Global ETD Search

1	Some properties of platinum pentafluoride and some properties of germanium difluoride Akhtar, Masud January 1965 (has links) Platinum pentafluoride has been prepared, by a new preparative method, in a more stable, pure and crystalline form than the material already described. It has been shown, by x-ray powder photography, to be isomorphous with other noble metal pentafluorides and almost isodimensional with rhodium pentafluoride. A tetrameric structural unit like that observed in ruthenium pentafluoride is also assumed for platinum pentafluoride. Its magnetic properties have been shown to be representative of a third transition series d⁵ ion in a distorted octahedral environment. The nature of the bonding in germanium difluoride is discussed in the light of the crystal structure, which has been deduced from data obtained from single crystals prepared in this work. The products of interaction of chlorine or bromine with the difluoride are consistent with the structural findings. The ¹⁹F n.m.r. spectra of the mixed chlorofluorides (GeFCl₃, GeF₂Cl₂, GeF₃CI, GeF₄ ) and bromofluorides, indicate that intermolecular exchange between these compounds must be extremely slow, at least in the absence of a catalyst. It has been shown that germanium difluoride is so strong a reducing agent that it reduces iodine pentafluoride to iodine below room temperature. The powerful reducing properties of the difluoride were also illustrated by the reduction of platinum tetrafluoride to the metal at room temperature. Attempts to reduce tungsten hexafluoride at 300° led to the formation of Ge₂WF₈. In glass the germanium difluoride reacted with tungsten hexafluoride and the container to yield WO₂F. / Science, Faculty of / Chemistry, Department of / Graduate Platinum pentaluoride Germanium difluoride
2	Studies of new oxidative rearrangements of imines and esters Nongkunsarn, Pakawan January 1996 (has links) No description available. 547 Sodium perborate; Xenon difluoride
3	A molecular orbital study of NF₃, PF₃, and NF₂ Olmstead, Marilyn M. January 1969 (has links) Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
4	Characterization of Sulfonated Perfluorocyclobutane /Poly(Vinylidene Difluoride)-co-Hexafluoropropylene (PFCB/PVDF-HFP) Blends for Use as Proton Exchange Membranes Finlay, Katherine A. 22 April 2013 (has links) The research herein focuses on the characterization of a PFCB/PVDF-HFP (70:30 wt:wt) blend fuel cell membrane including the constitutive and morphological properties, how these properties predict the stresses incurred under fuel cell operating conditions, and how these properties change over time under fuel cell operating conditions. Characterization was performed to mimic temperature and moisture conditions found in operating fuel cells to understand how these materials will behave in service. This included thermal and hygral expansion, mass uptake, and the stress relaxation modulus. These constitutive properties were chosen for characterization such that a model could be created to predict the stresses incurred during fuel cell operation, and examine how these stresses may change under different operating conditions and over time. Based on the results of this model, lifetime predictions were made resulting in recommendations to further extend the operating time of this membrane beyond the DOE 5000 hr requirement. Stress predictions are useful, however if the material properties are changing over time under the fuel cell operating conditions, they may no longer be valid. Therefore, PFCB/PVDF-HFP membranes were conditioned for different amounts of time under conditions similar to those commonly found in operating fuel cells. These conditioned membranes were then characterized and compared with solvent exchanged membranes, the same materials used for previous material characterization. The properties examined included stress relaxation modulus, bi-axial strength, mass uptake, water diffusion, and proton conductivity. To further understand any changes noted in these properties after different environmental exposures, morphological analysis was performed. This included small angle x-ray scattering, infrared spectroscopy, transmission electron microscopy, and differential scanning calorimetry. It was initially found that the proton conductivity decreased severely when the material was immersed at high temperatures over short time periods. This was consistent with changes noted in other properties, and morphological analysis showed a decrease in the ionic network as well as an increase in the phase separation of the PFCB block copolymer as well as the PVDF-HFP crystallinity. These large morphological changes could be very detrimental while in service, resulting in early termination of the fuel cell. However, it was also noted that if these materials are annealed at high temperature (140"C), the negative property changes are abated. This abatement is again tied to the morphology of the material, as annealing the material at high temperature creates stronger physical crosslinks, and induces a small amount of chemical crosslinking via condensation of the sulfonic acid groups, thus allowing the stress predictions performed earlier to have greater validity. Therefore, it is important to not only understand the properties of a material during characterization, but also the underlying polymer structure, and how this structure can change over time, as all of these items control the long term material performance while in service. / Ph. D. Perfluorocyclobutane Polyvinylidene Difluoride Polymer Blend Proton Exchange Membrane Fuel Cell Viscoelasticity Time Tempe
5	Electron Transfer and Other Reactions Using Atomic Metal Anions Butson, Jeffery M. 04 February 2014 (has links) The atomic metal anions Rb-, Cs-, Cu-, Ag- and Fe- have been generated in the gas phase and reacted with various neutral reactants in a triple quadrupole mass spectrometer. The metal anions were formed via electrospray ionization of the metal-oxalate solutions and form in gas phase between the capillary and the first quadrupole. Neutral gas phase reactants investigated include NO, NO2, SO2, C6F5OH, C6F5NH2, C6F6, E-octafluoro-butene and 1,2,3/1,2,4/1,3,5 trifluoro-benzene. When possible, CBS-4M methods were used to suggest the lowest energy products based on relative energy. Observed reactions of atomic metal anions with the aforementioned neutral species include electron transfer and dissociative electron transfer to the neutral gas phase reactants. In addition, hydrogen abstraction and fluorine abstraction forming a neutral metal hydride or fluoride as well as the formation of multiply substituted metal-oxide/fluoride anions was also observed. Metal-complex anions observed from the gas phase reactions include CuF-,CuF2-,CuO-,CuO2-, FeO-, FeO2-, FeO3-, FeF-, FeF2-, FeF3-, CsF- and CsF2-. Metal Anion Metal Anion Atomic Atomic Metal Anion Atomic Metals Atomic Metal Anions Anions Metals Mass Spectrometer Triple Quadrupole Rb Cs Fe Cu Ag Cs- Rb- Fe- Cu- Ag- pentafluoroaniline pentafluorophenol nitrogen dioxide sulfur dioxide nitrogen oxide nitrogen monoxide oxygen oxalic oxalic acid gas phase electrospray ionization electrospray ionization electro-spray ionization electro-spray hexafluorobenzene 1,2,3-trifluorobenzene 1,2,4-trifluorobenzene 1,3,5-trifluorobenzene fluorine E-octafluoro-butene octafluoro-butene octafluoro butene CBS-4M abstraction hydrogen abstraction fluorine abstraction hydride fluoride metal hydride metal fluoride caesium fluoride rubidium fluoride iron fluride copper fluoride rubidium caesium iron copper silver iron anion copper anion rubidium anion caesium anion silver anion cesium cesium anion atomic caesium anion atomic cesium anion atomic rubidium anion atomic iron anion atomic copper anion atomic silver anion 1,2,3 trifluorobenzene 1,2,4 trifluorobenzene 1,3,5 trifluorobenzene copper fluoride anion iron fluoride anion copper difluoride copper difluoride anion iron difluoride iron difluoride anion iron trifluoride iron trifluoride anion cesium fluoride cesium fluoride anion caesium difluoride anion caesium difluoride cesium difluoride cesium difluoride anion caesium fluoride anion nitrogen monoxide anion sulfur dioxide anion nitrogen dioxide anion copper oxide copper oxide anion copper dioxide copper dioxide anion iron oxide iron oxide anion iron dioxide iron dioxide anion iron trioxide iron trioxide anion electron transfer
6	Electron Transfer and Other Reactions Using Atomic Metal Anions Butson, Jeffery M. January 2014 (has links) The atomic metal anions Rb-, Cs-, Cu-, Ag- and Fe- have been generated in the gas phase and reacted with various neutral reactants in a triple quadrupole mass spectrometer. The metal anions were formed via electrospray ionization of the metal-oxalate solutions and form in gas phase between the capillary and the first quadrupole. Neutral gas phase reactants investigated include NO, NO2, SO2, C6F5OH, C6F5NH2, C6F6, E-octafluoro-butene and 1,2,3/1,2,4/1,3,5 trifluoro-benzene. When possible, CBS-4M methods were used to suggest the lowest energy products based on relative energy. Observed reactions of atomic metal anions with the aforementioned neutral species include electron transfer and dissociative electron transfer to the neutral gas phase reactants. In addition, hydrogen abstraction and fluorine abstraction forming a neutral metal hydride or fluoride as well as the formation of multiply substituted metal-oxide/fluoride anions was also observed. Metal-complex anions observed from the gas phase reactions include CuF-,CuF2-,CuO-,CuO2-, FeO-, FeO2-, FeO3-, FeF-, FeF2-, FeF3-, CsF- and CsF2-. Metal Anion Metal Anion Atomic Atomic Metal Anion Atomic Metals Atomic Metal Anions Anions Metals Mass Spectrometer Triple Quadrupole Rb Cs Fe Cu Ag Cs- Rb- Fe- Cu- Ag- pentafluoroaniline pentafluorophenol nitrogen dioxide sulfur dioxide nitrogen oxide nitrogen monoxide oxygen oxalic oxalic acid gas phase electrospray ionization electrospray ionization electro-spray ionization electro-spray hexafluorobenzene 1,2,3-trifluorobenzene 1,2,4-trifluorobenzene 1,3,5-trifluorobenzene fluorine E-octafluoro-butene octafluoro-butene octafluoro butene CBS-4M abstraction hydrogen abstraction fluorine abstraction hydride fluoride metal hydride metal fluoride caesium fluoride rubidium fluoride iron fluride copper fluoride rubidium caesium iron copper silver iron anion copper anion rubidium anion caesium anion silver anion cesium cesium anion atomic caesium anion atomic cesium anion atomic rubidium anion atomic iron anion atomic copper anion atomic silver anion 1,2,3 trifluorobenzene 1,2,4 trifluorobenzene 1,3,5 trifluorobenzene copper fluoride anion iron fluoride anion copper difluoride copper difluoride anion iron difluoride iron difluoride anion iron trifluoride iron trifluoride anion cesium fluoride cesium fluoride anion caesium difluoride anion caesium difluoride cesium difluoride cesium difluoride anion caesium fluoride anion nitrogen monoxide anion sulfur dioxide anion nitrogen dioxide anion copper oxide copper oxide anion copper dioxide copper dioxide anion iron oxide iron oxide anion iron dioxide iron dioxide anion iron trioxide iron trioxide anion electron transfer
7	Poly-Vinylidene Fluoride Based Vibration Spectrum Sensors and Energy Harvestors Nyayapati, Mahidhar Ramesh January 2014 (has links) (PDF) Mechanical vibrations in large structures such as buildings, bridges, dams and critical frequencies in large machinery generally have low frequencies (100Hz-1000Hz). To monitor large areas of such structures we need huge network of low cost, easily manufacturable, self-powered and stand-alone vibration spectrum sensors. The sensors should also consume very little power during their overall operation cycle and have moderately high frequency resoultion. The thesis provides mathematical analysis, design and development of stand-alone, low frequency vibration spectrum analyzer .A mechanically stretched polymer piezoelectric membrane, which has a fixed length and tension, can act as a single frequency detector due to its unique resonant frequency. Stretching multiple ribbons of diffferent lengths and tensions, a vibration spectrum analyzer, which gives the Fourier frequency components present in an arbitrary mechanical input vibration, can be designed. The thesis presents a detailed description of experiments to evaluate a low frequency vibration spectrum analyzer system that accepts an incoming input vibration and directly provides the spectrum as output. Polymer piezoelectric materials being easily manufacturable these sensors can be deployed in wide area sensor networks that monitor large structures. The thesis also shows design of a vibration energy harvesting system based on the concept of harvesting energy at low frequencies. The need for developing such an energy harvesting system arises from the necessity of making the vibration sensor, self-powered. Multiple experimental tests were performed before developing a prototype vibration energy harvesting circuit. Vibration Spectrum Sensors Vibration Energy Harvestors Piezoeletricity Vibration Spectrum Analyzer Polymer Piezoelectric Materials Mechanical Vibrations Poly-Vinylidene Difluoride(PVDF) Vibration Sensing Energy Harvesting Energy Harvestors Vibration Spectrum Sensing Harvesting Energy Vibration Energy Harvesting System Materials Science
8	SYNTHESES AND STRUCTURES OF RHENIUM(VII) AND MANGANESE(VII) OXIDE FLUORIDES, MANGANESE(V, IV) FLUORIDES, AND THE FIRST OXIDE OF XENON(II) Ivanova, Maria January 2016 (has links) This Thesis extends the chemistry of group VII transition metal oxide fluorides, namely ReO3F and MnO3F. The fundamental chemistry of ReO3F has been significantly extended with the development of its high-yield and high-purity synthesis. This has been achieved by solvolysis of Re2O7 in anhydrous HF (aHF) followed by reaction of the water formed with dissolved F2 at room temperature. The improved synthesis has allowed the Lewis acid and fluoride-ion donor-acceptor properties of ReO3F to be further investigated. The Lewis acid-base complex, (HF)2ReO3F·HF, was obtained by dissolution of ReO3F in aHF at room temperature and was characterized by vibrational spectroscopy with aid of quantum-chemical calculations and single-crystal X-ray diffraction at −173 °C. The HF molecules are F-coordinated to rhenium, representing the only known example of an HF complex with rhenium. The study of the fluoride-ion acceptor properties of ReO3F resulted in the syntheses and characterization of the [{ReO3(μ-F)}3(μ3-O)]2−, [ReO3F3]2−, and [ReO3F2]− anions. The [{ReO3(μ-F)}3(μ3-O)]2− anion was obtained as the [N(CH3)4]+ salt by the reaction of stoichiometric amounts of ReO3F and [N(CH3)4]F in CH3CN solvent. The anion was structurally characterized in CH3CN solution by 1D and 2D 19F NMR spectroscopy and in the solid state by Raman spectroscopy and a single-crystal X-ray structure determination of [N(CH3)4]2[{ReO3(μ-F)}3(μ3-O)]·CH3CN. The structure of the [{ReO3(μ-F)}3(μ3-O)]2– anion consists of three ReO3F units linked to each other through dicoordinate bridging fluorine atoms (F) and a central tricoordinate bridging oxygen atom (O3). Calculated vibrational frequencies and Raman intensities of the [{MO3(μ-F)}3(μ3-O)]2− (C3v) and [{MO3(μ-F)}3(μ3-F)]− (C3v) anions (M = Re, Tc) have been used to assign the Raman spectrum of [N(CH3)4]2[{ReO3(μ-F)}3(μ3-O)]·CH3CN. The fac-[ReO3F3]2− and [ReO3F2]− anions have been synthesized by the reactions of ReO3F with CsF and KF in aHF, and by reaction of ReO3F with NOF. Additionally, the [ReO3F2]− anion has been synthesized by the reaction of ReO3F with [NH4]F in aHF. Both anions were characterized by Raman spectroscopy in the solid state and single-crystal X-ray diffraction. The calculated vibrational frequencies of the fac-[ReO3F3]2− (C3v) and [(µ-F)4(ReO3F)4]4− (C4v) anions were used to assign the Raman spectra of fac-[ReO3F3]2− and [ReO3F2]−, respectively. The rhenium atoms in the open-chain, fluorine-bridged [ReO3F2]− anion and the monomeric fac-[ReO3F3]2− anion are six-coordinate with a facial arrangement of the oxygen ligands. The fluoride-ion donor properties were established by the reactions of ReO3F with excess AsF5 and SbF5/SO2ClF. Both reactions resulted in the formation of white friable solids, µ-O(ReO2F)(AsF5)∙2AsF5 and [ReO3][Sb3F16]. The [ReO3][Sb3F16] salt is stable at room temperature and decomposes to [ReO2F2][SbF5], when maintained at 45 oC under dynamic vacuum. The µ-O(ReO2F)(AsF5)∙2AsF5, however, slowly decomposes at 0 oC to ReO3F and AsF5. Both products were characterized by Raman spectroscopy in the solid state with aid of quantum-chemical calculations. The vibrational analyses revealed that the geometry of [ReO3][Sb3F16] is consistent with a trigonal pyramidal arrangement of oxygen atoms around rhenium, whereas in µ-O(ReO2F)(AsF5)∙2AsF5, ReO3F interacts with one of the AsF5 molecules through an O-bridge, which represents the first example of such type of bonding. The reactions of µ-O(ReO2F)(AsF5)∙2AsF5 and [ReO3][Sb3F16] with CH3CN resulted in the formation of the white salts, [O3Re(NCCH3)3][PnF6] (Pn = As, Sb), which were characterized by Raman spectroscopy. The reactivity of ReO3F has been extended to the synthesis of a new Re(VII) oxide fluoride, (μ-F)4{[μ-O(ReO2F)2](ReO2F2)2}, which was synthesized by the reaction of 1:3 molar ratio of ReO3F and ReO2F3. The compound, (μ-F)4{[μ-O(ReO2F)2](ReO2F2)2}, a rare example of an O-bridged rhenium oxide fluoride, has been characterized by single-crystal X-ray diffraction and solid-state Raman spectroscopy. The vibrational assignments of (μ-F)4{[μ-O(ReO2F)2](ReO2F2)2} were confirmed by 18O-enrichment and quantum-chemical calculations. The improved synthesis of ReO3F has also led to the synthesis and characterization of the novel [XeOXeOXe]2+ cation as its [μ-F(ReO2F3)2]− salt by the low-temperature reaction of ReO3F and XeF2 in aHF. The [XeOXeOXe]2+ cation provides an unprecedented example of a xenon(II) oxide and a noble-gas oxocation as well as a rare example of a noble-gas dication. The crystal structure of [XeOXeOXe][µ-F(ReO2F3)2]2 consists of a planar, zigzag-shaped [XeOXeOXe]2+ cation (C2h symmetry) that is fluorine bridged through its terminal xenon atoms to two [µ-F(ReO2F3)2]– anions. The Raman spectra of the natural abundance and 18O-enriched [XeOXeOXe]2+ salts are consistent with a centrosymmetric (C2h) cation geometry. Quantum-chemical calculations were used to aid in the vibrational assignments of [Xe16/18OXe16/18OXe][µ-F(Re16/18O2F3)2]2 and to assess the bonding in [XeOXeOXe]2+ by NBO, QTAIM, ELF, and MEPS analyses. Ion pair interactions occur through Re–Fμ---Xe bridges, which are predominantly electrostatic in nature and result from polarization of the Fμ-atom electron densities by the exposed core charges of the terminal xenon atoms. Each xenon(II) atom is surrounded by a torus of xenon valence electron density comprised of the three valence electron lone pairs. The positive regions of the terminal xenon atoms and associated fluorine bridge bonds correspond to the positive σ-holes and donor interactions that are associated with “halogen bonding”. The reactions of MnO3F with noble-gas fluorides, KrF2 and XeF6, have been studied as the possible synthetic routes to MnOF5 and MnO2F3. The reaction of MnO3F with KrF2 yielded a red solid, which was isolated as a crystalline solid at room temperature and its crystal structure was assigned to manganese(V) fluoride, MnF5. The crystal structure of polymeric MnF5 consists of MnF6-octahedra which are trans-coordinated through fluorine bridges. The geometrical parameters of MnF5 could not be reliably determined due to unresolved twinning issues. The reaction of MnO3F with KrF2 in the presence of K[HF2] yielded a red-orange solid mixture of K[MnF6] (soluble in HF) and MnF3 (insoluble in HF). The HF solution of the solid mixture was characterized by 19F NMR spectroscopy and the resonance observed in the 19F NMR spectrum was preliminary assigned to [MnF6] by comparison with the chemical shift observed in the 19F NMR spectrum of MnO3F. Additionally, MnO3F was characterized by 19F−55Mn COSY NMR and 55Mn NMR spectroscopies, the latter provided the first 1J(19F−55Mn) coupling constant. The K[MnF6] salt was also characterized by single-crystal X-ray diffraction. The resulting octahedral geometry is imposed by symmetry, therefore, the anticipated Jahn-Teller distortion, which would result in D4h symmetry for the [MnF6] anion, could not be observed. The reaction of MnO3F with XeF6 resulted in the isolation of [Xe2F11]2[MnF6] and [XeF5]2[MnF6]. Both salts were characterized by low-temperature single-crystal X-ray diffraction. The [Xe2F11]2[MnF6] salt was additionally characterized by low-temperature Raman spectroscopy with the aid of quantum-chemical calculations, whereas the assignment of the known Raman spectrum of [XeF5]2[MnF6] has been improved in the present work. / Thesis / Doctor of Philosophy (PhD)
9	Development of Multifunctional Biomaterials and Probing the Electric Field Stimulated Cell Functionality on Conducting Substrates : Experimental and Theoretical Studies Ravikumar, K January 2015 (has links) (PDF) Materials with appropriate combinations of multifunctional properties (strength, toughness, electrical conductivity and piezoelectricity) together with desired biocompatibility are promising candidates for biomedical applications. Apart from these material properties, recent studies have shown the eﬃcacy of electric ﬁeld in altering cell functionality in order to elicit various cell responses, like proliferation, diﬀerentiation, apoptosis (programmed cell death) on conducting substrates in vitro. In the above perspective, the current work demonstrates how CaTiO3 (CT) addition to Hydroxyapatite (HA) can be utilised to obtain an attractive combination of long crack fracture toughness (up to 1.7 MPa.m1/2 measured using single edge V-notch beam technique) and a ﬂexural strength of 155 MPa in addition to moderate electrical conductivity. The enhancement of fracture toughness in HA-CT composites has been explained based on the extensive characterization of twinned microstructure in CT along with the use of theoretical models for predicting the enhancement of toughening through crack tip tilt and twist mechanisms. Subsequent in vitro studies on HA-CT composites with human Mesenchymal Stem cells (hMSCs) in the presence of electric ﬁeld has shown enhanced diﬀerentiation towards bone like cells (osteogenic lineage) as evaluated by ALP activity, Collagen content and gene expression analyses through Polymerase Chain Reaction (PCR) at the end of two weeks. he extracellular matrix mineralization analysis at the end of 4 weeks of hMSC culture further substantiated the eﬃcacy of electric ﬁeld as a biochemical cue that can inﬂuence the stem cell fate processes on conducting substrates. The electric ﬁeld stimulation strategy was also implemented in in vitro studies with C2C12 mouse myoblast (muscle) cells on elastically compliant poly(vinylidene diﬂuoride) (PVDF)-multiwall carbon nanotube (MWNT) composite substrates. PVDF is a piezoelectric polymer and the addition of MWNTs makes the composite electrically conducting. Upon, electric ﬁeld stimulation of C2C12 mouse myoblast cells on these composites, has been observed that in a narrow window of electric ﬁeld parameters, the cell viability was enhanced along with excellent cell alignment and cell-cell contact indicating a potential application of PVDF-based materials in the muscle cell regeneration. In an eﬀort to rationalise such experimental observations, a theoretical model is proposed to explain the development of bioelectric stress ﬁeld induced cell shape stability and deformation. A single cell is modelled as a double layered membrane separating the culture medium and the cytoplasm with diﬀerent dielectric properties. This system is linearized by invoking Debye-Huckel approximation of the Poisson-Boltzmann equation. With appropriate boundary conditions, the system is solved to obtain intracellular and extracellular Maxwell stress as a function of multiple parameters like cell size, intracellular and extracellular permittivity and electric ﬁeld strength. Based on the stresses, we predict shape changes of cell membrane by approximating the deformation amplitude under the inﬂuence of electric ﬁeld. Apart from this, the shear stress on the membrane has been used to determine the critical electric ﬁeld required to induce membrane breakdown. The analysis is conducted for a cell in suspension/on a conducting substrate and on an insulating substrate to illustrate the eﬀect of substrate properties on cell response under the inﬂuence of external electric ﬁeld. Multi Functional Biomaterials Mechanical Properties - Composite Electric Field Induced Osteogenesis HA-Metal Composites HA-Polymer Composites HA-Ceramic Composites HA–CaTiO3 Composites PVDF-MWNT Composites poly(vinylidene difluoride) (PVDF) Multi-walled Carbon Nanotubes (MWNTN Hydroxyapatite- CaTiO3 Composites Materials Science
10	Synthèse et études photophysiques de matériaux PI-conjugés - Complexes de difluorure de Bore des ligands Beta-dicétone à conjugaison PI-étendue / Synthesis and Photophysical studies of π-conjugated materials-Boron difluoride complexes of β-diketonates ligands with extended π-conjugation Felouat, Abdellah 30 September 2014 (has links) Une nouvelle famille de complexes de difluorure de bore photosensibles est développée. Elle est basée sur des structures moléculaires contenant une unité β-dicétone à conjugaison électronique π.La grande variété de groupements aromatiques et la nature donneur ou accepteur d'électrons des différents substituants permet l'élaboration de systèmes électroniques donneur-accepteur-donneur d'électrons (D1-A-D1) et donneur-accepteur (D2-A).L'absorption électronique de cette famille de molécule se situe dans la partie visible du spectre électromagnétique et une partie du spectre ultraviolet, et est caractérisée par une bande d'absorption π-π* intense avec des coefficients d'absorption molaire supérieurs à 50 000 M-1cm-1.L'émission de fluorescence couvre une plage spectrale qui va du visible au proche infrarouge avec des rendements quantiques de fluorescence en solution relativement élevés pouvant atteindre 62 %.En fin, cette famille de molécule est photochimiquement stable et est, contrairement à d'autres familles de complexes de difluorure de bore, chimiquement très stable en solution.Mots-clés : Difluorure de bore, β-dicétone, matériaux π-conjugués, luminescence, fluorescence stationnaire et résolue dans le temps (TRES), synthèse organique, RMN-19F dynamique, complexes & colorants fluorescents, curcumine & curcuminoide, complexe BF2, photophysique. / A new photosensitive family of boron difluoride complex is developed. It is based on π-conjugated molecular structures containing β-diketonates unit.The wide variety of aromatic groups and the nature of donor or electron acceptor of the different substituents allow the development of electron donor-acceptor-donor (DAD) and donor-acceptor (DA) electronic systems.The electronic absorption of this family of molecules is in the visible part of the electromagnetic spectrum and a portion of the ultraviolet spectrum, and is characterized by an intense π-π* absorption band with molar absorption coefficient greater than 50 000 M-1.cm-1.The fluorescence emission covers a spectral range going from visible to near infrared, with relatively high fluorescence quantum yields of up to 62 % in solution.This new material family is photochemically stable and, unlike some other families of boron difluoride complexes, chemically very stable in solution. Difluorure de bore Β-Dicétone Matériaux π-Conjugués Luminescence Synthèse organique RMN-19F dynamique Complexes & colorants fluorescents Curcumine & curcuminoide Complexe BF Boron difluoride Β-Diketone Π-Conjugated materials Photophysics Organic synthesis Luminescence Fluorescent complexes & dyes Dynamic 19F-NMR (19F-DNMR) Curcumin & curcuminoid BF2 compl 540

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