A5067441864- Magnetism in coordination complexes
- Lanthanide and Transition Metal Complexes
- Molecular Junctions and Nanostructures
- Magnetic properties of thin films
- Porphyrin and Phthalocyanine Chemistry
- Metal-Organic Frameworks: Synthesis and Applications
- Covalent Organic Framework Applications
- Organic and Molecular Conductors Research
- Quantum and electron transport phenomena
- Mechanical and Optical Resonators
- Carbon dioxide utilization in catalysis
- Advanced NMR Techniques and Applications
- Electron Spin Resonance Studies
- Metal-Catalyzed Oxygenation Mechanisms
- Quantum-Dot Cellular Automata
- Supramolecular Chemistry and Complexes
- Force Microscopy Techniques and Applications
- Iron oxide chemistry and applications
- Advanced Chemical Physics Studies
- Diamond and Carbon-based Materials Research
- Advanced Materials and Mechanics
- Advanced Sensor and Energy Harvesting Materials
- Metal complexes synthesis and properties
- Nanomaterials for catalytic reactions
- Advanced Photocatalysis Techniques
Max Planck Institute of Colloids and Interfaces
2021-2022
Centre National de la Recherche Scientifique
2015-2020
Laboratoire de Chimie de Coordination
2015-2020
Université Toulouse III - Paul Sabatier
2015-2020
Université de Toulouse
2015-2020
Institut National Polytechnique de Toulouse
2015-2018
The fabrication of large-area vertical junctions with a molecular spin-crossover complex displaying concerted changes spin degrees freedom and charge-transport properties is reported. Fabricated devices allow spin-state switching in the layer to be triggered probed by optical means, while detecting associated electrical resistance junctions. As service our authors readers, this journal provides supporting information supplied authors. Such materials are peer reviewed may re-organized for...
Abstract Spin crossover particles of formula [Fe{(Htrz) 2 (trz)} 0.9 (NH ‐trz) 0.3 ](BF 4 ) 1.1 and average size 20 nm ± 8 are homogeneously dispersed in poly(vinylidene fluoride‐co‐trifluoro‐ethylene), P(VDF‐TrFE), fluoride) (PVDF) matrices to form macroscopic (cm‐scale), freestanding, flexible nanocomposite materials. The composites exhibit concomitant thermal expansion discharge current peaks on cycling around the spin transition temperatures, i.e., new “product properties” resulting from...
Molecular spin crossover complexes are promising candidates for mechanical actuation purposes. The relationships between their crystal structure and properties remain, however, not well understood. In this study, combining high pressure synchrotron X-ray diffraction, nuclear inelastic scattering, micromechanical measurements, we assessed the effective macroscopic bulk modulus (B = 11.5 ± 1.5 GPa), Young's (Y 10.9 1.0 Poisson's ratio (ν 0.34 0.04) of complex [FeII(HB(tz)3)2] (tz...
We report on thermally evaporated, crystalline films of [Fe(HB(tz)<sub>3</sub>)<sub>2</sub>] (tz = triazolyl), which display spin transition around 338 K.
Abstract We report on a bistable MEMS device actuated by spin‐crossover molecules. The consists of freestanding silicon microcantilever with an integrated piezoresistive detection system, which was coated 140 nm thick film the [Fe(HB(tz) 3 ) 2 ] (tz=1,2,4‐triazol‐1‐yl) molecular complex. Switching from low‐spin to high‐spin state ferrous ions at 338 K led reversible upward bending cantilever in agreement change lattice parameters strong mechanical coupling also evidenced decrease...
Two solvatomorphs of the mononuclear bis[hydrotris(1,2,4-triazol-1-yl)borate]iron(II) complex, [Fe(HB(tz)3)2] (1) and [Fe(HB(tz)3)2]·6H2O (1·6H2O), were obtained by modifying nature crystallization solvent. The crystal structure, thermal stability spin crossover properties crystals associated bulk powder samples analysed using variable-temperature single-crystal X-ray diffraction, thermogravimetry, calorimetry, Raman 57Fe Mössbauer spectroscopy as well means magnetic susceptibility optical...
Abstract [Fe II (Htrz) 2 (trz)](BF 4 ) spin crossover particles of 85 nm mean size are dispersed in an SU‐8 polymer matrix and spray‐coated onto silicon microcantilevers. The subsequent photothermal treatment the resist leads to micrometer thick, smooth, homogeneous coatings, which exhibit well‐reproducible actuation upon thermally induced transition. amplitude as a function temperature is accurately determined by combining integrated piezoresistive detection with external optical...
We report large-area (∼3 mm2), pinhole free crossbar junctions of thin films the molecular complex [Fe(HB(tz)3)2] displaying spin transition around 336 K. The charge transport in thinner (10 and 30 nm) occurs by a tunneling mechanism, which is not affected substantially transition. thicker (100 200 exhibit rectifying behavior reproducible drop their electrical resistance ca. 65–80% when switching molecules from high-spin to low-spin state. This current modulation ascribed bulk-limited...
Silicon MEMS cantilevers coated with a 200 nm thin layer of the molecular spin crossover complex [Fe(H2B(pz)2)2(phen)] (H2B(pz)2 = dihydrobis(pyrazolyl)borate and phen 1,10-phenantroline) were actuated using an external magnetic field their resonance frequency was tracked by means integrated piezoresistive detection. The light-induced spin-state switching molecules from ground low to metastable high state at 10 K led well-reproducible shift cantilever's (Δfr −0.52 Hz). Control experiments...
The influence of structural modifications on the catalytic activity carbon materials is poorly understood. A collection carbonaceous with different pore networks and high nitrogen content was characterized used to catalyze four reactions deduce structure-activity relationships. CO2 cycloaddition Knoevenagel reaction depend Lewis basic sites (electron-rich species). absence large conjugated domains resulting from introduction amounts in network responsible for poor redox activity, as observed...
Acetic anhydride (AA) is usually considered a stable molecule but shown here to be able polymerize in closed reactors cross-linked polyketone condensate. By using this chemistry, it was possible copolymerize AA with l-histidine, which gives nitrogen-doped functional nanoporous polymer that can act as an acid–base heterogeneous catalyst. The acidic and basic sites were screened by running acetal hydrolysis Knoevenagel condensation reaction cascade optimize catalyst synthesis. Furthermore,...
An unexpected upshift of the spin transition temperature by ca. 3 K is observed in thermally evaporated films [FeII(HB(tz)3)2] (tz = 1,2,4-triazol-1-yl) complex when reducing film thickness from 200 to 45 nm. Fitting experimental data continuum mechanics and thermodynamical models allows us propose an explanation based on anisotropy transformation strain leading ∼5 mJ/m2 higher 00l surface energy high-spin phase.
Abstract We report on a bistable MEMS device actuated by spin‐crossover molecules. The consists of freestanding silicon microcantilever with an integrated piezoresistive detection system, which was coated 140 nm thick film the [Fe(HB(tz) 3 ) 2 ] (tz=1,2,4‐triazol‐1‐yl) molecular complex. Switching from low‐spin to high‐spin state ferrous ions at 338 K led reversible upward bending cantilever in agreement change lattice parameters strong mechanical coupling also evidenced decrease...
Composite materials made of cellulose fibers and spin crossover micro-particles investigated by dynamic mechanical analysis revealed an abrupt reversible stiffening upon transition from the low to high state.
The spatiotemporal dynamics of the spin transition have been thoroughly investigated in single crystals mononuclear spin-crossover (SCO) complex $[\mathrm{Fe}(\mathrm{HB}(\mathrm{tz}{)}_{3}{)}_{2}]$ ($\mathrm{tz}=1,2$,4-triazol-1-yl) by optical microscopy. This compound exhibits an abrupt centered at 334 K with a narrow thermal hysteresis loop $\ensuremath{\sim}1$ (first-order transition). Most this reveal exceptional resilience upon repeated switching (several hundred cycles), which allowed...
We report the investigation of size evolution lattice dynamics in spin crossover coordination nanoparticles $\mathrm{[}\mathrm{Fe}(\mathrm{pyrazine})(\mathrm{Ni}{(\mathrm{CN})}_{4})]$ through nuclear inelastic scattering (NIS) measurements. Vibrational properties these bistable molecular materials are paramount importance and NIS permits access to partial vibrational density states both [high (HS) low (LS)] from which thermodynamical mechanical can be extracted. show that reduction leads...
A heat exchange dependence was evidenced on both the hysteresis properties and switching dynamics of a spin-crossover single crystal.
Abstract Optical microscopy measurements have been realized on single crystals of the [Fe(1-bpp) 2 ][BF 4 ] complex (1-bpp=2,6-di(pyrazol-1-yl)pyridine). The thermal spin transition around 253 K occurs by a heterogeneous nucleation and growth mechanism involves clear phase separation small hysteresis. This very abrupt complete is preceded premonitory conversion, which implies only fraction (ca. 2–3 %) molecules. peculiar behavior may be sign heterophase fluctuations. light-induced from...
Resistance switching properties of nanoscale junctions spin crossover molecules have received recently much interest. In many cases, this property has been traced back to the variation molecular orbital energies upon transition. However, one can also expect a substantial reorganization structure due charge localization, which calls for better understanding relationship between redox potential and state molecule. To investigate issue, we carried out detailed density functional theory variable...
Abstract The influence of structural modifications on the catalytic activity carbon materials is poorly understood. A collection carbonaceous with different pore networks and high nitrogen content was characterized used to catalyze four reactions deduce structure–activity relationships. CO 2 cycloaddition Knoevenagel reaction depend Lewis basic sites (electron‐rich species). absence large conjugated domains resulting from introduction amounts in network responsible for poor redox activity,...
This work describes the integration of molecular spin crossover (SCO) compound [Fe(H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> B(pz) ) (phen)] 1 (H = dihydrobis(pyrazolyl)borate, phen 1,10phenantroline) into silicon MEMS with aim to determine mechanical properties SCO thin film. Analytical methods using experimental resonance frequency before and after deposition are used extract elastic modulus (E) residual stress (σ) induced by...