[en] The main objective of the present thesis is the synthesis of new electroactive organic materials based on diketopirrolopirroles, which are designed to be components of the active layer of bulk heterojunction (BHJ) organic photovoltaic devices. Despite the fact in our research group there is a wide experience in organic synthesis of molecular materials, this thesis is the seminar work in the synthesis, characterization and application of diketopirrolopirrole (DPP). These molecules have notable optoelectronic properties and chemical versatility, and they have been combined with other equally interesting structural units, such as the phthalocyanines (Pc) and the perylendiimides (PDI), to obtain materials with improved properties. Chapter 1 serves to introduce the three main actors of this thesis in three parts: the first one, dedicated to the protagonists, the DPPs, the second one is dedicated to Pcs and the third one to PDI. Each section describes the basic structure of each of the materials, then their synthesis and reactivity, and finally their properties and applications. The two following chapters involve the central part of the present thesis, where the results of the research will be described. Chapter 2 is devoted to the synthesis of four DPPs and Pcs based small molecules that are a new family of molecules. Two of them are triads, formed by a central DPP unit attached covalently to two zinc phthalocyanines (ZnPc), and two dyads, whose structure includes a unit of DPP and another of ZnPc, also linked covalently.The most notable structural differences, in addition to the number of Pc units, are the degree of symmetry and connectors (simple and triple bonds) between the DPP and Pc units. A study of photophysical properties of these molecules has been carried out, finding in all cases that the excitation by light radiation triggers relevant intramolecular photphysical events. When the DPP unit absorbs radiation at 570 nm, it excites to its singlet state, which is disabled by an energy transfer to the ZnPc unit. On the other hand, when the ZnPc unit absorbs photons at 680 nm it reaches to its singlet state. This singlet state is turned off by an electronic transfer to the DPP unit, producing a charge separation state which decays through a long-lived triplet excited state. Thus, it is shown that this molecular material may act as antenna and reaction center in artificial photosynthetic systems. The ZnPc-DPP derivatives were applied as donors in BHJ photovoltaic cells along with acceptor such as fullerene derivatives, PC60BM and PC70BM. The results have been quite discreet, being the best efficiency achieved 1.04%, for devices with configuration glass/ITO/MoO3/(ZnPc)2- DPP 1: PC70BM (ratio 1.5:1)/Ca/Ag. Chapter 3 is related to the synthesis of polymeric materials and small molecules based in DPPs and PDIs through a very interesting reaction, direct (hetero)arylation (DHA). This reaction promises simpler, cheaper and greener synthesis processes, although has not yet been described on the core of the PDI. The synthesis of polymers or small molecules based on PDI, whose starting reagent is a mono or dibrominated PDI in bay positions, has not been successful. However, it has been achieved the synthesis of two polymers based on DPPs and PDIs by DHA, whose monomer units are exposed in Figure 2a. The synthetic strategy to reach the desired compounds was to couple by DHA 1,7(1.6)-dibromoPDI with di(bromofenil)DPP or 1 4-dibromobenzene throught the position 5 of the thiophene. Polymers synthesized by DHA have been compared to those same polymers, but synthesized by Suzuki-Miyaura reactions, by techniques as 1H-NMR, UV-Vis spectrophotometry, DSC and TGA. It is possible to conclude that the materials synthesized by DHA have defects, probably due to unwanted ramifications, β-couplings, the presence of different terminal groups and the use of monomers of 1,7(1,6)-ditienilPDI. Finally, two small molecules have also been synthesized by DHA, which are structurally similar to the aforementioned polymers, with pretty good yields . A very remarkable result has been the successful synthesis of a triad based on PDI and DPP (o-(PDI)2-DPP 5) by DHA, because it has managed to carry out successfully this type of coupling directly on the core of the PDI brominated for the first time, but in 2 or ortho position thereof. In addition, preliminary studies of new acceptor materials based on DPPs and PDIs have been made in the active layer of BHJ photovoltaic devices.

[es] La presente tesis tiene como objetivo principal la síntesis de nuevos materiales orgánicos electroactivos basados en dicetopirrolopirroles, los cuales han sido diseñados para ser componentes de la capa activa de dispositivos fotovoltaicos orgánicos de heterounión masiva (BHJ). En nuestro grupo de investigación existe una amplia experiencia en síntesis orgánica, pero ha sido mi trabajo iniciar la investigación en torno a la síntesis, caracterización y aplicación de derivados de dicetopirrolopirrol (DPP). Estas moléculas, que presentan unas propiedades optoelectrónicas y una versatilidad química notables, se han combinado con otras unidades estructurales igualmente interesantes, las ftalocianinas (Pc) y las perilenodiimidas (PDI), para obtener materiales con propiedades mejoradas.El capítulo 1 sirve de introducción para presentar a los tres actores principales de esta tesis en sendos apartados: el primero se dedica a los dicetopirrolopirroles, que son, sin duda, los protagonistas, el segundo a las ftalocianinas y el tercero a las perilenodiimidas. En cada apartado se describe la estructura básica de cada uno de los materiales, después la síntesis y la reactividad de éstos, y por último sus propiedades y las aplicaciones que se derivan de ellas. Los dos siguientes capítulos suponen la parte central de esta tesis, pues es donde se exponen los resultados del trabajo investigador.El capítulo 2 está dedicado a la síntesis de cuatro moléculas pequeñas basadas en DPPs y Pcs, que son una nueva familia molecular. Dos de ellas son tríadas constituidas por una unidad de DPP central conectada covalentemente a dos ftalocianinas de cinc (ZnPc), y dos díadas, cuya estructura comprende una unidad de DPP y otra de ZnPc, también enlazadas de forma covalente.Las diferencias estructurales más notables, además del número de unidades de Pc, son el grado de simetría y los conectores (enlaces sencillos y triples) entre las unidades de DPP y Pc. Se ha realizado un estudio de las propiedades fotofísicas de estas moléculas, hallándose en todos los casos que la excitación por radiación lumínica desencadena eventos fotofísicos intramoleculares relevantes. Cuando la unidad de DPP absorbe radiación a 570 nm se excita a su estado singlete, el cual se desactiva mediante una transferencia de energía hacia la unidad de ZnPc. Por otra parte, cuando la unidad de ZnPc absorbe fotones a 680 nm se excita a su estado singlete, el cual se desactiva por una transferencia electrónica hacia el DPP, produciéndose un estado de separación de cargas que decae pasando por un estado triplete. Así, se ha demostrado que este material molecular podría actuar como antena y centro de reacción en sistemas fotosintéticos artificiales. Los derivados ZnPc-DPP se han aplicado como dadores en células fotovoltaicas BHJ junto a aceptores derivados del fulereno, el PC60BM y el PC70BM. Los resultados han sido bastante discretos, siendo el mejor un 1.04% de eficiencia para dispositivos con configuración [vidrio/ITO/MoO3/(ZnPc)2-DPP 1:PC70BM (ratio 1.5:1)/Ca/Ag].Un resultado muy destacable ha sido el éxito en la síntesis por HAD de una tríada basada en PDI y DPP [o-(PDI)2-DPP 5], ya que, por primera vez, se ha conseguido llevar a cabo con éxito este tipo de acoplamiento directamente sobre el núcleo de la PDI bromada, pero en la posición 2 u orto de la misma y con un buen rendimiento.Asimismo, se han realizado estudios preliminares de los nuevos materiales aceptores basados en DPPs y PDIs en la capa activa de dispositivos fotovoltaicos BHJ.