Pub Date : 2024-10-22DOI: 10.1021/acs.accounts.4c00491
Islam E Khalil, Prasenjit Das, Arne Thomas
<p><p>ConspectusCovalent organic frameworks (COFs) are a rapidly emerging class of crystalline porous polymers, characterized by their highly defined, predictable, and tunable structure, porosity, and properties. COFs can form both two-dimensional (2D) and three-dimensional (3D) architectures, each with unique characteristics and potential applications. 2D COFs have attracted particular interest due to their favorable structural and optoelectronic properties. They can be equipped with a range of different functional moieties in their backbone, ranging from acidic to basic, from hydrophilic to hydrophobic, and from metal-coordinating to redox-active functions. In addition, their crystallinity, high specific surface area, and remarkable thermal and chemical stability make them attractive for a variety of applications, including gas separation, catalysis, energy storage, and optoelectronics.This Account provides a detailed overview of our recent efforts to synthesize and apply 2D COFs. First, various synthesis routes are discussed, focusing on methods that involve reversible and irreversible linkage reactions. Reversible reactions, such as imine or boronate ester formation, are advantageous for producing highly crystalline COFs because they allow for error correction during synthesis. In contrast, irreversible reactions, such as carbon-carbon or carbon-nitrogen bond formation, yield COFs with greater chemical stability, although controlling crystallinity can be more challenging. Our group has contributed significantly to refining these methods to balance crystallinity and stability, enhancing the performance of the resulting 2D COFs.In addition to different binding patterns, we have also developed strategies to control the micro- and macromorphologies of COFs, which is crucial for optimizing their properties for specific applications. For example, we have explored the synthesis of hierarchical porous COFs by using templating techniques or by forming composites with other functional materials. These strategies enable us to fine-tune the porosity and surface properties of COFs, thereby improving their performance in applications like catalysis. Hierarchical structures in particular enhance photocatalytic efficiency by providing a larger surface area for light absorption and facilitating the transport of photogenerated charge carriers.We further examine the practical applications of 2D COFs, with a primary focus on photocatalysis. Photocatalysis uses light to enable or accelerate chemical reactions, and 2D COFs are ideal for this purpose due to their tunable band gaps and large surface areas. Our research has shown that 2D COFs are highly versatile photocatalysts that can effectively catalyze reactions such as water splitting, carbon dioxide reduction, hydrogen peroxide formation, and cross-coupling reactions. By exploiting the unique properties of 2D COFs, we have achieved significant improvement in many photocatalytic reactions.With this comprehensiv
{"title":"Two-Dimensional Covalent Organic Frameworks: Structural Insights across Different Length Scales and Their Impact on Photocatalytic Efficiency.","authors":"Islam E Khalil, Prasenjit Das, Arne Thomas","doi":"10.1021/acs.accounts.4c00491","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00491","url":null,"abstract":"<p><p>ConspectusCovalent organic frameworks (COFs) are a rapidly emerging class of crystalline porous polymers, characterized by their highly defined, predictable, and tunable structure, porosity, and properties. COFs can form both two-dimensional (2D) and three-dimensional (3D) architectures, each with unique characteristics and potential applications. 2D COFs have attracted particular interest due to their favorable structural and optoelectronic properties. They can be equipped with a range of different functional moieties in their backbone, ranging from acidic to basic, from hydrophilic to hydrophobic, and from metal-coordinating to redox-active functions. In addition, their crystallinity, high specific surface area, and remarkable thermal and chemical stability make them attractive for a variety of applications, including gas separation, catalysis, energy storage, and optoelectronics.This Account provides a detailed overview of our recent efforts to synthesize and apply 2D COFs. First, various synthesis routes are discussed, focusing on methods that involve reversible and irreversible linkage reactions. Reversible reactions, such as imine or boronate ester formation, are advantageous for producing highly crystalline COFs because they allow for error correction during synthesis. In contrast, irreversible reactions, such as carbon-carbon or carbon-nitrogen bond formation, yield COFs with greater chemical stability, although controlling crystallinity can be more challenging. Our group has contributed significantly to refining these methods to balance crystallinity and stability, enhancing the performance of the resulting 2D COFs.In addition to different binding patterns, we have also developed strategies to control the micro- and macromorphologies of COFs, which is crucial for optimizing their properties for specific applications. For example, we have explored the synthesis of hierarchical porous COFs by using templating techniques or by forming composites with other functional materials. These strategies enable us to fine-tune the porosity and surface properties of COFs, thereby improving their performance in applications like catalysis. Hierarchical structures in particular enhance photocatalytic efficiency by providing a larger surface area for light absorption and facilitating the transport of photogenerated charge carriers.We further examine the practical applications of 2D COFs, with a primary focus on photocatalysis. Photocatalysis uses light to enable or accelerate chemical reactions, and 2D COFs are ideal for this purpose due to their tunable band gaps and large surface areas. Our research has shown that 2D COFs are highly versatile photocatalysts that can effectively catalyze reactions such as water splitting, carbon dioxide reduction, hydrogen peroxide formation, and cross-coupling reactions. By exploiting the unique properties of 2D COFs, we have achieved significant improvement in many photocatalytic reactions.With this comprehensiv","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>ConspectusMetal-organic frameworks (MOFs) represent a sophisticated blend of inorganic and organic components, promoting the development of coordination chemistry greatly and offering a versatile platform for tailored functionalities. By combining various metal nodes, organic linkers, and functional guests, MOFs provide numerous pathways for their design, synthesis, and customization. Among these, sequential linker installation (SLI) stands out as a novel and crucial strategy, enabling the precise integration of desired properties and functions at the atomic scale. SLI enhances structural diversity and stability while facilitating the meticulous construction of robust frameworks by leveraging open metal sites and functional organic linkers at targeted locations. Compared to the direct synthesis of MOFs, postsynthetic modification methods allow for precise regulation of their structures and corresponding properties. While unlike conventional postsynthetic modification methods, SLI requires the careful selection of linkers and framework design to ensure precise positioning for installation, which gives rise to the well-designed and ordered positions for the installed linkers, confirmed directly by X-ray diffraction technology.Recent advancements in MOF synthesis have led to the creation of increasingly tailored flexible matrix structures, particularly due to the diverse connection modes of multicore metal clusters, especially for the Zr<sub>6</sub> cluster. The spatial hindrance of certain ligands has resulted in the formation of unsaturated metal clusters and various missing linker pockets. Examples of these advanced MOFs include PCN-606, PCN-608, PCN-609, PCN-700, and PCN-808, which feature specific open metal sites and certain framework flexibility conducive to SLI. Strategically positioned open metal sites within these frameworks serve as predetermined anchor points for desired functional molecules, while the frameworks' flexibility can accommodate molecules of varying sizes to a certain extent, enlarging the scopes of application greatly. This precise positioning of functional groups enables the creation of tailored sites for enhanced applications, such as adsorption, catalysis, and recognition.In this Account, we delve into the intricate process of designing and synthesizing MOFs with appropriate missing-linker pockets for the aforementioned applications. We discuss the meticulous selection of functional linkers and the methods used to insert them into the corresponding missing-linker pockets within the MOFs. Additionally, we explore the diverse properties and functionalities of the resulting MOFs, focusing on their adsorptive, catalytic, and recognition performance. Furthermore, we provide insights into the future trajectory of SLI methods, complemented by our recent works. This Account not only reviews the evolution of the SLI method but also underscores its practical applications across various functional domains, paving a rational p
{"title":"Sequential Linker Installation in Metal-Organic Frameworks.","authors":"Zongsu Han, Yihao Yang, Joshua Rushlow, Rong-Ran Liang, Hong-Cai Zhou","doi":"10.1021/acs.accounts.4c00564","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00564","url":null,"abstract":"<p><p>ConspectusMetal-organic frameworks (MOFs) represent a sophisticated blend of inorganic and organic components, promoting the development of coordination chemistry greatly and offering a versatile platform for tailored functionalities. By combining various metal nodes, organic linkers, and functional guests, MOFs provide numerous pathways for their design, synthesis, and customization. Among these, sequential linker installation (SLI) stands out as a novel and crucial strategy, enabling the precise integration of desired properties and functions at the atomic scale. SLI enhances structural diversity and stability while facilitating the meticulous construction of robust frameworks by leveraging open metal sites and functional organic linkers at targeted locations. Compared to the direct synthesis of MOFs, postsynthetic modification methods allow for precise regulation of their structures and corresponding properties. While unlike conventional postsynthetic modification methods, SLI requires the careful selection of linkers and framework design to ensure precise positioning for installation, which gives rise to the well-designed and ordered positions for the installed linkers, confirmed directly by X-ray diffraction technology.Recent advancements in MOF synthesis have led to the creation of increasingly tailored flexible matrix structures, particularly due to the diverse connection modes of multicore metal clusters, especially for the Zr<sub>6</sub> cluster. The spatial hindrance of certain ligands has resulted in the formation of unsaturated metal clusters and various missing linker pockets. Examples of these advanced MOFs include PCN-606, PCN-608, PCN-609, PCN-700, and PCN-808, which feature specific open metal sites and certain framework flexibility conducive to SLI. Strategically positioned open metal sites within these frameworks serve as predetermined anchor points for desired functional molecules, while the frameworks' flexibility can accommodate molecules of varying sizes to a certain extent, enlarging the scopes of application greatly. This precise positioning of functional groups enables the creation of tailored sites for enhanced applications, such as adsorption, catalysis, and recognition.In this Account, we delve into the intricate process of designing and synthesizing MOFs with appropriate missing-linker pockets for the aforementioned applications. We discuss the meticulous selection of functional linkers and the methods used to insert them into the corresponding missing-linker pockets within the MOFs. Additionally, we explore the diverse properties and functionalities of the resulting MOFs, focusing on their adsorptive, catalytic, and recognition performance. Furthermore, we provide insights into the future trajectory of SLI methods, complemented by our recent works. This Account not only reviews the evolution of the SLI method but also underscores its practical applications across various functional domains, paving a rational p","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15Epub Date: 2024-10-03DOI: 10.1021/acs.accounts.4c00275
Debsouri Kundu, Natalia Del Rio, Jeanne Crassous
ConspectusRecently, helicene derivatives have emerged as an important class of molecules with potential applications spanning over asymmetric catalysis, biological activity, magnetism, spin filtering, solar cells, and polymer science. To harness their full potential, especially as emissive components in circularly polarized organic light-emitting diodes (CP-OLEDs), generating structural chemical diversity and understanding the resulting photophysical and chiroptical properties are crucial. In this Account, we shed light on chemical engineering combining helicene and N-heterocyclic carbene (NHC) chemistries to create transition-metal complexes with unique architectures and describe their photophysical and chiroptical attributes. The σ-donating and π-accepting capabilities of the helically chiral π-conjugated NHCs endow the complexes with remarkable structural and electronic features. These characteristics manifest in phenomena such as chirality induction, very long-lived phosphorescence, and strong chiroptical signatures (electronic circular dichroism and circularly polarized luminescence).We describe the different classes of ligands primarily developed in our group by classifying them according to their connection between the helicenic moiety and the imidazole precursor. This connection is essential in determining the degree of π-conjugation and characterizing the emissive state. We comprehensively discuss 6-coordinate, 4-coordinate, and 2-coordinate complexes, delving into their structural nuances and examining how the interplay between metals and auxiliary ligands shapes their photophysical properties, with interpretations enriched by DFT calculations. Helicenes are known to promote intersystem crossing thanks to strong spin-orbit coupling, while metals offer robust frameworks leading to a variety of molecular architectures with specific topologies together with distinct excited-state properties. The electronic configurations and energy levels of the ligand and metal orbitals thus significantly modulate the photophysical and chiroptical behaviors of these complexes. In-depth analysis of chiroptical properties, notably electronic circular dichroism and circularly polarized luminescence, emphasizes the influence of different stereogenic elements on the chiroptical responses across various energy ranges with appealing "match-mismatch" effects. Finally, we describe future prospects of helicene NHCs, particularly in the context of emerging research on cost-effective and abundant transition metals for materials science and for photocatalysis. Indeed, the inherent long-lived MLCT, excited-state delocalization, structural rigidity, and intrinsic chirality of these complexes present intriguing avenues for future investigations.
{"title":"Chiral Organometallic Complexes Derived from Helicenic <i>N</i>-Heterocyclic Carbenes (NHCs): Design, Structural Diversity, and Chiroptical and Photophysical Properties.","authors":"Debsouri Kundu, Natalia Del Rio, Jeanne Crassous","doi":"10.1021/acs.accounts.4c00275","DOIUrl":"10.1021/acs.accounts.4c00275","url":null,"abstract":"<p><p>ConspectusRecently, helicene derivatives have emerged as an important class of molecules with potential applications spanning over asymmetric catalysis, biological activity, magnetism, spin filtering, solar cells, and polymer science. To harness their full potential, especially as emissive components in circularly polarized organic light-emitting diodes (CP-OLEDs), generating structural chemical diversity and understanding the resulting photophysical and chiroptical properties are crucial. In this Account, we shed light on chemical engineering combining helicene and <i>N</i>-heterocyclic carbene (NHC) chemistries to create transition-metal complexes with unique architectures and describe their photophysical and chiroptical attributes. The σ-donating and π-accepting capabilities of the helically chiral π-conjugated NHCs endow the complexes with remarkable structural and electronic features. These characteristics manifest in phenomena such as chirality induction, very long-lived phosphorescence, and strong chiroptical signatures (electronic circular dichroism and circularly polarized luminescence).We describe the different classes of ligands primarily developed in our group by classifying them according to their connection between the helicenic moiety and the imidazole precursor. This connection is essential in determining the degree of π-conjugation and characterizing the emissive state. We comprehensively discuss 6-coordinate, 4-coordinate, and 2-coordinate complexes, delving into their structural nuances and examining how the interplay between metals and auxiliary ligands shapes their photophysical properties, with interpretations enriched by DFT calculations. Helicenes are known to promote intersystem crossing thanks to strong spin-orbit coupling, while metals offer robust frameworks leading to a variety of molecular architectures with specific topologies together with distinct excited-state properties. The electronic configurations and energy levels of the ligand and metal orbitals thus significantly modulate the photophysical and chiroptical behaviors of these complexes. In-depth analysis of chiroptical properties, notably electronic circular dichroism and circularly polarized luminescence, emphasizes the influence of different stereogenic elements on the chiroptical responses across various energy ranges with appealing \"match-mismatch\" effects. Finally, we describe future prospects of helicene NHCs, particularly in the context of emerging research on cost-effective and abundant transition metals for materials science and for photocatalysis. Indeed, the inherent long-lived MLCT, excited-state delocalization, structural rigidity, and intrinsic chirality of these complexes present intriguing avenues for future investigations.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15Epub Date: 2024-10-07DOI: 10.1021/acs.accounts.4c00337
Tao Zheng, Wenzhuo Tan, Li-Min Zheng
<p><p>ConspectusPorous metal phosphonate frameworks (PMPFs) as a subclass of metal-organic frameworks (MOFs) have promising applications in the fields of gas adsorption and separation, ion exchange and storage, catalysis, sensing, etc. Compared to the typical carboxylate-based MOFs, PMPFs exhibit higher thermal and water stability due to the strong coordination ability of the phosphonate ligands. Despite their robust frameworks, PMPFs account for less than 0.51% of the porous MOFs reported so far. This is because metal phosphonates are highly susceptible to the formation of dense layered or pillared-layered structures, and they precipitate easily and are difficult to crystallize. There is a tendency to use phosphonate ligands containing multiple phosphonate groups and large organic spacers to prevent the formation of dense structures and generate open frameworks with permanent porosity. Thus, many PMPFs are composed of chains or clusters of inorganic metal phosphonates interconnected by organic spacers. Using this feature, a wide range of metal ions and organic components can be selected, and their physical properties can be modulated. However, limited by the small number of PMPFs, there are still relatively few studies on the physical properties of PMPFs, some of which merely remain in the description of the phenomena and lack in-depth elaboration of the structure-property relationship. In this Account, we review the strategies for constructing PMPFs and their physical properties, primarily based on our own research. The construction strategies are categorized according to the number (<i>n</i> = 1-4) of phosphonate groups in the ligand. The physical properties include proton conduction, electrical conduction, magnetism, and photoluminescence properties. Proton conductivity of PMPFs can be enhanced by increasing the proton carrier concentration and mobility. The former can be achieved by adding acidic groups such as -POH and/or introducing acidic guests in the hydrophilic channels. The latter can be attained by introducing conjugate acid-base pairs or elevating the temperature. Semiconducting PMPFs, on the other hand, can be obtained by constructing highly conjugated networks of coordination bonds or introducing large conjugated organic linkers π-π stacked in the lattice. In the case of magnetic PMPFs, long-range magnetic ordering occurs at very low temperatures due to very weak magnetic exchange couplings propagated via O-P-O and/or O(P) units. However, lanthanide compounds may be interesting candidates for single-molecule magnets because of the strong single-ion magnetic anisotropy arising from the spin-orbit coupling and large magnetic moments of lanthanide ions. The luminescent properties of PMPFs depend on the metal ions and/or organic ligands. Emissive PMPFs containing lanthanides and/or uranyl ions are promising for sensing and photonic applications. We conclude with an outlook on the opportunities and challenges for the future development
{"title":"Porous Metal Phosphonate Frameworks: Construction and Physical Properties.","authors":"Tao Zheng, Wenzhuo Tan, Li-Min Zheng","doi":"10.1021/acs.accounts.4c00337","DOIUrl":"10.1021/acs.accounts.4c00337","url":null,"abstract":"<p><p>ConspectusPorous metal phosphonate frameworks (PMPFs) as a subclass of metal-organic frameworks (MOFs) have promising applications in the fields of gas adsorption and separation, ion exchange and storage, catalysis, sensing, etc. Compared to the typical carboxylate-based MOFs, PMPFs exhibit higher thermal and water stability due to the strong coordination ability of the phosphonate ligands. Despite their robust frameworks, PMPFs account for less than 0.51% of the porous MOFs reported so far. This is because metal phosphonates are highly susceptible to the formation of dense layered or pillared-layered structures, and they precipitate easily and are difficult to crystallize. There is a tendency to use phosphonate ligands containing multiple phosphonate groups and large organic spacers to prevent the formation of dense structures and generate open frameworks with permanent porosity. Thus, many PMPFs are composed of chains or clusters of inorganic metal phosphonates interconnected by organic spacers. Using this feature, a wide range of metal ions and organic components can be selected, and their physical properties can be modulated. However, limited by the small number of PMPFs, there are still relatively few studies on the physical properties of PMPFs, some of which merely remain in the description of the phenomena and lack in-depth elaboration of the structure-property relationship. In this Account, we review the strategies for constructing PMPFs and their physical properties, primarily based on our own research. The construction strategies are categorized according to the number (<i>n</i> = 1-4) of phosphonate groups in the ligand. The physical properties include proton conduction, electrical conduction, magnetism, and photoluminescence properties. Proton conductivity of PMPFs can be enhanced by increasing the proton carrier concentration and mobility. The former can be achieved by adding acidic groups such as -POH and/or introducing acidic guests in the hydrophilic channels. The latter can be attained by introducing conjugate acid-base pairs or elevating the temperature. Semiconducting PMPFs, on the other hand, can be obtained by constructing highly conjugated networks of coordination bonds or introducing large conjugated organic linkers π-π stacked in the lattice. In the case of magnetic PMPFs, long-range magnetic ordering occurs at very low temperatures due to very weak magnetic exchange couplings propagated via O-P-O and/or O(P) units. However, lanthanide compounds may be interesting candidates for single-molecule magnets because of the strong single-ion magnetic anisotropy arising from the spin-orbit coupling and large magnetic moments of lanthanide ions. The luminescent properties of PMPFs depend on the metal ions and/or organic ligands. Emissive PMPFs containing lanthanides and/or uranyl ions are promising for sensing and photonic applications. We conclude with an outlook on the opportunities and challenges for the future development","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>ConspectusElectrochemical CO<sub>2</sub> reduction to obtain formate or formic acid is receiving significant attention as a method to combat the global warming crisis. Significant efforts have been devoted to the advancement of CO<sub>2</sub> reduction techniques over the past few decades. This Account provides a unified discussion on various electrochemical methodologies for CO<sub>2</sub> to formate conversion, with a particular focus on recent advancements in utilizing 3d-transition-metal-based molecular catalysts. This Account primarily focuses on understanding molecular functions and mechanisms under homogeneous conditions, which is essential for assessing the optimized reaction conditions for molecular catalysts. The unique architectural features of the formate dehydrogenase (FDH) enzyme provide insight into the key role of the surrounding protein scaffold in modulating the active site dynamics for stabilizing the key metal-bound CO<sub>2</sub> intermediate. Additionally, the protein moiety also triggers a facile proton relay around the active site to drive electrocatalytic CO<sub>2</sub> reduction forward. The fine-tuning of FDH machinery also ensures that the electrocatalytic CO<sub>2</sub> reduction leads to the production of formic acid as the major yield without any other carbonaceous products, while limiting the competitive hydrogen evolution reaction. These lessons from the enzymes are key in designing biomimetic molecular catalysts, primarily based on multidentate ligand scaffolds containing peripheral proton relays. The subtle modifications of the ligand framework ensure the favored production of formic acid following electrocatalytic CO<sub>2</sub> reduction in the solution phase. Next, the molecular catalysts are required to be mounted on robust electroactive surfaces to develop their corresponding heterogeneous versions. The surface-immobilization provides an edge to the molecular electrocatalysts as their reactivity can be scaled up with improved durability for long-term electrocatalysis. Despite challenges in developing high-performance, selective catalysts for the CO<sub>2</sub> to formic acid transformation, significant progress is being made with the tactical use of graphene and carbon nanotube-based materials. To date, the majority of the research activity stops here, as the development of an operational CO<sub>2</sub> to formic acid converting electrolyzer prototype still remains in its infancy. To elaborate on the potential future steps, this Account covers the design, scaling parameters, and existing challenges of assembling large-scale electrolyzers. A short glimpse at the utilization of electrolyzers for industrial-scale CO<sub>2</sub> reduction is also provided here. The proper evaluation of the surface-immobilized electrocatalysts assembled in an electrolyzer is a key step for gauging their potential for practical viability. Here, the key electrochemical parameters and their expected values for industrial-scal
Conspectus 通过电化学方法还原二氧化碳以获得甲酸或甲酸作为应对全球变暖危机的一种方法，正受到广泛关注。过去几十年来，人们一直致力于二氧化碳还原技术的发展。本鸿运国际账户登录统一讨论了将二氧化碳转化为甲酸盐的各种电化学方法，尤其关注了利用基于 3d 过渡金属的分子催化剂的最新进展。本报告主要侧重于了解均相条件下的分子功能和机理，这对于评估分子催化剂的优化反应条件至关重要。甲酸脱氢酶（FDH）的独特结构特征让我们深入了解了周围蛋白质支架在调节活性位点动力学以稳定关键的金属结合二氧化碳中间体方面的关键作用。此外，蛋白质分子还能触发活性位点周围的质子中继，推动电催化二氧化碳还原向前发展。对 FDH 机制的微调还确保了电催化二氧化碳还原能够产生甲酸作为主要产物，而不产生任何其他碳质产物，同时限制了竞争性氢进化反应。从酶中汲取的这些经验是设计仿生分子催化剂的关键，这些催化剂主要基于含有外围质子中继的多叉配体支架。配体框架的微妙变化确保了在溶液阶段电催化二氧化碳还原后甲酸的有利生产。接下来，需要将分子催化剂安装在坚固的电活性表面上，以开发相应的异质催化剂。表面固定化为分子电催化剂提供了优势，因为它们的反应活性可以放大，并提高了长期电催化的耐久性。尽管在开发用于将二氧化碳转化为甲酸的高性能、选择性催化剂方面存在挑战，但在战术性使用石墨烯和碳纳米管基材料方面正在取得重大进展。迄今为止，由于二氧化碳转化为甲酸电解槽原型的开发仍处于起步阶段，因此大部分研究活动到此为止。为了详细阐述未来可能采取的步骤，本报告将介绍组装大型电解槽的设计、扩展参数和现有挑战。此外，还简要介绍了利用电解槽进行工业规模二氧化碳还原的情况。对组装在电解槽中的表面固定电催化剂进行适当评估，是衡量其实际应用潜力的关键步骤。这里讨论了工业规模电解槽的关键电化学参数及其预期值。最后，总结了电解槽装置的技术经济方面，从而完成了从分子催化剂的战术设计到其在商业上可行的二氧化碳到甲酸酯电还原电解槽装置中的适当应用的全过程。因此，本开户绑定手机领体验金描绘了从分子催化剂的演变到其在二氧化碳利用中的可持续应用的完整故事。
{"title":"Electrocatalytic Conversion of CO<sub>2</sub> to Formic Acid: A Journey from 3d-Transition Metal-Based Molecular Catalyst Design to Electrolyzer Assembly.","authors":"Chandan Das, Suhana Karim, Somnath Guria, Tannu Kaushik, Suchismita Ghosh, Arnab Dutta","doi":"10.1021/acs.accounts.4c00418","DOIUrl":"10.1021/acs.accounts.4c00418","url":null,"abstract":"<p><p>ConspectusElectrochemical CO<sub>2</sub> reduction to obtain formate or formic acid is receiving significant attention as a method to combat the global warming crisis. Significant efforts have been devoted to the advancement of CO<sub>2</sub> reduction techniques over the past few decades. This Account provides a unified discussion on various electrochemical methodologies for CO<sub>2</sub> to formate conversion, with a particular focus on recent advancements in utilizing 3d-transition-metal-based molecular catalysts. This Account primarily focuses on understanding molecular functions and mechanisms under homogeneous conditions, which is essential for assessing the optimized reaction conditions for molecular catalysts. The unique architectural features of the formate dehydrogenase (FDH) enzyme provide insight into the key role of the surrounding protein scaffold in modulating the active site dynamics for stabilizing the key metal-bound CO<sub>2</sub> intermediate. Additionally, the protein moiety also triggers a facile proton relay around the active site to drive electrocatalytic CO<sub>2</sub> reduction forward. The fine-tuning of FDH machinery also ensures that the electrocatalytic CO<sub>2</sub> reduction leads to the production of formic acid as the major yield without any other carbonaceous products, while limiting the competitive hydrogen evolution reaction. These lessons from the enzymes are key in designing biomimetic molecular catalysts, primarily based on multidentate ligand scaffolds containing peripheral proton relays. The subtle modifications of the ligand framework ensure the favored production of formic acid following electrocatalytic CO<sub>2</sub> reduction in the solution phase. Next, the molecular catalysts are required to be mounted on robust electroactive surfaces to develop their corresponding heterogeneous versions. The surface-immobilization provides an edge to the molecular electrocatalysts as their reactivity can be scaled up with improved durability for long-term electrocatalysis. Despite challenges in developing high-performance, selective catalysts for the CO<sub>2</sub> to formic acid transformation, significant progress is being made with the tactical use of graphene and carbon nanotube-based materials. To date, the majority of the research activity stops here, as the development of an operational CO<sub>2</sub> to formic acid converting electrolyzer prototype still remains in its infancy. To elaborate on the potential future steps, this Account covers the design, scaling parameters, and existing challenges of assembling large-scale electrolyzers. A short glimpse at the utilization of electrolyzers for industrial-scale CO<sub>2</sub> reduction is also provided here. The proper evaluation of the surface-immobilized electrocatalysts assembled in an electrolyzer is a key step for gauging their potential for practical viability. Here, the key electrochemical parameters and their expected values for industrial-scal","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1021/acs.accounts.4c00489
Nureshan Dias, Nicolas Suas-David, Shameemah Thawoos, Arthur G. Suits
The study of gas-phase chemical reactions at very low temperatures first became possible with the development and implementation of the CRESU (French acronym for Reaction Kinetics in Uniform Supersonic Flows) technique. CRESU relies on a uniform supersonic flow produced by expansion of a gas through a Laval (convergent-divergent) nozzle to produce a wall-less reactor at temperatures from 10 to 200 K and densities of 1016–1018 cm–3 for the study of low temperature kinetics, with particular application to astrochemistry. In recent years, we have combined uniform flows with revolutionary advances in broadband rotational spectroscopy to yield an instrument that affords near-universal detection for novel applications in photodissociation, reaction dynamics, and kinetics. This combination of uniform supersonic flows with chirped-pulse Fourier-transform microwave spectroscopy (Chirped-Pulse/Uniform Flow, CPUF) permits detection of any species with a modest dipole moment, thermalized to the uniform temperature of the gas flow, with isomer, conformer, and vibrational state specificity. In addition, the use of broadband, high-resolution, and time-dependent (microsecond time scale) micro- and mm-wave spectroscopy makes it an ideal tool for characterizing both transient and stable molecules, as well as studying their spectroscopy and dynamics.
{"title":"Broadband Rotational Spectroscopy in Uniform Supersonic Flows: Chirped Pulse/Uniform Flow for Reaction Dynamics and Low Temperature Kinetics","authors":"Nureshan Dias, Nicolas Suas-David, Shameemah Thawoos, Arthur G. Suits","doi":"10.1021/acs.accounts.4c00489","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00489","url":null,"abstract":"The study of gas-phase chemical reactions at very low temperatures first became possible with the development and implementation of the CRESU (French acronym for Reaction Kinetics in Uniform Supersonic Flows) technique. CRESU relies on a uniform supersonic flow produced by expansion of a gas through a Laval (convergent-divergent) nozzle to produce a wall-less reactor at temperatures from 10 to 200 K and densities of 10<sup>16</sup>–10<sup>18</sup> cm<sup>–3</sup> for the study of low temperature kinetics, with particular application to astrochemistry. In recent years, we have combined uniform flows with revolutionary advances in broadband rotational spectroscopy to yield an instrument that affords near-universal detection for novel applications in photodissociation, reaction dynamics, and kinetics. This combination of uniform supersonic flows with chirped-pulse Fourier-transform microwave spectroscopy (Chirped-Pulse/Uniform Flow, CPUF) permits detection of any species with a modest dipole moment, thermalized to the uniform temperature of the gas flow, with isomer, conformer, and vibrational state specificity. In addition, the use of broadband, high-resolution, and time-dependent (microsecond time scale) micro- and mm-wave spectroscopy makes it an ideal tool for characterizing both transient and stable molecules, as well as studying their spectroscopy and dynamics.","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":18.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15Epub Date: 2024-10-02DOI: 10.1021/acs.accounts.4c00385
Fei Wang, Guichao Dong, Suqi Yang, Cheng-Long Ji, Kai Liu, Jie Han, Jin Xie
<p><p>ConspectusAlkenes and alkynes are fundamental building blocks in organic synthesis due to their commercial availability, bench-stability, and easy preparation. Selective functionalization of alkenes and alkynes is a crucial step for the synthesis of value-added compounds. Precise control over these reactions allows efficient construction of complex molecules with new functionalities. In recent decades, second- and third-row precious transition metal catalysts (palladium, platinum, rhodium, ruthenium) have been pivotal in the development of metal-catalyzed synthetic methodology. These metals exhibit excellent catalytic activity and selectivity, enabling efficient synthesis of functionalized organic molecules. However, recovery and reuse of precious metals have long been a challenge in this field. In recent years, exploration of earth-abundant metal-catalyzed organic reactions has interested both academic and industrial researchers. The development of such catalytic systems offers a promising approach to overcome the limitations of precious metal catalysts. For example, manganese is the third most naturally abundant transition metal with minimal toxicity and excellent biocompatibility. It exhibits good catalytic activity in several organic reactions, including C-H bond functionalization, selective reduction, and radical reactions. This Account outlines our recent progress in dinuclear manganese catalysis for selective functionalization of alkenes and alkynes. We have established the elementary manganese(I)-catalysis in transmetalation with R-B(OH)<sub>2</sub>. This finding has enabled us to apply the catalyst for the selective 1,2-difunctionalization of structurally diverse alkenes and alkynes. Mechanistic studies suggest a double manganese center synergistic activation model, as superior to Mn(CO)<sub>5</sub>Br in some cases. In addition, we have developed a ligand-tuned metalloradical strategy of dinuclear manganese catalysts (Mn<sub>2</sub>(CO)<sub>10</sub>), bridging the gap between the organometallics and radical chemistry, highlighting the unique radical functionalization of alkenes. Interestingly, using the same starting materials, different ligands can deliver completely different products. Meanwhile, a cooperative catalysis strategy involving manganese and other catalysts (e.g., cobalt, iminium) has also been developed and is briefly discussed. For manganese/iminium synergistic catalysis, a new mechanism for migratory insertion and demetalization-isomerization in synergistic HOMO-LUMO activation was disclosed. This strategy expands the application of low-valent manganese catalysts for enantioselective C-C bond-forming reactions. New reaction discovery is outpacing mechanism studies for dinuclear manganese catalysis, and future studies with time-resolved spectroscopy will improve understanding of the mechanism. Based on these intriguing findings, the precise functionalization of alkenes and alkynes by dinuclear manganese catalysts wil
{"title":"Selective Functionalization of Alkenes and Alkynes by Dinuclear Manganese Catalysts.","authors":"Fei Wang, Guichao Dong, Suqi Yang, Cheng-Long Ji, Kai Liu, Jie Han, Jin Xie","doi":"10.1021/acs.accounts.4c00385","DOIUrl":"10.1021/acs.accounts.4c00385","url":null,"abstract":"<p><p>ConspectusAlkenes and alkynes are fundamental building blocks in organic synthesis due to their commercial availability, bench-stability, and easy preparation. Selective functionalization of alkenes and alkynes is a crucial step for the synthesis of value-added compounds. Precise control over these reactions allows efficient construction of complex molecules with new functionalities. In recent decades, second- and third-row precious transition metal catalysts (palladium, platinum, rhodium, ruthenium) have been pivotal in the development of metal-catalyzed synthetic methodology. These metals exhibit excellent catalytic activity and selectivity, enabling efficient synthesis of functionalized organic molecules. However, recovery and reuse of precious metals have long been a challenge in this field. In recent years, exploration of earth-abundant metal-catalyzed organic reactions has interested both academic and industrial researchers. The development of such catalytic systems offers a promising approach to overcome the limitations of precious metal catalysts. For example, manganese is the third most naturally abundant transition metal with minimal toxicity and excellent biocompatibility. It exhibits good catalytic activity in several organic reactions, including C-H bond functionalization, selective reduction, and radical reactions. This Account outlines our recent progress in dinuclear manganese catalysis for selective functionalization of alkenes and alkynes. We have established the elementary manganese(I)-catalysis in transmetalation with R-B(OH)<sub>2</sub>. This finding has enabled us to apply the catalyst for the selective 1,2-difunctionalization of structurally diverse alkenes and alkynes. Mechanistic studies suggest a double manganese center synergistic activation model, as superior to Mn(CO)<sub>5</sub>Br in some cases. In addition, we have developed a ligand-tuned metalloradical strategy of dinuclear manganese catalysts (Mn<sub>2</sub>(CO)<sub>10</sub>), bridging the gap between the organometallics and radical chemistry, highlighting the unique radical functionalization of alkenes. Interestingly, using the same starting materials, different ligands can deliver completely different products. Meanwhile, a cooperative catalysis strategy involving manganese and other catalysts (e.g., cobalt, iminium) has also been developed and is briefly discussed. For manganese/iminium synergistic catalysis, a new mechanism for migratory insertion and demetalization-isomerization in synergistic HOMO-LUMO activation was disclosed. This strategy expands the application of low-valent manganese catalysts for enantioselective C-C bond-forming reactions. New reaction discovery is outpacing mechanism studies for dinuclear manganese catalysis, and future studies with time-resolved spectroscopy will improve understanding of the mechanism. Based on these intriguing findings, the precise functionalization of alkenes and alkynes by dinuclear manganese catalysts wil","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>ConspectusMolecular clusters (MCs) are monodispersed, precisely defined ensembles of atom collections featured with shape-persistent architectures that can deliver certain functions independently. Their molecular compositions and surface functionalities can be tailored feasibly in a predefined manner, and they can be applied as basic structural units to be engineered into materials with desirable hierarchical structures and enriched functions. The chemical systems also offer great opportunities for the design and fabrication of soft structural materials without the chain topologies of polymers. The bulks of MC assemblies demonstrate viscoelasticity that is used to be considered as the unique feature of polymers, while the MC systems are distinct from polymers since their elasticities are resilient even at temperatures 100 K above their glass transition temperatures. The understanding of their anomalous viscoelasticity and the extended studies of general structure-property relationships are desired for the development of new chemical systems for emergent functions and the possibilities to resolve the intrinsic trade-offs of traditional materials.Meanwhile, general macroscopic functions or properties of materials are related to the transportation of mass, momentum, and/or energy, and they are basically realized or directed by the motions of structural units at different length scales. Structural relaxation dynamics research is critical in quantifying motions ranging from fast bond deformation, bond break/formation, and diffusion of ions and particles to the cooperative motions of structure units. Due to the advancement of measurement technology for relaxation dynamics (e.g., quasi-elastic scattering and broadband dielectric spectroscopy), the structural relaxation dynamics of MC materials have been probed for the first time, and their multiple relaxation modes across several temporal scales were systematically studied to bridge the correlation between molecular structures and macroscopic functions. The fingerprint information from dynamics studies, e.g., the temperature dependence of relaxation time and certain property, e.g., ion conductivity, was proposed to quantify the structure-property relationship, and the microscopic mechanism on the mechanical properties, ion conduction, and gas absorption and separation of MC materials can be fully understood.In this Account, to elucidate the uniqueness of MC materials, especially in comparison with polymers, four topics are mainly summarized: structural features, relaxation dynamics characterization techniques, relaxation dynamics characteristics, and quantified understanding of the structure-property relationship. The capability for new function prediction from relaxation dynamics studies is also introduced, and the typical example in impact resistant materials is provided. The Account aims to prove the significance of relaxation dynamics characterization for material innovation, while it also con
Conspectus 分子簇（MC）是单分散、精确定义的原子集合体，具有形状持久的结构，可独立实现某些功能。它们的分子组成和表面功能可以通过预定义的方式进行定制，并可作为基本结构单元应用于具有理想分层结构和丰富功能的材料中。化学体系还为设计和制造没有聚合物链拓扑结构的软结构材料提供了巨大的机遇。MC 组合物的块体表现出粘弹性，这曾被视为聚合物的独特特征，而 MC 系统则有别于聚合物，因为即使在高于其玻璃转化温度 100 K 的温度下，它们的弹性仍具有韧性。了解它们的反常粘弹性并扩展对一般结构-性质关系的研究，是开发具有新兴功能的新化学体系的需要，也是解决传统材料内在权衡问题的可能性所在。同时，材料的一般宏观功能或性质与质量、动量和/或能量的传输有关，它们基本上是通过不同长度尺度上的结构单元运动来实现或引导的。结构弛豫动力学研究对于量化从快速键变形、键断裂/形成、离子和粒子扩散到结构单元协同运动的各种运动至关重要。由于弛豫动力学测量技术（如准弹性散射和宽带介电光谱）的进步，人们首次探测了 MC 材料的结构弛豫动力学，并系统地研究了它们在多个时间尺度上的多种弛豫模式，从而弥合了分子结构与宏观功能之间的相关性。为了阐明 MC 材料的独特性，特别是与高分子材料的比较，本文主要总结了四个方面的内容：结构特征、弛豫动力学表征技术、弛豫动力学特征以及结构与性能关系的量化理解。此外，还介绍了通过弛豫动力学研究预测新功能的能力，并提供了抗冲击材料中的典型实例。该开户绑定手机领体验金旨在证明弛豫动力学表征对材料创新的重要意义，同时也证实 MCs 在功能材料制造方面的潜力。
{"title":"Emergent Research Trends on the Structural Relaxation Dynamics of Molecular Clusters: From Structure-Property Relationship to New Function Prediction.","authors":"Binghui Xue, Yuyan Lai, Linkun Cai, Yuan Liu, Jia-Fu Yin, Panchao Yin","doi":"10.1021/acs.accounts.4c00479","DOIUrl":"10.1021/acs.accounts.4c00479","url":null,"abstract":"<p><p>ConspectusMolecular clusters (MCs) are monodispersed, precisely defined ensembles of atom collections featured with shape-persistent architectures that can deliver certain functions independently. Their molecular compositions and surface functionalities can be tailored feasibly in a predefined manner, and they can be applied as basic structural units to be engineered into materials with desirable hierarchical structures and enriched functions. The chemical systems also offer great opportunities for the design and fabrication of soft structural materials without the chain topologies of polymers. The bulks of MC assemblies demonstrate viscoelasticity that is used to be considered as the unique feature of polymers, while the MC systems are distinct from polymers since their elasticities are resilient even at temperatures 100 K above their glass transition temperatures. The understanding of their anomalous viscoelasticity and the extended studies of general structure-property relationships are desired for the development of new chemical systems for emergent functions and the possibilities to resolve the intrinsic trade-offs of traditional materials.Meanwhile, general macroscopic functions or properties of materials are related to the transportation of mass, momentum, and/or energy, and they are basically realized or directed by the motions of structural units at different length scales. Structural relaxation dynamics research is critical in quantifying motions ranging from fast bond deformation, bond break/formation, and diffusion of ions and particles to the cooperative motions of structure units. Due to the advancement of measurement technology for relaxation dynamics (e.g., quasi-elastic scattering and broadband dielectric spectroscopy), the structural relaxation dynamics of MC materials have been probed for the first time, and their multiple relaxation modes across several temporal scales were systematically studied to bridge the correlation between molecular structures and macroscopic functions. The fingerprint information from dynamics studies, e.g., the temperature dependence of relaxation time and certain property, e.g., ion conductivity, was proposed to quantify the structure-property relationship, and the microscopic mechanism on the mechanical properties, ion conduction, and gas absorption and separation of MC materials can be fully understood.In this Account, to elucidate the uniqueness of MC materials, especially in comparison with polymers, four topics are mainly summarized: structural features, relaxation dynamics characterization techniques, relaxation dynamics characteristics, and quantified understanding of the structure-property relationship. The capability for new function prediction from relaxation dynamics studies is also introduced, and the typical example in impact resistant materials is provided. The Account aims to prove the significance of relaxation dynamics characterization for material innovation, while it also con","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1021/acs.accounts.4c00519
Kentaro Kadota, Satoshi Horike
The conversion of carbon dioxide (CO2) to value-added functional materials is a major challenge in realizing a carbon-neutral society. Although CO2 is an attractive renewable carbon resource with high natural abundance, its chemical inertness has made the conversion of CO2 into materials with the desired structures and functionality difficult. Molecular-based porous materials, such as metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs), are designable porous solids constructed from molecular-based building units. While MOF/COFs attract wide attention as functional porous materials, the synthetic methods to convert CO2 into MOF/COFs have been unexplored due to the lack of synthetic guidelines for converting CO2 into molecular-based building units.
{"title":"Conversion of Carbon Dioxide into Molecular-based Porous Frameworks","authors":"Kentaro Kadota, Satoshi Horike","doi":"10.1021/acs.accounts.4c00519","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00519","url":null,"abstract":"The conversion of carbon dioxide (CO<sub>2</sub>) to value-added functional materials is a major challenge in realizing a carbon-neutral society. Although CO<sub>2</sub> is an attractive renewable carbon resource with high natural abundance, its chemical inertness has made the conversion of CO<sub>2</sub> into materials with the desired structures and functionality difficult. Molecular-based porous materials, such as metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs), are designable porous solids constructed from molecular-based building units. While MOF/COFs attract wide attention as functional porous materials, the synthetic methods to convert CO<sub>2</sub> into MOF/COFs have been unexplored due to the lack of synthetic guidelines for converting CO<sub>2</sub> into molecular-based building units.","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":18.3,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-11DOI: 10.1021/acs.accounts.4c00495
Liang Ma, Xiaoshu Gong, Ruikang Dong, Jinlan Wang
Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), in particular molybdenum disulfide (MoS2), have recently attracted huge interest due to their proper bandgap, high mobility at 2D limit, and easy-to-integrate planar structure, which are very promising for extending Moore’s law in postsilicon electronics technology. Great effort has been devoted toward such a goal since the demonstration of protype MoS2 devices with high room-temperature on/off current ratios, ultralow standby power consumption, and atomic level scaling capacity down to sub-1-nm technology node. However, there are still several key challenges that need to be addressed prior to the real application of MoS2-based electronics technology. The controllable growth of wafer-scale single-crystal MoS2 on industry-compatible insulating substrates is the prerequisite of application while the currently synthesized MoS2 films mostly are polycrystalline with limited sizes of single-crystal domains and may involve metal substrates. The precise layer-control is also very important for MoS2 growth since its electronic properties are layer-dependent, whereas the layer-by-layer growth of multilayer MoS2 dominated by the van der Waals (vdW) epitaxy leads to poor thickness uniformity and noncontinuously distributed domains. High density up to 1013 cm–2 of sulfur vacancies (SVs) in grown MoS2 can cause unfavorable carrier scatting and electronic properties variations and will inevitably disturb the device performance. The dangling-bond-free surface of MoS2 gives rise to an inherent vdW gap at metal–semiconductor (M–S) contact, which leads to high electrical resistance and poor current-delivery capability at the contact interface and thereby substantially limits the performances of MoS2 devices.
{"title":"Mechanisms of Controllable Growth and Ohmic Contact of Two-Dimensional Molybdenum Disulfide: Insight from Atomistic Simulations","authors":"Liang Ma, Xiaoshu Gong, Ruikang Dong, Jinlan Wang","doi":"10.1021/acs.accounts.4c00495","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00495","url":null,"abstract":"Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), in particular molybdenum disulfide (MoS<sub>2</sub>), have recently attracted huge interest due to their proper bandgap, high mobility at 2D limit, and easy-to-integrate planar structure, which are very promising for extending Moore’s law in postsilicon electronics technology. Great effort has been devoted toward such a goal since the demonstration of protype MoS<sub>2</sub> devices with high room-temperature on/off current ratios, ultralow standby power consumption, and atomic level scaling capacity down to sub-1-nm technology node. However, there are still several key challenges that need to be addressed prior to the real application of MoS<sub>2</sub>-based electronics technology. The controllable growth of wafer-scale single-crystal MoS<sub>2</sub> on industry-compatible insulating substrates is the prerequisite of application while the currently synthesized MoS<sub>2</sub> films mostly are polycrystalline with limited sizes of single-crystal domains and may involve metal substrates. The precise layer-control is also very important for MoS<sub>2</sub> growth since its electronic properties are layer-dependent, whereas the layer-by-layer growth of multilayer MoS<sub>2</sub> dominated by the van der Waals (vdW) epitaxy leads to poor thickness uniformity and noncontinuously distributed domains. High density up to 10<sup>13</sup> cm<sup>–2</sup> of sulfur vacancies (SVs) in grown MoS<sub>2</sub> can cause unfavorable carrier scatting and electronic properties variations and will inevitably disturb the device performance. The dangling-bond-free surface of MoS<sub>2</sub> gives rise to an inherent vdW gap at metal–semiconductor (M–S) contact, which leads to high electrical resistance and poor current-delivery capability at the contact interface and thereby substantially limits the performances of MoS<sub>2</sub> devices.","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":18.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：