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

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.

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Syntheses, structures and magnetic properties of macrocyclic Schiff base-supported homodinuclear lanthanide complexes

Dalton Transactions ◽

10.1039/c8dt02243g ◽

2018 ◽

Vol 47 (33) ◽

pp. 11696-11704 ◽

Cited By ~ 5

Author(s):

Feng Gao ◽

Yi-Quan Zhang ◽

Wang Sun ◽

Huan Liu ◽

Xiaoyu Chen

Keyword(s):

Magnetic Properties ◽

Schiff Base ◽

Theoretical Analysis ◽

Lanthanide Complexes ◽

Magnetic Measurements ◽

Dysprosium Complex ◽

Macrocyclic Schiff Base

Five macrocyclic Schiff base-supported homodinuclear lanthanide complexes were successfully designed and synthesized by template strategy. Theoretical analysis and magnetic measurements reveal dysprosium complex 1 behaves as a typical SMM with intramolecular ferromagnetic Dy3+⋯Dy3+ interaction.

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Magnetic Properties of 1:2 Mixed Cobalt(II) Salicylaldehyde Schiff-Base Complexes with Pyridine Ligands Carrying High-Spin Carbenes (Scar = 2/2, 4/2, 6/2, and 8/2) in Dilute Frozen Solutions: Role of Organic Spin in Heterospin Single-Molecule Magnets

Inorganic Chemistry ◽

10.1021/ic403074d ◽

2014 ◽

Vol 53 (11) ◽

pp. 5447-5457 ◽

Cited By ~ 18

Author(s):

Satoru Karasawa ◽

Kimihiro Nakano ◽

Daisuke Yoshihara ◽

Noriko Yamamoto ◽

Jun-ichi Tanokashira ◽

...

Keyword(s):

Magnetic Properties ◽

Schiff Base ◽

High Spin ◽

Single Molecule ◽

Schiff Base Complexes ◽

Single Molecule Magnets ◽

Pyridine Ligands ◽

Frozen Solutions

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Spectral, thermal and magnetic properties of Cu(II) and Ni(II) complexes with Schiff base ligands

Journal of the Serbian Chemical Society ◽

10.2298/jsc101112140c ◽

2011 ◽

Vol 76 (12) ◽

pp. 1639-1648 ◽

Cited By ~ 14

Author(s):

Beata Cristóvão

Keyword(s):

Thermal Analysis ◽

Magnetic Properties ◽

Magnetic Susceptibility ◽

Schiff Base ◽

Ir Spectroscopy ◽

Magnetic Measurements ◽

Magnetic Moments ◽

Schiff Base Ligands

Mononuclear copper(II) and nickel(II) complexes of the formulae [Cu(L1)] (1), [Ni(L1)] (2), [Cu(L2)] (3) and [Cu(L3)H2O] (4) (where L1 = N,N?-ethylenebis(4,6-dimethoxysalicylidenaminato), L2 = N,N?-ethylenebis(5-bromosalicylidenaminato) and L3 = N,N?-ethylenebis(5-bromo-3-methoxysalicylidenaminato)) were synthesized as microcrystalline powders and characterized by IR spectroscopy, thermal analysis and magnetic measurements. The magnetic susceptibility of the Cu(II) complexes changed with temperature according to the Curie-Weiss law. The complexes 1, 3 and 4 exhibit magnetic moments of 2.29, 2.20 and 1.88 ?B, respectively, at 303 K. These values practically do not change with lowering the temperature to 77 K. The nickel(II) complex 2 is diamagnetic.

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Tuning of exchange coupling by the Mn–O distance and phenoxido bridging angle: an experimental and theoretical study of the family of Mn(iii) dimers with salen type ligands

Dalton Transactions ◽

10.1039/c5dt01224d ◽

2015 ◽

Vol 44 (28) ◽

pp. 12863-12870 ◽

Cited By ~ 20

Author(s):

Piya Seth ◽

Sanjib Giri ◽

Ashutosh Ghosh

Keyword(s):

Magnetic Properties ◽

Schiff Base ◽

Exchange Coupling ◽

Theoretical Study ◽

Structural Parameters ◽

Schiff Base Ligands ◽

The Family

Three new Mn(iii) complexes of salen type Schiff base ligands have been synthesized in order to correlate their magnetic properties with structural parameters, theoretically and experimentally.

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Luminescent Schiff-Base Lanthanide Single-Molecule Magnets: The Association Between Optical and Magnetic Properties

Frontiers in Chemistry ◽

10.3389/fchem.2019.00063 ◽

2019 ◽

Vol 7 ◽

Cited By ~ 18

Author(s):

Jérôme Long

Keyword(s):

Magnetic Properties ◽

Schiff Base ◽

Single Molecule ◽

Single Molecule Magnets ◽

Optical And Magnetic Properties

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

Magnetochemistry ◽

10.3390/magnetochemistry6040060 ◽

2020 ◽

Vol 6 (4) ◽

pp. 60 ◽

Cited By ~ 1

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.

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Theoretical Study of Magnetic Properties of Oxovanadium(IV) Complex Self-Assemblies with Tetradentate Schiff Base Ligands

The Journal of Physical Chemistry B ◽

10.1021/jp111779k ◽

2011 ◽

Vol 115 (26) ◽

pp. 8465-8473 ◽

Cited By ~ 5

Author(s):

Naoki Matsuoka ◽

Masanobu Tsuchimoto ◽

Naoki Yoshioka

Keyword(s):

Magnetic Properties ◽

Schiff Base ◽

Theoretical Study ◽

Schiff Base Ligands ◽

Tetradentate Schiff Base

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Slow Relaxation of the Magnetization in Anilato-Based Dy(III) 2D Lattices

Molecules ◽

10.3390/molecules26041190 ◽

2021 ◽

Vol 26 (4) ◽

pp. 1190

Author(s):

Samia Benmansour ◽

Antonio Hernández-Paredes ◽

María Bayona-Andrés ◽

Carlos J. Gómez-García

Keyword(s):

Magnetic Properties ◽

Single Molecule ◽

Related Compound ◽

Interlayer Space ◽

Magnetic Measurements ◽

Three Dimensional ◽

Slow Relaxation ◽

Two Dimensional ◽

Single Molecule Magnets ◽

Solvent Molecules

The search for two- and three-dimensional materials with slow relaxation of the magnetization (single-ion magnets, SIM and single-molecule magnets, SMM) has become a very active area in recent years. Here we show how it is possible to prepare two-dimensional SIMs by combining Dy(III) with two different anilato-type ligands (dianions of the 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone: C6O4X22−, with X = H and Cl) in dimethyl sulfoxide (dmso). The two compounds prepared, formulated as: [Dy2(C6O4H2)3(dmso)2(H2O)2]·2dmso·18H2O (1) and [Dy2(C6O4Cl2)3(dmso)4]·2dmso·2H2O (2) show distorted hexagonal honeycomb layers with the solvent molecules (dmso and H2O) located in the interlayer space and in the hexagonal channels that run perpendicular to the layers. The magnetic measurements of compounds 1, 2 and [Dy2(C6O4(CN)Cl)3(dmso)6] (3), a recently reported related compound, show that the three compounds present slow relaxation of the magnetization. In compound 1 the SIM behaviour does not need the application of a DC field whereas 2 and 3 are field-induced SIM (FI-SIM) since they show slow relaxation of the magnetization when a DC field is applied. We discuss the differences observed in the crystal structures and magnetic properties based on the X group of the anilato ligands (H, Cl and Cl/CN) in 1–3 and in the recently reported derivative [Dy2(C6O4Br2)3(dmso)4]·2dmso·2H2O (4) with X = Br, that is also a FI-SIM.

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

Inorganics ◽

10.3390/inorganics8120066 ◽

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.

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