Polímeros orgánicos conjugados: desde sistemas lineales a redes orgánicas covalentes

El campo de los polímeros conjugados ha experimentado un espectacular desarrollo en los últimos cincuenta años, aunque no fue hasta 1977, cuando Alan J. Heeger, Alan MacDiarmid y Hideki Shirakawa llevaron a cabo el dopaje en fase gaseosa de películas de poliacetileno que daba como resultado cambios dramáticos en las propiedades electrónicas, eléctricas, magnéticas, ópticas y estructurales de las mismas. A partir de ese momento, la combinación de las propiedades semiconductoras y la posibilidad de dopaje, junto con las características de los plásticos convencionales como son su facilidad y bajo coste de producción, flexibilidad, baja densidad, procesabilidad y buena estabilidad térmica y química, han atraído la atención de la comunidad científica, la cual ha realizado un gran esfuerzo sintético en el desarrollo de nuevos tipos de polímeros orgánicos conjugados semiconductores.Todo ello ha posibilitado que los polímeros conjugados encuentren aplicaciones en áreas tan diversas como sensores, transistores, dispositivos electrocrómicos, fotodetectores, así como dispositivos (opto)electrónicos entre otros. Sin embargo, aunque después de varias décadas de investigación se han conseguido grandes avances en el control de sus propiedades ópticas y electrónicas, la fabricación de dispositivos electrónicos competitivos sigue representando un gran reto debido principalmente a la falta de control sobre su estructura y orientación en la nanoescala. El desarrollo de las redes orgánicos covalentes bidimensionales o COFs 2D podría llegar a ser una alternativa viable para afrontar dichos desafíos de la tecnología de polímeros semiconductores..

Scalable Synthesis and Electrocatalytic Performance of Highly Fluorinated Covalent Organic Frameworks for Oxygen Reduction

In this study, we present a novel approach for the synthesis of covalent organic frameworks (COFs) that overcomes the common limitations of non-scalable solvothermal procedures. Our method allows for the room-temperature and scalable synthesis of a highly fluorinated DFTAPB-TFTA-COF, which exhibits intrinsic hydrophobicity. We used DFT-based calculations to elucidate the role of the fluorine atoms in enhancing the crystallinity of the material through corrugation effects, resulting in maximized interlayer interactions, as disclosed both from PXRD structural resolution and theoretical simulations. We further investigated the electrocatalytic properties of this material towards the oxygen reduction reaction (ORR). Our results show that the fluorinated COF produces hydrogen peroxide selectively with low overpotential (0.062 V) and high turnover frequency (0.0757 s−1) without the addition of any conductive additives. These values are among the best reported for non-pyrolyzed and metal-free electrocatalysts. Finally, we employed DFT-based calculations to analyse the reaction mechanism, highlighting the crucial role of the fluorine atom in the active site assembly. Our findings shed light on the potential of fluorinated COFs as promising electrocatalysts for the ORR, as well as their potential applications in other fieldsThis work was financially supported by Ministerio de Ciencia e Innovación of Spain MICINN (TED2021-129886B-C41, TED2021-129886BC42; TED2021-129886BC43; PID2019-106268GB-C32; PID2019-106268GB C33, PID2020-113608RB-I00; PID2022-138908NB-C33, PID2022-138470NB-100, RED2018-102412-T; PID2020-116728RB-I00). Comunidad de Madrid (P2018/NMT-4349 TRANSNANOAVANSENS Program; SI3/PJI/2021-0034). F.Z. acknowledge financial support from the Spanish Ministry of Science and Innovation, through the “María de Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-M). R.V. acknowledges “Programa Juan de la Cierva Formación” (FJC2020-045043-I). R.V. and J.A.R.N. acknowledge MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU/PRTR

Polímeros orgánicos conjugados: desde sistemas lineales a redes orgánicas covalentes

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Química Orgánica I, leída el 07-07-2017El campo de los polímeros conjugados ha experimentado un espectacular desarrollo en los últimos cincuenta años, aunque no fue hasta 1977, cuando Alan J. Heeger, Alan MacDiarmid y Hideki Shirakawa llevaron a cabo el dopaje en fase gaseosa de películas de poliacetileno que daba como resultado cambios dramáticos en las propiedades electrónicas, eléctricas, magnéticas, ópticas y estructurales de las mismas. A partir de ese momento, la combinación de las propiedades semiconductoras y la posibilidad de dopaje, junto con las características de los plásticos convencionales como son su facilidad y bajo coste de producción, flexibilidad, baja densidad, procesabilidad y buena estabilidad térmica y química, han atraído la atención de la comunidad científica, la cual ha realizado un gran esfuerzo sintético en el desarrollo de nuevos tipos de polímeros orgánicos conjugados semiconductores.Todo ello ha posibilitado que los polímeros conjugados encuentren aplicaciones en áreas tan diversas como sensores, transistores, dispositivos electrocrómicos, fotodetectores, así como dispositivos (opto)electrónicos entre otros. Sin embargo, aunque después de varias décadas de investigación se han conseguido grandes avances en el control de sus propiedades ópticas y electrónicas, la fabricación de dispositivos electrónicos competitivos sigue representando un gran reto debido principalmente a la falta de control sobre su estructura y orientación en la nanoescala. El desarrollo de las redes orgánicos covalentes bidimensionales o COFs 2D podría llegar a ser una alternativa viable para afrontar dichos desafíos de la tecnología de polímeros semiconductores...The field of conjugated polymers has undergone a spectacular development in the last fifty years. However, it was not until 1977 when Alan J. Heeger, Alan MacDiarmid and Hideki Shirakawa carried out the gas phase doping of polyacetylene films which resulted in dramatic changes in the electronic, electrical, magnetic, optical and structural properties of conjugated polymers. Since then, the combination of semiconductor properties and the possibility of doping, along with the characteristics of conventional plastics such as its easy and low cost production, flexibility, low density, processability and good thermal and chemical stability, have attracted the attention of the scientific community, which has made a great synthetic effort in the development of new types of semiconducting organic conjugated polymers.All these efforts have enabled the possibility of finding applications for conjugated polymers in different areas including sensors, transistors, electrochromic devices, photodetectors, as well as (opto)electronic devices among others. However, although considerable advances have been made in the control of its optical and electronic properties after several decades of research, the manufacture of competitive electronic devices continues to be a major challenge, mainly due to the lack of control over its structure and orientation at the nanoscale. The development of two-dimensional covalent organic networks or 2D COFs can be envisaged as a viable alternative to address these challenges of semiconducting polymer technology...Depto. de Química OrgánicaFac. de Ciencias QuímicasTRUEunpu

Direct on-surface patterning of a crystalline laminar covalent organic framework synthesized at room temperature

We report herein an efficient, fast, and simple synthesis of an imine-based covalent organic framework (COF) at room temperature (hereafter, RT-COF-1). RT-COF-1 shows a layered hexagonal structure exhibiting channels, is robust, and is porous to N2 and CO2. The roomtemperature synthesis has enabled us to fabricate and position low-cost micro- and submicropatterns of RT-COF-1 on several surfaces, including solid SiO2 substrates and flexible acetate paper, by using lithographically controlled wetting and conventional ink-jet printing.We thank the MINECO (Spain) for financial support through projects MAT2013-46753-C2-1-P, MAT2012-30994, and MAT2014-52305-P). A.P. acknowledges UCM for a predoctoral fellowship.Peer Reviewe

Scalable Synthesis and Electrocatalytic Performance of Highly Fluorinated Covalent Organic Frameworks for Oxygen Reduction

In this study, we present a novel approach for the synthesis of covalent organic frameworks (COFs) that overcomes the common limitations of non-scalable solvothermal procedures. Our method allows for the room-temperature and scalable synthesis of a highly fluorinated DFTAPB-TFTA-COF, which exhibits intrinsic hydrophobicity. We used DFT-based calculations to elucidate the role of the fluorine atoms in enhancing the crystallinity of the material through corrugation effects, resulting in maximized interlayer interactions, as disclosed both from PXRD structural resolution and theoretical simulations. We further investigated the electrocatalytic properties of this material towards the oxygen reduction reaction (ORR). Our results show that the fluorinated COF produces hydrogen peroxide selectively with low overpotential (0.062 V) and high turnover frequency (0.0757 s-1 ) without the addition of any conductive additives. These values are among the best reported for non-pyrolyzed and metal-free electrocatalysts. Finally, we employed DFT-based calculations to analyse the reaction mechanism, highlighting the crucial role of the fluorine atom in the active site assembly. Our findings shed light on the potential of fluorinated COFs as promising electrocatalysts for the ORR, as well as their potential applications in other fields.Depto. de Química InorgánicaDepto. de Química OrgánicaFac. de Ciencias QuímicasTRUEpubDescuento UC

Síntesis escalable y rendimiento electrocatalítico de marcos orgánicos covalentes altamente fluorados para la reducción del oxígeno

his work was financially supported by Ministerio de Ciencia e Innovación of Spain MICINN (TED2021-129886B-C41, TED2021-129886BC42; TED2021-129886BC43; PID2019-106268GB-C32; PID2019-106268GB-C33, PID2020-113608RB-I00; PID2022-138908NB-C33, PID2022-138470NB-100, RED2018-102412-T; PID2020-116728RB-I00). Comunidad de Madrid (P2018/NMT-4349 TRANSNANOAVANSENS Program; SI3/PJI/2021-0034). F. Z. acknowledge financial support from the Spanish Ministry of Science and Innovation, through the “María de Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-M). R. V. acknowledges “Programa Juan de la Cierva Formación” (FJC2020-045043-I). R. V. and J. A. R. N. acknowledge MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU/PRTR.Abstract In this study, we present a novel approach for the synthesis of covalent organic frameworks (COFs) that overcomes the common limitations of non‐scalable solvothermal procedures. Our method allows for the room‐temperature and scalable synthesis of a highly fluorinated DFTAPB‐TFTA‐COF, which exhibits intrinsic hydrophobicity. We used DFT‐based calculations to elucidate the role of the fluorine atoms in enhancing the crystallinity of the material through corrugation effects, resulting in maximized interlayer interactions, as disclosed both from PXRD structural resolution and theoretical simulations. We further investigated the electrocatalytic properties of this material towards the oxygen reduction reaction (ORR). Our results show that the fluorinated COF produces hydrogen peroxide selectively with low overpotential (0.062 V) and high turnover frequency (0.0757 s−1) without the addition of any conductive additives. These values are among the best reported for non‐pyrolyzed and metal‐free electrocatalysts. Finally, we employed DFT‐based calculations to analyse the reaction mechanism, highlighting the crucial role of the fluorine atom in the active site assembly. Our findings shed light on the potential of fluorinated COFs as promising electrocatalysts for the ORR, as well as their potential applications in other fields.MICINNComunidad de MadridDepto. de Química OrgánicaFac. de Ciencias QuímicasTRUEpu