Browse
Submit Data
Databases
API
Help

Dataset Information

37 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Rare "Janus"-faced single-molecule magnet exhibiting intramolecular ferromagnetic interactions.

ABSTRACT: A rare disk-like single-molecule magnet (SMM) exclusively bridged by end-on azides with a spin ground state of S = 14 was prepared by the reaction of a divalent FeII precursor with Me3SiN3 under basic conditions. AC magnetic susceptibility studies revealed unusual, "Janus"-faced SMM behavior for the dried and pristine forms of the compound attributed to solvation/de-solvation effects of the coordinated MeCN ligands which leads to alterations in the crystal field and symmetry of the metal ions. DFT calculations confirmed the ferromagnetic nature of the interactions between the FeII spin carriers with the zero-field splitting parameters D = -0.2323 cm-1 and E/D = 0.027. The results have important implications for the future study of single-molecule magnets incorporating volatile solvent molecules in the first coordination sphere of the metal ions and their effect on the relaxation dynamics.

SUBMITTER: Alexandropoulos DI

PROVIDER: S-EPMC6368239 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Rare "Janus"-faced single-molecule magnet exhibiting intramolecular ferromagnetic interactions.

Alexandropoulos Dimitris I DI Vignesh Kuduva R KR Stamatatos Theocharis C TC Dunbar Kim R KR

Chemical science 20181105 6

A rare disk-like single-molecule magnet (SMM) exclusively bridged by end-on azides with a spin ground state of S = 14 was prepared by the reaction of a divalent FeII precursor with Me3SiN3 under basic conditions. AC magnetic susceptibility studies revealed unusual, "Janus"-faced SMM behavior for the dried and pristine forms of the compound attributed to solvation/de-solvation effects of the coordinated MeCN ligands which leads to alterations in the crystal ...[more]

PMID: 30842825

Similar Datasets

3-Pyridylacetic-Based Lanthanide Complexes Exhibiting Magnetic Entropy Changes, Single-Molecule Magnet, and Fluorescence.

Project description:Four complexes from lanthanides, 3-pyridylacetate, and 1,10-phenanthroline, formulated as [Ln2(3-PAA)2(μ-Cl)2(phen)4](ClO4)2 [Ln = Gd(1), Dy(2), Eu(3), Tb(4), 3-PAA = 3-pyridylacetic acid, phen = 1,10-phenanthroline], were obtained. The four compounds were characterized by IR spectra, thermogravimetric analyses, powder X-ray diffraction, and single-crystal X-ray diffraction. Compounds 1-4 are isomorphous, and they have a dinuclear structure. Magnetic studies reveal that 1 shows the magnetocaloric effect with -ΔS m max = 19.03 J kg-1 K-1 at 2 K for ΔH = 5 T, and 2 displays a field-induced single-molecule magnet with U eff = 19.02 K. The photoluminescent spectra of 3 and 4 exhibit strong characteristic emission, which demonstrate that the ligand-to-EuIII/TbIII energy transfer is efficient.

| S-EPMC8793079 | biostudies-literature

Intramolecular London Dispersion Interactions in Single-Molecule Junctions.

Project description:This work shows the first example of using intramolecular London dispersion interactions to control molecular geometry and quantum transport in single-molecule junctions. Flexible σ-bonded molecular junctions typically occupy straight-chain geometries due to steric effects. Here, we synthesize a series of thiomethyl-terminated oligo(dimethylsilmethylene)s that bear [CH2-Si(CH3)2]n repeat units, where all backbone dihedral states are sterically equivalent. Scanning tunneling microscopy break-junction (STM-BJ) measurements and theoretical calculations indicate that in the absence of a strong steric bias concerted intramolecular London dispersion interactions staple the carbosilane backbone into coiled conformations that remain intact even as the junction is stretched to its breakpoint. As these kinked conformations are highly resistive to electronic transport, we observe record-high conductance decay values on an experimental junction length basis (β = 1.86 ± 0.12 Å-1). These studies reveal the potential of using intramolecular London dispersion interactions to design single-molecule electronics.

| S-EPMC10885141 | biostudies-literature

Suppressing of slow magnetic relaxation in tetracoordinate Co(II) field-induced single-molecule magnet in hybrid material with ferromagnetic barium ferrite.

Project description:The novel field-induced single-molecule magnet based on a tetracoordinate mononuclear heteroleptic Co(II) complex involving two heterocyclic benzimidazole (bzi) and two thiocyanido ligands, [Co(bzi)2(NSC)2], (CoL4), was prepared and thoroughly characterized. The analysis of AC susceptibility data resulted in the spin reversal energy barrier U = 14.7 cm(-1), which is in good agreement with theoretical prediction, U(theor). = 20.2 cm(-1), based on axial zero-field splitting parameter D = -10.1 cm(-1) fitted from DC magnetic data. Furthermore, mutual interactions between CoL4 and ferromagnetic barium ferrite BaFe12O19 (BaFeO) in hybrid materials resulted in suppressing of slow relaxation of magnetization in CoL4 for 1:2, 1:1 and 2:1 mass ratios of CoL4 and BaFeO despite the lack of strong magnetic interactions between two magnetic phases.

| S-EPMC4454148 | biostudies-literature

Ferroelectric Single-Molecule Magnet with Toroidal Magnetic Moments.

Project description:Materials that coexist magnetic and electric properties on the molecular scale in single-molecule magnets (SMMs) with peculiar quantum behaviors have promise in molecular electronics and spintronics. Nevertheless, such molecular materials are limited in potentials because their magnetic signal cannot be transformed into an electrical signal through magnetoresistance or Hall effects for their high insulativity. The discovery of an entirely new material, ferroelectric SMMs (FE SMMs) is reported. This FE SMM also shows single-molecule magnetic behaviors, toroidal magnetic moments, and room-temperature ferroelectricity. The toroidal moment is formed by a vortex distribution of magnetic dipoles in triangular Dy3 clusters. The analysis of ac magnetic susceptibility reveals the coexistence of three distinct magnetic relaxation processes at low temperatures. The ferroelectricity is introduced by incorporating polar alcohol molecules in the structure, which is confirmed by the X-ray diffraction and optical second harmonic generation (SHG) measurements. Moreover, the dielectric measurements reveal a ferroelectric-to-ferroelectric phase transition around 150 K due to the symmetry change from Pc to Pna21 . The coexistence of toroidal moment and ferroelectricity along with quantum magnetism in the rare-earth single-molecule magnets yields a unique class of multiferroics.

| S-EPMC9475528 | biostudies-literature

Spin state of a single-molecule magnet (SMM) creating long-range ordering on ferromagnetic layers of a magnetic tunnel junction - a Monte Carlo study.

Project description:Paramagnetic single-molecule magnets (SMMs) interacting with the ferromagnetic electrodes of a magnetic tunnel junction (MTJ) produce a new system. The properties and future scope of new systems differ dramatically from the properties of isolated molecules and ferromagnets. However, it is unknown how far deep in the ferromagnetic electrode the impact of the paramagnetic molecule and ferromagnet interactions can travel for various levels of molecular spin states. Our prior experimental studies showed two types of paramagnetic SMMs, the hexanuclear Mn6 and octanuclear Fe-Ni molecular complexes, covalently bonded to ferromagnets produced unprecedented strong antiferromagnetic coupling between two ferromagnets at room temperature leading to a number of intriguing observations (P. Tyagi, et al., Org. Electron., 2019, 64, 188-194. P. Tyagi, et al., RSC Adv., 2020, 10, (22), 13006-13015). This paper reports a Monte Carlo Simulations (MCS) study focusing on the impact of the molecular spin state on a cross junction shaped MTJ based molecular spintronics device (MTJMSD). Our MCS study focused on the Heisenberg model of MTJMSD and investigated the impact of various molecular coupling strengths, thermal energy, and molecular spin states. To gauge the impact of the molecular spin state on the region of ferromagnetic electrodes, we examined the spatial distribution of molecule-ferromagnet correlated phases. Our MCS study shows that under a strong coupling regime, the molecular spin state should be ∼30% of the ferromagnetic electrode's atomic spins to create long-range correlated phases.

| S-EPMC9042143 | biostudies-literature

Dysprosium Acetylacetonato Single-Molecule Magnet Encapsulated in Carbon Nanotubes.

Project description:Dy single-molecule magnets (SMMs), which have several potential uses in a variety of applications, such as quantum computing, were encapsulated in multi-walled carbon nanotubes (MWCNTs) by using a capillary method. Encapsulation was confirmed by using transmission electron microscopy (TEM). In alternating current magnetic measurements, the magnetic susceptibilities of the Dy acetylacetonato complexes showed clear frequency dependence even inside the MWCNTs, meaning that this hybrid can be used as magnetic materials in devices.

| S-EPMC5344606 | biostudies-literature

A Low Spin Manganese(IV) Nitride Single Molecule Magnet.

Project description:Structural, spectroscopic and magnetic methods have been used to characterize the tris(carbene)borate compound PhB(MesIm)3Mn≡N as a four-coordinate manganese(IV) complex with a low spin (S = 1/2) configuration. The slow relaxation of the magnetization in this complex, i.e. its single-molecule magnet (SMM) properties, is revealed under an applied dc field. Multireference quantum mechanical calculations indicate that this SMM behavior originates from an anisotropic ground doublet stabilized by spin-orbit coupling. Consistent theoretical and experiment data show that the resulting magnetization dynamics in this system is dominated by ground state quantum tunneling, while its temperature dependence is influenced by Raman relaxation.

| S-EPMC5058364 | biostudies-literature

Hydroxide-bridged five-coordinate DyIII single-molecule magnet exhibiting the record thermal relaxation barrier of magnetization among lanthanide-only dimers.

Project description:A hydroxide-bridged centrosymmetric DyIII dimer with each DyIII being five-coordinated has been synthesized using bulky hindered phenolate ligands. Magnetic studies revealed that this compound exhibits a slow magnetic relaxation of a single-ion origin together with a step-like magnetic hysteresis of the magnetic coupled cluster. The thermal relaxation barrier of magnetization is 721 K in the absence of a static magnetic field, while the intramolecular magnetic interaction is very large among reported 4f-only dimers. CASSCF calculations with a larger active space were performed to understand the electronic structure of the compound. The thermal relaxation regime and the quantum tunneling regime are well separated, representing a good model to study the relaxation mechanism of SMMs with intramolecular Dy-Dy magnetic interactions.

| S-EPMC5359878 | biostudies-literature

Single-molecule magnet behavior in 2,2'-bipyrimidine-bridged dilanthanide complexes.

Project description:A series of 2,2'-bipyrimidine-bridged dinuclear lanthanide complexes with the general formula [Ln(tmhd)3]2bpm (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate, bpm = 2,2'-bipyrimidine, Ln = Gd(III), 1; Tb(III), 2; Dy(III), 3; Ho(III), 4 and Er(III), 5) has been synthesized and characterized. Sublimation of [Tb(tmhd)3]2bpm onto a Au(111) surface leads to the formation of a homogeneous film with hexagonal pattern, which was studied by scanning tunneling microscopy (STM). The bulk magnetic properties of all complexes have been studied comprehensively. The dynamic magnetic behavior of the Dy(III) and Er(III) compounds clearly exhibits single molecule magnet (SMM) characteristics with an energy barrier of 97 and 25 K, respectively. Moreover, micro-SQUID measurements on single crystals confirm their SMM behavior with the presence of hysteresis loops.

| S-EPMC4734418 | biostudies-literature

Single-chain magnet behavior in a finite linear hexanuclear molecule.

Project description:The careful monitoring of crystallization conditions of a mixture made of a TbIII building block and a substituted nitronyl-nitroxide that typically provides infinite coordination polymers (chains), affords a remarkably stable linear hexanuclear molecule made of six TbIII ions and five NIT radicals. The hexanuclear units are double-bridged by water molecules but ab initio calculations demonstrate that this bridge is inefficient in mediating any magnetic interaction other than a small dipolar antiferromagnetic coupling. Surprisingly the hexanuclears, despite being finite molecules, show a single-chain magnet (SCM) behavior. This results in a magnetic hysteresis at low temperature whose coercive field is almost doubled when compared to the chains. We thus demonstrate that finite linear molecules can display SCM magnetic relaxation, which is a strong asset for molecular data storage purposes because 1D magnetic relaxation is more robust than the relaxation mechanisms observed in single-molecule magnets (SMMs) where under-barrier magnetic relaxation can operate.

| S-EPMC8356920 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data