京都大学 / 新制・課程博士 / 博士(理学) / 甲第22989号 / 理博第4666号 / 新制||理||1669(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 石田 憲二, 教授 柳瀬 陽一, 教授 前野 悦輝 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

About 85% of the world’s energy is derived from non-renewable sources—coal, petroleum, and natural gas. Solar photocatalysis is one way to potentially generate cheap renewable fuels by harnessing energy from the sun using a photosensitizer and converting it into chemical energy. The efficiency of a photosensitizer depends on its capacity to form a prolonged triplet excited state. Zinc dipyrrin complexes have the potential to be efficient sensitizers for reductive photochemistry, but their ability to form long-lived triplet excited states still needs extensive research. The overall aim of this research is to probe the role charge separation plays in the formation of triplet state in metal complexes of dipyrrin photosensitizers. The specific objectives are to synthesize and characterize zinc and boron dipyrrin complexes, analyze their photophysical properties—such as steady state spectroscopy, low temperature emission spectroscopy—and quantify their triplet states using time-resolved transient absorption spectroscopy.

Pluronics are triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) available in different molecular weights and PPO/PEO ratios. Pluronic hydrogels are able to dissolve hydrophobic compounds and they have application in different areas including drug delivery systems and oil recovery. The structure of Pluronic polymers can be designed for specific application by changing the size and ratio of the PPO and PEO blocks. In aqueous environments, the PPO blocks of different unimers form aggregates as they are more hydrophobic compared to the PEO blocks, and in the aggregates the PPOs have less exposure to water. The PEO blocks that are still hydrophilic remain soluble in water and form a shell around the PPO aggregated core. Moreover, some of the Pluronic copolymer aqueous solutions can form hydrogels at elevated temperatures. The aim of this thesis is to study the microheterogeneity of two different Pluronic hydrogels using singlet excited state probes and also study the mobility of small molecules in Pluronic hydrogels using triplet excited state probes. In the first project, the properties of different microenvironments in Pluronic F127 (PEO99PPO65PEO99) were characterized. The quenching of singlet excited state probes was used to determine the number and characteristics of solubilization sites in F127 hydrogels. This method was used to gain information on the accessibility of different quenchers to singlet excited molecules bound to the micellar structures. Singlet excited states are short lived, and these excited states do not move within the gel before their decay to the ground state. The techniques used for these studies were steady-state fluorescence and time-resolved fluorescence spectroscopies. My results showed that there are different solubilization sites in F127 micelles and the accessibility of quenchers to the singlet excited molecules bound to the micellar structure depends on the nature of the quencher and the size of the excited molecules. In the second project, the different microenvironments in Pluronic P104 (PEO27PPO61PEO27) were characterized, and these results were compared with those obtained for the Pluronic F127. Pluronic P104 has similar units of PPO blocks as F127 but different units of PEO blocks which results in different properties between these two Pluronic copolymers. My results showed that the solubilization sites inside Pluronic micelles changes with the change in PEO/PPO ratio. In the third project, I studied the mobility of different small molecules between aqueous and micellar environments in the F127 hydrogel by quenching triplet excited state probes. Excited triplet states are suitable for such studies because their lifetimes are longer than the lifetimes for singlet excited states. The laser flash photolysis technique was used for this aim. The results showed that the exit from the micellar environment is slow and depend on the size and hydrophobicity of the probe molecules. / Graduate / 2022-05-11

Les travaux de cette thèse ont pour cadre la vérification formelle, et plus spécifiquement le projet ANR Blanc CLIMT (Categorical and Logical Methods in Model Transformation) dédié aux grammaires de graphes. Ce projet, qui a démarré en février 2012 pour une durée de 48 mois, a donné lieu à la définition du langage Small-tALC, bâti sur la logique de description ALCQI. Ce langage prend la forme d’un DSL (Domain Specific Language) impératif à base de règles, chacune dérivant structurellement un graphe. Le langage s’accompagne d’un composant de preuve basé sur la logique de Hoare chargé d’automatiser le processus de vérification d’une règle. Cependant, force est de constater que tous les praticiens ne sont pas nécessairement familiers avec les méthodes formelles du génie logiciel et que les transformations sont complexes à écrire. En particulier, ne disposant que du seul prouveur, il s’agit pour le développeur Small-tALC d’écrire un triplet de Hoare {P} S {Q} et d’attendre le verdict de sa correction sous la forme d’un graphe contre-exemple en cas d’échec. Ce contre-exemple est parfois difficile à décrypter, et ne permet pas de localiser aisément l’erreur au sein du triplet. De plus, le prouveur ne valide qu’une seule règle à la fois, sans considérer l’ensemble des règles de transformation et leur ordonnancement d’exécution. Ce constat nous a conduits à proposer un environnement d’assistance au développeur Small-tALC. Cette assistance vise à l’aider à rédiger ses triplets et à prouver ses transformations, en lui offrant plus de rétroaction que le prouveur. Pour ce faire, les instructions du langage ont été revisitées selon l’angle ABox et TBox de la logique ALCQI. Ainsi, conformément aux logiques de description, la mise à jour du graphe par la règle s’assimile à la mise à jour ABox des individus (les nœuds) et de leurs relations (les arcs) d’un domaine terminologique TBox (le type des nœuds et les étiquettes des arcs) susceptible d’évoluer. Les contributions de cette thèse concernent : (1) un extracteur de préconditions ABox à partir d’un code de transformation S et de sa postcondition Q pour l’écriture d’une règle {P} S {Q} correcte par construction, (2) un raisonneur TBox capable d’inférer des propriétés sur des ensembles de nœuds transformés par un enchaînement de règles {Pi} Si {Qi}, et (3) d’autres diagnostics ABox et TBox sous la forme de tests afin d’identifier et de localiser des problèmes dans les programmes. L’analyse statique du code de transformation d’une règle, combinée à un calcul d’alias des variables désignant les nœuds du graphe, permet d’extraire un ensemble de préconditions ABox validant la règle. Les inférences TBox pour un enchaînement de règles résultent d’une analyse statique par interprétation abstraite des règles ABox afin de vérifier formellement des états du graphe avant et après les appels des règles. A ces deux outils formels s’ajoutent des analyseurs dynamiques produisant une batterie de tests pour une règle ABox, ou un diagnostic TBox pour une séquence de règles / The overall context of this thesis is formal verification, and more specifically the ANR Blanc CLIMT project (Categorical and Logical Methods in Model Transformation) dedicated to graph grammars. This project, which started in February 2012 for 48 months, gave rise to the development of the Small- tALC language, a graph transformation language based on the ALCQI description logic. This language takes the form of an imperative DSL (Domain Specific Language) based on rules; from each rule structurally derives a graph. It goes with a proof component based on Hoare's logic designed to automate the process of rule verification. However, it must be assumed that not all developers are familiar with formal methods of software engineering, and that graph transformations are complex to write. In particular, using exclusively the prover, the Small- tALC developer must write a Hoare triple {P} S {Q} and wait for the feedback in the form of a counterexample graph in case of failure. This counter-example is sometimes difficult to interpret, and so it does not allow to easily locate the error within the triple. Moreover, the prover validates only one rule at once, without considering all the transformation rules and their execution order. This fact led us to propose an assistance framework for Small- tALC to help developers write their triples and prove their transformations, providing them more feedback than the prover does. To this purpose, the Small- tALC instructions have been reviewed according to the ABox and TBox aspects of the ALCQI logic. Thus, in accordance with description logics, updating the graph by the rule corresponds to the ABox updating of individuals (nodes) and their relationships (edges) of a TBox terminology domain (nodes concepts and edges labels) that is also expected to evolve. The contributions of this thesis concern: (1) an ABox precondition extractor from a transformation code S and its post-condition Q in order to produce a correct by construction rule {P} S {Q}, (2) a TBox reasoner to infer properties on sets of nodes transformed by a rule sequence {Pi} Si {Qi}, and (3) other ABox and TBox diagnostics based on tests to identify and locate errors in programs. The static analysis of the code of a transformation rule, combined with an alias calculus of the variables that can not designate the same nodes of the graph, allows to extract a set of ABox preconditions validating the rule. TBox inferences related to a sequence of rules result from a static analysis by abstract interpretation of the ABox rules. These inferences formally check graph states before and after rule calls. Beside these two formal tools, the framework features dynamic analyzers that produce test cases for an ABox rule, or a TBox diagnosis for a sequence of rules

Highly correlated quantum chemical methods have been appliedto study the photophysical properties of substituted benzenes.With the inclusion of spin-orbit coupling, the phosphorescencesof these molecules have been calculated usingMulti-CongurationalSelf- Consistent Field (MCSCF) quadraticresponse theory. The Herzberg-Teller approximation has beenadopted to evaluate the vibronic contributions tophosphorescence. The performance of hybrid density functional theory (DFT) atthe B3LYP level is examined in comparison to the MP2, CCSD andCCSD(T) methods for the geometry and permanent dipole moment ofp-aminobenzoic acid. The time-dependent DFT/B3LYP method isapplied to calculate the two-photon absorption of a series ofZinc-porphyrin derivatives in combination with a two-statemodel. The transitions between excited singlet and tripletstates of Zinc and Platinum based organometallic compounds havebeen computed using DFT quadratic response theory. The resultsare used to simulate the non-linear propagation of laser pulsesthrough these materials utilizing a dynamical wave propagationmethod.

Molecular engineering of donor-acceptor dyads and multimodular systems to control the yield and lifetime of charge separation is one of the key goals of artificial photosynthesis for harvesting sustainably solar energy. The design of the donor-acceptor systems mimic a part of green plants and bacterial photosynthetic processes. The photochemical events in natural photosynthesis involve the capturing and funneling of solar energy by a group of well-organized chromophores referred to as an ‘antenna' system causing an electron transfer into the ‘reaction center,' where an electron transfer processes occur resulting a long-lived charge separated state. Over the last two to three decades, many efforts have been directed by the scientific community designing of multi-modular systems that are capable of capturing most of the useful sunlight and generating charge separated states of prolonged lifetimes with adequate amounts of energy. In this dissertation, we report on the design and synthesis of donor–acceptor conjugates with the goal of modulating the yield and lifetime of their charge separated states and hence, improving the conversion of light energy into chemical potential. In simple donor-acceptor systems, generally, the energy and electron transfer events originate from the singlet excited state of the donor or acceptor and can store the greatest amount of energy but must be fast to out compete intersystem crossing. To address this limitation, we have designed novel donor –acceptor conjugates that use high-energy triplet sensitizers in which electron transfer is initiated from the long lived triplet state of the donor. The triplet photosensitizers used were palladium(II) porphyrin and platinum(II) porphyrin. Heavy metal effect in these porphyrins promoted intersystem crossing and the energies of their excited state was quite high. For the case of palladium (II) porphyrin the energy stored was found to 1.89 eV and that of platinum(II) porphyrin 1.84 eV. In addition to using triplet photosensitizers as donors, we have used donors that are difficult to oxidize and hence producing long lived charge separated states with adequate amount of stored energy. The system that was used for this study is zinc porphyrin with meso-aryl pentafluorophenyl substituents and fullerene, C60 as the acceptor. The presence of fluorine substituents on zinc porphyrin makes it harder to undergo oxidation. When this high potential donor-acceptor system undergoes a photoinduced charge-separation, the estimated energy stored was found to be 1.70 eV, one of the highest reported in literature so far. To further extend the lifetime of the charge separated states generated in this high-potential zinc porphyrin-fullerene dyad a pyridine functionalized tetrathiafulvalene was axially coordinated to the Zn metal producing a supramolecular triad capable of producing long-lived charge separated state. In a subsequent study, a multi-modular donor-acceptor system composed of a porphyrin, fullerene (C60) and a BF2-chelated dipyrromethene (BODIPY) with a supramolecular arrangement in the form of porphyrin-BODIPY-C60, one of the few reported in literature. By selectively exciting BODIPY and ZnP moieties, efficient singlet-singlet energy transfer from 1BODIPY * to ZnP in toluene was observed in the case of the dyad ZnP-BODIPY. However, when ZnP is excited, electron transfer occurred with the formation ZnP.+-BODIPY-C60.- charge separated state persisting for microseconds.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18060号 / 理博第3938号 / 新制||理||1567(附属図書館) / 30918 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 石田 憲二, 教授 前野 悦輝, 教授 松田 祐司 / 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24399号 / 理博第4898号 / 新制||理||1700(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 石田 憲二, 教授 松田 祐司, 教授 柳瀬 陽一 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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