showing 27 related works from this author
Effect of the Mo atom flow on the molybdenum growth on TiO2 (110) surface
2004
Abstract Molybdenum has been deposited at room temperature on stoichiometric TiO 2 (1 1 0) surfaces with two deposition rates: 0.1 equivalent monolayer (eqML) and 1.5 eqML min −1 . X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy studies clearly reveal an effect of the deposition rate upon the growth mode and the interfacial reaction. Indeed, whereas a strong interfacial reaction between Mo and TiO 2 involves a Stranski–Krastanov growth mode with the formation of amorphous molybdenum oxide monolayers for the lowest deposition rate, no reaction can be observed for the highest deposition rate. Moreover in this latter case, the growth mode seems to be a 3D …
Surface Acoustic Wave Sensors for the Detection of Hazardous Compounds in Indoor Air
2017
Presented at the Eurosensors 2017 Conference, Paris, France, 3–6 September 2017.; International audience; In this work, the authors show the capabilities of Surface Acoustic Wave (SAW) devices coupled with various absorbents to probe the properties of gas sensitive materials for the manufacturing of hazardous gas sensors. The great capabilities of cobalt corroles for the trapping of carbon monoxide (CO) were exploited to produce selective sensors. These corroles were deposited on SAW delay lines surfaces and then exposed to carbon monoxide (CO) in standard conditions. Concentrations of a few hundreds of ppb were measured emphasizing the interest of such sensors for the detection of CO. Anot…
Synthesis, Characterization, and Electrochemistry of Open-Chain Pentapyrroles and Sapphyrins with Highly Electron-Withdrawing meso -Tetraaryl Substit…
2017
International audience; A series of open-chain pentapyrroles and sapphyrins with highly electron-withdrawing substituents (i.e., CN, CF3 , or CO2 Me) on the meso-phenyl rings was synthesized and characterized as to the spectral properties, protonation reactions, and electrochemistry in non-aqueous media. The investigated compounds are represented as (Ar)4 PPyH3 and (Ar)4 SapH3 where PPy and Sap correspond to the tri-anion of the open-chain pentapyrrole and sapphyrin, respectively, and Ar=p-CNPh, p-CF3 Ph, or p-CO2 MePh. UV/Vis and 1 H NMR spectroscopy as well as mass spectrometry data are given for the confirmation of the structures for the newly synthesized compounds. An X-ray structure fo…
Cobalt Corroles with Bis‐Ammonia or Mono‐DMSO Axial Ligands. Electrochemical, Spectroscopic Characterizations and Ligand Binding Properties
2018
International audience; Four bis-ammonia ligated cobalt corroles and four mono-DMSO ligated cobalt corroles with different mesoaryl substituents on the macrocycle (A 2 Band A 3-corroles) were synthesized and investigated as to their electrochemical and spec-troscopic properties under different solution conditions. The complexation energies of the investigated cobalt corroles were theoretically calculated to illustrate the propensity of the cobalt center for pentacoordination or hexa-coordination with various axial ligands (DMSO, CO, py and NH 3). The structure of one hexacoordinate bis-NH 3 cobalt corrole complex was also determined by X-ray diffraction.
MoO (x≤2) ultrathin film growth from reactions between metallic molybdenum and TiO2 surfaces
2001
Abstract Exposures to oxygen at room temperature and annealings under vacuum were carried out on deposits obtained from molybdenum interacting with (1 1 0) TiO 2 surfaces in order to obtain molybdenum oxide ultra thin films. Exposures to oxygen at room temperature show that the interfacial molybdenum oxide layers resulting from the TiO 2 /Mo interactions are inactive towards oxygen whereas the metallic molybdenum clusters, which grew on top of the interfacial layers, oxidise into MoO 3 . Besides, during annealings under vacuum, substrate oxygen anions can diffuse into the deposit. Thus, between 400 and 500°C, molybdenum oxide layers are progressively oxidised into MoO 2 . Moreover, from the…
Synthesis, electrochemistry, protonation and X-ray analysis of meso-aryl substituted open-chain pentapyrroles
2019
Five meso-tetraaryl open-chain pentapyrroles were synthesized and characterized as to their electrochemistry and protonation reactions in nonaqueous media. The investigated compounds are represented as (Ar)4PPyH3 where Ar [Formula: see text],[Formula: see text]-F2Ph, [Formula: see text]-BrPh, Ph, [Formula: see text],[Formula: see text],[Formula: see text]-(OMe)3Ph or [Formula: see text]-MePh and were characterized by UV-vis and 1H NMR spectroscopy, mass spectrometry and electrochemistry. Cyclic voltammetry was used to measure redox potentials, while protonation involving the conversion of (Ar)4PPyH3 to [(Ar)4PPyH5][Formula: see text] was monitored by UV-vis absorption spectroscopy. Equilib…
Covalent Organic Frameworks for the detection of CO
2021
International audience; Every year in the world, carbon monoxide (CO) is responsible for thousands of intoxications and hundreds of deaths. The detection (CO) at few ppm levels is thus a critical point for the control of the air quality. Corrole belongs to the family of porphyrinoids which is largely used for sensing applications [1]. We have shown that cobalt metallocorroles are able to bind carbon monoxide in the axial position with a high affinity even in the presence of nitrogen and dioxygen, the two main components of the atmosphere [2]. We have recently prepared sensing devices for low CO detection level (sub-ppm) using cobalt corroles deposited as films on a Surface Acoustic Wave dev…
Electrosynthesis of Poly(alanine)-Like Peptides in Concentrated Alanine Based Electrolytes, Characterization Coupled to DFT Study and Application to …
2014
The anodic oxidation of concentrated l-alanine on smooth electrodes such as platinum and glassy carbon electrodes was studied. Contrary to the previous studies performed up to now with diluted l-alanine, the electrochemical process generated here results in a completely different situation. The oxidation on smooth platinum was carried out by electrochemical quartz crystal microbalance (EQCM) coupled to cyclic voltammetry technique. The effects of concentration, scan rate, and pH (zwitterion at pH = 6 and alkaline media at pH = 13) on potential values were examined. Glassy carbon and smooth gold electrodes showed the same behavior as on smooth platinum electrode. Spectroscopic analysis such …
Molybdenum thin-film growth on rutile titanium dioxide ()
2002
Molybdenum films were deposited at room temperature on rutile TiO2(1 1 0) surfaces having different stoichiometries, surface roughnesses and crystallinities. The film structures and compositions and the substrate–film interfaces were investigated by X-ray diffraction, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. Different substrate pretreatments resulted in markedly different film and interface structures. Under the growth conditions studied, no amorphous molybdenum oxide interlayers were formed upon deposition in contrast to previous studies. Preferred (1 1 0) textured Mo films grew on both air-annealed and oxygen-bombarded substrates. While sh…
Detection and monitoring of carbon monoxide using cobalt corroles film on Love wave devices with delay line configuration
2011
Among specific sensitive materials synthesized for chemical sensor development, cobalt corrole have shown attractive capabilities for CO detection [1, 2]. In this paper, we investigate the possibility to exploit such materials to develop surface acoustic wave (SAW)-based sensors. We actually demonstrate that SAW devices using delay line configuration allow investigating the molecular recognition occurring in non-conductive sensing layers of cobalt corroles. We have monitored phase variations of SAW devices versus various CO concentrations. Moreover, a specific testing setup has been developed to precisely dose CO at low concentrations, to avoid any CO leakage in the environment, to systemat…
Effect of the surface stoichiometry on the interaction of Mo with TiO2 (110)
2000
Abstract Molydenum has been deposited at room temperature on (110) TiO2 surfaces with different stoichiometries, roughnesses and crystallinities. Whatever the substrate preparation is, in-situ Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) studies as well as ex-situ atomic force microscopy (AFM) and reflexion high-energy electron diffraction (RHEED) studies reveal a Stranski–Krastanov growth mode: the completion of three monolayers followed by islands growth is observed in every case. The three monolayers are always composed of amorphous molybdenum oxide with an oxidation state of molybdenum less than IV. The oxidation of the molybdenum layers generates Ti3+ an…
Reconstitution of a protein monolayer on thiolates functionalized gaas surface
2012
International audience; In the aim to realize an efficient resonant biosensor, gallium arsenide (GaAs) presents many advantages. In addition to its properties of transduction, GaAs is a crystal for which microfabrication processes were developed, conferring the possibility to miniaturize the device and integrate electronic circuit. Moreover, the biofunctionalization could be realized on the crystalline surface without layer deposition, constituting a real advantage to perform reusable sensor. The functionalization of GaAs surface was engaged in order to immobilize a protein monolayer on this substrate. Functionalization was done using a mixed self assembled monolayer of thiolate molecules. …
Experimental and theoretical studies on electropolymerization of polar amino acids on platinum electrode
2017
International audience; The anodic oxidation of polar amino acids (L-serine, L-threonine, L-asparagine, and L-glutamine) in aqueous electrolyte on smooth platinum electrode was carried out by cyclic voltammetry coupled to electrochemical quartz crystal microbalance (EQCM). pH (zwitterion, acidic and alkaline) effects on their electrochemical behavior were examined. The maximum current values are measured for zwitterion species. In addition, the current increases with increasing of concentration and scan rate, and decreases with increasing pH. The resulting passivation was studied by spectroscopic analysis such as attenuated total reflection FT infrared spectroscopy (ATR-FTIR), X-ray photoel…
Oxide or carbide nanoparticles synthesized by laser ablation of a bulk Hf target in liquids and their structural, optical, and dielectric properties
2016
International audience; Laser ablation of a bulk Hf target in deionized (DI) water, ethanol, or toluene was carried out for the production of nanoparticles' colloidal solutions. Due to the interaction of the ablation plasma plume species with the species which are produced by the liquid decomposition at the plume-liquid interface, hafnia (HfO2) nanoparticles are synthesized in DI water, hafnium carbide (HfC) nanoparticles in toluene, and a mixture of these in ethanol. The hafnia nanoparticles are in the monoclinic low temperature phase and in the tetragonal and fcc high temperature phases. Their size distribution follows log-normal function with a median diameter in the range of 4.3–5.3 nm.…
Electrochemistry of Bis(pyridine)cobalt (Nitrophenyl)corroles in Nonaqueous Media
2018
International audience; A series of bis(pyridine)cobalt corroles with one or three nitrophenyl groups on the meso positions of the corrole macrocycle were synthesized and characterized as to their electrochemical and spectroscopic properties in dichloromethane, benzonitrile, and pyridine. The potentials for each electrode reaction were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV-visible spectra of the neutral, electroreduced, and electroxidized forms of the corroles. The proposed electronic configurations of the initial compounds and the prevailing redox reactions involving the electroactive central c…
SAW based CO2 sensor: influence of functionalizing MOF crystal size on the sensor's selectivity
2021
International audience; The potential impact of indoor air quality on human health has become an increasingly important topic of public health and, thus, has stimulated an interest in hazardous compounds survey such as carbon dioxide. To address this issue, we started the development of a Surface Acoustic Wave device functionalized with metal-organic framework for the selective detection of carbon dioxide. Here, we propose preliminary results on the influence of the size of the metal-organic framework crystals on the sensor’s selectivity and on its evolution with the ageing of the sensor
Electrochemistry of Mono- and Bis-CN Ligated Cobalt Corroles
2021
International audience; The electrochemical properties of numerous transition metal corroles have been examined under a variety of<br>solution condition with special emphasis being placed on the innocent or non-innocent nature of the corrole<br>macrocycle. This property, as well as the half-wave potentials and sites of electron transfers, are known to be<br>strongly influenced by the type of central metal ion and degree of axial coordination, namely 4, 5 or 6-coordinate.<br>The redox potentials of metallocorroles are also dependent upon the solvent and inductive, resonance or steric<br>effects dictated by peripheral substituents at the meso or β-pyrrole positions of the corrole li…
Development of acoustic devices functionalized with cobalt corroles or metalloporphyrines for the detection of carbon monoxide at low concentration
2012
International audience; Progresses in synthetic chemistry methodologies has pushed to develop a large variety of artificial receptors of particular interest for chemical sensor applications. We investigate here the behavior of gas sensors based on surface acoustic wave (SAW) devices. The use of Love waves that are specially sensitive to surface perturbation enables to exploit the molecular recognition processes occurring in non conductive sensing layers of cobalt corroies [5,10,15-Tris(2,6-dichlorophenyl)corrolato]cobalt(III)] for CO detection. We have monitored phase variations of Love-wave-based delay lines under various operation conditions and studied the detection efficiency of a diffe…
Functionnalized Surface Acoustic Wave Sensors for the Detection of Hazardous Gases
2018
International audience; In this work, we show the capabilities of Surface Acoustic Wave (SAW) devices to probe the properties of gas sensitive materials for the manufacturing of hazardous gas sensors. The great capabilities of cobalt corroles for the trapping of carbon monoxide (CO) were exploited to produce selective sensors. These corroles were deposited on SAW delay lines surfaces and then exposed to carbon monoxide (CO) in standard conditions. Concentrations of a few hundreds of ppb were measured emphasizing the interest of such sensors for the detection of CO. Another type of sensitive layers exhibiting specific porosity adapted to the trapping of formaldehyde (CH$_2$O) were deposited …
Mono-DMSO ligated cobalt nitrophenylcorroles: electrochemical and spectral characterization
2018
Four mono-DMSO ligated cobalt corroles with one or three meso-nitrophenyl substituents on the macrocycle were synthesized and investigated as to their electrochemical and spectroscopic properties in CH2Cl2 and DMSO. Comparisons are made between redox reactions of the five-coordinate DMSO adducts in the current study and earlier examined five- and six-coordinate cobalt corroles with pyridine axial ligands which were characterized in a variety of nonaqueous electrochemical solvents. The binding of carbon monoxide (CO) is also investigated.
Porous Organic Polymers (POPs) based on cobalt corroles for the detection of carbon monoxide
2021
International audience; Detection of carbon monoxide (CO) at few ppm levels is a critical point for quality control of domestic and<br>industrial environment. CO is responsible for thousands of intoxications and hundreds of deaths per year in the<br>world. Moreover, CO is a residual gas found in the industrial dihydrogen used for Proton Exchange Membrane<br>fuel cell, and deactivates the fuel cell prematurely. Corroles have been largely used in sensing applications.[1]<br>Cobalt corroles display high binding affinity for carbon monoxide even in the presence of nitrogen and<br>dioxygen.[2] The affinity of the Co(III) metallocorroles for CO is directly correlated with the Lewis acid…
Influence of interfering gases on a carbon monoxide differential sensor based on SAW devices functionalized with cobalt and copper corroles
2021
International audience; <!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:TrackMoves/> <w:TrackFormatting/> <w:HyphenationZone>21</w:HyphenationZone> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:DoNotPromoteQF/> <w:LidThemeOther>FR</w:LidThemeOther> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> <w:SplitPgBreakAndParaMark/> <w:EnableOpenTypeKe…
CCDC 1539258: Experimental Crystal Structure Determination
2017
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CCDC 1578032: Experimental Crystal Structure Determination
2018
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CCDC 1812155: Experimental Crystal Structure Determination
2018
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CCDC 1554869: Experimental Crystal Structure Determination
2019
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CCDC 1815709: Experimental Crystal Structure Determination
2018
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