scholarly journals Lanthanide-Based Single-Molecule Magnets Derived from Schiff Base Ligands of Salicylaldehyde Derivatives

Inorganics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 66
Author(s):  
Mamo Gebrezgiabher ◽  
Yosef Bayeh ◽  
Tesfay Gebretsadik ◽  
Gebrehiwot Gebreslassie ◽  
Fikre Elemo ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Magnetic Behavior ◽  
Point Of View ◽  
Schiff Base Complexes ◽  
Magnetic Interactions ◽  
Single Molecule Magnets ◽  
Schiff Base Ligands ◽  
Synthetic Strategy ◽  
Slow Magnetic Relaxation

The breakthrough in Ln(III)-based SMMs with Schiff base ligands have been occurred for the last decade on account of their magnetic behavior, anisotropy and relaxation pathways. Herein, we review the synthetic strategy, from a structural point of view and magnetic properties of mono, di, tri and polynuclear Ln(III)-based single-molecule magnets mainly with Schiff bases of Salicylaldehyde origin. Special attention has been given to some important breakthroughs that are changing the perspective of this field with a special emphasis on slow magnetic relaxation. An overview of 50 Ln(III)-Schiff base complexes with SMM behavior, covering the period 2008–2020, which have been critical in understanding the magnetic interactions between the Ln(III)-centers, are presented and discussed in detail.

Cu(ii)–Dy(iii) and Co(iii)–Dy(iii) based single molecule magnets with multiple slow magnetic relaxation processes in the Cu(ii)–Dy(iii) complex

2015 ◽  
Vol 44 (29) ◽  
pp. 13242-13249 ◽  
Author(s):  
Malay Dolai ◽  
Mahammad Ali ◽  
Ján Titiš ◽  
Roman Boča
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Schiff Base Ligand ◽  
Magnetic Relaxation ◽  
Magnetic Behaviour ◽  
Dinuclear Complexes ◽  
Relaxation Processes ◽  
Single Molecule Magnets ◽  
Slow Magnetic Relaxation

Two CuII–DyIII and CoIII–DyIII dinuclear complexes of a Schiff base ligand (H3L) exhibit single-molecule magnetic behaviour with multiple slow magnetic relaxation processes for the former.

DyIII single-molecule magnets from ligands incorporating both amine and acylhydrazine Schiff base groups: the centrosymmetric {Dy2} displaying dual magnetic relaxation behaviors

2020 ◽  
Vol 49 (44) ◽  
pp. 15739-15749
Author(s):  
Sen-Da Su ◽  
Jia-Xin Li ◽  
Fan Xu ◽  
Chen-Xiao Wang ◽  
Kai Wang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Magnetic Interactions ◽  
Single Molecule Magnets

Using ligands incorporating both amine and acylhydrazine Schiff base groups, two {Dy2} and a {Dy6} SMMs are synthesized. Two {Dy2} show dual magnetic relaxation behaviors, which could be ascribed to the joint contributions of single ion anisotropy and magnetic interactions.

scholarly journals Ten-Coordinate Lanthanide [Ln(HL)(L)] Complexes (Ln = Dy, Ho, Er, Tb) with Pentadentate N3O2-Type Schiff-Base Ligands: Synthesis, Structure and Magnetism

2020 ◽  
Vol 6 (4) ◽  
pp. 60 ◽  
Author(s):  
Tamara A. Bazhenova ◽  
Ilya A. Yakushev ◽  
Konstantin A. Lyssenko ◽  
Olga V. Maximova ◽  
Vladimir S. Mironov ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Magnetic Measurements ◽  
Magnetic Behavior ◽  
Molecular Structures ◽  
Magnetic Characteristics ◽  
Terbium Complex ◽  
Schiff Base Ligands ◽  
The Difference ◽  
Lanthanide Salts

A series of five neutral mononuclear lanthanide complexes [Ln(HL)(L)] (Ln = Dy3+, Ho3+ Er3+ and Tb3+) with rigid pentadentate N3O2-type Schiff base ligands, H2LH (1-Dy, 3-Ho, 4-Er and 6-Tb complexes) or H2LOCH3, (2-Dy complex) has been synthesized by reaction of two equivalents of 1,1′-(pyridine-2,6-diyl)bis(ethan-1-yl-1-ylidene))dibenzohydrazine (H2LH, [H2DAPBH]) or 1,1′-(pyridine-2,6-diyl)bis(ethan-1-yl-1-ylidene))di-4-methoxybenzohydrazine (H2LOCH3, [H2DAPMBH]) with common lanthanide salts. The terbium complex [Tb(LH)(NO3)(H2O)2](DME)2 (5-Tb) with one ligand H2LH was also obtained and characterized. Single crystal X-ray analysis shows that complexes 1–4 have the composition {[Ln3+(HL)−(L)2−] solv} and similar molecular structures. In all the compounds, the central Ln3+ ion is chelated by two interlocked pentadentate ligands resulting in the coordination number of ten. Each lanthanide ion is coordinated by six nitrogen atoms and four oxygen atoms of the two N3O2 chelating groups forming together a distorted bicapped square antiprismatic polyhedron N6O4 with two capping pyridyl N atoms in the apical positions. The ac magnetic measurements reveal field-induced single-molecule magnet (SMM) behavior of the two dysprosium complexes (with barriers of Ueff = 29 K at 800 Oe in 1-Dy and Ueff = 70 K at 300 Oe in 2-Dy) and erbium complex (Ueff = 87 K at 1500 Oe in 4-Er); complex 3-Ho with a non-Kramers Ho3+ ion is SMM-silent. Although 2-Dy differs from 1-Dy only by a distant methoxy-group in the phenyl ring of the ligand, their dynamic magnetic properties are markedly different. This feature can be due to the difference in long-range contributions (beyond the first coordination sphere) to the crystal-field (CF) potential of 4f electrons of Dy3+ ion that affects magnetic characteristics of the ground and excited CF states. Magnetic behavior and the electronic structure of Ln3+ ions of 1–4 complexes are analyzed in terms of CF calculations.

Step-by-Step and Competitive Assembly of Two Dy(III) Single-Molecule Magnets with Their Performance Tuned by Schiff Base Ligands

2019 ◽  
Vol 19 (9) ◽  
pp. 5369-5375 ◽  
Author(s):  
Hai-Ling Wang ◽  
Jin-Mei Peng ◽  
Zhong-Hong Zhu ◽  
Kai-Qiang Mo ◽  
Xiong-Feng Ma ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Single Molecule Magnets ◽  
Schiff Base Ligands

scholarly journals A Series of Novel Pentagonal-Bipyramidal Erbium(III) Complexes with Acyclic Chelating N3O2 Schiff-Base Ligands: Synthesis, Structure, and Magnetism

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6908
Author(s):  
Tamara A. Bazhenova ◽  
Vyacheslav A. Kopotkov ◽  
Denis V. Korchagin ◽  
Yuriy V. Manakin ◽  
Leokadiya V. Zorina ◽  
...  
Keyword(s):  
Experimental Study ◽  
Magnetic Properties ◽  
Schiff Base ◽  
Theoretical Analysis ◽  
Single Molecule ◽  
Theoretical Study ◽  
Magnetic Measurements ◽  
Single Molecule Magnets ◽  
Schiff Base Ligands ◽  
Axial Ligands

A series of six seven-coordinate pentagonal-bipyramidal (PBP) erbium complexes, with acyclic pentadentate [N3O2] Schiff-base ligands, 2,6-diacetylpyridine bis-(4-methoxybenzoylhydrazone) [H2DAPMBH], or 2,6-diacethylpyridine bis(salicylhydrazone) [H4DAPS], and various apical ligands in different charge states were synthesized: [Er(DAPMBH)(C2H5OH)Cl] (1); [Er(DAPMBH)(H2O)Cl]·2C2H5OH (2); [Er(DAPMBH)(CH3OH)Cl] (3); [Er(DAPMBH)(CH3OH)(N3)] (4); [(Et3H)N]+[Er(H2DAPS)Cl2]− (5); and [(Et3H)N]+[Y0.95Er0.05(H2DAPS)Cl2]− (6). The physicochemical properties, crystal structures, and the DC and AC magnetic properties of 1–6 were studied. The AC magnetic measurements revealed that most of Compounds 1–6 are field-induced single-molecule magnets, with estimated magnetization energy barriers, Ueff ≈ 16–28 K. The experimental study of the magnetic properties was complemented by theoretical analysis based on ab initio and crystal field calculations. An experimental and theoretical study of the magnetism of 1–6 shows the subtle impact of the type and charge state of the axial ligands on the SMM properties of these complexes.

Two Dy(III) Single-Molecule Magnets with Their Performance Tuned by Schiff Base Ligands

2019 ◽  
Vol 58 (2) ◽  
pp. 1191-1200 ◽  
Author(s):  
Shui Yu ◽  
Zhaobo Hu ◽  
Zilu Chen ◽  
Bo Li ◽  
Yi-Quan Zhang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Single Molecule Magnets ◽  
Schiff Base Ligands

scholarly journals Dysprosium Single-Molecule Magnets with Bulky Schiff Base Ligands: Modification of the Slow Relaxation of the Magnetization by Substituent Change

2018 ◽  
Vol 25 (2) ◽  
pp. 474-478 ◽  
Author(s):  
Jérôme Long ◽  
Ivan V. Basalov ◽  
Natalia V. Forosenko ◽  
Konstantin A. Lyssenko ◽  
Ekaterina Mamontova ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Molecule ◽  
Slow Relaxation ◽  
Single Molecule Magnets ◽  
Schiff Base Ligands

scholarly journals Low-Coordinate Dinuclear Dysprosium(III) Single Molecule Magnets Utilizing LiCl as Bridging Moieties and tris(amido)amine as Blocking Ligands

2021 ◽  
Vol 7 (9) ◽  
pp. 125
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Mikolaj Zychowicz ◽  
Dawid Pinkowicz
Keyword(s):  
Single Molecule ◽  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Magnetic Interactions ◽  
Ac Magnetic Susceptibility ◽  
Easy Magnetization ◽  
Single Molecule Magnets ◽  
Slow Magnetic Relaxation ◽  
Dysprosium Complex

A low-coordinate dinuclear dysprosium complex {[Dy(N3N)(THF)][LiCl(THF)]}2 (Dy2) with a double bridging ‘LiCl’ moiety and tris(amido)amine (N3N)3- anions as a blocking ligand is synthesized and characterized structurally and magnetically. Thanks to the use of the chelating blocking ligand (N3N)3− equipped with large steric –SiMe3 groups, the coordination sphere of both DyIII ions is restricted to only six donor atoms. The three amido nitrogen atoms determine the orientation of the easy magnetization axes of both DyIII centers. Consequently, Dy2 shows slow magnetic relaxation typical for single molecule magnets (SMMs). However, the effective energy barrier for magnetization reversal determined from the AC magnetic susceptibility measurements is much lower than the separation between the ground and the first excited Kramers doublet based on the CASSCF ab initio calculations. In order to better understand the possible influence of the anticipated intramolecular magnetic interactions in this dinuclear molecule, its GdIII-analog {[Gd(N3N)(THF)][LiCl(THF)]}2 (Gd2) is also synthesized and studied magnetically. Detailed magnetic measurements reveal very weak antiferromagnetic interactions in Gd2. This in turn suggests similar antiferromagnetic interactions in Dy2, which might be responsible for its peculiar SMM behavior and the absence of the magnetic hysteresis loop.

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