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

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.

scholarly journals Air-Stable Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets with Nearly Perfect D6h Local Symmetry

2019 ◽  
Author(s):  
Zi-Han Li ◽  
Yuan-Qi Zhai ◽  
Wei-Peng Chen ◽  
You-Song Ding ◽  
Yan-Zhen Zheng
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Local Symmetry ◽  
Fine Tuning ◽  
Magnetic Reversal ◽  
Single Molecule Magnets ◽  
Experimental Realization ◽  
High Coordination Number ◽  
Macrocyclic Schiff Base ◽  
High Coordination

Local eight-coordination of the Dy(III) with D<sub>6h</sub> symmetry receives much expectation for high-performance single-molecule magnets (SMMs) due to the simultaneous fulfillment of the magnetic axiality and high coordination number (a requisite for the air stability). But the experimental realization is challenging due to the required restriction of six coordination atoms in the equatorial plane of the hexagonal-bipyramid, which is usually too crowded for the central Dy(III) ion. Here we show by using the hexaaza macrocyclic Schiff base ligand and fine-tuning the axial alkoxide/phenol type ligands, a family of hexagonal-bipyramidal Dy(III) complexes, namely [Dy<sup>III</sup>(L)(Cl)<sub>2</sub>(H<sub>2</sub>O/CH<sub>3</sub>OH)]Cl <b>1</b>, [Dy<sup>III</sup>(L)(C<sub>6</sub>F<sub>5</sub>O)<sub>2</sub>(H<sub>2</sub>O)](BPh<sub>4</sub>)·<b>2</b>, [Dy<sup>III</sup>(L)(PhO)<sub>2</sub>](BPh<sub>4</sub>) <b>3</b>, [Dy<sup>III</sup>(L)(4-MeO-PhO)<sub>2</sub>](BPh<sub>4</sub>) <b>4</b>, [Dy<sup>III</sup>(L)(naPhO)<sub>2</sub>](BPh<sub>4</sub>) <b>5 </b>and [Dy<sup>III</sup>(L)(Ph<sub>3</sub>SiO)<sub>2</sub>](BPh<sub>4</sub>) <b>6</b><b> </b>, can be isolated. Among them, complexes <b>3</b>, <b>4</b> and <b>5</b> possess nearly perfect D<sub>6h</sub> local symmetry. Complex <b>4</b> shows the highest effective magnetic reversal barrier 1338 K and an open hysteresis temperature 6 K at the field sweeping rate of 1.2 mT/s, which represents a new record for D<sub>6h</sub> SMMs.

scholarly journals Air-Stable Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets with Nearly Perfect D6h Local Symmetry

2019 ◽  
Author(s):  
Zi-Han Li ◽  
Yuan-Qi Zhai ◽  
Wei-Peng Chen ◽  
You-Song Ding ◽  
Yan-Zhen Zheng
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Local Symmetry ◽  
Fine Tuning ◽  
Magnetic Reversal ◽  
Single Molecule Magnets ◽  
Experimental Realization ◽  
High Coordination Number ◽  
Macrocyclic Schiff Base ◽  
High Coordination

Local eight-coordination of the Dy(III) with D<sub>6h</sub> symmetry receives much expectation for high-performance single-molecule magnets (SMMs) due to the simultaneous fulfillment of the magnetic axiality and high coordination number (a requisite for the air stability). But the experimental realization is challenging due to the required restriction of six coordination atoms in the equatorial plane of the hexagonal-bipyramid, which is usually too crowded for the central Dy(III) ion. Here we show by using the hexaaza macrocyclic Schiff base ligand and fine-tuning the axial alkoxide/phenol type ligands, a family of hexagonal-bipyramidal Dy(III) complexes, namely [Dy<sup>III</sup>(L)(Cl)<sub>2</sub>(H<sub>2</sub>O/CH<sub>3</sub>OH)]Cl <b>1</b>, [Dy<sup>III</sup>(L)(C<sub>6</sub>F<sub>5</sub>O)<sub>2</sub>(H<sub>2</sub>O)](BPh<sub>4</sub>)·<b>2</b>, [Dy<sup>III</sup>(L)(PhO)<sub>2</sub>](BPh<sub>4</sub>) <b>3</b>, [Dy<sup>III</sup>(L)(4-MeO-PhO)<sub>2</sub>](BPh<sub>4</sub>) <b>4</b>, [Dy<sup>III</sup>(L)(naPhO)<sub>2</sub>](BPh<sub>4</sub>) <b>5 </b>and [Dy<sup>III</sup>(L)(Ph<sub>3</sub>SiO)<sub>2</sub>](BPh<sub>4</sub>) <b>6</b><b> </b>, can be isolated. Among them, complexes <b>3</b>, <b>4</b> and <b>5</b> possess nearly perfect D<sub>6h</sub> local symmetry. Complex <b>4</b> shows the highest effective magnetic reversal barrier 1338 K and an open hysteresis temperature 6 K at the field sweeping rate of 1.2 mT/s, which represents a new record for D<sub>6h</sub> SMMs.

scholarly journals Cadmium-Inspired Self-Polymerization of {LnIIICd2} Units: Structure, Magnetic and Photoluminescent Properties of Novel Trimethylacetate 1D-Polymers (Ln = Sm, Eu, Tb, Dy, Ho, Er, Yb)

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4296
Author(s):  
Maxim A. Shmelev ◽  
Ruslan A. Polunin ◽  
Natalia V. Gogoleva ◽  
Igor S. Evstifeev ◽  
Pavel N. Vasilyev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Luminescence Decay ◽  
Decay Kinetics ◽  
Single Molecule Magnets ◽  
Excitation Spectra ◽  
Magnetization Relaxation ◽  
Trinuclear Complexes ◽  
Applied External Magnetic Field ◽  
Luminescence Decay Kinetics

A series of heterometallic carboxylate 1D polymers of the general formula [LnIIICd2(piv)7(H2O)2]n·nMeCN (LnIII = Sm (1), Eu (2), Tb (3), Dy (4), Ho (5), Er (6), Yb (7); piv = anion of trimethylacetic acid) was synthesized and structurally characterized. The use of CdII instead of ZnII under similar synthetic conditions resulted in the formation of 1D polymers, in contrast to molecular trinuclear complexes with LnIIIZn2 cores. All complexes 1–7 are isostructural. The luminescent emission and excitation spectra for 2–4 have been studied, the luminescence decay kinetics for 2 and 3 was measured. Magnetic properties of the complexes 3–5 and 7 have been studied; 4 and 7 exhibited the properties of field-induced single-molecule magnets in an applied external magnetic field. Magnetic properties of 4 and 7 were modelled using results of SA-CASSCF/SO-RASSI calculations and SINGLE_ANISO procedure. Based on the analysis of the magnetization relaxation and the results of ab initio calculations, it was found that relaxation in 4 predominantly occurred by the sum of the Raman and QTM mechanisms, and by the sum of the direct and Raman mechanisms in the case of 7.

Carboxylate-Bridged Dinuclear Dy2 Single-Molecule Magnets: Synthesis, Structure, and Magnetic Studies

2013 ◽  
Vol 66 (1) ◽  
pp. 98 ◽  
Author(s):  
Yu-mei Song ◽  
Feng Luo ◽  
Yan Zhu ◽  
Xiao-zhao Tian ◽  
Gong-ming Sun
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Coordination Geometry ◽  
Magnetic Studies ◽  
Single Molecule Magnets ◽  
Chlorobenzoic Acid ◽  
Ferromagnetic Interaction ◽  
Single Molecule Magnet ◽  
The Difference

In this work, the synthesis, structure, and magnetic studies of three dinuclear Dy2 compounds, namely Dy2(bpy)2(L)6 (1), Dy2(phen)2(L)6 (2), Dy2(μ-H2O)2(bpy)2(L)6 (3) are reported in detail, where HL, phen, and bpy are 4-chlorobenzoic acid, 1,10-phenanthroline, and 2,2′-bipyridine. Magnetic studies reveal the intramolecular ferromagnetic interaction and single-molecule magnetic properties of these compounds. The fine-tuned single-molecule magnet properties of compounds 1–3, mainly due to the difference of the coordination geometry of DyIII ions, are highlighted.

Single-Molecule Magnets:  Two-Electron Reduced Version of a Mn12Complex and Environmental Influences on the Magnetization Relaxation of (PPh4)2[Mn12O12(O2CCHCl2)16(H2O)4]

2003 ◽  
Vol 125 (12) ◽  
pp. 3576-3588 ◽  
Author(s):  
Monica Soler ◽  
Wolfgang Wernsdorfer ◽  
Khalil A. Abboud ◽  
John C. Huffman ◽  
Ernest R. Davidson ◽  
...  
Keyword(s):  
Single Molecule ◽  
Environmental Influences ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation

scholarly journals Leveraging Surface Siloxide Electronics to Enhance Relaxation Properties of a Single-Molecule Magnet

2020 ◽  
Author(s):  
Maciej Korzynski ◽  
Zachariah Berkson ◽  
Boris Le Guennic ◽  
Olivier Cador ◽  
Christophe Copéret
Keyword(s):  
Single Molecule ◽  
Relaxation Times ◽  
Device Fabrication ◽  
Information Storage ◽  
Commercial Application ◽  
Surface Immobilization ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation ◽  
Surface Deposition ◽  
Magnitude Increase

Single-molecule magnets (SMMs) hold promise for unmatched information storage density as well as applications in quantum computing and spintronics. To date, the most successful SMMs are organometallic lanthanide complexes. However, their surface immobilization, one of the requirements for device fabrication and commercial application, remains challenging due to sensitivity of magnetic properties to small changes in the electronic structure of the parent SMM. Thus, finding controlled approaches to SMM surface deposition is a timely challenge. In this contribution we apply the concept of isolobality to identify siloxides present at the surface of partially dehydroxylated silica as a suitable replacement for archetypal ligand architectures in organometallic SMMs. We demonstrate theoretically and experimentally that isolated siloxide anchorages not only enable successful immobilization, but also lead to two-orders-of-magnitude increase in magnetization relaxation times and provide magnetic site dilution.

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

2012 ◽  
Vol 81 (6) ◽  
pp. 064716 ◽  
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

scholarly journals Multireference Ab Initio Studies of Magnetic Properties of Terbium-Based Single-Molecule Magnets

2019 ◽  
Vol 123 (32) ◽  
pp. 6996-7006 ◽  
Author(s):  
Ryan Pederson ◽  
Aleksander L. Wysocki ◽  
Nicholas Mayhall ◽  
Kyungwha Park
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Single Molecule ◽  
Single Molecule Magnets

Single-molecule magnets under dc field with an anion effect: self-assembly of pure dysprosium(iii) metallacycles

2021 ◽  
Vol 50 (1) ◽  
pp. 262-269
Author(s):  
Jianfeng Wu ◽  
Qianqian Yang ◽  
Haoyu Wang ◽  
Yan Ge ◽  
Jinkui Tang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Self Assembly ◽  
Structural Factors ◽  
Single Molecule Magnets ◽  
Anion Effect

The anion-adaptive self-assembly described here not only offers a facile approach to produce large single-molecule magnets but also provides an understanding of how structural factors affect the magnetic properties.

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