In traditional electronics, inorganic materials such as silicon and germanium are used as semiconductors due to their outstanding semiconducting properties. Unfortunately, inorganic materials are rigid due to their high crystalline nature, and processing these materials is complex and expensive. Furthermore, traditional semiconducting materials do not have favorable mechanical properties in applications such as wearable devices and large-area applications with complicated shapes. Conjugated conducting polymers (CCPs) are being explored as alternative materials to conventional semiconductors due to their mechanical properties and high conductivity. CCPs offer properties such as solution and low-temperature processability, flexibility, thermal and optical properties that traditional semiconductors could not provide. These characteristics are essential in Organic Light-Emitting Diodes (OLEDs), Organic Field-Effect Transistors (OFETs), and Photovoltaic (PVs) devices. This dissertation focuses on synthesizing rhodamine- and diketopyrrolopyrrole- containing CCPs. Chapter I focuses on the synthesis, and characterization of polyrhodamine (PRho), a semiconducting conjugated polymer containing the rhodamine core in the polymer’s backbone. PRho was synthesized by the Buchwald-Hartwig polycondensation and characterized for its optical and electrochemical properties. We have discovered that the polymer is electrochemically reversible and stable up to 1000 cycles as recorded by cyclic voltammetry between -0.4 and 1.0 V vs. Ag/AgCl and stable to extreme acidic and basic conditions without noticeable degradation. Remarkably, the polymer has a conductivity in the semiconductor range of 8.38 x 10-2 S cm–1 when treated with 20% HCl. Chapter II focuses on the synthesis and characterization of four different alkenyl flanked diketopyrrolopyrrole (DPP) polymers ( PDPPVTV, PDPPVTT, PDPPV3T, and PDPPV4T) synthesized via Stille polycondensation. Different pi-conjugated segments (alkenyl/ PDPPVTV, thiophene/ PDPPVTT, thienothiophene/ PDPPV3T, and dithienothiophene/ PDPPV4T) were used to tune the optoelectrical properties of the polymers. The effect of the alkenyl groups and different pi-conjugated segments on the optoelectrical and charge mobility properties were determined by UV/visible spectroscopy, cyclic voltammetry, and FET characteristics. Three of the four polymers, except PPP4T, showed good solubility in chloroform. All the polymers showed high thermal stabilities in TGA and semi-crystalline nature in X-Ray diffraction patterns. PDPPVTV and PDPPVTT exhibited hole mobilities of 1.8 x 10-3 cm2 V-1 s-1 and 0.25 cm2 V-1 s-1, respectively. .

By examining structure activity relationships for a given catalytic reaction it is possible to discover what ligand features and parameters lead to stable and highly active/selective catalyst systems. With this knowledge in hand it may be possible to rationally design next generation ligands and catalysts to affect improved substrate transformations, with higher selectivities and faster reaction times. The success of Burk's DuPhos ligands in asymmetric hydrogenation demonstrated that chiral phosphacycles can be a potent source of chiral induction, whilst in a similar vein the work of van Leeuwen and Kamer established the wide bite angle xanthene based ligands as excellent catalysts in a range of reactions including hydroformylation. In a preliminary study with Osborne they showed that combining these wide bite angle ligand backbones with Burk's phospholane moieties led to a new powerful ligand in asymmetric allylic substitution. To examine the potential of combining these two ligand features further we designed and synthesised nine new C2-symmetric bidentate wide bite angle bisphosphacyclic ligands, featuring phosphetane, phospholane or diazaphospholane rings, aiming at a wide diversity of steric and electronic properties. The application of these ligands as chiral auxiliaries in transition metal catalysed reactions, including; hydrogenation, hydrocyanation, hydroformylation and allylic alkylation has been investigated. Good to excellent enantioselectivities were observed in all reactions, with maximum ee's of 92.5% observed in hydrogenation, using N-(3,4-dihydro-1-napthalenyl)-acetamide as substrate, and of 96.2% in the alkylation of 1,3-diphenyl-2-propenyl acetate.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-05-10T11:48:36Z No. of bitstreams: 1 jeffersondasilvamartins.pdf: 3798520 bytes, checksum: 36b404dfc17447ab2b47b8addd04eceb (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-05-22T15:42:34Z (GMT) No. of bitstreams: 1 jeffersondasilvamartins.pdf: 3798520 bytes, checksum: 36b404dfc17447ab2b47b8addd04eceb (MD5) / Made available in DSpace on 2018-05-22T15:42:34Z (GMT). No. of bitstreams: 1 jeffersondasilvamartins.pdf: 3798520 bytes, checksum: 36b404dfc17447ab2b47b8addd04eceb (MD5) Previous issue date: 2018-01-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O projeto contínuo de desenvolvimento de pesquisas em novos materiais orgânicos mais eficientes, mais puros e com boa estabilidade térmica e morfológica é fundamental para a aplicação em novos dispositivos orgânicos. Nesse contexto, o objetivo dessa tese é a fabricação e caracterização de novos dispositivos orgânicos emissores de luz (OLEDs). Essa pesquisa foi desenvolvida com duas abordagens e aplicações distintas. Na primeira, utiliza-se uma nova classe de derivados de xanteno (XD) como materiais transportadores de buracos, e na segunda, apresenta-se dois novos complexos de Európio como materiais emissores de luz. Na aplicação dos XD como camada transportadora de buracos (CTB) foram fabricados OLEDs bicamada, utilizando-se o material comercial Alq3 como emissor de luz. Os resultados desse estudo foram comparados com dispositivos de referência fabricados com o material comercial α-NPD no lugar dos XD. Todos os dispositivos baseados nos XD apresentaram uma eficiência de corrente mais elevada quando comparados com dispositivos de referência α-NPD. Um estudo teórico e experimental sobre a mobilidade de buracos dos XD e α-NPD mostram que todos os XD possuem mobilidade de buraco mais elevada que o material comercial. A mobilidade de buraco mais elevado na camada dos XD proporcionou um melhor equilíbrio de buracos e elétrons e, portanto, maior recombinação, resultando em eficiência aprimorada. Na segunda parte deste trabalho, foram estudados dois complexos de Európio como emissores de luz na região do vermelho do espectro visível. Os complexos de Európio, [Eu(btfa)3(dmbpy)2] e [Eu (TTA)3(PhenSe)], apresentaram as transições características ⁵D₀ → ⁷FJ (J = 0-4), em solução e em filme fino evaporado termicamente. Com o complexo [Eu(btfa)3(dmbpy)2] foram fabricados dispositivos com duas configurações de diferentes e, embora os OLEDs tenham apresentado uma banda larga devido à contribuição do Alq3, demonstrou-se a fabricação de um OLED eficiente. Já o complexo [Eu (TTA)3(PhenSe)] as eletroluminescências dos dispositivos apresentaram uma banda larga centrada em 580 nm, dificultando assim a observação das transições ⁵D₀ → ⁷FJ (J = 0,1). / The continuing research project to develop new organic materials that are more efficient, purest and with a good morphological and thermal stability is essential to apply them to new organic devices. Therefore, the aim of this thesis is the fabrication and the characterization of organic electroluminescent devices (OLEDs). This research was developed based on two distinctive approaches. At first, it was used a new xanthene derivative (XD) class as a hole transporting material and, secondly, it is shown two new Europium complex as light emitters. The use of XD as hole transporting layer (HTL) was made to fabricated bilayers OLEDs using the commercial material Alq3 as light emitters. Their results were compared to the reference device previously fabricated with the commercial material α-NPD. All XD devices presented a higher current efficiency when compared to the α-NPD reference device. A theoretical and experimental study of the XD and α-NPD holes mobility showed that all XD has a higher hole mobility than the commercial material. The higher hole mobility of the XD layer resulted in a better balance between hole and electrons and consequently, in a higher number of combinations, resulting in devices with improved efficiency. At the second part of this study, it was studied two Europium complexes as red-light emitters. The Europium complex, [Eu(btfa)3(dmbpy)] and [Eu(TTA)3(PhenSe)], showed the transitions characteristic of ⁵D₀ → ⁷FJ (J = 0-4) in solution and in a thermal evaporated thin film. The [Eu(btfa)3(dmbpy)] complex was used to fabricate devices with two different configurations and, although the OLEDs have shown a wide band due to the Alq3 contribution, the OLEDs presented good efficiency. In contrast, the electroluminescence of the [Eu (TTA)3(PhenSe)] complex based devices showed a wide band centered in 580 nm, in this case, covering the narrow ⁵D₀ → ⁷FJ (J = 0,1) transitions.

A number of novel isoindoline nitroxides have been synthesised using a variety of synthetic techniques. Several carbon-carbon bond forming methodologies, including the first examples of Heck and Sonogashira coupling applied to the isoindoline nitroxide class, were utilised to give novel robust aromatic frameworks. Palladium-catalysed Heck coupling of brominated nitroxides and ester-substituted olefins generates novel nitroxides possessing extended conjugation. Hydrolysis of the nitroxide esters gave the corresponding carboxylic acids, which showed enhanced water solubility. Sonogashira coupling of an iodo-isoindoline nitroxide gave several novel alkynesubstituted nitroxides in high yield. Subsequent coupling of a deprotected ethynyl nitroxide with aromatic iodides gave acetylene-linked nitroxides and an acetylene linked nitroxide dimer. A butadiyne linked dinitroxide was successfully synthesised via Eglinton oxidative coupling of two ethynyl nitroxides. The synthesis of a novel water-soluble dicarboxy nitroxide was achieved by base hydrolysis of a dinitrile. Functional group interconversion furnished anhydride and imide substituted nitroxides from the diacid. Subjecting the imide to the Hofmann rearrangement gave an unexpected brominated amino-carboxy nitroxide. The dicarboxy nitroxide and the brominated amino-carboxy nitroxide were both shown to have a protective effect on Ataxia-Telangiectasia cells, indicating a possible role as antioxidants in the treatment of this disease. A fluorescein nitroxide was successfully synthesised through the condensation of the anhydride substituted nitroxide and resorcinol. After limited success using a variety of other techniques, Buchwald-Hartwig amination was able to furnish a rhodamine nitroxide, via a triflate-fluorescein nitroxide. The extended aromatic nitroxides possess suppressed fluorescence and we have described these systems as profluorescent. The profluorescent nitroxides were found to have significantly lower quantum yields than the non-radical analogues and displayed a substantial increase in fluorescence intensity upon radical trapping, making them useful probes for free radical reactions.

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