A5054683190- Magnetism in coordination complexes
- Lanthanide and Transition Metal Complexes
- Metal-Catalyzed Oxygenation Mechanisms
- Spectroscopy Techniques in Biomedical and Chemical Research
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Alzheimer's disease research and treatments
- Electron Spin Resonance Studies
- Gold and Silver Nanoparticles Synthesis and Applications
- Protein Interaction Studies and Fluorescence Analysis
- Organic and Molecular Conductors Research
- Electrochemical Analysis and Applications
- Metal complexes synthesis and properties
- Porphyrin and Phthalocyanine Chemistry
- Lipid Membrane Structure and Behavior
- Nanocluster Synthesis and Applications
- Organometallic Complex Synthesis and Catalysis
- Advanced biosensing and bioanalysis techniques
- Plasmonic and Surface Plasmon Research
- Supramolecular Self-Assembly in Materials
- X-ray Spectroscopy and Fluorescence Analysis
- Molecular Junctions and Nanostructures
- Hemoglobin structure and function
- Laser-Matter Interactions and Applications
- Advanced Memory and Neural Computing
Centre National de la Recherche Scientifique
2016-2025
Institut des Sciences Moléculaires
2016-2025
Université de Bordeaux
2016-2025
Institut Polytechnique de Bordeaux
2019-2025
Laboratoire de Chimie de Coordination
2005-2009
Université de Toulouse
2005-2009
Université Toulouse III - Paul Sabatier
2003-2009
Université Hassan II Mohammedia
2009
Institut National Polytechnique de Toulouse
2009
Helmholtz-Zentrum Berlin für Materialien und Energie
2009
Lightening the load Permanent magnets are generally produced from solid metals or alloys. Less dense compositions involving lighter elements tend to demagnetize well below room temperature under modest applied external fields. Perlepe et al. now report that chemical reduction of a low-density chromium-pyrazine network produces magnet remains stable above 200°C and resists demagnetization with 7500-oersted coercivity at temperature. The straightforward synthetic route material shows promise...
In the loop: A reversible spin transition was observed by Raman spectroscopy on application of a single laser pulse (8 ns) in hysteresis loop spin-crossover complex [Fe(pyrazine){Pt(CN)4}]. This bi-directional, photoinduced switching occurs at room temperature over wide region bistability and involves magnetization as well color changes (see picture).
Single crystals of the {FeII(pyrazine)[Pt(CN)4]} spin crossover complex were synthesized by a slow diffusion method. The exhibit thermal transition around room temperature (298 K), which is accompanied 14 K wide hysteresis loop. X-ray single-crystal analysis confirms that this compound crystallizes in tetragonal P4/mmm space group both states. Within region complete bidirectional photoconversion was induced between two phases (high ⇄ low spin) when short single laser pulse (4 ns, 532 nm)...
Much research has been directed toward the development of electrically switchable optical materials for applications in memory and display devices. Here we present experimental evidence an electric-field-induced charge-transfer phase transition two cyanometalate complexes: Rb(0.8)Mn[Fe(CN)(6)](0.93).1.62H(2)O Co(3)[W(CN)(8)](2)(pyrimidine)(4).6H(2)O, involving changes their magnetic, optical, electronic properties as well. Application electric field above a threshold value within thermal...
Photoswitching of the dielectric constant has been observed for first time in spin-crossover complex [Fe(L)(CN)2]⋅H2O (L=2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene, see picture). The electrical detection a photoinduced change spin state could allow use such complexes optical information-storage devices.
Double-stranded (ds) DNA of a λ-phage virus are combed on octadecyltrichlorosilane (OTS)-modified borosilicate glass substrates and investigated by means tip-enhanced Raman spectroscopy (TERS) using tips coated with an Ag/Au bilayer. Owing to enhancement factor higher than 6 × 102 lateral spatial resolution better 9 nm (which is below the size tip apex radius), cross-sections nanowire-shaped thin bundles can be spatially resolved. TER spectra reveal vibrational modes typical nucleobases...
In der Schleife: Ein reversibler Spinübergang ließ sich Raman-spektroskopisch bei Anwendung eines einzelnen Laserpulses (8 ns) in Hystereseschleife des Spin-Crossover-Komplexes [Fe(pyrazin){Pt(CN)4}] beobachten. Dieses bidirektionale, photoinduzierte Spinumschalten passiert Raumtemperatur über einen weiten Bistabilitätsbereich und umfasst Magnetisierungs- wie Farbänderungen (siehe Bild).
Abstract For the first time, natural Aβ 1–42 fibrils (WT) implicated in Alzheimer's disease, as well two synthetic mutants forming less toxic amyloid (L34T) and highly oligomers (oG37C), are chemically characterized at scale of a single structure using tip‐enhanced Raman spectroscopy (TERS). While proportion TERS features associated with amino acid residues is similar for three peptides, careful examination amide I III bands allows us to clearly distinguish WT L34T fibers organized parallel...
The attractive electronic properties of metal-pyrazine materials─electrical conductivity, magnetic order, and strong coupling─can be tuned in a wide range depending on the metal employed, as well its ligand-imposed redox environment. Using solvent-directed synthesis to control dimensionality such systems, discrete tetranuclear chromium(III) complex, exhibiting rare example bridging radical pyrazine, has been prepared from chromium(II) triflate neutral pyrazine. antiferromagnetic interaction...
The low-spin (LS-LS, S = 0) diamagnetic form of the binuclear spin crossover complex {[Fe(bt)(NCS)(2)](2)(bpm)} was selectively photoconverted into two distinct macroscopic phases at different excitation wavelengths (1342 or 647.1 nm). These long-lived metastable have been identified, respectively, as symmetry-broken paramagnetic (HS-LS, 2) and antiferromagnetically coupled (HS-HS, high-spin compound. selectivity may be explained by strong coupling primary excited states to state.
We investigated the recently found superconductor ${\text{LaFeAsO}}_{1\ensuremath{-}x}{\text{F}}_{x}$ by x-ray absorption spectroscopy. From a comparison of $\text{O}\text{ }K$ edge with LDA calculations we find good agreement and are able to explain structure changes in spectra electron doping. experimental $\text{Fe}\text{ }{L}_{2,3}$-edge charge-transfer multiplet gain further information on important physical values such as hopping parameters, energy $\ensuremath{\Delta}$, Hubbard $U$....
Abstract For the first time, natural Aβ 1–42 fibrils (WT) implicated in Alzheimer's disease, as well two synthetic mutants forming less toxic amyloid (L34T) and highly oligomers (oG37C), are chemically characterized at scale of a single structure using tip‐enhanced Raman spectroscopy (TERS). While proportion TERS features associated with amino acid residues is similar for three peptides, careful examination amide I III bands allows us to clearly distinguish WT L34T fibers organized parallel...
Soft-x-ray absorption spectroscopy at the L_{2,3} edge of iron center in bovine hemoglobin and hemin under physiological conditions is reported for first time. Spectra same compounds solid form are presented comparison. Striking differences electronic structure metalloporphyrin observed between liquid compounds. We unambiguously show that a high-spin ferric state solution, 2p spin-orbit coupling decreases compared to hemoglobin, while this not case solids. The spectra were simulated using...
A series of thin films Prussian blue analogues is investigated by X-ray absorption spectroscopy (XAS) at the Fe, Co and Mn L2,3-edges. The ligand field multiplet theory enables us to examine accurately electronic structure these materials. Experimental XAS spectra CoFe are successfully reproduced using a ground state configuration including metal-to-ligand (MLCT) ligand-to-metal charge transfer (LMCT) Fe In particular, huge improvement achieved for satellite peaks Co(III) L2,3-edges compared...
Cocrystallization of 7,7′,8,8′-tetracyanoquinodimethane radical anion (TCNQ–•) and 3-methylpyridinium-1,2,3,5-dithiadiazolyl cation (3-MepyDTDA+•) afforded isostructural acetonitrile (MeCN) or propionitrile (EtCN) solvates containing cofacial π dimers homologous components. Loss lattice solvent from the diamagnetic above 366 K affords a high-temperature paramagnetic phase discrete TCNQ–• weakly bound 3-MepyDTDA+•, as evidenced by X-ray diffraction methods magnetic susceptibility...
Silane-based self-assembled monolayers (SAMs) are widely used to control the surface properties of materials. The spin coating technique is an interesting alternative conventional immersion solution for organosilane deposition owing its speed and ease use under ambient conditions. In this work, we study impact drying step following by coating. We investigated influence temperature duration on quality monolayers. Two trimethoxysilanes bearing a phthalimide end group with alkyl chain or urea...
The synthesis and detailed study of the new mononuclear spin crossover complex [Fe(II)H2L(2-Me)](ClO4)2 (where H2L(2-Me) = bis[((2-methylimidazol-4-yl)methylidene)-3-aminopropyl]ethylenediamine) are reported. Variable-temperature magnetic susceptibility measurements show occurrence a steep centered at 171.5 K with hysteresis loop ca. 5 width (T(/2)(increasing) 174 T(1/2)(decreasing) 169 K, for increasing decreasing temperatures, respectively). crystal structure has been resolved high-spin...
The effects of pulsed magnetic fields and pressure on the spin crossover phenomenon between high-spin low-spin electronic states in ferrous compounds are investigated by introducing a model based macroscopic master equation written mean-field approximation. A bidirectional transition is predicted spontaneous thermal hysteresis light-induced (LITH) loops. also witnesses that pulse displays mirror effect compared to field different behaviors can be obtained depending intensity shape these...
Photochemisches Schalten der Dielektrizitätskonstante trifft man erstmalig in dem Spin-Crossover-Komplex [Fe(L)(CN)2]⋅H2O an (siehe Bild; L=2,13-Dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaen). Die elektrische Detektion des photoinduzierten Wechsels Spinzustands lässt derartige Komplexe für optische Informationsspeicher interessant erscheinen. Supporting information for this article is available on the WWW under...
The quadratic hyperpolarizability of two inorganic Schiff base metal complexes which differ from each other by the nature central ion (FeII or ZnII) is estimated using hyper-Rayleigh light-scattering (HRS) measurements. investigated FeII microcrystals exhibit a thermal spin-crossover (SCO) diamagnetic to paramagnetic state centered at T1/2 = 233 K that can be reproduced HRS signal whose modest intensity mainly due their centrosymmetric packing structure. Diamagnetic ZnII even lead much...