The details of dye sensitized solar cells was explained and phenothiazine and porphyrin based dyes were synthesized for use in DSSCs. DSSCs offer a unique and cost effective method of renewable energy. DSSCs are characterized through various tests, with the overall efficiency, η, bearing the greatest importance. Incident photon to current conversion efficiency, or IPCE, is also another important characterization of DSSCs. Effect of positioning of the cyanoacrylic acid anchoring group on ring periphery of phenothiazine dye on the performance of dye sensitized solar cells (DSSCs) is reported. The performances of the cells are found to be prominent for solar cells made out of Type-1 dyes compared to Type-2 dyes. This trend has been rationalized based on spectral, electrochemical, computational and electrochemical impedance spectroscopy results. Free-base and zinc porphyrins bearing a carboxyl anchoring group at the para, meta, or ortho positions of one of the meso-phenyl rings were synthesized for DSSCs. Photoelectrochemical studies were performed after immobilization of porphyrins onto nanocrystalline TiO2. The performance of DSSCs with the porphyrin anchoring at the para or meta position were found to greatly exceed those in the ortho position. Additionally, zinc porphyrin derivatives outperformed the free-base porphyrin analogs, including better dye regeneration efficiency for the zinc porphyrin derivatives and for the meta and para derivatives through electrochemical impedance spectroscopy studies. The overall structure-performance trends observed for the present porphyrin DSSCs have been rationalized based on spectral, electrochemical, electrochemical impedance spectroscopy and transient spectroscopy results.

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Au cours de cette thèse, nous avons synthétisé et caractérisé de nouveaux composés en utilisant le macrocycle porphyrinique comme brique moléculaire de départ. Le but de ce travail étant l’étude des propriétés optiques de ces nouveaux composés obtenus. Après avoir effectué l’étude bibliographique sur les porphyrines, nous avons fait une présentation générale des porphyrines symétriques et non symétriques, de leurs propriétés et de leurs synthèses. D’autre part, nous avons aussi considéré l’unité fluorène qui possède des propriétés photophysiques très intéressantes comme antenne collectrice de lumière. Puis, nous avons abordé des méthodes de synthèse permettant d’associer le macrocycle porphyrinique avec de nombreuses unités fluorènes. Cette association a pu être réalisée de différentes manières : soit de façon dendritique ou par connexion directe sur la porphyrine (dimère et trimère). Nous avons également décrit l’obtention d’une nouvelle famille de porphyrines substituées par des groupements organométalliques de type acétylure de ruthénium et de fer pour l’optique non linéaire de troisième ordre (ONL TO). Lors de la dernière partie de mes travaux de thèse, comme application de ces composés luminescents dans le rouge, nous avons reporté l’élaboration de différents dispositifs de diodes électroluminescentes (OLED) émettant dans le rouge. / During this thesis, we have worked on the synthesis and characterization of new compounds using the porphyrin macrocycle as a starting material. The aim, after synthesis, is to study the photophysical properties of these new molecules. A general bibliographic study was presented followed by introducing the synthetic methods of porphyrins and characterization means. Then, fluorene was considered to be an attracting unit due to its interesting photophysical properties: acting as efficient antennae for collecting light. First, we have presented the synthesis of porphyrin dendrimers having fluorenyl arms of different generations. That is to test the effect of number of fluorenes on the photophysical properties. Another way is to connect the fluorenes directly to the porphyrin core by synthesizing porphyrin dimer and trimer. We have also detailed the synthesis and characterization of a new family of porphyrin organometallic assemblies possessing ruthenium and iron moieties. In addition, a new organometallic porphyrin dendrimer bearing twelve ruthenium species was reported as well. These organometallic porphyrins are of interest in the third order of Nonlinear Optics (NLO). In the last chapter of this thesis we showed an example of application of porphyrin chemistry. We reported the elaboration of a new organic light emitting Diode (OLED) using these new porphyrins that emits in the red region.

Biosensoren werden oft für die Messung einzelner Substanzen in komplexen Medien verwendet, wie z.B. bei der Blutzuckerbestimmung. Sie bestehen aus einem physikochemischen Sensor, dem Transduktionselement, und einer darauf immobilisierten biologischen Komponente, dem Erkennungselement. In dieser Arbeit wurde als Transduktionselement eine Elektrode und als Biokomponente das Enzym „Meerrettich Peroxidase“ (engl. horseradish peroxidase, HRP) verwendet. Solche HRP-Elektroden werden für die Messung von Wasserstoffperoxid (H2O2) eingesetzt. H2O2 wird im Körper von weißen Blutkörperchen produziert, um Bakterien abzutöten, wird teilweise ausgeatmet und kann in kondensierter Atemluft nachgewiesen werden. Da viele weiße Blutkörperchen bei einer Chemotherapie abgetötet und dadurch die Patienten anfälliger für Infektionen werden, muss ihre Anzahl regelmäßig überwacht werden. Dazu wird zurzeit Blut abgenommen. Im ersten Teil dieser Arbeit wurde untersucht, ob eine Überwachung der Anzahl an weißen Blutkörperchen ohne Blutabnahme durch eine H2O2-Messung erfolgen kann. Ein direkter Zusammenhang zwischen der ausgeatmeten H2O2-Menge und der Zahl der weißen Blutkörperchen konnte dabei nicht festgestellt werden. Für empfindliche H2O2-Messungen mit einer HRP-Elektrode ist ein schneller Austausch von Elektronen zwischen der Elektrode und dem Enzym notwendig. Eine Vorraussetzung dafür ist eine kurze Distanz zwischen dem aktiven Zentrum des Enzyms und der Elektrodenoberfläche. Um einen kurzen Abstand zu erreichen wurden im zweiten Teil dieser Arbeit verschiedene poröse graphitähnliche Materialien aus pyrolysierten Kobalt-Porphyrinen für die Elektrodenherstellung verwendet. Dabei stellte sich heraus, dass eines der untersuchten Materialien, welches Poren von etwa der Größe eines Enzyms hat, Elektronen etwa 200mal schneller mit dem Enzym austauscht als festes Graphit. Die HRP selbst enthält in seinem aktiven Zentrum ein Eisen-Protoporphyrin, also ein aus vier Ringen bestehendes flaches Molekül mit einem Eisenatom im Zentrum. Reagiert die HRP mit H2O2, so entzieht es dem Peroxid zwei Elektronen. Eines dieser Elektronen wird am Eisen, das andere im Ringsystem zwischengespeichert, bevor sie an ein anderes Molekül oder an die Elektrode weitergegeben werden. Im letzten Teil dieser Arbeit wurde das Eisen durch Osmium ausgetauscht. Das so veränderte Enzym entzieht Peroxiden nur noch ein Elektron. Dadurch reagiert es zwar langsamer mit Wasserstoffperoxid, dafür aber schneller mit tert-Butylhydroperoxid, einem organischen Vertreter der Peroxid-Familie. / Biosensors are often used for the measurement of specific substances in complex media, e.g. glucose in blood. They consist of a physicochemical sensor, the transducer, onto which a biological component, the recognition element, is immobilised. In this work, an electrode was used as transducer and the enzyme “horseradish peroxidase” (HRP) as biological component. Such HRP electrodes are used for the measurement of hydrogen peroxide (H2O2). H2O2 is produced in the body by white blood cells to destroy bacteria, is partially exhaled and can be measured in breath condensate. Since a lot of white blood cells are destroyed during chemotherapy and patients get more prone to infections, their amount must be checked regularly. Currently blood samples are taken for this purpose. In the first part of this work it was investigated, if the amount of white blood cells can be checked without taking blood by measuring H2O2. A correlation between the amount of exhaled H2O2 and the number of white blood cells could not be found. For a sensitive H2O2 measurement with an HRP electrode a quick exchange of electrons between electrode and enzyme is needed. One condition for this is a short distance between the active centre of the enzyme and the electrode surface. In order to achieve a short distance, several porous graphite-like materials made of pyrolysed cobalt porphyrins where used in the second part of this work for the electrode production. It turned out that one of the tested materials, which had pores about the same size as the enzyme, did exchange electrons with the enzyme about 200 times faster than solid graphite. HRP itself contains an iron protoporphyrin, i.e. a planar molecule consisting of four rings with an iron atom in the middle, its active centre. When HRP reacts with H2O2, it takes two electrons from the peroxide. One of these electrons is stored at the iron, the other in the ring system, until they are passed on to another molecule or the electrode. In the last part of this work, the iron was exchanged with osmium. The modified enzyme takes only one electron from peroxides. Thus it reacts slower with hydrogen peroxide, but faster with tert-butylhydroperoxide, an organic member of the peroxide family.

The fascinating role that porphyrins play in natural processes such as photosynthesis and respiration, continues to provide a compelling motivation to study these chromophores and to design new analogues with improved functions. This dissertation describes the interdisciplinary study of several classes of compounds that include π-extended porphyrins, expanded porphyrins, porphycenes, polypyrroles and porphyrins. Dictated by the need to capture efficiently red and near-infrared light, the so-called π-extension approach has been established as a powerful tool in the synthesis of large aromatic chromophores. Many of these artificial systems demonstrate properties similar to natural porphyrins. Often, however, a reduced bandgap is seen due to a greater π-system. Synthetic challenges associated with the preparation of the linearly annulated porphyrins have long been recognized. Many of these have now beed overcome as the result of a newly developed synthetic protocol described in Chapter 1. This protocol allows for the synthesis of a pyrrolic building block under milder conditions. As a continuation of this work, naphthobipyrroles were obtained via the π-extension strategy applied to a benzobipyrrole. The utility of this new building block was demonstrated with the syntheses of an electrochromic polynaphthobipyrrolic polymer (Chapter 3) and a dinaphthoporphycene (Chapter 2), a chromophore isomeric to porphyrin. Chapter 4 describes a different approach to porphyrin functionalization. Here, the goal was to effect substitution at the so-called β pyrrolic positions with using two bithiophene groups. Although, the resulting product is not completely rigid, enhancement in the sensitizing properties of the basic porphyrin chromophore was seen in a dye sensitized solar cell (DSSC) assembly, as studied by scanning electrochemical microscopy (SECM). The synthetic contributions concerning this work, carried in collaboration with Bard group, are expected to lay the groundwork for the development future photovoltaic materials. Expanded porphyrins are the more diverse group of porphyrinic derivatives. In effort to develop new conjugated expanded porphyrin systems and to understand their spectroscopic behavior in greater detail, a set of expanded porphyrins, based on the direct electrochemical oxidation of terpyrrole-like fragments, was developed in conjunction with the Bucher group (Grenoble, France). This effort is described in Chapter 5. Specifically it is shown that trithiacyclo[9]pyrrole may be prepared by means of an electrochemical synthesis. / text

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22269号 / 理博第4583号 / 新制||理||1658(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 大須賀 篤弘, 教授 時任 宣博, 教授 依光 英樹 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19524号 / 理博第4184号 / 新制||理||1601(附属図書館) / 32560 / 京都大学大学院理学研究科化学専攻 / (主査)教授 大須賀 篤弘, 教授 依光 英樹, 教授 丸岡 啓二 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24441号 / 理博第4940号 / 新制||理||1706(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)准教授 齊藤 尚平, 教授 依光 英樹, 教授 畠山 琢次 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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