Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (−)-trans-dihydroxygirinimbine and the assignment of its absolute configuration. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Ein vielversprechendes Design für organische lichtemittierende Dioden (OLEDs) verwendet eine Wirt-Gast-Strategie durch Dispergieren einer kleinen Menge eines hocheffizienten Emitters (der Gast) in eine passende Transportmatrix (der Wirt). Die Aufgabe des Wirts ist den Exzitonentranport zum Emitter sicherzustellen und den Zerfall von Triplet-Exzitonen zu verhindern, und damit eine hohe Bauteilperformance zu erreichen. Die vorliegende Arbeit konzentriert sich auf die Beziehung zwischen Molekülstruktur und optoelektrischer Eigenschaften von Carbazol/Dibenzothiophen-Derivaten. Die Untersuchung umfasst sieben dieser Derivate für den Wirt, bei denen die Carbazoleinheit als Donator und die Dibenzothiopheneinheit als Akzeptor fungiert, wobei beide durch einen oder mehrere Phenylabstandshalter verbunden sind. Diese Wahl der Wirtsmaterialien erlaubt es den Einfluss der erweiterten Phenylabstandshalter und der unterschiedlichen molaren Verhältnisse von Akzeptor zu Donator zu untersuchen. Es ergab sich, dass eine kürzere Phenylabstandshalterlänge die Bauteilperformance durch eine größere Löcher- und Elektronendichte in der Emitterschicht verbessert; und ein 1:1 Carbazol-zu-Dibenzothiophen-Verhältnis der Bauteilperformance zuträglich ist, da es zu einem Ladungsträgergleichgewicht in der Emitterschicht führt. Diese Arbeit zeigt, unter Verwendung dieser Wirtsmaterialien, blaue FIrpic-basierte phosphoreszierende OLEDs (PhOLEDs) und grüne 4CzIPN-basierte thermisch aktivierte verzögerte Phosphoreszenz (TADF) OLEDs. Die blauen PhOLEDs und grünen TADF OLEDs mit mDCP zeigten Effizienzen von 43 cd/A (18.6%) beziehungsweise 66 cd/A (21%). / A particularly interesting organic light-emitting diodes (OLEDs) design adopts a host-guest strategy by dispersing a small amount of highly efficient emitter (the guest) into an appropriate transport matrix (the host). The host is utilized to transfer excitons to the emitter and to prevent triplet exciton quenching, thus high device performance can be achieved. The present thesis focuses on the relationship between the molecular structure and opto-electrical properties of carbazole/dibenzothiophene derivatives. The investigation encompasses seven of these derivatives for the host, in which the carbazole unit acts as a donor and the dibenzothiophene as an acceptor while they are linked through phenyl spacer(s). This choice of host materials enables to assess the impact of extended phenyl spacers and different acceptor to donor molar ratios. It was found that decreasing the phenyl spacer length enhances the device performance due to the larger both hole and electron densities in the emitting layer; and a 1:1 carbazole to dibenzothiophene ratio is favorable for device performance, since it balances the charge carriers in the emitting layer. Using these host materials, the work presented in this thesis demonstrates high-performance blue FIrpic-based phosphorescent OLEDs (PhOLEDs) and green 4CzIPN-based thermally activated delayed fluorescence (TADF) OLEDs. The blue PhOLEDs and green TADF OLEDs with mDCP showed efficiencies of 43 cd/A (18.6%) and 66 cd/A (21%), respectively.

We describe the regioselective prenylation of 3-bromocarbazole by palladium(0)-catalysed cross coupling with a prenylstannane or a prenylboronate. The procedure is applied to the synthesis of precursors for biologically active carbazole alkaloids.

Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (−)-trans-dihydroxygirinimbine and the assignment of its absolute configuration. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

No description available.

Спроектирована установка для нанесения органических покрытий. Установка термовакуумного нанесения и виртуальный прибор «ThermoVAC&Co» позволяют осуществлять синтез тонкопленочных покрытий, контролируя температуру нагрева испаряемого вещества до 500 °C. Выполнен синтез тонких пленок 5,11-диметил-5,11-дигидроиндоло [3.2-b]карбазола 5,11-дигексил-5,11-дигидроиндоло[3.2-b]карбазола, 5,11-бис(2-метоксиэтил)-5,11-дигидроиндоло[3,2-b]карбазола и 5,11-бис[2-(2-метоксиэтокси)этокси]-5,11-дигидроиндоло[3,2-b]карбазола для исследования оптических и электрических характеристик. С помощью конфокального микроскопа Axio CSM 700 была проведена аттестация поверхности синтезируемых покрытий. Спектры оптического поглощения были получены на спектрометре Shimadzu UV-2450. Расчетный потенциал ионизации для исследованных соединений ICZ составляет 6,82-7,1 эВ. Обсуждается влияние отдельных блоков соединений на спектр оптического поглощения. На базе микрозондовой станции Cascade Microtech MPS150 произведены измерения вольтамперных характеристик структуры ITO/-ICZ/Al. По данным ВАХ были рассчитаны подвижности зарядов по модели инжекционных токов. Подвижность носителей заряда, оцененная по вольтамперным характеристикам, находится в диапазоне 2,2 ∙ 10-9–1,43 ∙ 10-6 см2 / (В·сек) для исследованных соединений ICZ. Установлена связь между интенсивностью полос поглощения с максимумом около 430 нм и подвижностью носителей заряда. / The installation for applying organic coatings is designed. The thermal vacuum deposition unit and the «ThermoVAC & Co» virtual instrument allow the synthesis of thin-film coatings, controlling the temperature of heating the evaporated substance up to 500 ° C. The thin films of 5,11-dimethyl-5,11-dihydroindolo [3.2-b] carbazole 5,11-dihexyl-5,11-dihydroindolo [3.2-b] carbazole, 5,11-bis (2-methoxyethyl) - 5,11-dihydroindolo [3,2-b] carbazole and 5,11-bis [2- (2-methoxyethoxy) ethoxy] -5,11-dihydroindolo [3,2-b] carbazole were synthesized to study optical and electrical characteristics. The surface of the synthesized coatings was certified using the Axio CSM 700 confocal microscope. Optical absorption spectra were obtained with the Shimadzu UV-2450 spectrometer. The calculated ionization potential is 6.82–7.1 eV for the studied ICZ compounds. The effect of individual blocks of compounds on the optical absorption spectrum is discussed. The current-voltage characteristics of the ITO / -ICZ / Al structure were measured with the Cascade Microtech MPS150 microprobe station. According to the I-V characteristics data, the charge mobility was calculated using the injection current model. The mobility of charge carriers, estimated by the current-voltage characteristics, is in the range 2,2 ∙ 10-9–1,43 ∙ 10-6 cm2/ (V·sec) for the studied ICZ compounds. The relationship between the intensity of absorption bands with a maximum near 430 nm, and the mobility of charge carriers were found.

L’objectif général de cette thèse est de développer une plateforme d’immobilisation d’enzymes efficace pour application en biopile. Grâce à la microencapsulation ainsi qu’au choix judicieux des matériaux polymériques pour la fabrication de la plateforme d’immobilisation, l’efficacité du transfert électronique entre l’enzyme encapsulée et l’électrode serait amélioré. Du même coup, les biopiles employant cette plateforme d’immobilisation d’enzymes pourrait voir leur puissance délivrée être grandement augmentée et atteindre les niveaux nécessaires à l’alimentation d’implants artificiels pouvant remplacer des organes telque le pancréas, les reins, le sphincter urinaire et le coeur. Dans un premier temps, le p-phénylènediamine a été employé comme substrat pour la caractérisation de la laccase encapsulée dans des microcapsules de poly(éthylèneimine). La diffusion de ce substrat à travers les microcapsules a été étudiée sous diverses conditions par l’entremise de son oxidation électrochimique et enzymatique afin d’en évaluer sa réversibilité et sa stabilité. La voltampérométrie cyclique, l’électrode à disque tournante (rotating disk electrode - RDE) et l’électrode à O2 ont été les techniques employées pour cette étude. Par la suite, la famille des poly(aminocarbazoles) et leurs dérivés a été identifée pour remplacer le poly(éthylèneimine) dans la conception de microcapsules. Ces polymères possèdent sur leurs unités de répétition (mono- ou diamino) des amines primaires qui seraient disponibles lors de la polymérisation interfaciale avec un agent réticulant tel qu’un chlorure de diacide. De plus, le 1,8-diaminocarbazole (unité de répétition) possède, une fois polymérisé, les propriétés électrochimiques recherchées pour un transfert d’électrons efficace entre l’enzyme et l’électrode. Il a toutefois été nécessaire de développer une route de synthèse afin d’obtenir le 1,8-diaminocarbazole puisque le protocole de synthèse disponible dans la littérature a été jugé non viable pour être utilisé à grande échelle. De plus, aucun protocole de synthèse pour obtenir du poly(1,8-diaminocarbazole) directement n’a été trouvé. Ainsi, deux isomères de structure (1,6 et 1,8-diaminocarbazole) ont pu être synthétisés en deux étapes. La première étape consistait en une substitution électrophile du 3,6-dibromocarbazole en positions 1,8 et/ou 1,6 par des groupements nitro. Par la suite, une réaction de déhalogénation réductive à été réalisée en utilisant le Et3N et 10% Pd/C comme catalyseur dans le méthanol sous atmosphère d’hydrogène. De plus, lors de la première étape de synthèse, le composé 3,6-dibromo-1-nitro-carbazole a été obtenu; un monomère clé pour la synthèse du copolymère conducteur employé. Finalement, la fabrication de microcapsules conductrices a été réalisée en incorporant le copolymère poly[(9H-octylcarbazol-3,6-diyl)-alt-co-(2-amino-9H-carbazol-3,6-diyl)] au PEI. Ce copolymère a pu être synthétisé en grande quantité pour en permettre son utilisation lors de la fabrication de microcapsules. Son comportement électrochimique s’apparentait à celui du poly(1,8-diaminocarbazole). Ces microcapsules, avec laccase encapsulée, sont suffisamment perméables au PPD pour permettre une activité enzymatique détectable par électrode à O2. Par la suite, la modification de la surface d’une électrode de platine a pu être réalisée en utilisant ces microcapsules pour l’obtention d’une bioélectrode. Ainsi, la validité de cette plateforme d’immobilisation d’enzymes développée, au cours de cette thèse, a été démontrée par le biais de l’augmentation de l’efficacité du transfert électronique entre l’enzyme encapsulée et l’électrode. / The main objective of this thesis is the development of a conductive enzyme immobilisation template for laccase through microencapsulation allowing an efficient electron transfer between the enzyme and the electrode for application in biofuel cells. First, p-phenylenediamine was used as substrate for the characterisation of the microencapsulated laccase. The diffusion of this substrate through the microcapsules was studied under various conditions by means of its electrochemical and enzymatic oxidation processes in order to assess its reversibility and stability. Cyclic voltammetry, rotating disk electrode and Clark electrode were the techniques used in this study. Moreover, poly(aminocarbazole) compounds and their derivatives were identified to replace poly(ethyleneimine) in the fabrication of the microcapsules. These polymers exhibit primary amines (mono- or di-amino) that could be available for an interfacial polymerisation using a cross-linker agent. Also, the monomer 1,8-diaminocarbazole presents the desired electrochemical propreties for an efficient electron transfer between the enzyme and the electrode. Therefore, a synthetic pathway was developed in order to synthesise this monomer since the available literature protocol was considered inappropriate for large scale synthesis. As for the direct synthesis of the poly(1,8-diaminocarbazole), to our knowledge, there is no protocol currently available. Two structural isomers (1,6 and 1,8-diaminocarbazole) were thus synthesised in two steps. The first step consists in the electrophilic substitution of 3,6-dibromocarbazole in 1,8 and/or 1,6 positions by nitro groups. This step was followed by a dehydrodehalogenation reaction that comes along with reduction of nitro to amino functions using Et3N and 10% Pd/C as the catalyst in methanol under H2 flux. During the first step, the 3,6-dibromo-1-nitro-carbazole was also obtained and appeared to be an efficient monomer in the synthesis of the desired conductive copolymer. Finally, the fabrication of the conductive microcapsules was realised by adding the copolymer poly[(9H-octylcarbazol-3,6-diyl)-alt-co-(2-amino-9H-carbazol-3,6-diyl)] to the PEI. This copolymer was synthesised in large quantities, which allowed its use in the design of microcapsules. Its electrochemical behaviour was similar in many ways to the one of poly(1,8-diaminocarbazole). These conductive microcapsules were then used to modify the surface of a platinum electrode to fabricate the bioelectrode. The main objective of this project was achieved through this final step.

Unprecedented Ullmann couplings of murrayafoline-A with either 6-bromo- or 4-bromocarbazole derivatives provide highly efficient synthetic routes to the biscarbazole alkaloids murrastifoline-A (6 steps, 66% overall yield) and bismurrayafoline-A (6 steps, 28% overall yield). / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

We report the first total synthesis of oxydimurrayafoline via nucleophilic substitution at the benzylic position at C-3 of the carbazole framework. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

This work investigates the correlation of structural and photovoltaic properties of dyes used in dye-sensitized solar cells. Experimental methods, including ultraviolet-visible spectroscopy, fluorescence spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy are employed to study optical and electrochemical properties of dye molecules. Computational methods, including density functional theory and time-dependent density functional theory, are used to validate and predict the optical and electronic properties of dye molecules, in their isolated state and once embedded into a working electrode device environment that comprises a dye...TiO2 interface. The results chapters begin with the presentation of a series of quinodimethene dyes that are experimentally validated for their photovoltaic application, and associated computational studies reveal that an inner structural factor - a phenyl ring rotation occurring during the optical excitation process - leads to the competitive photovoltaic device performance of these dyes. Carbazole-based dyes are then systematically studied by computation, especially considering charge transfer paths and binding modes of these dyes on a titania surface. The theoretical models for the basic building block of this chemical family of dyes, known as MK-44, successfully support and explain structural discoveries from X-ray diffraction and reflectometry that impact of their function. A benzothiadiazole-based dye, RK-1, is then systematically studied by both experimental and computational methods, and the results show that the π-bridge composed of thiophene, benzothiadiazole and benzene rings leads to excellent charge separation; and the rotation of these rings during the optical excitation process may well be consistent with the fluorescence spectrum. Finally, the well-known ruthenium-based dyes are theoretically studied to determine the properties of different ligands connected to the metal core of the complex. Conformations with different NCS ligands are calculated in terms of energy and explain well the corresponding results from X-ray diffraction. Acid-base properties of carboxyl groups connected to pyridine ligands in N3 and N749 are theoretically calculated based on thermodynamics and density functional theory. Implicit and explicit models are both adopted to predict these acid dissociative constant values, which are generally in a good agreement with the reported experimental data. The thesis concludes with conclusions and a future outlook.