Single-chain magnets constructed with a twisting arrangement of the easy-plane of iron(II) ions

2008 ◽  
Vol 80 (11) ◽  
pp. 2297-2308 ◽  
Author(s):  
Takashi Kajiwara ◽  
Hiroki Tanaka ◽  
Masahiro Yamashita
Keyword(s):  
Structural Changes ◽  
Easy Axis ◽  
Muon Spin ◽  
Ac Susceptibility ◽  
Magnetic Interaction ◽  
Easy Plane ◽  
Structural Motif ◽  
Time Range ◽  
Single Chain ◽  
Single Chain Magnets

A novel class of single-chain magnets (SCMs), catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 and its derivative, were synthesized using the spin-carrier components possessing hard-axis anisotropy (or easy-plane anisotropy, D > 0). The easy-axis-type anisotropy of whole molecules of these compounds, which is essential for the formation of SCMs, arises from the twisted arrangement of easy-planes of Fe(II) along the chain axis. Alternating high-spin Fe(II) and low-spin Fe(III) chain complexes behave as an SCM with a typical frequency-dependent ac susceptibility which obeys Arrhenius law. Below 7 K, catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 showed a short-range spin-ordering even in zero external field in a time range of Mössbauer spectroscopy as well as the muon-spin-relaxation (μSR) spectroscopy. Since the easy-axis-type magnetic anisotropy originated from the structural motif of the twisting arrangement of Fe(II) ions, the overall magnetic property was very sensitive to the small structural changes arising from adsorption/desorption of the crystal solvents, and catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 showed a reversible change in magnetism that has been referred to as "a magnetic sponge". In its derivative, controls of the molecular structure, the arrangement of chains in the crystal, and magnetic properties both in dc and ac susceptibility have been achieved by the introduction of methyl group on a bpca- ligand, which bridges and mediates the magnetic interaction of the adjoining Fe(II)/Fe(III) ions.

Molecular Engineering To Control the Magnetic Interaction between Single-Chain Magnets Assembled in a Two-Dimensional Network

2012 ◽  
Vol 134 (37) ◽  
pp. 15265-15268 ◽  
Author(s):  
Luminita M. Toma ◽  
Catalina Ruiz-Pérez ◽  
Jorge Pasán ◽  
Wolfgang Wernsdorfer ◽  
Francesc Lloret ◽  
...  
Keyword(s):  
Magnetic Interaction ◽  
Molecular Engineering ◽  
Two Dimensional ◽  
Single Chain ◽  
Dimensional Network ◽  
Single Chain Magnets

Crystal engineering to control the magnetic interaction between weak ferromagnetic single-chain magnets assembled in a 3D framework

2016 ◽  
Vol 52 (56) ◽  
pp. 8722-8725 ◽  
Author(s):  
Lei Su ◽  
Wei-Chao Song ◽  
Jiong-Peng Zhao ◽  
Fu-Chen Liu
Keyword(s):  
Crystal Engineering ◽  
Magnetic Interaction ◽  
High Dimensional ◽  
Single Chain ◽  
Synthetic Strategy ◽  
Dimensional Network ◽  
3D Framework ◽  
Single Chain Magnets ◽  
Weak Ferromagnetic

A synthetic strategy of control of the arrangement and the magnetism of the SCMs by assembly of the chains into a high dimensional network was illustrated in a family of a weak antiferromagnetic chain based 3D framework.

Cryo-electron microscopy of two-dimensional crystals of reduced type B botulinum neurotoxin

1992 ◽  
Vol 50 (1) ◽  
pp. 530-531
Author(s):  
P. F. Flicker ◽  
V.S. Kulkarni ◽  
J. P. Robinson ◽  
G. Stubbs ◽  
B. R. DasGupta
Keyword(s):  
Disulfide Bonds ◽  
Clostridium Botulinum ◽  
Structural Changes ◽  
Two Dimensional ◽  
Type B ◽  
Single Chain ◽  
Muscle Paralysis ◽  
Cryo Electron Microscopy ◽  
Disulfide Linkages ◽  
Intracellular Action

Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum. The toxin inhibits release of neurotransmitter, causing muscle paralysis. There are several serotypes, A to G, all of molecular weight about 150,000. The protein exists as a single chain or or as two chains, with two disulfide linkages. In a recent investigation on intracellular action of neurotoxins it was reported that type B neurotoxin can inhibit the release of Ca++-activated [3H] norepinephrine only if the disulfide bonds are reduced. In order to investigate possible structural changes in the toxin upon reduction of the disulfide bonds, we have prepared two-dimensional crystals of reduced type B neurotoxin. These two-dimensional crystals will be compared with those of the native (unreduced) type B toxin.

Sterically-induced synthesis of 3d–4f one-dimensional compounds: A new route towards 3d–4f single chain magnets

2008 ◽  
Vol 361 (14-15) ◽  
pp. 3997-4003 ◽  
Author(s):  
G. Calvez ◽  
K. Bernot ◽  
O. Guillou ◽  
C. Daiguebonne ◽  
A. Caneschi ◽  
...  
Keyword(s):  
Single Chain ◽  
One Dimensional ◽  
Sterically Induced ◽  
Single Chain Magnets

scholarly journals Field Induced Slow Magnetic Relaxation in a Non Kramers Tb(III) Based Single Chain Magnet

2018 ◽  
Vol 4 (4) ◽  
pp. 59 ◽  
Author(s):  
Ajit Kumar Kharwar ◽  
Arpan Mondal ◽  
Sanjit Konar
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Energy State ◽  
Ac Susceptibility ◽  
Fluorescence Emission ◽  
Green Light ◽  
Single Chain ◽  
Ferromagnetic Interaction ◽  
Susceptibility Data ◽  
Nitrobenzoic Acid

Herein, we report a novel Tb(III) single chain magnet with the chemical formulae [Tb(μ-OH2)(phen)(μ-OH)(nb)2]n by using 4-nitrobenzoic acid (Hnb) and 1,10-phenanthroline (phen) as ligand system. The single-crystal X-ray diffraction reveals that 4-nitrobenzoic acid acts as a monodentate ligand, water and hydroxyl ions are the bridging ligand and the phen serves as a bidentate chelating ligand. The static magnetic susceptibility measurement (from 2 K to 300 K) shows ferromagnetic interaction at very low temperature (below 6 K). The alternating current (AC) susceptibility data of the complex show temperature and frequency dependence under an applied 2000 Oe DC (direct current) field. The phen moiety behaves as an antenna and enables the complex to show the green light fluorescence emission by absorption-energy transfer-emission mechanism. To calculate the exchange interaction, broken symmetry density functional theory (BS-DFT) calculations have been performed on a model compound which also reveals weak ferromagnetic interaction. Ab initio calculations reveals the anisotropic nature (gz = 15.8, gy, gy = 0) of the metal centre and the quasi doublet nature of ground state with small energy gap and that is well separated from the next excited energy state.

Design of single chain magnets through cyanide-bearing six-coordinate complexes

2005 ◽  
Vol 249 (23) ◽  
pp. 2691-2729 ◽  
Author(s):  
Rodrigue Lescouëzec ◽  
Luminita Marilena Toma ◽  
Jacqueline Vaissermann ◽  
Michel Verdaguer ◽  
Fernando S. Delgado ◽  
...  
Keyword(s):  
Single Chain ◽  
Single Chain Magnets

scholarly journals Исследование строения, ионной, молекулярной подвижности и термических свойств гидратов пентафторидоцирконата аммония

2019 ◽  
Vol 126 (2) ◽  
pp. 147
Author(s):  
Е.И. Войт ◽  
А.Б. Слободюк ◽  
Н.А. Диденко
Keyword(s):  
Structural Changes ◽  
Chemical Shifts ◽  
Molecular State ◽  
Structural Motif ◽  
Nmr Data ◽  
State Of Water ◽  
Hydrate Number ◽  
Bond Strengths ◽  
Isotropic Chemical Shifts ◽  
Ir And Raman

AbstractThe effect of hydrate number on the structural changes, thermal properties, and ionic (molecular) mobility character in NH_4ZrF_5 ⋅ H_2O, NH_4ZrF_5 ⋅ 0.75H_2O crystal hydrates have been investigated by the methods of IR, Raman, nuclear magnetic resonance (NMR) (^1H, ^19F, including ^19F MAS), and TG-DTA spectroscopy. Differences in crystal hydrate structures—anion structure, molecular state of water, and O–H⋅⋅⋅F, N–H⋅⋅⋅F hydrogen bond strengths—have been corroborated by IR and Raman spectroscopy data. Isotropic chemical shifts of magnetic inequivalent positions have been determined and attributed to crystal structures of the studied compounds by the method of ^19F MAS NMR. It has been established that the removal of water molecules from NH_4ZrF_5 ⋅ H_2O and NH_4ZrF_5 ⋅ 0.75H_2O results in the transformation of chain or layered structures accompanied by the increase of the number of bridge bonds while retaining or increasing the dimensionality of the anion structural motif. According to the ^1H NMR data, the NH $$_{4}^{ + }$$ cation diffusion in NH_4ZrF_5 occurs only in the temperature range of 370–520 K.

Polyoxometalate-Assisted Assembly of Pearl-Chain-Like Cyanide-Bridged Single-Chain Magnets

2021 ◽  
Author(s):  
Zi-Yi Chen ◽  
Yue Cheng ◽  
Qi Liu ◽  
Yi-Fei Deng ◽  
Yuan-Zhu Zhang
Keyword(s):  
Single Chain ◽  
Single Chain Magnets

scholarly journals Magnetic Domain Transition of Adjacent Narrow Thin Film Strips with Inclined Uniaxial Magnetic Anisotropy

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 279
Author(s):  
Tomoo Nakai
Keyword(s):  
Magnetic Field ◽  
Easy Axis ◽  
Magnetic Domain ◽  
Magnetic Interaction ◽  
Individual Element ◽  
Typical Characteristic ◽  
Many Body ◽  
Uniaxial Magnetic Anisotropy ◽  
Line Arrangement ◽  
Normal Magnetic Field

This study deals a phenomenon of magnetic domain transition for the stepped magneto-impedance element. Our previous research shows that an element with 70° inclined easy axis has a typical characteristic of the domain transition, and the transition can be controlled by the normal magnetic field. In this paper, we apply this phenomenon and controlling method to the line arrangement adjacent to many body elements, in which mutual magnetic interaction exists. The result shows that the hidden inclined Landau–Lifshitz domain appears by applying a distributed normal field the same as an individual element.

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