Fonctionalization methods of boradiazaindacenes for specific applications

Ce travail de thèse a consisté en la synthèse et la modification de composés fluorescents de type bora-diaza-indacène (ou BODIPY). Dans un premier temps, nous nous sommes intéressés à la synthèse de systèmes multichromophoriques entièrement organiques. L'The objective of this thesis was the synthesis and the modification of boradiazaindacenes (or BODIPYs) for various applications. At first, we focused on the synthesis of organic multichromophoric arrays containing up to five different chromophores. The p

Méthodes de fonctionnalisation de boradiazaindacènes pour des applications spécifiques

Ce travail de thèse a consisté en la synthèse et la modification de composés fluorescents de type bora-diaza-indacène (ou BODIPY). Dans un premier temps, nous nous sommes intéressés à la synthèse de systèmes multichromophoriques entièrement organiques. L étude photophysique a montré que plus de 80% de l énergie absorbée par ces systèmes était transférée vers le chromophore de plus basse énergie. Dans le projet suivant, nous nous sommes intéressés à l introduction d une fonction bioconjugable sur ces dérivés BODIPYs à l aide de la réaction de carbonylation catalysée au palladium. Après une étude méthodologique, au cours de laquelle plusieurs substrats ont pu être introduits efficacement, nous avons été en mesure d obtenir un acide aminé marqué qui a pu être utilisé dans une synthèse peptidique automatisée. Ce mémoire expose également une méthode originale de fonctionnalisation sélective d un ou des deux méthyles en position a-pyrroliques des BODIPYs à l aide de nucléophiles. L'étude photophysique des nouveaux composés a montré que cette transformation permettait d introduire de nouveaux substituants sans modifier les propriétés d'absorption et d'émission du fluorophore. Enfin, la présence d un atome de bore tétravalent dans les BODIPYs nous a permis d envisager la synthèse d un fluorophore chiral comportant un bore stéréogène. Après plusieurs essais infructueux, nous sommes parvenus à synthétiser de façon racémique un BODIPY chiral qui a pu être dédoublé sur HPLC chirale. Les deux énantiomères ont été entièrement caractérisés et la stabilité configurationnelle du bore dans les conditions ambiantes a été démontrée.The objective of this thesis was the synthesis and the modification of boradiazaindacenes (or BODIPYs) for various applications. At first, we focused on the synthesis of organic multichromophoric arrays containing up to five different chromophores. The photophysical study showed that the energy absorbed by these systems was almost quantitatively transferred towards the lowest energy chromophore. In the following project, we focused on the introduction of a bioconjugable function on BODIPYs using the Palladium catalysed carbonylation reaction. After a methodological study, during which several substrates were efficiently introduced, we were able to synthesize a fluorescent-labeled amino acid which was used in automated peptide synthesis. We also developped an original and selective fonctionnalization of one or both methyl groups in alpha-pyrrolic position of BODIPYs by the use of nucleophiles. The photophysical study of the new compounds showed that this transformation allowed the introduction of new substituants without modifying the spectroscopic properties of the fluorophore. Finally, the presence of a tetravalent boron atom in BODIPYs allowed us to synthesize a chiral fluorophore containing a stereogenic boron. After several unsuccessfull attempts, we succeeded in synthetizing a chiral BODIPY which was resolved on chiral HPLC. Both enantiomers were completely characterized and configurational stability of the boron in ambient conditions was demonstrated.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

An artificial light-harvesting array constructed from multiple Bodipy dyes.

International audienceAn artificial light-harvesting array, comprising 21 discrete chromophores arranged in a rational manner, has been synthesized and characterized fully. The design strategy follows a convergent approach that leads to a molecular-scale funnel, having an effective chromophore concentration of 0.6 M condensed into ca. 55 nm(3), able to direct the excitation energy to a focal point. A cascade of electronic energy-transfer steps occurs from the rim to the focal point, with the rate slowing down as the exciton moves toward its ultimate target. Situated midway along each branch of the V-shaped array, two chromophoric relays differ only slightly in terms of their excitation energies, and this situation facilitates reverse energy transfer. Thus, the excitation energy becomes spread around the array, a situation reminiscent of a giant holding pattern for the photon that can sample many different chromophores before being trapped by the terminal acceptor. At high photon flux under conditions of relatively slow off-load to a device, such as a solar cell, electronic energy transfer encounters one or more barriers that hinder forward progress of the exciton and thereby delays arrival of the second photon. Preliminary studies have addressed the ability of the array to function as a sensitizer for amorphous silicon solar cells

Development of a caspase-3 probe for apoptosis detection by dual optical-nuclear imaging

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Development of a caspase-3 probe for apoptosis detection by dual optical-nuclear imaging

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Development of chemiluminescent probes for enzymatic activity detection.

International audienc

Development of a caspase-3 probe for apoptosis detection by dual optical-nuclear imaging

International audienc

Development of chemiluminescent probes for enzymatic activity detection.

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Boron Dipyrromethene Chromophores: Next Generation Triplet Acceptors/Annihilators for Low Power Upconversion Schemes

International audienceIn the present study, the red-light absorbing platinum(II) tetraphenyltetrabenzoporphyrin (PtTPBP) was used as a triplet sensitizer in conjunction with two distinct iodophenyl-bearing BODIPY derivatives independently serving as triplet acceptors/annihilators poised for photon upconversion based on triplet-triplet annihilation. In deaerated benzene solutions, extremely stable and high quantum efficiency green (Phi(UC) = 0.0313 +/- 0.0005) and yellow (Phi(UC) = 0.0753 +/- 0.0036) upconverted emissions were observed from selective red excitation of the PtTPBP sensitizer at 635 +/- 5 nm. The current systems represent the first examples of photon upconversion where aromatic hydrocarbons do not serve the role of triplet acceptor/annihilator. Notably, the nature of the current chromophore compositions permitted highly reproducible upconversion quantum efficiency determinations while permitting the evaluation of the triplet-triplet annihilation quantum yields in both instances

Borondipyrromethene dyes with pentane-2,4-dione anchors

New, acetylacetone-linked borondipyrromethene (BODIPY) dyes were readily obtained from BODIPY cores by various protocols involving direct grafting with acetylacetone or cross-coupling from a preorganized phenylacacH derivative bearing either an iodo or an ethynyl function. Facile anchoring on TiO(2) powder is obtained and scrutinized by FT-IR spectroscopy