Pub Date : 2024-08-20Epub Date: 2024-08-06DOI: 10.1021/acs.accounts.4c00153
S Osella, S Knippenberg
ConspectusLight is ubiquitously available to probe the structure and dynamics of biomolecules and biological tissues. Generally, this cannot be done directly with visible light, because of the absence of absorption by those biomolecules. This problem can be overcome by incorporating organic molecules (chromophores) that show an optical response in the vicinity of those biomolecules. Since those optical properties are strongly dependent on the chromophore's environment, time-resolved spectroscopic studies can provide a wealth of information on biosystems at the molecular scale in a nondestructive way. In this work, we give an overview on the multiscale computational strategy developed by us in the last eight years and prove that theoretical studies and simulations are needed to explain, guide, and predict observations in fluorescence experiments. As we challenge the accepted views on existing probes, we discover unexplored abilities that can discriminate surrounding lipid bilayers and their temperature-dependent as well as solvent-dependent properties. We focus on three archetypal chromophores: diphenylhexatriene (DPH), Laurdan, and azobenzene. Our method shows that conformational changes should not be neglected for the prototype rod-shaped molecule DPH. They determine its position and orientation in a liquid-ordered (Lo) sphingomyelin/cholesterol (SM/Chol) bilayer and are responsible for a strong differentiation of its absorption spectra and fluorescence decay times in dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) membranes, which are at room temperature in liquid-disordered (Ld) and solid-gel (So) phases, respectively. Thanks to its pronounced first excited state dipole moment, Laurdan has long been known as a solvatochromic probe. Since this molecule has however two conformers, we prove that they exhibit different properties in different lipid membrane phases. We see that the two conformers are only blocked in one phase but not in another. Supported by fluorescence anisotropy decay simulations, Laurdan can therefore be regarded as a molecular rotor. Finally, the conformational versatility of azobenzene in saturated Ld lipid bilayers is simulated, along with its photoisomerization pathways. By means of nonadiabatic QM/MM surface hopping analyses (QM/MM-SH), a dual mechanism is found with a torsional mechanism and a slow conversion for trans-to-cis. For cis-to-trans, simulations show a much higher quantum yield and a so-called "pedal-like" mechanism. The differences are related to the different potential energy surfaces as well as the interactions with the surrounding alkyl chains. When tails of increased length are attached to this probe, cis is pushed toward the polar surface, while trans is pulled toward the center of the membrane.
{"title":"Photophysics in Biomembranes: Computational Insight into the Interaction between Lipid Bilayers and Chromophores.","authors":"S Osella, S Knippenberg","doi":"10.1021/acs.accounts.4c00153","DOIUrl":"10.1021/acs.accounts.4c00153","url":null,"abstract":"<p><p>ConspectusLight is ubiquitously available to probe the structure and dynamics of biomolecules and biological tissues. Generally, this cannot be done directly with visible light, because of the absence of absorption by those biomolecules. This problem can be overcome by incorporating organic molecules (chromophores) that show an optical response in the vicinity of those biomolecules. Since those optical properties are strongly dependent on the chromophore's environment, time-resolved spectroscopic studies can provide a wealth of information on biosystems at the molecular scale in a nondestructive way. In this work, we give an overview on the multiscale computational strategy developed by us in the last eight years and prove that theoretical studies and simulations are needed to explain, guide, and predict observations in fluorescence experiments. As we challenge the accepted views on existing probes, we discover unexplored abilities that can discriminate surrounding lipid bilayers and their temperature-dependent as well as solvent-dependent properties. We focus on three archetypal chromophores: diphenylhexatriene (DPH), Laurdan, and azobenzene. Our method shows that conformational changes should not be neglected for the prototype rod-shaped molecule DPH. They determine its position and orientation in a liquid-ordered (Lo) sphingomyelin/cholesterol (SM/Chol) bilayer and are responsible for a strong differentiation of its absorption spectra and fluorescence decay times in dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) membranes, which are at room temperature in liquid-disordered (Ld) and solid-gel (So) phases, respectively. Thanks to its pronounced first excited state dipole moment, Laurdan has long been known as a solvatochromic probe. Since this molecule has however two conformers, we prove that they exhibit different properties in different lipid membrane phases. We see that the two conformers are only blocked in one phase but not in another. Supported by fluorescence anisotropy decay simulations, Laurdan can therefore be regarded as a molecular rotor. Finally, the conformational versatility of azobenzene in saturated Ld lipid bilayers is simulated, along with its photoisomerization pathways. By means of nonadiabatic QM/MM surface hopping analyses (QM/MM-SH), a dual mechanism is found with a torsional mechanism and a slow conversion for trans-to-cis. For cis-to-trans, simulations show a much higher quantum yield and a so-called \"pedal-like\" mechanism. The differences are related to the different potential energy surfaces as well as the interactions with the surrounding alkyl chains. When tails of increased length are attached to this probe, cis is pushed toward the polar surface, while trans is pulled toward the center of the membrane.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11339915/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141892244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20Epub Date: 2024-07-29DOI: 10.1021/acs.accounts.4c00292
Hyebeen Jeong, Geunchan Park, Jaemin Jeon, Sarah S Park
ConspectusRecent years have witnessed significant interest in two-dimensional metal-organic frameworks (MOFs) due to their unique properties and promising applications across various fields. These materials offer distinct advantages, including high porosity and excellent charge transport properties. Their tunability allows precise control over various factors, including the electronic structure adjustments and local reactivity modulation, facilitating a wide range of properties and applications, such as material sensing and spin dynamics control. Moreover, the precise crystal structure of 2D MOFs supports rational design and mechanism studies, providing insights into their potential applications and enhancing their utility in various scientific and technological endeavors.To fully unveil the latent capabilities of 2D MOFs and advance their applications across diverse fields, thin film synthesis is crucial. Thin films provide a platform for investigating the intrinsic electrical properties of 2D MOFs with anisotropic structures, enabling the exploration of their unique characteristics comprehensively. Additionally, thin films offer the advantage of minimizing interference at contacts and junctions, thereby enhancing the performance of 2D MOFs for various applications. Furthermore, the properties of thin films can vary with thickness, presenting an opportunity to tailor their characteristics based on specific requirements.In this Account, we present an overview of our research focusing on the synthesis of 2D conductive MOF thin films encompassing two primary methods: chemical vapor deposition and solution processing. The chemical vapor deposition method allows for one-step, all-vapor-phase processes resulting in MOFs with edge-on orientation, controllable film thicknesses ranging from 55 to 662.7 nm, and smooth, homogeneous surfaces. On the other hand, solution-processing introduces a novel MOF, Cu3(HHTATP)2, by reducing interlayer interactions through the addition of pendent Brønsted bases on a ligand, enabling spin coating for thin film synthesis. This method yields a concentrated 2D MOF solution, enabling spin coating for thin film synthesis, where reversible electrical conductivity changes occur through doping with an acid and dedoping with a base. Additionally, we discuss various other synthesis methods, such as interfacial synthesis, layer-by-layer assembly, and microfluidic-assisted synthesis, offering versatile approaches for fabricating large-area thin films with tailored properties. Finally, we address ongoing challenges and potential strategies for further advancement in 2D conductive MOF thin film synthesis. We hope that this Account provides insights for selecting synthesis methods tailored to specific purposes, contributes to the development of varied synthesis techniques, and facilitates the exploration of diverse applications, unlocking the full potential of 2D conductive MOFs for next-generation technolo
{"title":"Fabricating Large-Area Thin Films of 2D Conductive Metal-Organic Frameworks.","authors":"Hyebeen Jeong, Geunchan Park, Jaemin Jeon, Sarah S Park","doi":"10.1021/acs.accounts.4c00292","DOIUrl":"10.1021/acs.accounts.4c00292","url":null,"abstract":"<p><p>ConspectusRecent years have witnessed significant interest in two-dimensional metal-organic frameworks (MOFs) due to their unique properties and promising applications across various fields. These materials offer distinct advantages, including high porosity and excellent charge transport properties. Their tunability allows precise control over various factors, including the electronic structure adjustments and local reactivity modulation, facilitating a wide range of properties and applications, such as material sensing and spin dynamics control. Moreover, the precise crystal structure of 2D MOFs supports rational design and mechanism studies, providing insights into their potential applications and enhancing their utility in various scientific and technological endeavors.To fully unveil the latent capabilities of 2D MOFs and advance their applications across diverse fields, thin film synthesis is crucial. Thin films provide a platform for investigating the intrinsic electrical properties of 2D MOFs with anisotropic structures, enabling the exploration of their unique characteristics comprehensively. Additionally, thin films offer the advantage of minimizing interference at contacts and junctions, thereby enhancing the performance of 2D MOFs for various applications. Furthermore, the properties of thin films can vary with thickness, presenting an opportunity to tailor their characteristics based on specific requirements.In this Account, we present an overview of our research focusing on the synthesis of 2D conductive MOF thin films encompassing two primary methods: chemical vapor deposition and solution processing. The chemical vapor deposition method allows for one-step, all-vapor-phase processes resulting in MOFs with edge-on orientation, controllable film thicknesses ranging from 55 to 662.7 nm, and smooth, homogeneous surfaces. On the other hand, solution-processing introduces a novel MOF, Cu<sub>3</sub>(HHTATP)<sub>2</sub>, by reducing interlayer interactions through the addition of pendent Brønsted bases on a ligand, enabling spin coating for thin film synthesis. This method yields a concentrated 2D MOF solution, enabling spin coating for thin film synthesis, where reversible electrical conductivity changes occur through doping with an acid and dedoping with a base. Additionally, we discuss various other synthesis methods, such as interfacial synthesis, layer-by-layer assembly, and microfluidic-assisted synthesis, offering versatile approaches for fabricating large-area thin films with tailored properties. Finally, we address ongoing challenges and potential strategies for further advancement in 2D conductive MOF thin film synthesis. We hope that this Account provides insights for selecting synthesis methods tailored to specific purposes, contributes to the development of varied synthesis techniques, and facilitates the exploration of diverse applications, unlocking the full potential of 2D conductive MOFs for next-generation technolo","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786359","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 : 2024-08-20Epub Date: 2024-08-08DOI: 10.1021/acs.accounts.4c00390
Tomoya Ishizuka, Takahiko Kojima
ConspectusTo tackle the energy and environmental concerns the world faces, much attention is given to catalytic reactions converting methane (CH4) and carbon dioxide (CO2) as abundant C1 resources into value-added chemicals with high efficiency and selectivity. In the oxidative conversion of CH4 to methanol, it is necessary to solve the requirement of strong oxidants due to the large bond-dissociation energy (BDE) of the C-H bonds in methane and achieve suppression of overoxidation due to the smaller BDE of the C-H bond in methanol as the product. On the other hand, to efficiently perform CO2 reduction, proton-coupled electron transfer (PCET) processes are required since the reduction potential of CO2 becomes positive by using proton-coupled processes; however, under the acidic conditions required for PCET, hydrogen evolution by the reduction of protons becomes competitive with CO2 reduction. Thus, it is indispensable to develop efficient catalysts for selective CO2 reduction. Recently, we have developed efficient catalytic reactions toward the alleviation of the concerns mentioned above. Concerning CH4 oxidation, inspired by metalloenzymes that oxidize hydrophobic organic substrates, a hydrophobic second coordination sphere (SCS) was introduced to an FeII complex bearing a pentadentate N-heterocyclic carbene ligand, and the FeII complex was used as a catalyst for CH4 oxidation in aqueous media. Consequently, CH4 was efficiently and selectively oxidized to methanol with 83% selectivity and a turnover number of 500. In contrast, when methanol was used as a substrate for catalytic oxidation by the FeII complex, oxidation products were obtained in a negligible yield, which was comparable to that of the control experiment without the catalyst. Therefore, the hydrophobic SCS of the FeII complex can capture only hydrophobic substrates such as CH4 and release hydrophilic products such as methanol to the aqueous medium for suppressing overoxidation ("catch-and-release" mechanism). On the other hand, for photocatalytic CO2 reduction, we have developed NiII complexes with N2S2-chelating ligands as catalysts, which have been inspired by carbon monoxide dehydrogenase, and have also introduced a binding site of Lewis-acidic metal ions to the SCS of the Ni complex. When Mg2+ was applied as a moderate Lewis acid, a Mg2+-bound Ni catalyst allowed us to achieve remarkable enhancement of the photocatalytic CO2 reduction to afford CO as the product with over 99% selectivity and a quantum yield of 11.4%. Divalent metal ions besides Mg2+ also showed similar positive impacts on photocatalytic CO2 reduction, whereas monovalent metal ions exhibited almost no effects and trivalent metal ions exclusi
{"title":"Oxidative and Reductive Manipulation of C1 Resources by Bio-Inspired Molecular Catalysts to Produce Value-Added Chemicals.","authors":"Tomoya Ishizuka, Takahiko Kojima","doi":"10.1021/acs.accounts.4c00390","DOIUrl":"10.1021/acs.accounts.4c00390","url":null,"abstract":"<p><p>ConspectusTo tackle the energy and environmental concerns the world faces, much attention is given to catalytic reactions converting methane (CH<sub>4</sub>) and carbon dioxide (CO<sub>2</sub>) as abundant C1 resources into value-added chemicals with high efficiency and selectivity. In the oxidative conversion of CH<sub>4</sub> to methanol, it is necessary to solve the requirement of strong oxidants due to the large bond-dissociation energy (BDE) of the C-H bonds in methane and achieve suppression of overoxidation due to the smaller BDE of the C-H bond in methanol as the product. On the other hand, to efficiently perform CO<sub>2</sub> reduction, proton-coupled electron transfer (PCET) processes are required since the reduction potential of CO<sub>2</sub> becomes positive by using proton-coupled processes; however, under the acidic conditions required for PCET, hydrogen evolution by the reduction of protons becomes competitive with CO<sub>2</sub> reduction. Thus, it is indispensable to develop efficient catalysts for selective CO<sub>2</sub> reduction. Recently, we have developed efficient catalytic reactions toward the alleviation of the concerns mentioned above. Concerning CH<sub>4</sub> oxidation, inspired by metalloenzymes that oxidize hydrophobic organic substrates, a hydrophobic second coordination sphere (SCS) was introduced to an Fe<sup>II</sup> complex bearing a pentadentate <i>N</i>-heterocyclic carbene ligand, and the Fe<sup>II</sup> complex was used as a catalyst for CH<sub>4</sub> oxidation in aqueous media. Consequently, CH<sub>4</sub> was efficiently and selectively oxidized to methanol with 83% selectivity and a turnover number of 500. In contrast, when methanol was used as a substrate for catalytic oxidation by the Fe<sup>II</sup> complex, oxidation products were obtained in a negligible yield, which was comparable to that of the control experiment without the catalyst. Therefore, the hydrophobic SCS of the Fe<sup>II</sup> complex can capture only hydrophobic substrates such as CH<sub>4</sub> and release hydrophilic products such as methanol to the aqueous medium for suppressing overoxidation (\"catch-and-release\" mechanism). On the other hand, for photocatalytic CO<sub>2</sub> reduction, we have developed Ni<sup>II</sup> complexes with N<sub>2</sub>S<sub>2</sub>-chelating ligands as catalysts, which have been inspired by carbon monoxide dehydrogenase, and have also introduced a binding site of Lewis-acidic metal ions to the SCS of the Ni complex. When Mg<sup>2+</sup> was applied as a moderate Lewis acid, a Mg<sup>2+</sup>-bound Ni catalyst allowed us to achieve remarkable enhancement of the photocatalytic CO<sub>2</sub> reduction to afford CO as the product with over 99% selectivity and a quantum yield of 11.4%. Divalent metal ions besides Mg<sup>2+</sup> also showed similar positive impacts on photocatalytic CO<sub>2</sub> reduction, whereas monovalent metal ions exhibited almost no effects and trivalent metal ions exclusi","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904926","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 : 2024-08-20Epub Date: 2024-08-08DOI: 10.1021/acs.accounts.4c00299
Kueyoung E Kim, Rebecca V Balaj, Lauren D Zarzar
ConspectusThe multifunctionality and resilience of living systems has inspired an explosion of interest in creating materials with life-like properties. Just as life persists out-of-equilibrium, we too should try to design materials that are thermodynamically unstable but can be harnessed to achieve desirable, adaptive behaviors. Studying minimalistic chemical systems that exhibit relatively simple emergent behaviors, such as motility, communication, or self-organization, can provide insight into fundamental principles which may enable the design of more complex and life-like synthetic materials in the future.Emulsions, which are composed of liquid droplets dispersed in another immiscible fluid phase, have emerged as fascinating chemically minimal materials in which to study nonequilibrium, life-like properties. As covered in this Account, our group has focused on studying oil-in-water emulsions, specifically those which destabilize by solubilization, a process wherein oil is released into the continuous phase over time to create gradients of oil-filled micelles. These chemical gradients can create interfacial tension gradients that lead to droplet self-propulsion as well as mediate communication between neighboring oil droplets. As such, oil-in-water emulsions present an interesting platform for studying active matter. However, despite being chemically minimal with sometimes as few as three chemicals (oil, water, and a surfactant), emulsions present surprising complexity across the molecular to macroscale. Fundamental processes governing their active behavior, such as micelle-mediated interfacial transport, are still not well understood. This complexity is compounded by the challenges of studying systems out-of-equilibrium which typically require new analytical methods and may break our intuition derived from equilibrium thermodynamics.In this Account, we highlight our group's efforts toward developing chemical frameworks for understanding active and interactive oil-in-water emulsions. How do the chemical properties and physical spatial organization of the oil, water, and surfactant combine to yield colloidal-scale active properties? Our group tackles this question by employing systematic studies of active behavior working across the chemical space of oils and surfactants to link molecular structure to active behavior. The Account begins with an introduction to the self-propulsion of single, isolated droplets and how by applying biases, such as with a gravitational field or interfacially adsorbed particles, drop speeds can be manipulated. Next, we illustrate that some droplets can be attractive, as well as self-propulsive/repulsive, which does not fall in line with the current understanding of the impact of oil-filled micelle gradients on interfacial tensions. The mechanisms by which oil-filled micelles influence interfacial tensions of nonequilibrium interfaces is poorly understood and requires deeper molecular understanding. Regardless,
{"title":"Chemical Programming of Solubilizing, Nonequilibrium Active Droplets.","authors":"Kueyoung E Kim, Rebecca V Balaj, Lauren D Zarzar","doi":"10.1021/acs.accounts.4c00299","DOIUrl":"10.1021/acs.accounts.4c00299","url":null,"abstract":"<p><p>ConspectusThe multifunctionality and resilience of living systems has inspired an explosion of interest in creating materials with life-like properties. Just as life persists out-of-equilibrium, we too should try to design materials that are thermodynamically unstable but can be harnessed to achieve desirable, adaptive behaviors. Studying minimalistic chemical systems that exhibit relatively simple emergent behaviors, such as motility, communication, or self-organization, can provide insight into fundamental principles which may enable the design of more complex and life-like synthetic materials in the future.Emulsions, which are composed of liquid droplets dispersed in another immiscible fluid phase, have emerged as fascinating chemically minimal materials in which to study nonequilibrium, life-like properties. As covered in this Account, our group has focused on studying oil-in-water emulsions, specifically those which destabilize by solubilization, a process wherein oil is released into the continuous phase over time to create gradients of oil-filled micelles. These chemical gradients can create interfacial tension gradients that lead to droplet self-propulsion as well as mediate communication between neighboring oil droplets. As such, oil-in-water emulsions present an interesting platform for studying active matter. However, despite being chemically minimal with sometimes as few as three chemicals (oil, water, and a surfactant), emulsions present surprising complexity across the molecular to macroscale. Fundamental processes governing their active behavior, such as micelle-mediated interfacial transport, are still not well understood. This complexity is compounded by the challenges of studying systems out-of-equilibrium which typically require new analytical methods and may break our intuition derived from equilibrium thermodynamics.In this Account, we highlight our group's efforts toward developing chemical frameworks for understanding active and interactive oil-in-water emulsions. How do the chemical properties and physical spatial organization of the oil, water, and surfactant combine to yield colloidal-scale active properties? Our group tackles this question by employing systematic studies of active behavior working across the chemical space of oils and surfactants to link molecular structure to active behavior. The Account begins with an introduction to the self-propulsion of single, isolated droplets and how by applying biases, such as with a gravitational field or interfacially adsorbed particles, drop speeds can be manipulated. Next, we illustrate that some droplets can be attractive, as well as self-propulsive/repulsive, which does not fall in line with the current understanding of the impact of oil-filled micelle gradients on interfacial tensions. The mechanisms by which oil-filled micelles influence interfacial tensions of nonequilibrium interfaces is poorly understood and requires deeper molecular understanding. Regardless, ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904927","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 : 2024-08-20Epub Date: 2024-08-03DOI: 10.1021/acs.accounts.4c00380
Lai-Sheng Wang
ConspectusWith three valence electrons and four valence orbitals, boron (2s22p1) is an electron-deficient element, resulting in interesting chemical bonding and structures in both borane molecules and bulk boron materials. The electron deficiency leads to electron sharing and delocalization in borane compounds and bulk boron allotropes, characterized by polyhedral cages, in particular, the ubiquitous B12 icosahedral cage. During the past two decades, the structures and bonding of size-selected boron clusters have been elucidated via combined photoelectron spectroscopy and theoretical investigations. Unlike bulk boron materials, finite boron clusters have been found to possess 2D structures consisting of B3 triangles, dotted with tetragonal, pentagonal, or hexagonal holes. The discovery of the planar B36 cluster with a central hexagonal hole provided the first experimental evidence for the viability of 2D boron nanostructures (borophene), which have been synthesized on inert substrates. The B7-, B8-, and B9- clusters were among the first few boron clusters to be investigated by joint photoelectron spectroscopy and theoretical calculations, and they were all found to possess 2D structures with a central B atom inside a Bn ring. Recently, the B73- (C6v), B82- (D7h), and B9- (D8h) series of closed-shell species were shown to possess similar π bonding akin to that in the C5H5-, C6H6, and C7H7+ series, respectively, and the name "borozene" was coined to highlight their analogy to the classical aromatic hydrocarbon molecules.Among the borozenes, the D7h B82- species is unique for its high stability originating from both its double aromaticity and the fact that the B7 ring has the perfect size to host a central B atom. The B82- borozene has been realized experimentally in a variety of MB8 and M2B8 complexes. In particular, the B82- borozene has been observed to stabilize the rare valence-I oxidation state of lanthanides in LnB8- complexes, as well as a Cu2+ species in Cu2B8-. The B6 ring in B73- is too small to host a B atom, resulting in a slight out-of-plane distortion. Interestingly, the bowl-shaped B7 borozene is perfect for coordination to a metal atom, leading to the observation of a series of highly stable MB7 borozene complexes. On the other hand, the B8 ring is slightly too large to host the central B atom
{"title":"Borozenes: Benzene-Like Planar Aromatic Boron Clusters.","authors":"Lai-Sheng Wang","doi":"10.1021/acs.accounts.4c00380","DOIUrl":"10.1021/acs.accounts.4c00380","url":null,"abstract":"<p><p>ConspectusWith three valence electrons and four valence orbitals, boron (2s<sup>2</sup>2p<sup>1</sup>) is an electron-deficient element, resulting in interesting chemical bonding and structures in both borane molecules and bulk boron materials. The electron deficiency leads to electron sharing and delocalization in borane compounds and bulk boron allotropes, characterized by polyhedral cages, in particular, the ubiquitous B<sub>12</sub> icosahedral cage. During the past two decades, the structures and bonding of size-selected boron clusters have been elucidated via combined photoelectron spectroscopy and theoretical investigations. Unlike bulk boron materials, finite boron clusters have been found to possess 2D structures consisting of B<sub>3</sub> triangles, dotted with tetragonal, pentagonal, or hexagonal holes. The discovery of the planar B<sub>36</sub> cluster with a central hexagonal hole provided the first experimental evidence for the viability of 2D boron nanostructures (borophene), which have been synthesized on inert substrates. The B<sub>7</sub><sup>-</sup>, B<sub>8</sub><sup>-</sup>, and B<sub>9</sub><sup>-</sup> clusters were among the first few boron clusters to be investigated by joint photoelectron spectroscopy and theoretical calculations, and they were all found to possess 2D structures with a central B atom inside a B<sub><i>n</i></sub> ring. Recently, the B<sub>7</sub><sup>3-</sup> (<i>C</i><sub>6<i>v</i></sub>), B<sub>8</sub><sup>2-</sup> (<i>D</i><sub>7<i>h</i></sub>), and B<sub>9</sub><sup>-</sup> (<i>D</i><sub>8<i>h</i></sub>) series of closed-shell species were shown to possess similar π bonding akin to that in the C<sub>5</sub>H<sub>5</sub><sup>-</sup>, C<sub>6</sub>H<sub>6</sub>, and C<sub>7</sub>H<sub>7</sub><sup>+</sup> series, respectively, and the name \"borozene\" was coined to highlight their analogy to the classical aromatic hydrocarbon molecules.Among the borozenes, the <i>D</i><sub>7<i>h</i></sub> B<sub>8</sub><sup>2-</sup> species is unique for its high stability originating from both its double aromaticity and the fact that the B<sub>7</sub> ring has the perfect size to host a central B atom. The B<sub>8</sub><sup>2-</sup> borozene has been realized experimentally in a variety of MB<sub>8</sub> and M<sub>2</sub>B<sub>8</sub> complexes. In particular, the B<sub>8</sub><sup>2-</sup> borozene has been observed to stabilize the rare valence-I oxidation state of lanthanides in LnB<sub>8</sub><sup>-</sup> complexes, as well as a Cu<sub>2</sub><sup>+</sup> species in Cu<sub>2</sub>B<sub>8</sub><sup>-</sup>. The B<sub>6</sub> ring in B<sub>7</sub><sup>3-</sup> is too small to host a B atom, resulting in a slight out-of-plane distortion. Interestingly, the bowl-shaped B<sub>7</sub> borozene is perfect for coordination to a metal atom, leading to the observation of a series of highly stable MB<sub>7</sub> borozene complexes. On the other hand, the B<sub>8</sub> ring is slightly too large to host the central B atom","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141887477","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 : 2024-08-20DOI: 10.1021/acs.accounts.4c00465
Stefan Grimme, Peter R Schreiner
{"title":"The Role of London Dispersion Interactions in Modern Chemistry.","authors":"Stefan Grimme, Peter R Schreiner","doi":"10.1021/acs.accounts.4c00465","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00465","url":null,"abstract":"","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002926","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 : 2024-08-20Epub Date: 2024-07-18DOI: 10.1021/acs.accounts.4c00215
Zhi Jiang, Ming Zhu, Xiaodong Chen
ConspectusIn the field of neuroscience, understanding the complex interactions within the intricate neuron-motor system depends crucially on the use of high-density, physiological multiple electrode arrays (MEAs). In the neuron-motor system, the transmission of biological signals primarily occurs through electrical and chemical signaling. Taking neurons for instance, when a neuron receives external stimuli, it generates an electrical signal known as the action potential. This action potential propagates along the neuron's axon and is transmitted to other neurons via synapses. At the synapse, chemical signals (neurotransmitters) are released, allowing the electrical signal to traverse the synaptic gap and influence the next neuron. MEAs can provide unparalleled insights into neural signal patterns when interfacing with the nerve systems through their excellent spatiotemporal resolution. However, the inherent differences in mechanical and chemical properties between these artificial devices and biological tissues can lead to serious complications after chronic implantation, such as body rejection, infection, tissue damage, or device malfunction. A promising strategy to enhance MEAs' biocompatibility involves minimizing their thickness, which aligns their bending stiffness with that of surrounding tissues, thereby minimizing damage over time. However, this solution has its limits; the resulting ultrathin devices, typically based on plastic films, lack the necessary stretchability, restricting their use to organs that neither stretch nor grow.For practical deployments, devices must exhibit certain levels of stretchability (ranging from 20 to 70%), tailored to the specific requirements of the target organs. In this Account, we outline recent advancements in developing stretchable MEAs that balance stretchability with sufficient electrical conductivity for effective use in physiological research, acting as sensors and stimulators. By concentrating on the neuron-motor pathways, we summarize how the stretchable MEAs meet various application needs and examine their effectiveness. We distinguish between on-skin and implantable uses, given their vastly different requirements. Within each application scope, we highlight cutting-edge technologies, evaluating their strengths and shortcomings. Recognizing that most current devices rely on elastic films with a Young's modulus value between ∼0.5 and 5 MPa, we delve into the potential for softer MEAs, particularly those using multifunctional hydrogels for an optimizing tissue-device interface and address the challenges in adapting such hydrogel-based MEAs for chronic implants. Additionally, transitioning soft MEAs from lab to fab involves connecting them to a rigid adapter and external machinery, highlighting a critical challenge at the soft-rigid interface due to strain concentration, especially in chronic studies subject to unforeseen mechanical strains. We discuss innovative solutions to this integration
前言 在神经科学领域,要了解错综复杂的神经元-运动系统内部的复杂相互作用,关键在于使用高密度、生理多电极阵列(MEA)。在神经元-运动系统中,生物信号的传递主要通过电子和化学信号进行。以神经元为例,当神经元接收到外部刺激时,会产生称为动作电位的电信号。这种动作电位沿着神经元的轴突传播,并通过突触传递给其他神经元。在突触处,化学信号(神经递质)被释放,使电信号穿过突触间隙,影响下一个神经元。当与神经系统连接时,MEA 凭借其出色的时空分辨率,可以提供对神经信号模式的无与伦比的洞察力。然而,这些人工设备与生物组织之间在机械和化学特性上的固有差异会导致长期植入后出现严重的并发症,如机体排斥、感染、组织损伤或设备故障。增强 MEA 生物相容性的一个可行策略是尽量减小其厚度,使其弯曲刚度与周围组织的弯曲刚度一致,从而最大限度地减少随着时间的推移而造成的损伤。然而,这种解决方案也有其局限性;由此产生的超薄装置通常以塑料薄膜为基础,缺乏必要的伸展性,因此只能用于既不会伸展也不会生长的器官。在本报告中,我们概述了在开发可拉伸 MEA 方面取得的最新进展,这些 MEA 在可拉伸性与足够导电性之间取得了平衡,可有效用于生理研究,充当传感器和刺激器。通过集中研究神经元-运动通路,我们总结了可拉伸 MEA 如何满足各种应用需求并检验其有效性。鉴于皮肤和植入式应用的要求大相径庭,我们对它们进行了区分。在每种应用范围内,我们都重点介绍了前沿技术,评估了它们的优势和不足。我们认识到目前的大多数设备都依赖于杨氏模量值介于 0.5 至 5 兆帕之间的弹性薄膜,因此我们深入研究了更柔软的 MEA 的潜力,特别是那些使用多功能水凝胶来优化组织-设备界面的 MEA,并探讨了将这种基于水凝胶的 MEA 用于慢性植入物所面临的挑战。此外,将软性 MEA 从实验室过渡到工厂需要将其连接到刚性适配器和外部机械,这凸显了软硬界面因应变集中而面临的严峻挑战,尤其是在受到不可预见的机械应变影响的慢性研究中。我们讨论了这一集成挑战的创新解决方案,并乐观地认为,耐用、生物兼容、可拉伸的 MEA 的开发将极大地推动神经科学及相关领域的发展。
{"title":"Interfacing Neuron-Motor Pathways with Stretchable and Biocompatible Electrode Arrays.","authors":"Zhi Jiang, Ming Zhu, Xiaodong Chen","doi":"10.1021/acs.accounts.4c00215","DOIUrl":"10.1021/acs.accounts.4c00215","url":null,"abstract":"<p><p>ConspectusIn the field of neuroscience, understanding the complex interactions within the intricate neuron-motor system depends crucially on the use of high-density, physiological multiple electrode arrays (MEAs). In the neuron-motor system, the transmission of biological signals primarily occurs through electrical and chemical signaling. Taking neurons for instance, when a neuron receives external stimuli, it generates an electrical signal known as the action potential. This action potential propagates along the neuron's axon and is transmitted to other neurons via synapses. At the synapse, chemical signals (neurotransmitters) are released, allowing the electrical signal to traverse the synaptic gap and influence the next neuron. MEAs can provide unparalleled insights into neural signal patterns when interfacing with the nerve systems through their excellent spatiotemporal resolution. However, the inherent differences in mechanical and chemical properties between these artificial devices and biological tissues can lead to serious complications after chronic implantation, such as body rejection, infection, tissue damage, or device malfunction. A promising strategy to enhance MEAs' biocompatibility involves minimizing their thickness, which aligns their bending stiffness with that of surrounding tissues, thereby minimizing damage over time. However, this solution has its limits; the resulting ultrathin devices, typically based on plastic films, lack the necessary stretchability, restricting their use to organs that neither stretch nor grow.For practical deployments, devices must exhibit certain levels of stretchability (ranging from 20 to 70%), tailored to the specific requirements of the target organs. In this Account, we outline recent advancements in developing stretchable MEAs that balance stretchability with sufficient electrical conductivity for effective use in physiological research, acting as sensors and stimulators. By concentrating on the neuron-motor pathways, we summarize how the stretchable MEAs meet various application needs and examine their effectiveness. We distinguish between on-skin and implantable uses, given their vastly different requirements. Within each application scope, we highlight cutting-edge technologies, evaluating their strengths and shortcomings. Recognizing that most current devices rely on elastic films with a Young's modulus value between ∼0.5 and 5 MPa, we delve into the potential for softer MEAs, particularly those using multifunctional hydrogels for an optimizing tissue-device interface and address the challenges in adapting such hydrogel-based MEAs for chronic implants. Additionally, transitioning soft MEAs from lab to fab involves connecting them to a rigid adapter and external machinery, highlighting a critical challenge at the soft-rigid interface due to strain concentration, especially in chronic studies subject to unforeseen mechanical strains. We discuss innovative solutions to this integration ","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631928","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 : 2024-08-20DOI: 10.1021/acs.accounts.4c0044910.1021/acs.accounts.4c00449
Wen Zhang, Jihong Liu, Ping Li*, Xin Wang* and Bo Tang*,
<p >Hepatic ischemia-reperfusion injury (HIRI) is an inevitable complication of clinical surgeries such as liver resection or transplantation, often resulting in postoperative liver dysfunction, hepatic failure in up to 13% of postresection patients, and early graft failure in 11–18% of liver transplantation patients. HIRI involves a series of biochemical events triggered by abnormal alterations in multiple biomarkers, characterized by short lifespans, dynamic changes, subcellular regional distribution, and multicollaborative regulation. However, traditional diagnosis, including serology, imaging, and liver puncture biopsy, suffers from low sensitivity, poor resolution, and hysteresis, which hinder effective monitoring of HIRI markers. Thus, to address the unique properties of HIRI markers, there is a pressing demand for developing novel detection strategies that are highly selective, transiently responsive, dynamically reversible, subcellular organelle-targeted, and capable of simultaneous multicomponent analysis.</p><p >Optical probe-based fluorescence imaging is a powerful tool for real-time monitoring of biomarkers with the advantages of high sensitivity, noninvasiveness, rapid analysis, and high-fidelity acquisition of spatiotemporal information on signaling molecules compared with conventional methods. Moreover, with the growing demand for continuous monitoring of biomarkers, probes with reversible detection features are receiving more and more attention. Importantly, reversible probes can not only monitor fluctuations in marker concentrations but also distinguish between transient bursts of markers during physiological events and long-term sustained increases in pathological marker levels. This can effectively avoid false-positive test results, and in addition, reversible probes can be reutilized with green and economical features. Therefore, our team has employed various effective methods to design reversible optical probes for HIRI. We proposed reversible recognition strategies based on specific reactions or interactions to detect dynamic changes in markers. Given the biomarkers’ unique signaling in subcellular organelles and the synergistic regulatory properties of multiple markers for HIRI, bifunctional reversible detection strategies are exploited, including organelle-targeted reversible and multicomponent simultaneous detection. With these strategies, we have tailored a variety of high-fidelity fluorescent probes for a series of HIRI markers, including reactive oxygen/nitrogen species (O<sub>2</sub><sup>•–</sup> and ONOO<sup>–</sup>), ATP, protein (Keap1), mitochondrial DNA, etc. Utilizing the probes, the in situ dynamic imaging detection of the HIRI markers was successfully achieved. While performing the precise examination of the earlier occurrence of HIRI disease and visualizing the real-time monitoring of the disease process, we have also further elucidated the HIRI-associated signaling pathways. It is envisioned that our summar
肝脏缺血再灌注损伤(HIRI)是肝脏切除或移植等临床手术不可避免的并发症,通常会导致术后肝功能障碍,高达13%的肝切除术后患者会出现肝功能衰竭,11-18%的肝移植患者会出现早期移植失败。HIRI 涉及由多种生物标志物异常改变引发的一系列生化事件,其特点是寿命短、动态变化、亚细胞区域分布和多重协作调节。然而,包括血清学、影像学和肝穿刺活检在内的传统诊断方法存在灵敏度低、分辨率差和滞后等问题,阻碍了对 HIRI 标志物的有效监测。与传统方法相比,基于光学探针的荧光成像技术具有灵敏度高、无创伤、分析迅速、能高保真地获取信号分子的时空信息等优点,是实时监测生物标志物的有力工具。此外,随着对持续监测生物标记物的需求日益增长,具有可逆检测功能的探针正受到越来越多的关注。重要的是,可逆探针不仅能监测标记物浓度的波动,还能区分生理事件中标记物的瞬时爆发和病理标记物水平的长期持续上升。这可以有效避免假阳性检测结果,此外,可逆探针还可以重复利用,具有绿色、经济的特点。因此,我们团队采用了多种有效方法来设计用于 HIRI 的可逆光学探针。我们提出了基于特定反应或相互作用的可逆识别策略,以检测标记物的动态变化。鉴于生物标记物在亚细胞器中的独特信号传导以及多种标记物对 HIRI 的协同调控特性,我们采用了双功能可逆检测策略,包括细胞器靶向可逆检测和多组分同时检测。利用这些策略,我们为一系列 HIRI 标记物定制了多种高保真荧光探针,包括活性氧/氮物种(O2 和 ONOO-)、ATP、蛋白质(Keap1)、线粒体 DNA 等。利用这些探针,成功实现了对 HIRI 标记的原位动态成像检测。在精确检测 HIRI 疾病的早期发生和可视化实时监测疾病过程的同时,我们还进一步阐明了与 HIRI 相关的信号通路。展望未来,我们总结的工作将对未来可逆荧光探针的设计有所启发,并有助于提高此类疾病的临床诊断和治疗效率。
{"title":"Reversible Fluorescent Probes for Dynamic Imaging of Liver Ischemia-Reperfusion Injury","authors":"Wen Zhang, Jihong Liu, Ping Li*, Xin Wang* and Bo Tang*, ","doi":"10.1021/acs.accounts.4c0044910.1021/acs.accounts.4c00449","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00449https://doi.org/10.1021/acs.accounts.4c00449","url":null,"abstract":"<p >Hepatic ischemia-reperfusion injury (HIRI) is an inevitable complication of clinical surgeries such as liver resection or transplantation, often resulting in postoperative liver dysfunction, hepatic failure in up to 13% of postresection patients, and early graft failure in 11–18% of liver transplantation patients. HIRI involves a series of biochemical events triggered by abnormal alterations in multiple biomarkers, characterized by short lifespans, dynamic changes, subcellular regional distribution, and multicollaborative regulation. However, traditional diagnosis, including serology, imaging, and liver puncture biopsy, suffers from low sensitivity, poor resolution, and hysteresis, which hinder effective monitoring of HIRI markers. Thus, to address the unique properties of HIRI markers, there is a pressing demand for developing novel detection strategies that are highly selective, transiently responsive, dynamically reversible, subcellular organelle-targeted, and capable of simultaneous multicomponent analysis.</p><p >Optical probe-based fluorescence imaging is a powerful tool for real-time monitoring of biomarkers with the advantages of high sensitivity, noninvasiveness, rapid analysis, and high-fidelity acquisition of spatiotemporal information on signaling molecules compared with conventional methods. Moreover, with the growing demand for continuous monitoring of biomarkers, probes with reversible detection features are receiving more and more attention. Importantly, reversible probes can not only monitor fluctuations in marker concentrations but also distinguish between transient bursts of markers during physiological events and long-term sustained increases in pathological marker levels. This can effectively avoid false-positive test results, and in addition, reversible probes can be reutilized with green and economical features. Therefore, our team has employed various effective methods to design reversible optical probes for HIRI. We proposed reversible recognition strategies based on specific reactions or interactions to detect dynamic changes in markers. Given the biomarkers’ unique signaling in subcellular organelles and the synergistic regulatory properties of multiple markers for HIRI, bifunctional reversible detection strategies are exploited, including organelle-targeted reversible and multicomponent simultaneous detection. With these strategies, we have tailored a variety of high-fidelity fluorescent probes for a series of HIRI markers, including reactive oxygen/nitrogen species (O<sub>2</sub><sup>•–</sup> and ONOO<sup>–</sup>), ATP, protein (Keap1), mitochondrial DNA, etc. Utilizing the probes, the in situ dynamic imaging detection of the HIRI markers was successfully achieved. While performing the precise examination of the earlier occurrence of HIRI disease and visualizing the real-time monitoring of the disease process, we have also further elucidated the HIRI-associated signaling pathways. It is envisioned that our summar","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142135534","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 : 2024-08-19DOI: 10.1021/acs.accounts.4c0033810.1021/acs.accounts.4c00338
Bin Han, and , Paolo Samorì*,
<p >Engineering all interfaces between different components in electronic devices is the key to control and optimize fundamental physical processes such as charge injection at metal–semiconductor interfaces, gate modulation at the dielectric–semiconductor interface, and carrier modulation at semiconductor–environment interfaces. The use of two-dimensional (2D) crystals as semiconductors, by virtue of their atomically flat dangling bond-free structures, can facilitate the tailoring of such interfaces effectively. In this context, 2D transition metal dichalcogenides (TMDs) have garnered tremendous attention over the past two decades owing to their exclusive and outstanding physical and chemical characteristics such as their strong light–matter interactions and high charge mobility. These properties position them as promising building blocks for next-generation semiconductor materials. The combination of their large specific surface area, unique electronic structure, and properties highly sensitive to environmental changes makes 2D TMDs appealing platforms for applications in optoelectronics and sensing. While a broad arsenal of TMDs has been made available that exhibit a variety of electronic properties, the latter are unfortunately hardly tunable. To overcome this problem, the controlled functionalization of TMDs with molecules and assemblies thereof represents a most powerful strategy to finely tune their surface characteristics for electronics. Such functionalization can be used not only to encapsulate the electronic material, therefore enhancing its stability in air, but also to impart dynamic, stimuli-responsive characteristics to TMDs and to selectively recognize the presence of a given analyte in the environment, demonstrating unprecedented application potential.</p><p >In this Account, we highlight the most enlightening recent progress made on the interface engineering in 2D TMD-based electronic devices via covalent and noncovalent functionalization with suitably designed molecules, underlining the remarkable synergies achieved. While electrode functionalization allows modulating charge injection and extraction, the functionalization of the dielectric substrate enables tuning of the carrier concentration in the device channel, and the functionalization of the upper surface of 2D TMDs allows screening the interaction with the environment and imparts molecular functionality to the devices, making them versatile for various applications. The tailored interfaces enable enhanced device performance and open up avenues for practical applications. This Account specifically focuses on our recent endeavor in the unusual properties conferred to 2D TMDs through the functionalization of their interfaces with stimuli-responsive molecules or molecular assemblies. This includes electrode-functionalized devices with modulable performance and charge carriers, molecular-bridged TMD network devices with overall enhanced electrical properties, sensor devices t
{"title":"Engineering the Interfacing of Molecules with 2D Transition Metal Dichalcogenides: Enhanced Multifunctional Electronics","authors":"Bin Han, and , Paolo Samorì*, ","doi":"10.1021/acs.accounts.4c0033810.1021/acs.accounts.4c00338","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00338https://doi.org/10.1021/acs.accounts.4c00338","url":null,"abstract":"<p >Engineering all interfaces between different components in electronic devices is the key to control and optimize fundamental physical processes such as charge injection at metal–semiconductor interfaces, gate modulation at the dielectric–semiconductor interface, and carrier modulation at semiconductor–environment interfaces. The use of two-dimensional (2D) crystals as semiconductors, by virtue of their atomically flat dangling bond-free structures, can facilitate the tailoring of such interfaces effectively. In this context, 2D transition metal dichalcogenides (TMDs) have garnered tremendous attention over the past two decades owing to their exclusive and outstanding physical and chemical characteristics such as their strong light–matter interactions and high charge mobility. These properties position them as promising building blocks for next-generation semiconductor materials. The combination of their large specific surface area, unique electronic structure, and properties highly sensitive to environmental changes makes 2D TMDs appealing platforms for applications in optoelectronics and sensing. While a broad arsenal of TMDs has been made available that exhibit a variety of electronic properties, the latter are unfortunately hardly tunable. To overcome this problem, the controlled functionalization of TMDs with molecules and assemblies thereof represents a most powerful strategy to finely tune their surface characteristics for electronics. Such functionalization can be used not only to encapsulate the electronic material, therefore enhancing its stability in air, but also to impart dynamic, stimuli-responsive characteristics to TMDs and to selectively recognize the presence of a given analyte in the environment, demonstrating unprecedented application potential.</p><p >In this Account, we highlight the most enlightening recent progress made on the interface engineering in 2D TMD-based electronic devices via covalent and noncovalent functionalization with suitably designed molecules, underlining the remarkable synergies achieved. While electrode functionalization allows modulating charge injection and extraction, the functionalization of the dielectric substrate enables tuning of the carrier concentration in the device channel, and the functionalization of the upper surface of 2D TMDs allows screening the interaction with the environment and imparts molecular functionality to the devices, making them versatile for various applications. The tailored interfaces enable enhanced device performance and open up avenues for practical applications. This Account specifically focuses on our recent endeavor in the unusual properties conferred to 2D TMDs through the functionalization of their interfaces with stimuli-responsive molecules or molecular assemblies. This includes electrode-functionalized devices with modulable performance and charge carriers, molecular-bridged TMD network devices with overall enhanced electrical properties, sensor devices t","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142135183","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 : 2024-08-19DOI: 10.1021/acs.accounts.4c0039410.1021/acs.accounts.4c00394
Jun Zhou, Jing-Yang You, Yi-Ming Zhao, Yuan Ping Feng and Lei Shen*,
<p >Electrides make up a fascinating group of materials with unique physical and chemical properties. In these materials, excess electrons do not behave like normal electrons in metals or form any chemical bonds with atoms. Instead, they “float” freely in the gaps within the material’s structure, acting like negatively charged particles called anions (see the graph). Recently, there has been a surge of interest in van der Waals (vdW) electrides or electrenes in two dimensions. A typical example is layered lanthanum bromide (LaBr<sub>2</sub>), which can be taken as [La<sup>3+</sup>(Br<sup>1–</sup>)<sub>2</sub>]<sup>+</sup>•(e<sup>–</sup>). Each excess free electron is trapped within a hexagonal pore, forming dense dots of electron density. These anionic electrons are loosely bound, giving vdW electrides some unique properties such as ferromagnetism, superconductivity, topological features, and Dirac plasmons. The high density of the free electron makes electrides very promising for applications in thermionic emission, organic light-emitting diodes, and high-performance catalysts.</p><p >In this Account, we first discuss the discovery of numerous vdW electrides through high-throughput computational screening of over 67,000 known inorganic crystals in Materials Project. A dozen of them have been newly discovered and have not been reported before. Importantly, they possess completely different structural prototypes and properties of anionic electrons compared to widely studied electrides such as Ca<sub>2</sub>N. Finding these new vdW electrides expands the variety of electrides that can be made in the experiment and opens up new possibilities for studying their unique properties and applications.</p><p >Then, based on the screened vdW electrides, we delve into their various emerging properties. For example, we developed a new magnetic mechanism specific to atomic-orbital-free ferromagnetism in electrides. We uncover the dual localized and extended nature of the anionic electrons in such electrides and demonstrate the formation of the local moment by the localized feature and the ferromagnetic interaction by the direct overlapping of their extended states. We further show the effective tuning of the magnetic properties of vdW electrides by engineering their structural, electronic, and compositional properties. Besides, we show that the complex interaction between the multiple quantum orderings in vdW electrides leads to many interesting properties including valley polarization, charge density waves, a topological property, a superconducting property, and a thermoelectrical property.</p><p >Moreover, we discuss strategies to leverage the unique intrinsic properties of vdW electrides for practical applications. We show that these properties make vdW electrides potential candidates for advanced applications such as spin–orbit torque memory devices, valleytronic devices, K-ion batteries, and thermoelectricity. Finally, we discuss the current challenges a
{"title":"Van der Waals Electrides","authors":"Jun Zhou, Jing-Yang You, Yi-Ming Zhao, Yuan Ping Feng and Lei Shen*, ","doi":"10.1021/acs.accounts.4c0039410.1021/acs.accounts.4c00394","DOIUrl":"https://doi.org/10.1021/acs.accounts.4c00394https://doi.org/10.1021/acs.accounts.4c00394","url":null,"abstract":"<p >Electrides make up a fascinating group of materials with unique physical and chemical properties. In these materials, excess electrons do not behave like normal electrons in metals or form any chemical bonds with atoms. Instead, they “float” freely in the gaps within the material’s structure, acting like negatively charged particles called anions (see the graph). Recently, there has been a surge of interest in van der Waals (vdW) electrides or electrenes in two dimensions. A typical example is layered lanthanum bromide (LaBr<sub>2</sub>), which can be taken as [La<sup>3+</sup>(Br<sup>1–</sup>)<sub>2</sub>]<sup>+</sup>•(e<sup>–</sup>). Each excess free electron is trapped within a hexagonal pore, forming dense dots of electron density. These anionic electrons are loosely bound, giving vdW electrides some unique properties such as ferromagnetism, superconductivity, topological features, and Dirac plasmons. The high density of the free electron makes electrides very promising for applications in thermionic emission, organic light-emitting diodes, and high-performance catalysts.</p><p >In this Account, we first discuss the discovery of numerous vdW electrides through high-throughput computational screening of over 67,000 known inorganic crystals in Materials Project. A dozen of them have been newly discovered and have not been reported before. Importantly, they possess completely different structural prototypes and properties of anionic electrons compared to widely studied electrides such as Ca<sub>2</sub>N. Finding these new vdW electrides expands the variety of electrides that can be made in the experiment and opens up new possibilities for studying their unique properties and applications.</p><p >Then, based on the screened vdW electrides, we delve into their various emerging properties. For example, we developed a new magnetic mechanism specific to atomic-orbital-free ferromagnetism in electrides. We uncover the dual localized and extended nature of the anionic electrons in such electrides and demonstrate the formation of the local moment by the localized feature and the ferromagnetic interaction by the direct overlapping of their extended states. We further show the effective tuning of the magnetic properties of vdW electrides by engineering their structural, electronic, and compositional properties. Besides, we show that the complex interaction between the multiple quantum orderings in vdW electrides leads to many interesting properties including valley polarization, charge density waves, a topological property, a superconducting property, and a thermoelectrical property.</p><p >Moreover, we discuss strategies to leverage the unique intrinsic properties of vdW electrides for practical applications. We show that these properties make vdW electrides potential candidates for advanced applications such as spin–orbit torque memory devices, valleytronic devices, K-ion batteries, and thermoelectricity. Finally, we discuss the current challenges a","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142135193","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}