scholarly journals Synthesis and Applications of New Spin Crossover Compounds

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 382 ◽  
Author(s):  
Takafumi Kitazawa
Keyword(s):  
Electromagnetic Field ◽  
Transition Metal ◽  
Guest Molecule ◽  
Spin Crossover ◽  
Nuclear Decay ◽  
Stable States ◽  
Molecular Switching ◽  
X Ray ◽  
Field Radiation ◽  
External Stimuli

The spin crossover (SCO) between multi-stable states in transition metal material is one of the attractive molecular switching phenomena which is responsive to various external stimuli such as temperature, pressure, light, electromagnetic field, radiation, nuclear decay, soft-X-ray, guest molecule inclusion, chemical environments and so forth [...]

scholarly journals Soft X-ray Absorption Spectroscopy Study of Spin Crossover Fe-Compounds: Persistent High Spin Configurations under Soft X-ray Irradiation

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 433 ◽  
Author(s):  
Ahmed Mohamed ◽  
Minji Lee ◽  
Kosuke Kitase ◽  
Takafumi Kitazawa ◽  
Jae-Young Kim ◽  
...  
Keyword(s):  
High Spin ◽  
Absorption Spectroscopy ◽  
Spin Crossover ◽  
Structural Adaptation ◽  
Critical Temperatures ◽  
Spin Configuration ◽  
X Ray ◽  
Metal Organic ◽  
External Stimuli ◽  
X Ray Absorption

Metal-organic complex exhibiting spin crossover (SCO) behavior has drawn attention for its functionality as a nanoscale spin switch. The spin states in the metal ions can be tuned by external stimuli such as temperature or light. This article demonstrates a soft X-ray–induced excited spin state trapping (SOXEISST) effect in Hofmann-like SCO coordination polymers of FeII(4-methylpyrimidine)2[Au(CN)2]2 and FeII(pyridine)2[Ni(CN)4]. A soft X-ray absorption spectroscopy (XAS) study on these polymers showed that the high spin configuration (HS; S = 2) was prevalent in Fe2+ ions during the measurement even at temperatures much lower than the critical temperatures (>170 K), manifesting HS trapping due to the X-ray irradiation. This is in strong contrast to the normal SCO behavior observed in FeII(1,10-phenanthroline)2(NCS)2, implying that the structure of the ligand chains in the polymers with relatively loose Fe-N coordination might allow a structural adaptation to stabilize the metastable HS state under the soft X-ray irradiation.

Structural dynamics of photoinduced molecular switching in the solid state

2010 ◽  
Vol 66 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Hervé Cailleau ◽  
Maciej Lorenc ◽  
Laurent Guérin ◽  
Marina Servol ◽  
Eric Collet ◽  
...  
Keyword(s):  
Solid State ◽  
Structural Dynamics ◽  
Degrees Of Freedom ◽  
Spin Crossover ◽  
Structural Information ◽  
Fast Time ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Molecular Switching ◽  
X Ray

Fast and ultra-fast time-resolved diffraction is a fantastic tool for directly observing the structural dynamics of a material rearrangement during the transformation induced by an ultra-short laser pulse. The paper illustrates this ability using the dynamics of photoinduced molecular switching in the solid state probed by 100 ps X-ray diffraction. This structural information is crucial for establishing the physical foundations of how to direct macroscopic photoswitching in materials. A key feature is that dynamics follow a complex pathway from molecular to material scales through a sequence of processes. Not only is the pathway indirect, the nature of the dynamical processes along the pathway depends on the timescale. This dictates which types of degrees of freedom are involved in the subsequent dynamics or kinetics and which are frozen or statistically averaged. We present a recent investigation of the structural dynamics in multifunctional spin-crossover materials, which are prototypes of molecular bistability in the solid state. The time-resolved X-ray diffraction results show that the dynamics span from subpicosecond molecular photoswitching followed by volume expansion (on a nanosecond timescale) and additional thermoswitching (on a microsecond timescale).

MOBILE PHONES ELECTROMAGNETIC FIELD RADIATION RESEARCH AND ANALYSIS OF ITS DISPERSION BY APPLYING MATLAB7 SOFTWARE

2017 ◽  
Vol 16 (5) ◽  
pp. 1177-1184
Author(s):  
Raimondas Buckus ◽  
Pranas Baltrenas ◽  
Jonas Skeivalas ◽  
Raimondas Grubliauskas ◽  
Igor Cretescu
Keyword(s):  
Electromagnetic Field ◽  
Mobile Phones ◽  
Field Radiation ◽  
Radiation Research

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

scholarly journals X-ray diffraction analysis of matter taking into account the second harmonic in the scattering of powerful ultrashort pulses of an electromagnetic field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. K. Eseev ◽  
A. A. Goshev ◽  
K. A. Makarova ◽  
D. N. Makarov
Keyword(s):  
Electromagnetic Field ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
Second Harmonic ◽  
Ultrashort Pulses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Spectra ◽  
Technical Possibility ◽  
2D And 3D

AbstractIt is well known that the scattering of ultrashort pulses (USPs) of an electromagnetic field in the X-ray frequency range can be used in diffraction analysis. When such USPs are scattered by various polyatomic objects, a diffraction pattern appears from which the structure of the object can be determined. Today, there is a technical possibility of creating powerful USP sources and the analysis of the scattering spectra of such pulses is a high-precision instrument for studying the structure of matter. As a rule, such scattering occurs at a frequency close to the carrier frequency of the incident USP. In this work, it is shown that for high-power USPs, where the magnetic component of USPs cannot be neglected, scattering at the second harmonic appears. The scattering of USPs by the second harmonic has a characteristic diffraction pattern which can be used to judge the structure of the scattering object; combining the scattering spectra at the first and second harmonics therefore greatly enhances the diffraction analysis of matter. Scattering spectra at the first and second harmonics are shown for various polyatomic objects: examples considered are 2D and 3D materials such as graphene, carbon nanotubes, and hybrid structures consisting of nanotubes. The theory developed in this work can be applied to various multivolume objects and is quite simple for X-ray structural analysis, because it is based on analytical expressions.

Spin-crossover iron(II) long-chain complex with slow spin equilibrium at low temperature

2021 ◽  
Author(s):  
Qi Zhao ◽  
Jin-Peng Xue ◽  
Zhi-Kun Liu ◽  
Zi-Shuo Yao ◽  
Jun Tao
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Spin Crossover ◽  
Chain Complex ◽  
Mononuclear Complex ◽  
X Ray ◽  
Alkyl Chains ◽  
Long Chain

A mononuclear complex with long alkyl chains, [FeII(H2Bpz2)2(C9bpy)] (1; H2Bpz2 = dihydrobis(1-pyrazolyl)borate, C9bpy = 4,4'-dinonyl-2,2'-bipyridine), was synthesized. Single-crystal X-ray crystallographic studies revealed that - and - forms of the complex...

Regiospezifische Insertion von [SCN]- und [SeCN]- in die S – C- bzw. Se– C-Bindung Übergangsmetall-koordinierter Thietane und SelenetaneRegiospecific Insertion of [SCN]- and [SeCN]- in the S–C- and Se–C-Bond of Transition-Metal-Coordinated Thietanes and Selenetanes

1993 ◽  
Vol 48 (11) ◽  
pp. 1613-1620 ◽  
Author(s):  
Helmut Fischer ◽  
Claudia Kalbas ◽  
Carsten Troll ◽  
Klaus H. Fluck
Keyword(s):  
Nitrogen Atom ◽  
Transition Metal ◽  
Structure Analysis ◽  
Trans Isomer ◽  
X Ray ◽  
Tungsten Complexes ◽  
Membered Heterocycle

Pentacarbonyl(thietane)tungsten complexes react with thiocyanate, [SCN]-, and SiO2/H2O by insertion of the CN group into a S—C bond of the four-membered heterocycle, 1,3-migration of the pentacarbonyltungsten fragment and protonation of the nitrogen atom to give tungsten-coordinated thiazinthione complexes. Analogously, the reactions of a thietane tungsten complex with [SeCN]- and SiO2/H2O affords a thiazinselone complex. A selenazinthione complex is obtained from a selenetane complex and [SCN]- (+ SiO2/H2O). The insertions are regiospecific and stereoselective. The structure of the trans-isomer of a pentacarbonyl-(thiazinthione) complex has been established by X-ray structure analysis.

X-RAY ABSORPTION EDGES OF TRANSITION- METAL-DOPED Y1Ba2Cu3−xMxO7−∂

1988 ◽  
Vol 02 (05) ◽  
pp. 1153-1156 ◽  
Author(s):  
J. B. BOYCE ◽  
F. BRIDGES ◽  
T. CLAESON ◽  
T. H. GEBALLE ◽  
M. NYGREN ◽  
...  
Keyword(s):  
Transition Metal ◽  
X Ray ◽  
Metal Doped ◽  
X Ray Absorption ◽  
Absorption Edges
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