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

10.26434/chemrxiv.12696578 ◽

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

<a></a><a></a><a>Three six-coordinate Dy(III) single-molecule magnets (SMMs) [Dy(OtBu)2(L)4]+ with D4h local symmetry are obtained by optimising the equatorial ligands. Compound 1 where L = 4-phenylpyridine shows an energy barrier (Ueff) of 2075(11) K, which is the third largest Ueff, and the first Ueff > 2000 K for SMMs with axial-type symmetry so far.</a>

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Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

10.26434/chemrxiv.7067669 ◽

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 (SMM) with an energy barrier of 1110 K for thermal relaxation of magnetization. The sample shows no retention of magnetization even at 2 K and this led us to find a good correlation between the blocking temperature and the Raman relaxation regime for SMMs. The key parameter is the relaxation time (𝜏switch) at the point where the Raman relaxation mechanism becomes more important than Orbach.

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Polyoxometalate-Supported Lanthanoid Single-Molecule Magnets

Australian Journal of Chemistry ◽

10.1071/ch14166 ◽

2014 ◽

Vol 67 (11) ◽

pp. 1542 ◽

Cited By ~ 24

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].

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A remarkable energy barrier for spin reversal in a field induced dinuclear ytterbium single molecule magnet

Dalton Transactions ◽

10.1039/d1dt02130c ◽

2021 ◽

Vol 50 (39) ◽

pp. 13666-13670

Author(s):

Arpan Mondal ◽

Sanjit Konar

Keyword(s):

Single Molecule ◽

Energy Barrier ◽

Slow Relaxation ◽

Single Molecule Magnets ◽

Single Molecule Magnet ◽

Crystal Fields ◽

Spin Reversal

Strong equatorial and weak axial crystal fields enhance the energy barrier for slow relaxation of magnetization in Yb-based single molecule magnets.

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Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

10.26434/chemrxiv.7067669.v1 ◽

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 (SMM) with an energy barrier of 1110 K for thermal relaxation of magnetization. The sample shows no retention of magnetization even at 2 K and this led us to find a good correlation between the blocking temperature and the Raman relaxation regime for SMMs. The key parameter is the relaxation time (𝜏switch) at the point where the Raman relaxation mechanism becomes more important than Orbach.

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Switching the Local Symmetry from D5h to D4h for Single-Molecule Magnets by Non-Coordinating Solvents

Inorganics ◽

10.3390/inorganics9080064 ◽

2021 ◽

Vol 9 (8) ◽

pp. 64

Author(s):

Xia-Li Ding ◽

Qian-Cheng Luo ◽

Yuan-Qi Zhai ◽

Qian Zhang ◽

Lei Tian ◽

...

Keyword(s):

Single Molecule ◽

Energy Barrier ◽

Local Symmetry ◽

Structure Change ◽

Blocking Temperature ◽

Magnetic Studies ◽

Single Molecule Magnets ◽

Magnetic Anisotropy Energy ◽

Local Coordination ◽

Symmetry Effect

A solvent effect towards the performance of two single-molecule magnets (SMMs) was observed. The tetrahydrofuran and toluene solvents can switch the equatorial coordinated 4-Phenylpyridine (4-PhPy) molecules from five to four, respectively, in [Dy(OtBu)2(4-PhPy)5]BPh41 and Na{[Dy(OtBu)2(4-PhPy)4][BPh4]2}∙2thf∙hex 2. This alternation significantly changes the local coordination symmetry of the Dy(III) center from D5h to D4h for 1 and 2, seperately. Magnetic studies show that the magnetic anisotropy energy barrier of 2 is higher than that of 1, while the relation of blocking temperature is just on the contrary due to the symmetry effect. The calculations of the electrostatic potential successfully explained the driving force of solvents for the molecular structure change, confirming the feasibility of adjusting the performance of SMMs via diverse solvents.

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

10.26434/chemrxiv.10260494 ◽

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 [Dy2L2(µ-Cl)2(THF)2] has been made using a diamine-bis(phenolate) ligand, H2L. Magnetic studies show an energy barrier for magnetization reversal (Ueff) around 1000 K. Exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 4 K. Ab initio calculations exclude the possibility of pure dipolar origin of this effect leading to the conclusion that super-exchange via the chloride bridging ligands is important.

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Slow magnetic relaxation in dinuclear dysprosium and holmium phenoxide bridged complexes: a Dy2 single molecule magnet with a high energy barrier

Inorganic Chemistry Frontiers ◽

10.1039/d1qi00152c ◽

2021 ◽

Author(s):

Matilde Fondo ◽

Julio Corredoira-Vázquez ◽

Ana M. Garcia-Deibe ◽

Jesus Sanmartin Matalobos ◽

Silvia Gómez-Coca ◽

...

Keyword(s):

Crystal Structures ◽

Single Molecule ◽

Energy Barrier ◽

Magnetic Relaxation ◽

High Energy ◽

Single Molecule Magnet ◽

High Energy Barrier ◽

Slow Magnetic Relaxation

Dinuclear [M(H3L1,2,4)]2 (M = Dy, Dy2; M = Ho, Ho2) complexes were isolated from an heptadentate aminophenol ligand. The crystal structures of Dy2·2THF, and the pyridine adducts Dy2·2Py and Ho2·2Py,...

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