Estudi metabolòmic dels efectes d'agents estressants sobre cultius d'arròs

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2015, Tutors: José Fermín López Sánchez i Joaquim Jaumot SolerMetabolomics is defined as the study of biochemical processes that involve small molecules, namely metabolites. Metabolomics has an important role on studies aimed at the understanding of living organisms at molecular level. Since metabolites are involved in most of biological mechanisms, their quantification and identification serve as an approximation of cellular state. To achieve so, it analyzes the metabolites of organisms submitted to any perturbation and compares the profiles to non-perturbed organisms. Therefore, it can be found how this perturbation affects the organism’s metabolome. In this work a lipidomic study, which only involves the hydrophobic metabolites, will be performed on rice. It aims to evaluate the effect of water scarcity as a physical stressor and influence of the harvesting hour. The study includes lipid extraction, analysis using LC-MS and data processing by chemometric means. Additionally, an optimization of the extracting method is included, studying three different factors

Towards the bisbenzothienocarbazole core: a route of sulfurated carbazole derivatives with assorted optoelectronic properties and applications

Ladder-type molecules, which possess an extended aromatic backbone, are particularly sought within the optoelectronic field. In view of the potential of the 14H-bis[1]benzothieno[3,2-b:2’,3’-h]carbazole core as a p-type semiconductor, herein we studied a set of two derivatives featuring a different alkylation patterning. The followed synthetic route, involving various sulfurated carbazole-based molecules, also resulted in a source of fluorophores with different emitting behaviors. Surprisingly, the sulfoxide-containing fluorophores substantially increased their blue fluorescence with respect to the nearly non-emitting sulfur counterparts. On this basis, we could shed light on the relationship between their chemical structure and their emission as an approach for future applications. Considering the performance in organic thin-film transistors, both bisbenzothienocarbazole derivatives displayed p-type characteristics, with hole mobility values up to 1.1 × 10-3 cm2 V-1 s-1 and considerable air stability. Moreover, the role of the structural design has been correlated with the device performance by means of X-ray analysis and the elucidation of the corresponding single crystal structures.This research was funded by the Ministerio de Economía, Indústria y Competitividad, grant number FUNMAT-PGC2018-095477-B-I00, and the Ministerio de Ciencia e Innovación, grant number PID2020-116719RB-C41.Peer ReviewedPostprint (published version

Insight into the diindolo[3,2-b:2',3'-h]carbazole core as an air-stable semiconductor for OTFTs

Encouraged by the outstanding performance of pentacene, the perspective over enhanced organic semiconductors has been focused on studying analogous ladder-type materials. In this context, the case of the diindolo[3,2-b:2',3'-h]carbazole core is a promising example of a semiconductor with improved stability. Herein, we report the synthesis of five diindolo[3,2-b:2',3'-h]carbazole derivatives displaying different alkylation patterning, as well as their integration in organic thin-film transistors. The elucidation of the single-crystal structures of three of the derivatives, accomplished by means of powder X-ray diffraction (PXRD), provided further insight into the intermolecular disposition of this core. As a result, the relationship between the structural design and the performance of the final devices could be analyzed. Globally, a scope of mobility values from 10–6 to 10–3 cm2 V–1 s–1 was achieved by just fine-tuning the length of the alkyl chains and the type of passivation layer applied onto the SiO2 surface. Remarkably, all the fabricated devices excel in terms of temporal and air stability with a shelf lifetime up to years, a coveted feature in organic electronics that confirms the potential of this core.ThisresearchwasfundedbytheMinisteriodeEconomía,IndústriayCompetitividad(grantnumberFUNMAT-PGC2018-095477-B-I00).Peer ReviewedPostprint (published version

Role of the alkylation patterning in the performance of OTFTs: the case of thiophene-functionalized triindoles

Organic semiconductors have emerged as potential alternatives to conventional inorganic materials due to their numerous assets and applications. In this context, the star-shaped triindole core stands as a promising system to design new organic materials with enticing charge-transporting properties. Herein, we present the synthesis of three thiophene-containing triindole derivatives that feature N-alkyl chains of different lengths, from methyl to decyl. The impact of the alkylation patterning on the crystallinity of the thin films and their resultant performance as semiconductor have been analyzed. All derivatives displayed p-type semiconductor properties, as demonstrated via both TOF measurements and integration in organic thin-film transistor (OTFT) devices. The attachment of longer alkyl chains and the functionalization of the silicon substrate with octadecyltrichlorosilane (OTS) prompted better OTFT characteristics, with a hole mobility value up to 5 × 10-4 cm2 V-1 s-1. As elucidated from the single crystal, this core is arranged in a convenient cofacial packing that maximizes the p-overlapping. The analysis of the thin films also corroborates that derivatives possessing longer N-alkyl chains confer a higher degree of order and a more adequate morphology.Peer ReviewedPostprint (published version

New organic semiconductors based on the carbazole core: synthesis and application in optoelectronic devices

[eng] The increasing demand on next-generation displays encourages an exhaustive research on the development of new and enhanced semiconductors. Apart from the conventional inorganic materials, organic-based semiconductors can also fulfil this role while affording unique features. Indeed, organic materials claim coveted properties such as electronic tunability and the feasibility to fabricate flexible displays with large areas at a lower cost, thus finding enormous applicability in different optoelectronic devices. The capability to transport charges in organic compounds is strongly related to the molecular design, which determines key factors such as the electronic profile and the disposition in the solid state. In this context, the aim of this Thesis is focalized on the synthesis and application of new organic semiconductors designed from a common building block: the carbazole heterocycle. The envisioned applications go from Organic Thin-Film Transistors (OTFTs) to Organic Light-Emitting Diodes (OLEDs). As an initial approach towards p-type semiconductors, the π-system of the carbazole nucleus has been extended to furnish three ladder-type constructions, namely diindolocarbazole, bisbenzothienocarbazole and diphenanthrocarbazole. The main molecular backbones have been tailored with the inclusion of different alkylation patternings. The integration of the resulting compounds in OTFT devices led to hole mobility values ranging from 10−6 up to 10−3 cm2 V–1 s–1, accentuating the importance of both the molecular and the device architecture. The most promising materials arise from the homogeneous N-alkylation of diindolocarbazole with short-to-medium chains and the incorporation of peripheral alkyl chains to the diphenanthrocarbazole core. The availability of these cores is facilitated by accessible synthetic procedures, which conclude with a microwave-assisted Cadogan reaction in the former and the Scholl reaction in the latter. As corroborated by means of X-ray diffraction, both cores arrange in a favorable gamma packing in the solid state that justify these enticing results. Remarkably, all the studied compounds feature an extraordinary air-stability, with some of the devices featuring a shelf lifetime that surpass the milestone of 1000 days. As a second strategy, the carbazole core has been substituted by its sulfurated analog dibenzothiophene as the main building block. By means of sequential Suzuki-Miyaura and Scholl reactions, diverse diphenanthro[9,10-b:9',10'-d]thiophene derivatives have been synthesized from the commercially available tetrabromothiophene. The envisioned synthetic route could provide not only homogeneous structures, but also heterogeneous ones in a two-step procedure. The latter systems also behaved as p-type semiconductors, with hole mobility values up to 6 × 10−5 cm2 V–1 s–1 in OTFTs. The redesign of the triindole core, which is a well-known carbazole-based semiconductor, constituted another part of this Thesis. Specifically, it included the synthesis and physical characterization of triindole analogs, featuring: carbazole moieties attached to different positions, oxygen or sulfur substituting the nitrogen as heteroatom and the inclusion of peripheral alkyl chains. The collected results prompt further study in this direction. Finally, the promising optical properties of the 3-(phenylethynyl)-9H-carbazole unit have been exploited in the OLED technology. The two analyzed constructions, i.e. 6,6′-bis(phenylethynyl)-9H,9′H-3,3′-bicarbazole and 1,3,5-tris((9H-carbazol-3-yl)ethynyl)-benzene, exhibited blue emission in the solid state and in solution-processed OLEDs. The hexylated derivative of the first system, apart from emitting in the sought deep-blue region, also stood out as the most appropriate to perform as host for iridium complexes in white OLEDs. The emission of the fabricated devices covered a wide range of white hues, depending on the composition and the applied voltage.[cat] Aquesta Tesi té com a objectiu la síntesi de semiconductors orgànics de tipus p basats en l’heterocicle 9H-carbazole i la seva aplicació en diferents dispositius electrònics, com poden ser els transistors orgànics de capa prima (OTFTs) i els díodes emissors de llum orgànics (OLEDs). Per assolir aquest objectiu, s’ha treballat en primer lloc en l’extensió lineal del sistema π de l’anell de carbazole. També s’ha fet èmfasi en la incorporació de cadenes alquíliques a les estructures dissenyades, ja que són fonamentals per modular la disposició en l’estat sòlid. Cal destacar especialment els nuclis derivats diindolocarbazole i difenantrocarbazole, ja que no només impliquen una ruta sintètica accessible, si no que a més han proporcionat mobilitats que arriben a 10−3 cm2 V−1 s−1 en dispositius OTFT i una estabilitat que pot superar els 1000 dies. En segon lloc s’ha considerat el nucli dibenzotiofè, que és l’anàleg sulfurat del carbazole, com a building block. A través de les reaccions de Suzuki-Miyaura i Scholl s’han format l’anell de difenantrotiofè i compostos derivats que inclouen diferents grups i extensions aromàtiques. La integració d’alguns d’aquests compostos en dispositius OTFT ha demostrat la seva viabilitat com a semiconductors. En vista de l’èxit de l’anell de triindole en treballs anteriors, s’han aplicat els coneixements adquirits al llarg de la tesi per modificar la seva estructura i intentar millorar els resultats com a semiconductor orgànic. Els canvis estructurals estudiats impliquen l’enllaç d’anells de carbazole suplementaris, la substitució dels nitrògens del nucli per oxígens o sofres i l’annexió de cadenes alquíliques perifèriques. Per últim, les propietats òptiques que aporta la unitat 3-(feniletinil)-9H-carbazole s’han aprofitat per dissenyar una sèrie de compostos derivats emissors en el blau com a components per a dispositius OLED. A més, la incorporació de diferents cadenes alquíliques ha permès millorar-ne la solubilitat i facilitar la fabricació dels dispositius en solució, fet que abarateix molt el cost de producció. Els compostos també s’han integrat juntament amb complexos d’iridi en OLEDs blancs. Factors com la composició i el voltatge aplicat han permès modular la temperatura de la llum, des del blanc pur fins a tonalitats molt més càlides

Exploring the 3-(phenylethynyl)-9H-carbazole unit in the search of deep-blue emitting fluorophores

Two new types of molecular constructions based on the 3-(phenylethynyl)-9H-carbazole moiety have been developed. Specifically, the synthesized bicarbazole and triethynylbenzene derived fluorophores display emission ranging from deep-blue to green-blue in the solid state, depending on the N-alkyl chain length and their intermolecular arrangement, which has been elucidated from the crystallographic data. Their photophysical and electrochemical properties have permitted the construction of blue OLEDs with a simple device architecture compatible with the solution-processing. In addition, the combination of the synthesized emitters with a small ratio of commercial iridium complexes has allowed the preparation of pure white OLEDs by spin coating the different layers. The characteristics of the emitted white light depend not only on the emissive layer composition but also on the applied voltage, standing as two key factors to easily modulate the color temperature