[2 + 2] Photochemical modulation of the Dy(iii) single-molecule magnet: opposite influence on the energy barrier and relaxation time

2017 ◽  
Vol 4 (8) ◽  
pp. 1311-1318 ◽  
Author(s):  
Long-Fei Wang ◽  
Jiang-Zhen Qiu ◽  
Yan-Cong Chen ◽  
Jun-Liang Liu ◽  
Quan-Wen Li ◽  
...  

The photochemical [2 + 2] reaction on a mononuclear Dy(iii) single-molecule magnet leads to the higher energy barrier after UV irradiation, along with the shorter magnetic relaxation time that is due to the acceleration of Raman process at low temperatures.

2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  

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.


Author(s):  
Matilde Fondo ◽  
Julio Corredoira-Vázquez ◽  
Ana M. Garcia-Deibe ◽  
Jesus Sanmartin Matalobos ◽  
Silvia Gómez-Coca ◽  
...  

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,...


2014 ◽  
Vol 67 (11) ◽  
pp. 1542 ◽  
Author(s):  
Michele Vonci ◽  
Colette Boskovic

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].


2020 ◽  
Vol 56 (27) ◽  
pp. 3887-3890 ◽  
Author(s):  
Jianfeng Wu ◽  
Serhiy Demeshko ◽  
Sebastian Dechert ◽  
Franc Meyer

A hexanuclear cluster containing six {Cp*Dy} units shows a high energy barrier (Ueff = 561 K) for magnetic relaxation and butterfly-shaped hysteresis loops up to 4.5 K.


2017 ◽  
Vol 53 (61) ◽  
pp. 8561-8564 ◽  
Author(s):  
Yoji Horii ◽  
Keiichi Katoh ◽  
Brian K. Breedlove ◽  
Masahiro Yamashita

Clamshell-type terbium(iii)-phthalocyaninato quadruple-decker complex was synthesized. Magnetic measurements revealed that Tb–Tb interactions caused an increase in the magnetic relaxation time.


2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  

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.


2021 ◽  
Vol 7 (2) ◽  
pp. 24
Author(s):  
Konstantin Martyanov ◽  
Jessica Flores Gonzalez ◽  
Sergey Norkov ◽  
Bertrand Lefeuvre ◽  
Vincent Dorcet ◽  
...  

The coordination reaction of the [Dy(hfac)3(H2O)2] units (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate) with the two quinone-based derivatives 4,7-di-tert-butyl-2-(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)benzo[d][1,3]dithiole-5,6-dione (L1) and 7,8-dithiabicyclo[4.2.0]octa-1,5-diene-3,4-dione,2,5bis(1,1-dimethylethyl) (L2) led respectively to the complexes [Dy(hfac)3(H2O)(L1)] (1) and [Dy(hfac)3(H2O) (L2)]⋅(C6H14)(CH2Cl2) (2)⋅(C6H14)(CH2Cl2). X-ray structures on single crystal of 1 and 2⋅(C6H14)(CH2Cl2) revealed the coordination of the DyIII on the bischelating oxygenated quinone site and the formation of dimeric species through hydrogen bonds. Ac magnetic measurements highlighted field-induced single-molecule magnet behavior with magnetic relaxation through a Raman process.


2016 ◽  
Vol 45 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Hong-Ling Gao ◽  
Li Jiang ◽  
Shuang Liu ◽  
Hai-Yun Shen ◽  
Wen-Min Wang ◽  
...  

A multi-relaxation single-molecule magnet (SMM) of a {Dy4} complex exhibits two distinct relaxation processes, with a high energy barrier of 121 K.


2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  

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.


Inorganics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 51
Author(s):  
Lin Miao ◽  
Mei-Jiao Liu ◽  
Man-Man Ding ◽  
Yi-Quan Zhang ◽  
Hui-Zhong Kou

The complexes of lanthanide metals, especially dysprosium, can generally exhibit excellent magnetic properties. By means of modifying ligands, dual functions or even multi-functions can be achieved. Here, we synthesized an eight-coordinate Dy(III) complex 1, [Dy(HL-o)2(MeOH)2](ClO4)3·4.5MeOH, which is single-molecule magnet (SMM), and the introduction of the rhodamine 6G chromophore in the ring-opened ligand HL-o realizes ligand-centered fluorescence in addition to SMM. Magnetic measurements and ab initio calculations indicate that the magnetic relaxation for complex 1 should be due to the Raman relaxation process. Studies on magneto-structural correlationship of the rhodamine salicylaldehyde hydrazone Dy(III) complexes show that the calculated energy of the first Kramers Doublet (EKD1) is basically related to the Ophenoxy-Dy-Ophenoxy bond angle, i.e., the larger Ophenoxy-Dy-Ophenoxy bond angle corresponds to a larger EKD1.


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