The Separation of the Mn12 Single-Molecule Magnets onto Spherical Silica Nanoparticles

Controlling the distribution of the Mn12–stearate, single-molecule magnets (SMMs) anchored on a select surface is expected to be a new method for tuning its interactions, and an investigation on the magnetic properties of separated magnetic molecules is also lacking. The anchoring of the SMMs at the surface with an assumed statistic distance between each other is not an easy task; nevertheless, in this work, we show a synthesis which allows for this in detail. The immobilization of the Mn12–stearate was demonstrated with the use of FTO glasses and spherical silica as substrates. Based on differential pulse anodic stripping voltammetry (DPASV) and transmission electron microscopy (TEM) observations, we proved the efficiency of the method proposed. We observed continuous decreasing the number of bonds, and afterward, decreasing in the number of immobilized molecules with an increasing the number of spacer units used for separation of the magnetic particles.

Download Full-text

Magnetic Behaviour of Mn12-Stearate Single-Molecule Magnets Immobilized on the Surface of 300 nm Spherical Silica Nanoparticles

Materials ◽

10.3390/ma13112624 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2624 ◽

Cited By ~ 3

Author(s):

Magdalena Laskowska ◽

Oleksandr Pastukh ◽

Piotr Konieczny ◽

Mateusz Dulski ◽

Marcin Zalsiński ◽

...

Keyword(s):

Silica Nanoparticles ◽

Single Molecule ◽

Silica Surface ◽

Magnetic Measurements ◽

Magnetic Behaviour ◽

Silica Spheres ◽

Squid Magnetometry ◽

Single Molecule Magnets ◽

Transmission Electron ◽

Spherical Silica

The magnetic behaviour of Mn 12 -stearate single-molecule magnets (SMMs) ([ Mn 12 O 12 ( CH 3 ( CH 2 ) 16 CO 2 ) 16 ] · 2 CH 3 COOH · 4 H 2 O ) on the surface of 300 nm spherical silica nanoparticles were investigated. The SMMs were bonded at the silica surface with the assumed number of anchoring points, which influenced on their degree of freedom and distribution. In order to check the properties of Mn 12 -stearate molecules separated on the silica surface, and check their interactions, the samples containing four different concentration of spacers per single anchoring unit and variously bonded Mn 12 -stearate particles were prepared. The materials have been examined using Raman spectroscopy, transmission electron microscopy, and SQUID magnetometry. The results of magnetic measurements showed a correlation between the way of single-molecule magnets immobilization onto the silica spheres and the magnetic properties of the obtained hybrid materials.

Download Full-text

The Application Research of Single-Molecule Magnets and Molecular Spin Electronics Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.485.522 ◽

2012 ◽

Vol 485 ◽

pp. 522-525

Author(s):

Hai Mei Xiao ◽

Li Chun Shi

Keyword(s):

Single Molecule ◽

Degrees Of Freedom ◽

Organic Ligand ◽

Chemical Properties ◽

Molecular Magnets ◽

Single Molecule Magnets ◽

Spin Electronics ◽

Molecular Spin ◽

Basic And Applied Research ◽

Physical And Chemical

In the basic and applied research, the electronics and spin degrees of freedom is a very promising field of research and development over the past decade, spintronics from fundamental physics to technical devices already have a great deal of progress. This study made an overview of the synthesis, structure and properties of single molecular magnets and their applications in molecular spin combined with the latest research on this study sphere. Single molecular magnets are made of inner magnetic nuclei and peripheral organic molecule lamella, which can improve physical and chemical properties by means of adorn radical of organic ligand and exchange internal magnetic ions. And this paper also analyzes the molecular spin of the electron spin and charge electronic devices at the molecular level.

Download Full-text

Ferromagnetic [Mn3] Single-Molecule Magnets and Their Supramolecular Networks

Australian Journal of Chemistry ◽

10.1071/ch09236 ◽

2009 ◽

Vol 62 (9) ◽

pp. 1108 ◽

Cited By ~ 22

Author(s):

Ross Inglis ◽

Giannis S. Papaefstathiou ◽

Wolfgang Wernsdorfer ◽

Euan K. Brechin

Keyword(s):

Single Molecule ◽

Quantum Physics ◽

Three Dimensional ◽

Exchange Interactions ◽

Molecular Magnets ◽

Single Molecule Magnets ◽

Spin Networks ◽

Quantum Tunnelling ◽

Field Bias ◽

Supramolecular Networks

The complexes [MnIII3O(Et-sao)3(O2CPh(Cl)2)(MeOH)3(H2O)] (1), [MnIII3O(Et-sao)3(ClO4)(MeOH)3] (2), [MnIII3O(Et-sao)3(O2Ph(CF3)2)(EtOH)(H2O)3] (3), and [MnIII3O(Ph-sao)3(O2C-anthra)(MeOH)4]·Ph-saoH2 (4·Ph-saoH2) display dominant ferromagnetic exchange interactions leading to molecules with S = 6 ground states. The molecules are single molecule magnets (SMM) displaying large effective energy barriers for magnetization reversal. In each case their crystal structures reveal multiple intermolecular H-bonding interactions. Single crystal hysteresis loop measurements demonstrate that these interactions are strong enough to cause a clear field bias, but too weak to transform the spin networks into classical antiferromagnets. These three-dimensional networks of exchange coupled SMMs demonstrate that quantum tunnelling magnetization can be controlled using exchange interactions, suggesting supramolecular chemistry can be exploited to modulate the quantum physics of molecular magnets.

Download Full-text

Polarized Neutron Diffraction: An Excellent Tool to Evidence the Magnetic Anisotropy—Structural Relationships in Molecules

Magnetochemistry ◽

10.3390/magnetochemistry7120158 ◽

2021 ◽

Vol 7 (12) ◽

pp. 158

Author(s):

Dominique Luneau ◽

Béatrice Gillon

Keyword(s):

Neutron Diffraction ◽

Magnetic Anisotropy ◽

Single Molecule ◽

Coordination Compounds ◽

Single Molecule Magnets ◽

Structural Relationships ◽

Polarized Neutron ◽

The Individual ◽

The Relationship ◽

Excellent Tool

This publication reviews recent advances in polarized neutron diffraction (PND) studies of magnetic anisotropy in coordination compounds comprising d or f elements and having different nuclearities. All these studies illustrate the extent to which PND can provide precise and direct information on the relationship between molecular structure and the shape and axes of magnetic anisotropy of the individual metal sites. It makes this experimental technique (PND) an excellent tool to help in the design of molecular-based magnets and especially single-molecule magnets for which strong uniaxial magnetic anisotropy is required.

Download Full-text

Dalton technical issue “Lanthanide and transition metal complexes as molecular magnets Single-molecule magnets within polyoxometalate-based frameworks

Dalton Transactions ◽

10.1039/d1dt01708j ◽

2021 ◽

Author(s):

Malihe Babaei Zarch ◽

Masoud Mirzaei ◽

Maryam Bazargan ◽

Sandeep K Gupta ◽

Franc Meyer ◽

...

Keyword(s):

Transition Metal ◽

Metal Complexes ◽

Transition Metal Complexes ◽

Single Molecule ◽

Molecular Magnets ◽

Technical Issue ◽

Hydrothermal Conditions ◽

Single Molecule Magnets ◽

Design And Synthesis

As an extension of our interest in polyoxometalates (POMs) and lanthanoids, we report the design and synthesis of two polyoxometalate-based frameworks under hydrothermal conditions; [Ho4(PDA)4(H2O)11][(SiO4)@W12O36]·8H2O (1) and [Tb4(PDA)4(H2O)12][(SiO4)@W12O36]·4H2O (2) (H2PDA...

Download Full-text

Insight into D6h Symmetry: Targeting Strong Axiality in Stable Dysprosium(III) Hexagonal Bipyramidal Single-Ion Magnets

10.26434/chemrxiv.8100509 ◽

2019 ◽

Author(s):

Angelos Canaj ◽

Sourav Dey ◽

Emma Regincós Martí ◽

Claire Wilson ◽

Gopalan Rajaraman ◽

...

Keyword(s):

Single Molecule ◽

Magnetization Reversal ◽

Ligand Field ◽

Single Molecule Magnets ◽

Uniaxial Magnetic Anisotropy ◽

Synthetic Strategy ◽

High Anisotropy ◽

First Time ◽

Opening Up ◽

Insight Into

Three dysprosium(III) single-molecule magnets (SMMs) with the rare hexagonal bipyramidal geometry have been isolated for the first time. Following a novel synthetic strategy where the strong uniaxial ligand field generated by the Ph3SiO- (Ph3SiO- = anion of triphenylsilanol) and the 2,4-di-tBu-PhO- (2,4-di-tBu-PhO- = anion of 2,4-di-tertbutylphenol) ligands combined with the weak equatorial field of the ligand LN6, leads to [DyIII(LN6)(2,4-di-tBu-PhO)2](PF6) (1), [DyIII(LN6)(Ph3SiO)2](PF6) (2) and [DyIII(LN6)(Ph3SiO)2](BPh4) (3) hexagonal bipyramidal complexes with high anisotropy barriers of Ueff = 973 K for 1, Ueff = 1080 K for 2 and Ueff = 1124 K for 3 under zero applied dc field. Ab initio calculations predict that the dominant magnetization reversal barrier of these complexes expands up to the 3rd Kramers doublet, thus revealing for the first time the exceptional uniaxial magnetic anisotropy that even the six equatorial donor atoms fail to negate, opening up the possibility to other higher-order symmetry SMMs.

Download Full-text

AC Susceptibility Studies of Magnetic Relaxation in Mn12-Stearate SMMs on the Spherical Silica Surface

Magnetochemistry ◽

10.3390/magnetochemistry7090122 ◽

2021 ◽

Vol 7 (9) ◽

pp. 122

Author(s):

Oleksandr Pastukh ◽

Piotr Konieczny ◽

Magdalena Laskowska ◽

Łukasz Laskowski

Keyword(s):

Single Molecule ◽

Silica Surface ◽

Ac Susceptibility ◽

Relaxation Times ◽

Single Molecule Magnets ◽

Relaxation Parameters ◽

Spherical Silica ◽

Measuring Techniques ◽

Different Temperatures ◽

Nanostructured Silica

The study of magnetic relaxations in Mn12-stearate single-molecule magnets deposited on the surface of spherical silica nanoparticles was performed. For such a purpose, the investigation of AC magnetic susceptibility dependence on the frequency and temperature was performed. Based on the Argand plots obtained for different temperatures and temperature dependencies of susceptibility, obtained for different frequencies of AC field, the corresponding relaxation times were derived. Fitting to the Arrhenius law revealed the values of an effective energy barrier and a mean relaxation time, which were consistent for both measuring techniques (Ueff/kB∼ 50 K and τ0∼ 10−7 s) and similar to the corresponding values for the analogous bulk compounds. Additionally, the obtained relaxation parameters for the Mn12-stearate molecules on the spherical silica surface were compared with corresponding values for the Mn12-based single-molecule magnets deposited upon other types of nanostructured silica surface.

Download Full-text

Insight into D6h Symmetry: Targeting Strong Axiality in Stable Dysprosium(III) Hexagonal Bipyramidal Single-Ion Magnets

10.26434/chemrxiv.8100509.v1 ◽

2019 ◽

Author(s):

Angelos Canaj ◽

Sourav Dey ◽

Emma Regincós Martí ◽

Claire Wilson ◽

Gopalan Rajaraman ◽

...

Keyword(s):

Single Molecule ◽

Magnetization Reversal ◽

Ligand Field ◽

Single Molecule Magnets ◽

Uniaxial Magnetic Anisotropy ◽

Synthetic Strategy ◽

High Anisotropy ◽

First Time ◽

Opening Up ◽

Insight Into

Three dysprosium(III) single-molecule magnets (SMMs) with the rare hexagonal bipyramidal geometry have been isolated for the first time. Following a novel synthetic strategy where the strong uniaxial ligand field generated by the Ph3SiO- (Ph3SiO- = anion of triphenylsilanol) and the 2,4-di-tBu-PhO- (2,4-di-tBu-PhO- = anion of 2,4-di-tertbutylphenol) ligands combined with the weak equatorial field of the ligand LN6, leads to [DyIII(LN6)(2,4-di-tBu-PhO)2](PF6) (1), [DyIII(LN6)(Ph3SiO)2](PF6) (2) and [DyIII(LN6)(Ph3SiO)2](BPh4) (3) hexagonal bipyramidal complexes with high anisotropy barriers of Ueff = 973 K for 1, Ueff = 1080 K for 2 and Ueff = 1124 K for 3 under zero applied dc field. Ab initio calculations predict that the dominant magnetization reversal barrier of these complexes expands up to the 3rd Kramers doublet, thus revealing for the first time the exceptional uniaxial magnetic anisotropy that even the six equatorial donor atoms fail to negate, opening up the possibility to other higher-order symmetry SMMs.

Download Full-text