vol 70 (a1) ◽  
pp. C903-C903
Author(s):  
Christopher Woodall ◽  
Francisco Jose Martinez Lillo ◽  
Martin Míšek ◽  
Alessandro Prescimone ◽  
Dave Allan ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Susceptibility ◽  
Hydrostatic Pressure ◽  
Single Molecule ◽  
High Hydrostatic Pressure ◽  
Magnetic Behaviour ◽  
Magnetic Interactions ◽  
Antiferromagnetic Coupling ◽  
X Ray Diffraction ◽  
Single Molecule Magnets

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.

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