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

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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Effects of Pressure on Two-Dimensional Networked Single-Molecule Magnets Exhibiting AC-Field-Switchable Magnetic Properties

Journal of the Physical Society of Japan ◽

10.1143/jpsj.81.064716 ◽

2012 ◽

Vol 81 (6) ◽

pp. 064716 ◽

Cited By ~ 3

Author(s):

Masaki Mito ◽

Masashi Ogawa ◽

Hiroyuki Deguchi ◽

Masahiro Yamashita ◽

Hitoshi Miyasaka

Keyword(s):

Magnetic Properties ◽

Single Molecule ◽

Two Dimensional ◽

Single Molecule Magnets ◽

Ac Field

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Slow Relaxation of the Magnetization in Bis-Decorated Chiral Helicene-Based Coordination Complexes of Lanthanides

Magnetochemistry ◽

10.3390/magnetochemistry4030039 ◽

2018 ◽

Vol 4 (3) ◽

pp. 39 ◽

Cited By ~ 5

Author(s):

Jessica Flores Gonzalez ◽

Vincent Montigaud ◽

Nidal Saleh ◽

Olivier Cador ◽

Jeanne Crassous ◽

...

Keyword(s):

Magnetic Properties ◽

Ab Initio Calculations ◽

Ab Initio ◽

Single Molecule ◽

Crystalline Phase ◽

Coordination Complexes ◽

Slow Relaxation ◽

Single Molecule Magnets ◽

Racemic Form

The complexes [Ln2(hfac)6(L)]·nC6H14 (Ln = Dy (1) n = 0, Yb (2) n = 1) with the L chiral 3,14-di-(2-pyridyl)-4,13-diaza[6]helicene ligand (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate) have been synthesized in their racemic form and structurally and magnetically characterized. Both complexes behave as field-induced single molecule magnets in the crystalline phase. These magnetic properties were rationalized by ab initio calculations.

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

Molecules ◽

10.3390/molecules26226908 ◽

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.

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Copper(II) Complexes with cis-Epoxysuccinate Ligand: Syntheses, Crystal Structures, and Magnetic Properties

Australian Journal of Chemistry ◽

10.1071/ch10371 ◽

2011 ◽

Vol 64 (2) ◽

pp. 217 ◽

Cited By ~ 3

Author(s):

Shao-Ming Fang ◽

E. Carolina Sañudo ◽

Min Hu ◽

Qiang Zhang ◽

Li-Ming Zhou ◽

...

Keyword(s):

Magnetic Properties ◽

Magnetic Measurements ◽

Three Dimensional ◽

Magnetic Coupling ◽

Supramolecular Interactions ◽

Stacking Interactions ◽

Ferromagnetic Coupling ◽

Two Dimensional ◽

Structural Comparison ◽

Higher Dimensional

Three CuII complexes with cis-epoxysuccinate ligand were synthesized and structurally characterized: [Cu(ces)(phen)]2 (1), [Cu(ces)(bpy)]2 (2), and {[Cu2(ces)(pp)2(CH3OH)]}∞ (3), (ces = cis-epoxysuccinate, phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine, and pp = 3-(2-pyridyl)pyrazole with pyrazolyl N-donor deprotonated). Structural analysis reveals that both 1 and 2 have the very similar dinuclear units that are extended by the intermolecular supramolecular interactions, such as C–H⋯O, C–H⋯π, and aromatic π⋯π stacking interactions, to give rise to the higher-dimensional frameworks. Complex 3 has a two-dimensional (2D) layered structure that is further assembled to form a three-dimensional framework by the inter-layer C–H⋯O hydrogen-bonding and C–H⋯π interactions. A structural comparison with those of our previous work in the absence of auxiliary co-ligand suggests that the introduction of 2,2′-bipyridyl-like molecules plays an important role in constructing the final structures of 1–3. Magnetic measurements demonstrate that 1 and 2 exhibit ferromagnetic coupling with the corresponding J values of 1.8 cm–1 for 1 and 1.5 cm–1 for 2, whereas 3 shows more complicated magnetic coupling.

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High-Coordinate Mononuclear Ln(III) Complexes: Synthetic Strategies and Magnetic Properties

Magnetochemistry ◽

10.3390/magnetochemistry7010001 ◽

2020 ◽

Vol 7 (1) ◽

pp. 1

Author(s):

Joydev Acharya ◽

Pankaj Kalita ◽

Vadapalli Chandrasekhar

Keyword(s):

Magnetic Properties ◽

Single Molecule ◽

Fine Tuning ◽

Coordination Geometry ◽

Single Molecule Magnets ◽

Magnetization Relaxation ◽

Quantum Tunneling Of Magnetization ◽

Structural Correlation ◽

High Coordination Number ◽

High Coordination

Single-molecule magnets involving monometallic 4f complexes have been investigated extensively in last two decades to understand the factors that govern the slow magnetization relaxation behavior in these complexes and to establish a magneto-structural correlation. The prime goal in this direction is to suppress the temperature independent quantum tunneling of magnetization (QTM) effect via fine-tuning the coordination geometry/microenvironment. Among the various coordination geometries that have been pursued, complexes containing high coordination number around Ln(III) are sparse. Herein, we present a summary of the various synthetic strategies that were used for the assembly of 10- and 12-coordinated Ln(III) complexes. The magnetic properties of such complexes are also described.

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A Dy(III) Fluorescent Single-Molecule Magnet Based on a Rhodamine 6G Ligand

Inorganics ◽

10.3390/inorganics9070051 ◽

2021 ◽

Vol 9 (7) ◽

pp. 51

Author(s):

Lin Miao ◽

Mei-Jiao Liu ◽

Man-Man Ding ◽

Yi-Quan Zhang ◽

Hui-Zhong Kou

Keyword(s):

Magnetic Properties ◽

Single Molecule ◽

Magnetic Relaxation ◽

Rhodamine 6G ◽

Bond Angle ◽

Magnetic Measurements ◽

Single Molecule Magnet ◽

Lanthanide Metals ◽

Process Studies ◽

Dual Functions

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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Robust hypothesis tests for detecting statistical evidence of two-dimensional and three-dimensional interactions in single-molecule measurements

Physical Review E ◽

10.1103/physreve.89.052705 ◽

2014 ◽

Vol 89 (5) ◽

Cited By ~ 7

Author(s):

Christopher P. Calderon ◽

Lucien E. Weiss ◽

W. E. Moerner

Keyword(s):

Single Molecule ◽

Three Dimensional ◽

Statistical Evidence ◽

Two Dimensional ◽

Hypothesis Tests

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Square-grid coordination networks of (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) in its clathrate with two guest molecules of 1,2-dichlorobenzene: supramolecular isomerism of the porphyrin self-assembly

Acta Crystallographica Section C Crystal Structure Communications ◽

10.1107/s0108270109005691 ◽

2009 ◽

Vol 65 (3) ◽

pp. m139-m142 ◽

Cited By ~ 10

Author(s):

Rajesh Koner ◽

Israel Goldberg

Keyword(s):

Self Assembly ◽

Metal Ion ◽

Three Dimensional ◽

Two Dimensional ◽

Coordination Networks ◽

Guest Molecules ◽

Square Grid ◽

Supramolecular Isomerism ◽

Self Assembled ◽

Solvent Molecules

The title compound, (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) 1,2-dichlorobenzene disolvate, [Zn(C40H24N8)]·2C6H4Cl2, contains a clathrate-type structure. It is composed of two-dimensional square-grid coordination networks of the self-assembled porphyrin moiety, which are stacked one on top of the other in a parallel manner. The interporphyrin cavities of the overlapping networks combine into channel voids accommodated by the dichlorobenzene solvent. Molecules of the porphyrin complex are located on crystallographic inversion centres. The observed two-dimensional assembly mode of the porphyrin units represents a supramolecular isomer of the unique three-dimensional coordination frameworks of the same porphyrin building block observed earlier. The significance of this study lies in the discovery of an additional supramolecular isomer of the rarely observed structures of metalloporphyrins self-assembled directly into extended coordination polymers without the use of external ligand or metal ion auxiliaries.

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Cobalt(II) chloride adducts with acetonitrile, propan-2-ol and tetrahydrofuran: considerations on nuclearity, reactivity and synthetic applications

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229617000705 ◽

2017 ◽

Vol 73 (2) ◽

pp. 104-114 ◽

Cited By ~ 1

Author(s):

Danilo Stinghen ◽

André Luis Rüdiger ◽

Siddhartha O. K. Giese ◽

Giovana G. Nunes ◽

Jaísa F. Soares ◽

...

Keyword(s):

Single Molecule ◽

Building Blocks ◽

Direct Reaction ◽

X Ray Diffraction ◽

Single Molecule Magnets ◽

X Ray ◽

Ft Ir ◽

Bond Network ◽

Solvent Molecules ◽

Intramolecular Hydrogen

High-spin cobalt(II) complexes are considered useful building blocks for the synthesis of single-molecule magnets (SMM) because of their intrinsic magnetic anisotropy. In this work, three new cobalt(II) chloride adducts with labile ligands have been synthesized from anhydrous CoCl2, to be subsequently employed as starting materials for heterobimetallic compounds. The products were characterized by elemental, spectroscopic (EPR and FT–IR) and single-crystal X-ray diffraction analyses.trans-Tetrakis(acetonitrile-κN)bis(tetrahydrofuran-κO)cobalt(II) bis[(acetonitrile-κN)trichloridocobaltate(II)], [Co(C2H3N)4(C4H8O)2][CoCl3(C2H3N)]2, (1), comprises mononuclear ions and contains both acetonitrile and tetrahydrofuran (thf) ligands, The coordination polymercatena-poly[[tetrakis(propan-2-ol-κO)cobalt(II)]-μ-chlorido-[dichloridocobalt(II)]-μ-chlorido], [Co2Cl4(C3H8O)4], (2′), was prepared by direct reaction between anhydrous CoCl2and propan-2-ol in an attempt to rationalize the formation of the CoCl2–alcohol adduct (2), probably CoCl2(HOiPr)m. The binuclear complex di-μ-chlorido-1:2κ4Cl:Cl-dichlorido-2κ2Cl-tetrakis(tetrahydrofuran-1κO)dicobalt(II), [Co2Cl4(C4H8O)4], (3), was obtained from (2) after recrystallization from tetrahydrofuran. All three products present cobalt(II) centres in both octahedral and tetrahedral environments, the former usually less distorted than the latter, regardless of the nature of the neutral ligand. Product (2′) is stabilized by an intramolecular hydrogen-bond network that appears to favour atransarrangement of the chloride ligands in the octahedral moiety; this differs from thecisdisposition found in (3). The expected easy displacement of the bound solvent molecules from the metal coordination sphere makes the three compounds good candidates for suitable starting materials in a number of synthetic applications.

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