Konstanz, Univ., Diss., 2008.

Konstanz, Univ., Diss., 2008. / Ersch. auch gedruckt im Cuvillier-Verlag. - ISBN 9783867275996.

Este trabalho apresenta a síntese, caracterização e estudo fotofísico de novos heterociclos benzazólicos fluorescentes com potencial aplicação como sondas de ambientes lipídicos. Para isso, foram sintetizados três corantes que contêm em sua estrutura cadeias alquílicas de oito, doze e dezoito átomos de carbono ligados a um núcleo benzazólico que é o responsável pela fluorescência destes compostos. O corante que possui a cadeia alquílica de dezoito carbonos apresenta-se ainda na forma de um sal de amônio quaternário, com o objetivo de tornar a sua estrutura mais anfifílica do que os seus análogos neutros de oito e doze carbonos, e com isso, promover a interação entre meios que apresentam polaridade diferente como, por exemplo, água e membrana. A obtenção dos derivados contendo oito e doze carbonos foi realizada a partir da reação de substituição nucleofílica entre o heterociclo 2-(5’-amino-2’-hidroxifenil)benzoxazol e os respectivos iodoalcanos em presença de uma base, com rendimentos na faixa de 45%. O derivado com dezoito carbonos foi obtido em duas etapas, sendo a primeira a reação entre o 2- (5’-amino-2’-hidroxifenil)benzoxazol e a epicloridrina para formar o intermediário 2-(5’(N-3- cloro-2-hidroxipropilamina)-2’-hidroxifenil)benzoxazol. A reação deste intermediário com a N,N-dimetiloctadecilamina levou a formação do corante na forma de sal de amônio quaternário com 68% de rendimento. Os corantes foram caracterizados por Infravermelho, Ressonância Magnética Nuclear de Hidrogênio e de Carbono, Análise Elementar e ponto de fusão, além da caracterização fotofísica. O estudo fotofísico do sistema fosfatidilcolina/corante mostrou que os corantes sofrem a influência do meio lipídico, bem como a afinidade do corante quaternizado pelo sistema lipídico diferencia-se dos corantes neutros. Além disso, os corantes com cadeias alquílicas de oito e doze átomos de carbono se mostraram sondas mais eficientes para meios apolares ou polares apróticos e são liberados para o meio com o aumento da diluição do sistema. Já o corante com cadeia alquílica de dezoito átomos de carbono apresentou maior afinidade com o ambiente hidrofílico do sistema lipídico, ficando incorporado na bicamada lipídica, mesmo com o aumento da diluição. / This work presents the synthesis, characterization and photophysical study of new fluorescent benzazólicos heterocycles with potential application as probes of lipid environments. For this, three dyes were synthesized containing alkyl chains in the structure of eight, twelve and eighteen carbon atoms attached to a core benzazólico which is responsible for the fluorescence of these compounds. The dye that has the alkyl chain of eighteen carbons still presents as a quaternary ammonium salt, with the goal of making its structure more amphiphilic than their neutral analogues of eight and twelve carbons, and thereby promote the interaction means that present different polarity, for example, water and membrane. The obtaining of derivatives containing eight twelve carbons was made from the nucleophilic substitution reaction between the heterocycle 2-(5'-amino-2'-hydroxyphenyl) benzoxazole and its iodoalcanos in the presence of a base, with yields around 45%. The derivative eighteen carbons was obtained in two steps, the first being the reaction between 2- (5'-amino-2'-hydroxyphenyl) benzoxazole and epichlorohydrin to form the intermediate 2- (5'(N-3-chloro-2-hydroxypropylamine)-2'-hydroxyphenyl) benzoxazole. The reaction of this intermediate with N, N-dimetiloctadecilamina led to the formation of the desired compound quaternised 68% yield. The compounds were characterized by infrared, nuclear magnetic resonance of hydrogen and carbon, elemental analysis and melting point, besides the characterization photophysics. The photophysical study of the phosphatidylcholine/dye system showed that the dyes suffer the influence of the lipid and affinity of the dye quaternized by the system differs from dyes that show no load. In addition, the neutral dyes with alkyl chains content eight and twelve carbon atoms, proved most interesting probes for apolar media or polar aprotic media and are released into the medium with increasing dilution of the system. Already the derivative with eighteen carbon atoms and having quaternary nitrogen showed higher affinity for hydrophilic environment lipid system, becoming incorporated into the lipid bilayer, even with increased dilution.

Este trabalho apresenta a síntese, caracterização e estudo fotofísico de novos heterociclos benzazólicos fluorescentes com potencial aplicação como sondas de ambientes lipídicos. Para isso, foram sintetizados três corantes que contêm em sua estrutura cadeias alquílicas de oito, doze e dezoito átomos de carbono ligados a um núcleo benzazólico que é o responsável pela fluorescência destes compostos. O corante que possui a cadeia alquílica de dezoito carbonos apresenta-se ainda na forma de um sal de amônio quaternário, com o objetivo de tornar a sua estrutura mais anfifílica do que os seus análogos neutros de oito e doze carbonos, e com isso, promover a interação entre meios que apresentam polaridade diferente como, por exemplo, água e membrana. A obtenção dos derivados contendo oito e doze carbonos foi realizada a partir da reação de substituição nucleofílica entre o heterociclo 2-(5’-amino-2’-hidroxifenil)benzoxazol e os respectivos iodoalcanos em presença de uma base, com rendimentos na faixa de 45%. O derivado com dezoito carbonos foi obtido em duas etapas, sendo a primeira a reação entre o 2- (5’-amino-2’-hidroxifenil)benzoxazol e a epicloridrina para formar o intermediário 2-(5’(N-3- cloro-2-hidroxipropilamina)-2’-hidroxifenil)benzoxazol. A reação deste intermediário com a N,N-dimetiloctadecilamina levou a formação do corante na forma de sal de amônio quaternário com 68% de rendimento. Os corantes foram caracterizados por Infravermelho, Ressonância Magnética Nuclear de Hidrogênio e de Carbono, Análise Elementar e ponto de fusão, além da caracterização fotofísica. O estudo fotofísico do sistema fosfatidilcolina/corante mostrou que os corantes sofrem a influência do meio lipídico, bem como a afinidade do corante quaternizado pelo sistema lipídico diferencia-se dos corantes neutros. Além disso, os corantes com cadeias alquílicas de oito e doze átomos de carbono se mostraram sondas mais eficientes para meios apolares ou polares apróticos e são liberados para o meio com o aumento da diluição do sistema. Já o corante com cadeia alquílica de dezoito átomos de carbono apresentou maior afinidade com o ambiente hidrofílico do sistema lipídico, ficando incorporado na bicamada lipídica, mesmo com o aumento da diluição. / This work presents the synthesis, characterization and photophysical study of new fluorescent benzazólicos heterocycles with potential application as probes of lipid environments. For this, three dyes were synthesized containing alkyl chains in the structure of eight, twelve and eighteen carbon atoms attached to a core benzazólico which is responsible for the fluorescence of these compounds. The dye that has the alkyl chain of eighteen carbons still presents as a quaternary ammonium salt, with the goal of making its structure more amphiphilic than their neutral analogues of eight and twelve carbons, and thereby promote the interaction means that present different polarity, for example, water and membrane. The obtaining of derivatives containing eight twelve carbons was made from the nucleophilic substitution reaction between the heterocycle 2-(5'-amino-2'-hydroxyphenyl) benzoxazole and its iodoalcanos in the presence of a base, with yields around 45%. The derivative eighteen carbons was obtained in two steps, the first being the reaction between 2- (5'-amino-2'-hydroxyphenyl) benzoxazole and epichlorohydrin to form the intermediate 2- (5'(N-3-chloro-2-hydroxypropylamine)-2'-hydroxyphenyl) benzoxazole. The reaction of this intermediate with N, N-dimetiloctadecilamina led to the formation of the desired compound quaternised 68% yield. The compounds were characterized by infrared, nuclear magnetic resonance of hydrogen and carbon, elemental analysis and melting point, besides the characterization photophysics. The photophysical study of the phosphatidylcholine/dye system showed that the dyes suffer the influence of the lipid and affinity of the dye quaternized by the system differs from dyes that show no load. In addition, the neutral dyes with alkyl chains content eight and twelve carbon atoms, proved most interesting probes for apolar media or polar aprotic media and are released into the medium with increasing dilution of the system. Already the derivative with eighteen carbon atoms and having quaternary nitrogen showed higher affinity for hydrophilic environment lipid system, becoming incorporated into the lipid bilayer, even with increased dilution.

Este trabalho apresenta a síntese, caracterização e estudo fotofísico de novos heterociclos benzazólicos fluorescentes com potencial aplicação como sondas de ambientes lipídicos. Para isso, foram sintetizados três corantes que contêm em sua estrutura cadeias alquílicas de oito, doze e dezoito átomos de carbono ligados a um núcleo benzazólico que é o responsável pela fluorescência destes compostos. O corante que possui a cadeia alquílica de dezoito carbonos apresenta-se ainda na forma de um sal de amônio quaternário, com o objetivo de tornar a sua estrutura mais anfifílica do que os seus análogos neutros de oito e doze carbonos, e com isso, promover a interação entre meios que apresentam polaridade diferente como, por exemplo, água e membrana. A obtenção dos derivados contendo oito e doze carbonos foi realizada a partir da reação de substituição nucleofílica entre o heterociclo 2-(5’-amino-2’-hidroxifenil)benzoxazol e os respectivos iodoalcanos em presença de uma base, com rendimentos na faixa de 45%. O derivado com dezoito carbonos foi obtido em duas etapas, sendo a primeira a reação entre o 2- (5’-amino-2’-hidroxifenil)benzoxazol e a epicloridrina para formar o intermediário 2-(5’(N-3- cloro-2-hidroxipropilamina)-2’-hidroxifenil)benzoxazol. A reação deste intermediário com a N,N-dimetiloctadecilamina levou a formação do corante na forma de sal de amônio quaternário com 68% de rendimento. Os corantes foram caracterizados por Infravermelho, Ressonância Magnética Nuclear de Hidrogênio e de Carbono, Análise Elementar e ponto de fusão, além da caracterização fotofísica. O estudo fotofísico do sistema fosfatidilcolina/corante mostrou que os corantes sofrem a influência do meio lipídico, bem como a afinidade do corante quaternizado pelo sistema lipídico diferencia-se dos corantes neutros. Além disso, os corantes com cadeias alquílicas de oito e doze átomos de carbono se mostraram sondas mais eficientes para meios apolares ou polares apróticos e são liberados para o meio com o aumento da diluição do sistema. Já o corante com cadeia alquílica de dezoito átomos de carbono apresentou maior afinidade com o ambiente hidrofílico do sistema lipídico, ficando incorporado na bicamada lipídica, mesmo com o aumento da diluição. / This work presents the synthesis, characterization and photophysical study of new fluorescent benzazólicos heterocycles with potential application as probes of lipid environments. For this, three dyes were synthesized containing alkyl chains in the structure of eight, twelve and eighteen carbon atoms attached to a core benzazólico which is responsible for the fluorescence of these compounds. The dye that has the alkyl chain of eighteen carbons still presents as a quaternary ammonium salt, with the goal of making its structure more amphiphilic than their neutral analogues of eight and twelve carbons, and thereby promote the interaction means that present different polarity, for example, water and membrane. The obtaining of derivatives containing eight twelve carbons was made from the nucleophilic substitution reaction between the heterocycle 2-(5'-amino-2'-hydroxyphenyl) benzoxazole and its iodoalcanos in the presence of a base, with yields around 45%. The derivative eighteen carbons was obtained in two steps, the first being the reaction between 2- (5'-amino-2'-hydroxyphenyl) benzoxazole and epichlorohydrin to form the intermediate 2- (5'(N-3-chloro-2-hydroxypropylamine)-2'-hydroxyphenyl) benzoxazole. The reaction of this intermediate with N, N-dimetiloctadecilamina led to the formation of the desired compound quaternised 68% yield. The compounds were characterized by infrared, nuclear magnetic resonance of hydrogen and carbon, elemental analysis and melting point, besides the characterization photophysics. The photophysical study of the phosphatidylcholine/dye system showed that the dyes suffer the influence of the lipid and affinity of the dye quaternized by the system differs from dyes that show no load. In addition, the neutral dyes with alkyl chains content eight and twelve carbon atoms, proved most interesting probes for apolar media or polar aprotic media and are released into the medium with increasing dilution of the system. Already the derivative with eighteen carbon atoms and having quaternary nitrogen showed higher affinity for hydrophilic environment lipid system, becoming incorporated into the lipid bilayer, even with increased dilution.

Les travaux de cette thèse portent sur l'élaboration et l'étude de sondes fluorescentes construites autour d'un squelette iminophénol, permettant ainsi d'accéder à un panel de composés absorbants et émettant sur une large gamme spectrale {UV, visible, proche infrarouge) et présentant des propriétés optiques remarquables : des coefficients d'absorption importants,des rendements quantiques élevés et de grands déplacements de Stockes. Des voies synthétiques simples et efficaces ont permis la constitution d'un catalogue de fluorophores modulables sur une large gamme du spectre électromagnétique. En particulier, la fluorescence liée à un phénomène de transfert de proton intramoléculaire dans l'état excité {ESIPT) a fait l'objet d'une grande partie des travaux. Une autre partie conséquente de ce travail de thèse concerne la synthèse et l'étude de complexes de bore luminescents. Les ligands sont rigidifiés par un atome de bore trivalent de configuration tétraédrique, ce qui permet une modulation des propriétés optiques des composés ainsi qu'une augmentation du rendement quantique de fluorescence. / Projects of this thesis focus on development and photophysical studies of new fluorescent probes built around an iminophenol skeleton, providing access to a panel of compounds absorbing and emitting over a broad spectral range {UV, visible, near infrared) and having excellent optical properties: significant absorption coefficients, high quantum yields and large Stokes shifts. Simple and efficient synthetic routes allowed the creation of a catalog of fluorophores emitting on a wide range of the electromagnetic spectrum. The fine tuning of the absorption and emission wavelength of the fluorescent dyes were achieved by the substitution of different electro-attracting or -donating groups. ln particular, fluorescence due to an excited state intramolecular proton transfer process {ESIPT) has been studied. Syntheses and studies of boron complexes have also been achieved. Ligands are coordinated to a trivalent boron fragment, allowing a modulation of the optical properties and leading to highly luminescent B{lll) complexes.

Ces travaux de thèse concernent la synthèse et l’étude des propriétés optiques de fluorophores organiques appliqués à la détection de deux biomarqueurs de la maladie d’Alzheimer : la protéine kinase C (PKC) et les fibrilles de peptides amyloïdes Aβ42. La détection de la PKC est réalisée à l’aide de dyades comprenant un émetteur de type boradiazaindacène (BODIPY) relié de manière covalente à un inhibiteur de cette enzyme. Ces composés obtenus via une synthèse multi-étape présentent des coefficients d’absorption molaires et des rendements quantiques de fluorescence en solution importants. Ces sondes ont ensuite été utilisées en cytométrie de flux par la société Amoneta Diagnostics afin de détecter la PKC en surface des globules rouges et d’évaluer le potentiel de ces sondes dans le diagnostic de la maladie d’Alzheimer par test sanguin. Pour la détection des fibrilles de peptides amyloïdes, deux séries de fluorophores de la famille des 2-(2’-hydroxyphényl)-benzoxazoles ont été étudiées. Ces molécules présentent un phénomène de transfert de proton intramoléculaire à l’état excité (ESIPT) qui leur confère des propriétés optiques remarquables, telles que d’importants déplacements de Stokes et une émission duale. Enfin, un test de détection in vitro a été mis au point. Une interaction entre ces fluorophores et les fibrilles amyloïdes a pu être observée permettant la détection de ces peptides en solution. / This research concerns the synthesis and photophysical studies of organic fluorescent probes applied to the detection of two Alzheimer’s disease biomarkers: the protein kinase C and fibrils of amyloid Aβ42 peptides. PKC detection is achieved by dyads composed of boradiazaindacene dye (BODIPY) covalently linked to an inhibitor of this enzyme. These compounds afforded by a multistep synthesis display high molar absorption coefficients and quantum yields in solution. These probes were then used in flow cytometry by Amoneta Diagnostics to detect PKC on the surface of red blood cells in order to asses the potential of these molecules for the diagnostic of Alzheimer’s disease by blood test. Two series of fluorophores from the 2-(2’-hydroxyphenyl)-benzazole family have been studied for the detection of amyloid fibrils. These molecules display an excited state intramolecular proton transfer (ESIPT) phenomenon which confer them remarkable optical properties such as important Stokes shifts and dual emission. Finally, an in vitro detection test has been developed. Interactions between these dyes and amyloid fibrils has been observed, allowing the detection of these peptides in solution.

Le travail de cette thèse de doctorat est axé sur le design, la synthèse et la caractérisation de systèmes moléculaires organiques et organométalliques luminescents dans le but de déclencher des processus de transfert photoinduit d’électron (PeT) ou d’énergie (EET) pour des applications dans les dispositifs optiques ou électroniques. Nous nous sommes d’abord intéressés aux molécules de type push-pull car elless’avèrent être des modèles intéressants pour l’étude du PeT. Nos systèmes sont construits autour de BτDIPY qui sert d’espaceur entre le donneur d’électron (julolidine ou triazatruxène) et l’accepteur d’électron (une unité dicyanovinyl). Les études en électrochimie et spectroscopie ont montrés un caractère à transfert de charge très prononcé. Entre autre nous avons synthétisé et étudié une série de ligands de type N^O (type base de Schiff) dérivés de la julolidine, une amine cyclique avec des propriétés électroniques très inattendues. Ces ligands, subissent des processus de transfert photoinduit de proton à l’état excité (ESIPT) et leurs spectres d’émission présentent une luminescence panchromatique. La compléxation desligands N^O au BF2 supprime l’ESIPT et augment les rendements quantiques de fluorescence. Les ligands derivés de la julolidine sont combinés avec d’autres unités chromophoriques i.e. Ir(III), Pt(II) afin de construire des systèmes multichromophoriques et stimuler des processus de EET entre les composants.Lors de ces travaux de thèse nous nous somme particulièrement intéressés aux systèmes moléculaires photocommutables dont l’unité centrale est un photochrome, le [1,3]oxazine. L’oxazine est combiné à un module moléculaire qui sert de donneur d’énergie et un module accepteur d’énergie choisie de façon optimale afin d’induire un transfert électronique d’énergie de manière contrôlé. / The present doctoral thesis work deals with the design, synthesis and characterization of organic and organometallic luminescent molecular frameworks for triggering Photoinduced electron Transfer (PeT) and Electronic Energy Transfer (EET) processes for applications in optical andelectronic devices. First, we turned toward the organic push-pull chromophores because they are useful model systems for studying the mechanism of PeT process. We synthesized new push-pull systems bearing a dicyanovinyl fragment as the electron-acceptor and a strong electron-donorsuch as julolidine and triazatruxene covalently linked through a BODIPY dye bridge. Electrochemical and photophysical studies showed a pronounced charge transfer character within the new push-pull systems. Furthermore, we synthesized and studied a series of chelating N^O-type ligands (Schiff base-type), based on the strong electron-donating julolidine motif, displaying ESIPT process. Their luminescence profiles exhibited panchromatic luminescence band covering the whole visible spectrum. Complexation of N^O-site with boron difluoride fragment suppressed the ESPIT process and highly increased the fluorescence quantum yield. The N^O-chelating ligands were combined with Pt(II) chromophore, B(III) and Ir(III) such as to obtainmultichromophoric frameworks. According to the photophysical studies, EET processes were observed within the multichromophoric systems. We successfully obtained a new florescent switching triad constructed around a photochromic core, [1,3]oxazine, which bears an energy-donor and an energy-acceptor module such as to directly control the EET process.

Les travaux réalisés dans le cadre de la thèse avaient pour but la synthèse de nouveaux fluorophores basés sur les unités BODIPYs et hydroxyphényl-s-triazines. Pour être utilisées comme sondes efficaces dans des applications en chimie et en biologie, les chromophores doivent présenter une forte brillance et des rendements quantiques de fluorescence élevés, une modulation aisée de ses propriétés optiques ainsi qu’une bonne stabilité chimique et photochimique. Une stratégie originale et efficace a été développée pour l’obtention de dérivés d’o-hydroxyphényl-s-triazine. Ces derniers présentent des déplacements de Stokes anormalement élevés ayant pour origine un transfert de proton intramoléculaire ultrarapide à l’état excité (ESIPT). L’extension du système π-conjugué sur les différentes plateformes de départ a été réalisée par couplages pallado-catalysés et/ou condensation de Knoevenagel, permettant ainsi d’accéder à une large gamme spectrale en absorption et en émission. Le développement d’une nouvelle voie de synthèse à permis l’obtention d’oligo-BODIPYs par couplage oxydant réalisé en associant PIFA et un acide de Lewis. Toutes les propriétés photophysiques des nouvelles sondes ont été étudiées et ont fait l’objet de discussions détaillées. / The study undertaken in this thesis was the engeneering of new fluorescent dyes based on BODIPY and o-hydroxyphenyl-s-triazine units. The focus has been on the development of dyes displaying large absorption cross sections, emission wavelength tunability, high photostability and fluorescent quantum yields by using original synthetic strategies. As a part of our research program on the design of novel fluorescent dyes exhibiting large Stokes shifts, we developped an efficient method for the synthesis of o-hydroxyphenyl-s-trazine for which an anormalous emission was observed due to an intramolecular proton transfert in the excited state (ESIPT process). The fine tuning of the absorption and emission wavelength for both plateforms were achieved by extension of the π-conjugated system with aryl and alkyl moieties using palladium cross coupling or via a styryl linkage using Knoevenagel condensation. Another strategy to enhance the fluorescence performances consists in the rigidization of the plateforms. Various oligo-BODIPYs have been obtained by an unprecedented oxydative coupling reaction using Phenyliodine(III)bis(trifluoroacetate) (PIFA) in conjunction with a Lewis acid. All compounds spectral characteristics were investigated and their photophysical properties discussed.

O trabalho apresenta a síntese e a caracterização de novos compostos heterocíclicos benzazólicos dos tipos 2-(4’-aminofenil)-6-nitrobenzazóis fluorescentes por apresentar provável transferência de carga intramolecular no estado excitado (ICT) e iminas aromáticas basedas nos compostos 2-(4’-amino-2’- hidroxifenil)-6-nitrobenzazóis fluorescentes devido a mecanismo de transferência protônica intramolecular no estado excitado (ESIPT). Estes compostos foram caracterizados por espectroscopia de absorção na região do Infravermelho, ressonância magnética nuclear de hidrogênio (1H-RMN). Foram realizados estudos fotofísicos através das espectroscopia de absorção na região do ultravioleta-visível e de emissão de fluorescência, determinando assim, os prováveis estados eletrônicos excitados em solventes polares e apolares. / This work presents the synthesis and characterization of new fluorescent heterocyclic derivatives based on 2-(4'-aminophenyl)-6-nitrobenzazoles, as well as aromatic imines based on 2-(4'-amino-2'-hydroxyphenyl)-6-nitrobenzazoles. These molecules are photoactive due to an intramolecular proton transfer in the excited state (ESIPT) or a intramolecular charge transfer (ICT) mechanism. These compounds were characterized by infrared spectroscopy and nuclear magnetic resonance 1H-NMR. Photophysical studies were performed using the absorption spectroscopy in the ultraviolet-visible and fluorescence emission, thereby determining the excited electronic states in polar and nonpolar solvents.