Periodic Reporting for period 1 - LA2DCOFS (Light-Addressable 2D Covalent-Organic Framework Semiconductors)
Berichtszeitraum: 2022-01-01 bis 2023-12-31
Among the most prominent fields of contemporary materials and chemical sciences is the design and synthesis of synthetic porous materials. Among these materials, reticulated crystalline 2D covalent organic frameworks (COFs) are progressively taking a prominent role. These porous polymers consist of entirely organic building blocks interconnected in 2D structures, showcasing considerable potential in applications such as catalysis, molecular sieving, gas storage, and, more recently, electronics. The synthetic adaptability of COFs, achievable through a diverse array of well-established organic reactions, enables the customization of their composition and properties using dynamic covalent chemistry approaches and post-synthetic modification. This synthetic flexibility positions them as ideal candidates for the production of cost-effective, flexible devices. Despite their versatility, most of these structures remain “passive”, which renders their function predefined by the choice of the building blocks used for construction of the interconnected network. Yet, the ability to remotely control the properties of these materials could open avenues for responsive device fabrication and drive the advancement of adaptive materials.
Among the various types of stimuli, light offers opportunities for non-invasive, waste-free control over the properties of the materials with the highest spatial temporal precision. Consequently, the aim of the LAD2DCOFs project was to develop photoswitchable semiconductive 2D COFs, establishing a foundation for future reconfigurable and adaptive devices. By integrating photoswitchable moieties into porous solids, this research places a primary focus on the understanding of the behavior of the photoswitchable elements in the porous scaffold, with the ultimate goal of leveraging fundamental studies for the development of new materials.
Among the various types of stimuli, light offers opportunities for non-invasive, waste-free control over the properties of the materials with the highest spatial temporal precision. Consequently, the aim of the LAD2DCOFs project was to develop photoswitchable semiconductive 2D COFs, establishing a foundation for future reconfigurable and adaptive devices. By integrating photoswitchable moieties into porous solids, this research places a primary focus on the understanding of the behavior of the photoswitchable elements in the porous scaffold, with the ultimate goal of leveraging fundamental studies for the development of new materials.
Over the past two years, the LAD2DCOFs project has made significant progress in advancing the field of light-responsive porous materials. Throughout this initiative, we successfully engineered a photoswitchable electrochemical transistor by leveraging the impact of photoisomerization of a spiropyran photoswitch on an organic semiconductor. We showcased a simple method for the fabrication of responsive materials by the integration of various spiropyran photoswitches into porous organic frameworks through a sequence of two post-synthetic reactions, both proceeding with nearly quantitative yields. Moreover, our research revealed that the scaffold can dynamically reconfigure in response to the isomerization of the pendant moieties, resulting in the emergence of additional available states and thereby unexpected properties. We further demonstrated the selective isomerization of a dithienylethene–spiropyran dyad incorporated into a porous aromatic framework upon irradiation with light of a specific wavelength. Notably, our investigation of the isomerization of molecular motors in thin films of metal–organic frameworks showcased a significant impact on the diffusion of guests within the materials. Continuing our efforts, we are currently engaged in the development of imine-linked 2D COFs appended with peri-aryloxyanthraquinone photoswitches. In order to improve the quality of the synthetic films, we developed an innovative technique for producing oriented films of 2D COFs. This method allows for the creation of large-area, free-standing, and highly porous materials.
The findings from this project have been disseminated in five scientific articles published in high-impact peer-reviewed journals. Additionally, several other publications are in the preparation phase or have been submitted for peer review.
The findings from this project have been disseminated in five scientific articles published in high-impact peer-reviewed journals. Additionally, several other publications are in the preparation phase or have been submitted for peer review.
The research conducted throughout this initiative represents a significant qualitative advancement beyond the current state of the art. Our investigations of the incorporation of light-responsive artificial molecular switches into porous solids not only represent a successful proof of concept, but also offer fundamental insights into the behavior of these moieties in confinement, providing the design principles of these materials. We anticipate that these breakthroughs will spark further research in this direction, paving the way for adaptive materials with diverse applications ranging from energy storage to molecular sieving. The novel method for the fabrication of oriented films of 2D COFs holds considerable potential for scale-up, offering the prospect of constructing tailorable and finely tuned isoporous membranes. Additionally, the demonstration that oriented materials can spontaneously form upon solvent evaporation is expected to stimulate further efforts toward the development of anisotropic materials.
The interdisciplinary nature of this research is not only expected to influence the fields of smart materials, photochemistry, and broad materials sciences, but also holds promise for practical applications. Societal impact is foreseen in the development of adaptive materials that can address a spectrum of challenges and contribute to advancements in various scientific and technological domains.
The interdisciplinary nature of this research is not only expected to influence the fields of smart materials, photochemistry, and broad materials sciences, but also holds promise for practical applications. Societal impact is foreseen in the development of adaptive materials that can address a spectrum of challenges and contribute to advancements in various scientific and technological domains.