In an effort to investigate the cooperative activation of boranes, we have designed Os(<small>III</small>) based paramagnetic mono- and bis-κ<small><sup>2</sup></small>-1,3-<em>N</em>,<em>Se</em>-chelated complexes, [Os(PPh<small><sub>3</sub></small>)<small><sub>2</sub></small>(κ<small><sup>2</sup></small>-<em>N</em>,<em>Se</em>-L)Cl<small><sub>2</sub></small>], <strong>1</strong> and [Os(PPh<small><sub>3</sub></small>)(κ<small><sup>2</sup></small>-<em>N</em>,<em>Se</em>-L)<small><sub>2</sub></small>(L′)], <strong>2–3</strong> (L = C<small><sub>5</sub></small>H<small><sub>4</sub></small>NSe; <strong>2</strong>: L′ = Cl and <strong>3</strong>: L′ = κ<small><sup>1</sup></small>-<em>Se</em>-L). These complexes were synthesised by the thermolysis of [Os(PPh<small><sub>3</sub></small>)<small><sub>3</sub></small>Cl<small><sub>2</sub></small>] with the potassium salt of 2-selenopyridine, which also afforded a diamagnetic species, [Os(PPh<small><sub>3</sub></small>)<small><sub>2</sub></small>(κ<small><sup>2</sup></small>-<em>N</em>,<em>Se</em>-L)<small><sub>2</sub></small>], <strong>4</strong>. A comprehensive study utilizing EPR spectroscopy, DFT calculations, and both photochemical and electrochemical analyses has elucidated the distinctive electronic characteristics of these complexes. To probe the electronic influence on hemilability, the OsNCSe osmaheterocycle-based paramagnetic complexes featuring a hard Os(<small>III</small>) centre and a soft Se donor were studied for B–H activation, highlighting synergistic hemilability and metal–ligand cooperativity. Treatment of <strong>2</strong> with [BH<small><sub>3</sub></small>·SMe<small><sub>2</sub></small>] yielded the Os(dihydridoborate)(octatrihydridoborate) complex, [Os(PPh<small><sub>3</sub></small>)(κ<small><sup>3</sup></small>-<em>H</em>,<em>H</em>,<em>N</em>-BH<small><sub>3</sub></small>L)(κ<small><sup>2</sup></small>-<em>H</em>,<em>Se</em>-B<small><sub>3</sub></small>H<small><sub>7</sub></small>L)] (<strong>5</strong>) <em>via</em> ring opening of both Os–Se and Os–N bonds and the Os–borallyl complex, [(PPh<small><sub>3</sub></small>)(H)<small><sub>2</sub></small>Os(η<small><sup>5</sup></small>-B<small><sub>3</sub></small>H<small><sub>5</sub></small>L<small><sub>2</sub></small>)] (<strong>6</strong>) through cleavage of the Os–N bonds. To further assess steric effects on cooperative borane activation, <strong>2</strong> was treated with the bulky aryl-substituted borane BH<small><sub>2</sub></small>R (R = (CF<small><sub>3</sub></small>)<small><sub>2</sub></small>C<small><sub>6</sub></small>H<small><sub>3</sub></small>), which afforded [(PPh<small><sub>3</sub></small>)Os{κ<small><sup>3</sup></small>-<em>H</em>,<em>Se</em>,<em>Se</em>′-(NHRBSeBHRN)(SeC<small><sub>5</sub></small>H<small><sub>4</sub></small>)<small><sub>2</sub></small>}], <strong>7</strong> <em>via</em> dual Os–N bond cleavage and insertion of two BHR units followed by B–Se bond formation. Interestingly, we have isolated a unique ve
{"title":"Cooperative borane activation by tuning hemilability of different Os-κ2-N,Se-chelated complexes","authors":"Faneesha Assanar, Sourav Gayen, Deepak Kumar Patel, Thalappil Pradeep, Sundargopal Ghosh","doi":"10.1039/d5sc06346a","DOIUrl":"https://doi.org/10.1039/d5sc06346a","url":null,"abstract":"In an effort to investigate the cooperative activation of boranes, we have designed Os(<small>III</small>) based paramagnetic mono- and bis-κ<small><sup>2</sup></small>-1,3-<em>N</em>,<em>Se</em>-chelated complexes, [Os(PPh<small><sub>3</sub></small>)<small><sub>2</sub></small>(κ<small><sup>2</sup></small>-<em>N</em>,<em>Se</em>-L)Cl<small><sub>2</sub></small>], <strong>1</strong> and [Os(PPh<small><sub>3</sub></small>)(κ<small><sup>2</sup></small>-<em>N</em>,<em>Se</em>-L)<small><sub>2</sub></small>(L′)], <strong>2–3</strong> (L = C<small><sub>5</sub></small>H<small><sub>4</sub></small>NSe; <strong>2</strong>: L′ = Cl and <strong>3</strong>: L′ = κ<small><sup>1</sup></small>-<em>Se</em>-L). These complexes were synthesised by the thermolysis of [Os(PPh<small><sub>3</sub></small>)<small><sub>3</sub></small>Cl<small><sub>2</sub></small>] with the potassium salt of 2-selenopyridine, which also afforded a diamagnetic species, [Os(PPh<small><sub>3</sub></small>)<small><sub>2</sub></small>(κ<small><sup>2</sup></small>-<em>N</em>,<em>Se</em>-L)<small><sub>2</sub></small>], <strong>4</strong>. A comprehensive study utilizing EPR spectroscopy, DFT calculations, and both photochemical and electrochemical analyses has elucidated the distinctive electronic characteristics of these complexes. To probe the electronic influence on hemilability, the OsNCSe osmaheterocycle-based paramagnetic complexes featuring a hard Os(<small>III</small>) centre and a soft Se donor were studied for B–H activation, highlighting synergistic hemilability and metal–ligand cooperativity. Treatment of <strong>2</strong> with [BH<small><sub>3</sub></small>·SMe<small><sub>2</sub></small>] yielded the Os(dihydridoborate)(octatrihydridoborate) complex, [Os(PPh<small><sub>3</sub></small>)(κ<small><sup>3</sup></small>-<em>H</em>,<em>H</em>,<em>N</em>-BH<small><sub>3</sub></small>L)(κ<small><sup>2</sup></small>-<em>H</em>,<em>Se</em>-B<small><sub>3</sub></small>H<small><sub>7</sub></small>L)] (<strong>5</strong>) <em>via</em> ring opening of both Os–Se and Os–N bonds and the Os–borallyl complex, [(PPh<small><sub>3</sub></small>)(H)<small><sub>2</sub></small>Os(η<small><sup>5</sup></small>-B<small><sub>3</sub></small>H<small><sub>5</sub></small>L<small><sub>2</sub></small>)] (<strong>6</strong>) through cleavage of the Os–N bonds. To further assess steric effects on cooperative borane activation, <strong>2</strong> was treated with the bulky aryl-substituted borane BH<small><sub>2</sub></small>R (R = (CF<small><sub>3</sub></small>)<small><sub>2</sub></small>C<small><sub>6</sub></small>H<small><sub>3</sub></small>), which afforded [(PPh<small><sub>3</sub></small>)Os{κ<small><sup>3</sup></small>-<em>H</em>,<em>Se</em>,<em>Se</em>′-(NHRBSeBHRN)(SeC<small><sub>5</sub></small>H<small><sub>4</sub></small>)<small><sub>2</sub></small>}], <strong>7</strong> <em>via</em> dual Os–N bond cleavage and insertion of two BHR units followed by B–Se bond formation. Interestingly, we have isolated a unique ve","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"18 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753068","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}
Symmetry-breaking charge separation (SB-CS) in a far-red capturing, orthogonally linked BODIPY dimer, 2, revealing minimal electronic coupling, is demonstrated under isoenergetic conditions (with little or no energy loss), thus helping to maximize the process of solar light capture and conversion. The orthogonal design of the dimer and proximity resulted in poor orbital overlaps between the chromophores, promoting a long-lived SB-CS state without the need for a thermodynamic driving force -a crucial factor for increasing solar device efficiency. Multiple techniques were employed to establish and prove this phenomenon. Steady-state and time-resolved emission studies revealed substantial quenching of the dimer in both nonpolar and polar solvents compared to the BODIPY monomer, 1, providing initial evidence of SB-CS. The redox gap, measured to assess thermodynamic feasibility through electrochemical studies, confirmed the event as a barrierless process (∆G ET ~ 0.0 eV). TD-DFT calculations supported this realization by illustrating the generation of excited-state electron density and hole-electron distribution, revealing an unsymmetrical dipolar distribution. Short-range and long-range electronic coupling calculations yielded negligible values, confirming weak excitonic coupling, reducing the Coulombic interactions between the hole and electron, thereby facilitating the formation of radical ion pairs with minimal energy loss. Transient absorption spectroscopy further provided conclusive evidence of SB-CS and allowed the extraction of kinetic parameters.Finally, Marcus's theory of electron transfer was applied, yielding a low electronic coupling (V) value of as little as 7.6 meV.These findings indicate that electron transfer can occur even under weak-coupling (null-exciton) conditions without an energy barrier -a step forward in maximizing solar energy harvesting.
对称破缺电荷分离（SB-CS）在远红色捕获，正交连接的BODIPY二聚体，2，揭示最小的电子耦合，证明在等能条件下（很少或没有能量损失），从而有助于最大化太阳能光捕获和转换过程。二聚体的正交设计和邻近导致发色团之间的轨道重叠较差，促进了长寿命的SB-CS状态，而不需要热力学驱动力-这是提高太阳能器件效率的关键因素。多种技术被用来建立和证明这一现象。稳态和时间分辨发射研究表明，与BODIPY单体相比，二聚体在非极性和极性溶剂中都有明显的猝灭，1提供了SB-CS的初步证据。通过电化学研究测量氧化还原间隙以评估热力学可行性，确认该事件为无障过程（∆G ET ~ 0.0 eV）。TD-DFT计算通过说明激发态电子密度和空穴电子分布的产生，揭示了不对称的偶极分布，支持了这一实现。短程和远程电子耦合计算得到的值可以忽略不计，证实了弱激子耦合，减少了空穴和电子之间的库仑相互作用，从而促进了自由基离子对的形成，能量损失最小。瞬态吸收光谱进一步提供了SB-CS的确凿证据，并允许提取动力学参数。最后，应用Marcus的电子转移理论，得到低电子耦合(V)值，低至7.6 meV。这些发现表明，即使在没有能量屏障的弱耦合（零激子）条件下，电子转移也可以发生，这是在最大化太阳能收集方面迈出的一步。
{"title":"Isoenergetic Symmetry Breaking Charge Separation in Far-Red Absorbing Orthogonal BODIPY Dimer -a Classic Case of No Energy Loss During the Process of Light Capture and Conversion","authors":"Ram R. Kaswan, Aida Yahagh, Francis D'Souza","doi":"10.1039/d5sc07818k","DOIUrl":"https://doi.org/10.1039/d5sc07818k","url":null,"abstract":"Symmetry-breaking charge separation (SB-CS) in a far-red capturing, orthogonally linked BODIPY dimer, 2, revealing minimal electronic coupling, is demonstrated under isoenergetic conditions (with little or no energy loss), thus helping to maximize the process of solar light capture and conversion. The orthogonal design of the dimer and proximity resulted in poor orbital overlaps between the chromophores, promoting a long-lived SB-CS state without the need for a thermodynamic driving force -a crucial factor for increasing solar device efficiency. Multiple techniques were employed to establish and prove this phenomenon. Steady-state and time-resolved emission studies revealed substantial quenching of the dimer in both nonpolar and polar solvents compared to the BODIPY monomer, 1, providing initial evidence of SB-CS. The redox gap, measured to assess thermodynamic feasibility through electrochemical studies, confirmed the event as a barrierless process (∆G ET ~ 0.0 eV). TD-DFT calculations supported this realization by illustrating the generation of excited-state electron density and hole-electron distribution, revealing an unsymmetrical dipolar distribution. Short-range and long-range electronic coupling calculations yielded negligible values, confirming weak excitonic coupling, reducing the Coulombic interactions between the hole and electron, thereby facilitating the formation of radical ion pairs with minimal energy loss. Transient absorption spectroscopy further provided conclusive evidence of SB-CS and allowed the extraction of kinetic parameters.Finally, Marcus's theory of electron transfer was applied, yielding a low electronic coupling (V) value of as little as 7.6 meV.These findings indicate that electron transfer can occur even under weak-coupling (null-exciton) conditions without an energy barrier -a step forward in maximizing solar energy harvesting.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"29 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753070","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}
The rational design of polyester materials plays a crucial role in the development of functional polymers with tailored properties. In this work, we introduce a novel symmetry-guided molecular design strategy, which is a symmetry-aware, parameter-controlled design paradigm that both broadens and rationalizes the accessible chemical space of functional molecules. By introducing the concept of pairwise atomic symmetry index (PASI) metric and applying targeted modifications to small molecules, a library of 10,614 diacids and 9,983 diols is constructed. enabling a systematic and unexplored expansion of the chemical space of polyesters. The combinatorial pairing of these diacids and diols leads to the generation of over 100 million polyester structures. High-throughput prediction of the glass transition temperature (Tg) by the Tg-QSPR model aligns well with the typical thermal behavior in polyester materials. To validate the design methodology, a two-level verification process is performed. The predicted Tg values are first examined using molecular dynamics (MD) simulations and subsequently confirmed by differential scanning calorimetry experiments. The calculated Tg values show good agreement with both MD simulations (average absolute error (AAE) of 17.54 °C) and experimental measurements (AAE of 16.45 °C). These results further confirm the reliability and robustness of the proposed approach. This study not only provides an effective strategy for the large-scale generation of polyester library and screening of property targeted polyesters, but also carries broader chemical implications beyond polyester design, offering potential insights for the development of functional molecules.
{"title":"Symmetry-Guided Monomer Design Enables the Combinatorial Synthesis and Targeted Screening of Polyesters","authors":"Xiaojie Feng, Xiaoying He, Jiayi Zhu, Li-Hong Lin, Qiaoyan Shang, Zheng-Hong Luo, Yin-Ning Zhou, Fangyou Yan","doi":"10.1039/d5sc07720f","DOIUrl":"https://doi.org/10.1039/d5sc07720f","url":null,"abstract":"The rational design of polyester materials plays a crucial role in the development of functional polymers with tailored properties. In this work, we introduce a novel symmetry-guided molecular design strategy, which is a symmetry-aware, parameter-controlled design paradigm that both broadens and rationalizes the accessible chemical space of functional molecules. By introducing the concept of pairwise atomic symmetry index (PASI) metric and applying targeted modifications to small molecules, a library of 10,614 diacids and 9,983 diols is constructed. enabling a systematic and unexplored expansion of the chemical space of polyesters. The combinatorial pairing of these diacids and diols leads to the generation of over 100 million polyester structures. High-throughput prediction of the glass transition temperature (Tg) by the Tg-QSPR model aligns well with the typical thermal behavior in polyester materials. To validate the design methodology, a two-level verification process is performed. The predicted Tg values are first examined using molecular dynamics (MD) simulations and subsequently confirmed by differential scanning calorimetry experiments. The calculated Tg values show good agreement with both MD simulations (average absolute error (AAE) of 17.54 °C) and experimental measurements (AAE of 16.45 °C). These results further confirm the reliability and robustness of the proposed approach. This study not only provides an effective strategy for the large-scale generation of polyester library and screening of property targeted polyesters, but also carries broader chemical implications beyond polyester design, offering potential insights for the development of functional molecules.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"11 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753073","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}
Carlos Alarcon-Miranda, Isis Amanda Middleton, Olivia Rusli, Nicolas Caceres, Mohan Bhadbhade, Nicole Joy Rijs, Pall Thordarson, Marcelo Kogan, Claudio Saitz
We report a series of N-arylsulfonamidocalix[4]arene hosts with tunable acidity and conformational flexibility designed to explore narrow pH-responsive binding. Using two cationic dyes as model guests, we performed a systematic analysis across pH 5.8-10.2 in a 1:1 (v/v) water:acetonitrile mixture (χH2O 0.74). Fluorescence experiments confirmed pH-and conformation-dependent affinity, with host Tf-SA4 (bearing the most acidic sulfonamide groups in the cone conformer) inducing a sharp fluorescence enhancement within a narrow range of pHapp 7.8 and 8.2 (ΔpH = 0.4). Detailed analysis revealed a 1:2 complex with coupled charge and geometry changes in the host that are pH-dependent and induce a steep increase in binding stability, consistent with a proposed "binding switch" over the narrow ΔpH = 0.4. This study introduces a proof-of-concept for a synthetic host with narrow pH responsiveness near neutral pH, offering a foundation for further research into N-arylsulfonamidocalixarenes for potential biomedical applications.
{"title":"N-arylsulfonamidocalix[4]arenes with Narrow pH-Responsive Binding near Neutral pH","authors":"Carlos Alarcon-Miranda, Isis Amanda Middleton, Olivia Rusli, Nicolas Caceres, Mohan Bhadbhade, Nicole Joy Rijs, Pall Thordarson, Marcelo Kogan, Claudio Saitz","doi":"10.1039/d5sc07965a","DOIUrl":"https://doi.org/10.1039/d5sc07965a","url":null,"abstract":"We report a series of N-arylsulfonamidocalix[4]arene hosts with tunable acidity and conformational flexibility designed to explore narrow pH-responsive binding. Using two cationic dyes as model guests, we performed a systematic analysis across pH 5.8-10.2 in a 1:1 (v/v) water:acetonitrile mixture (χ<small><sub>H<small><sub>2</sub></small>O</sub></small> 0.74). Fluorescence experiments confirmed pH-and conformation-dependent affinity, with host <strong>Tf-SA4</strong> (bearing the most acidic sulfonamide groups in the cone conformer) inducing a sharp fluorescence enhancement within a narrow range of pH<small><sub>app</sub></small> 7.8 and 8.2 (ΔpH = 0.4). Detailed analysis revealed a 1:2 complex with coupled charge and geometry changes in the host that are pH-dependent and induce a steep increase in binding stability, consistent with a proposed \"binding switch\" over the narrow ΔpH = 0.4. This study introduces a proof-of-concept for a synthetic host with narrow pH responsiveness near neutral pH, offering a foundation for further research into N-arylsulfonamidocalixarenes for potential biomedical applications.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"1 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753072","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}
Atomically precise metal nanoclusters (NCs, < 2 nm) with precise number of metal atoms and ligands have attracted enormous attention as highly promising photosensitizers owing to peculiar atom-stacking mode, quantum confinement effect, enriched active sites and discrete molecular-like energy band structures. Despite these merits, metal NCs still suffer from inherent drawbacks such as ultrafast photogenerated carrier recombination, poor photostability and difficulties in regulating charge transport pathway, which severely hinder their applications in photocatalysis. Herein, we strategically constructed the spatially hierarchically ordered MOs/(PDDA/MQDs/PDDA/Agy)n heterostructure artificial photosystems by layer-by-layer assembly of oppositely charged poly(diallyldimethylammonium chloride) (PDDA), MXene quantum dots (MQDs) and Agy NCs [Agx@GSH, Ag9(GSH)6, Ag16(GSH)9] building blocks on the metal oxides (MOs) substrate under ambient conditions for customizing directional charge migration/separation pathway over atomically precise metal NCs. In these on-demand artificial photosystems, Agy NCs serve as highly efficient photosensitizers that markedly enhance the visible light absorption capacity, while the synergistic and concurrent electron-withdrawing roles of PDDA (as an electron extraction medium) and MQDs (as electron acceptors) contributes to the long-range tandem charge transport chain, synergistically driving the directional electron transfer from the metal NCs to the MOs framework. This significantly accelerates the charge separation/transfer of metal NCs and markedly improves the solar water oxidation performances of the MOs/(PDDA/MQDs/PDDA/Agy)n heterostructures. The essential roles of each building blocks are specifically explored with photoelectrochemical mechanism clearly elucidated. Our work offers an accessible and universal route to strategically construct metal NCs-based heterostructure photosystem and unveils the multi-functional synergy in regulating the electron migration pathway of atomically precise metal NCs towards solar energy conversion.
{"title":"Optimization of Electron Transfer Pathways in Atomically Precise Metal Nanoclusters: Catalyzing a Leap in Solar Water Oxidation","authors":"Peng Su, Jialiang Liu, Fangxing Xiao","doi":"10.1039/d5sc08806b","DOIUrl":"https://doi.org/10.1039/d5sc08806b","url":null,"abstract":"Atomically precise metal nanoclusters (NCs, < 2 nm) with precise number of metal atoms and ligands have attracted enormous attention as highly promising photosensitizers owing to peculiar atom-stacking mode, quantum confinement effect, enriched active sites and discrete molecular-like energy band structures. Despite these merits, metal NCs still suffer from inherent drawbacks such as ultrafast photogenerated carrier recombination, poor photostability and difficulties in regulating charge transport pathway, which severely hinder their applications in photocatalysis. Herein, we strategically constructed the spatially hierarchically ordered MOs/(PDDA/MQDs/PDDA/Agy)n heterostructure artificial photosystems by layer-by-layer assembly of oppositely charged poly(diallyldimethylammonium chloride) (PDDA), MXene quantum dots (MQDs) and Agy NCs [Agx@GSH, Ag9(GSH)6, Ag16(GSH)9] building blocks on the metal oxides (MOs) substrate under ambient conditions for customizing directional charge migration/separation pathway over atomically precise metal NCs. In these on-demand artificial photosystems, Agy NCs serve as highly efficient photosensitizers that markedly enhance the visible light absorption capacity, while the synergistic and concurrent electron-withdrawing roles of PDDA (as an electron extraction medium) and MQDs (as electron acceptors) contributes to the long-range tandem charge transport chain, synergistically driving the directional electron transfer from the metal NCs to the MOs framework. This significantly accelerates the charge separation/transfer of metal NCs and markedly improves the solar water oxidation performances of the MOs/(PDDA/MQDs/PDDA/Agy)n heterostructures. The essential roles of each building blocks are specifically explored with photoelectrochemical mechanism clearly elucidated. Our work offers an accessible and universal route to strategically construct metal NCs-based heterostructure photosystem and unveils the multi-functional synergy in regulating the electron migration pathway of atomically precise metal NCs towards solar energy conversion.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"12 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753071","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}
Electrochemical sodium- and lithium-insertion into hard carbon (HC) relies on two main reactions: adsorption/intercalation and pore-filling. The rates of these two reactions are key to attaining high power densities and fast charging in batteries, but distinguishing the rate-limitations can be challenging due to their overlap and issue with Na+ and Li+ transport in conventional composite electrodes. Herein, we focus on the usage of the diluted electrode method to better evaluate the kinetics of electrochemical sodiation and lithiation at HC. Through galvanostatic charge/discharge testing, cyclic voltammetry and potential step analysis performed on diluted HC-electrodes in aprotic Na cells, we confirm that the sodium-insertion rate into HC is faster than lithium-insertion when we consider both adsorption/intercalation and pore-filling reactions with apparent diffusion coefficients, Dapp, on the order of 10−10 −10−11 and 10−10 −10−12 cm2 s−1 for sodium- and lithium-insertion of HC, respectively. Additionaly, the sodiation into diluted HC-electrode showed comparable rate-capability and Dapp of adsorption/intercalation to lithium intercalation into diluted graphite-electrodes. We further evaluated temperature dependence using potential-step and electrochemical impedance methods, finding that activation energies, Ea, were ~55 and ~65 kJ mol−1 for sodiation and lithiation, respectively. We find reactions in solid-state, i.e., nucleation of pseudo-metallic cluster can limit the rate-performance in diluted HC-electrodes as well as the charge-transfer at the electrolyte/HC interface, at the lower potential region.
{"title":"Revealing the Kinetic Limits of Sodiation and Lithiation at Hard Carbon Using the Diluted Electrode Method","authors":"Yuki Fujii, Ryoichi Tatara, Zachary Tyson Gossage, Shinichi Komaba","doi":"10.1039/d5sc07762a","DOIUrl":"https://doi.org/10.1039/d5sc07762a","url":null,"abstract":"Electrochemical sodium- and lithium-insertion into hard carbon (HC) relies on two main reactions: adsorption/intercalation and pore-filling. The rates of these two reactions are key to attaining high power densities and fast charging in batteries, but distinguishing the rate-limitations can be challenging due to their overlap and issue with Na<small><sup>+</sup></small> and Li<small><sup>+</sup></small> transport in conventional composite electrodes. Herein, we focus on the usage of the diluted electrode method to better evaluate the kinetics of electrochemical sodiation and lithiation at HC. Through galvanostatic charge/discharge testing, cyclic voltammetry and potential step analysis performed on diluted HC-electrodes in aprotic Na cells, we confirm that the sodium-insertion rate into HC is faster than lithium-insertion when we consider both adsorption/intercalation and pore-filling reactions with apparent diffusion coefficients, <em>D</em><small><sub>app</sub></small>, on the order of 10<small><sup>−10</sup></small> −10<small><sup>−11</sup></small> and 10<small><sup>−10</sup></small> −10<small><sup>−12</sup></small> cm<small><sup>2</sup></small> s<small><sup>−1</sup></small> for sodium- and lithium-insertion of HC, respectively. Additionaly, the sodiation into diluted HC-electrode showed comparable rate-capability and <em>D</em><small><sub>app</sub></small> of adsorption/intercalation to lithium intercalation into diluted graphite-electrodes. We further evaluated temperature dependence using potential-step and electrochemical impedance methods, finding that activation energies, <em>E</em><small><sub>a</sub></small>, were ~55 and ~65 kJ mol<small><sup>−1</sup></small> for sodiation and lithiation, respectively. We find reactions in solid-state, i.e., nucleation of pseudo-metallic cluster can limit the rate-performance in diluted HC-electrodes as well as the charge-transfer at the electrolyte/HC interface, at the lower potential region.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"9 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753228","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}
Wenqian Li, Miao Xu, Gang Chen, Xiaoping Chen, Jie-Sheng Chen, Tian-Nan Ye
Ammonia is a key component in fertilizer and chemical production, with its synthesis currently dominated by the energyintensive Haber-Bosch process. To address this challenge, there is growing interest in photocatalytic approaches for ammonia synthesis under ambient conditions. Plasmonic nanomaterials have emerged as particularly promising candidates, thanks to their localized surface plasmon resonance (LSPR) effects, which combine photochemical and thermal advantages within a single system. This review introduces the fundamental principles of LSPR, including hot carrier injection, photoheating, and near-field enhancement. It then provides a comprehensive overview of state-of-the-art catalysts for plasmon-driven photocatalytic ammonia synthesis. Finally, we outline future directions, including strategies for designing plasmonic photocatalysts, advances in in situ characterization and theoretical simulations, and the need for standardized reaction conditions and ammonia detection methods.
{"title":"Enabling plasmon-assisted ammonia synthesis: from mechanistic insights to catalyst design","authors":"Wenqian Li, Miao Xu, Gang Chen, Xiaoping Chen, Jie-Sheng Chen, Tian-Nan Ye","doi":"10.1039/d5sc05725f","DOIUrl":"https://doi.org/10.1039/d5sc05725f","url":null,"abstract":"Ammonia is a key component in fertilizer and chemical production, with its synthesis currently dominated by the energyintensive Haber-Bosch process. To address this challenge, there is growing interest in photocatalytic approaches for ammonia synthesis under ambient conditions. Plasmonic nanomaterials have emerged as particularly promising candidates, thanks to their localized surface plasmon resonance (LSPR) effects, which combine photochemical and thermal advantages within a single system. This review introduces the fundamental principles of LSPR, including hot carrier injection, photoheating, and near-field enhancement. It then provides a comprehensive overview of state-of-the-art catalysts for plasmon-driven photocatalytic ammonia synthesis. Finally, we outline future directions, including strategies for designing plasmonic photocatalysts, advances in in situ characterization and theoretical simulations, and the need for standardized reaction conditions and ammonia detection methods.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"162 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753074","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}
The built-in electric field (IEF) could be improved via developing donor-acceptor (D-A) type COF photocatalysts, yet available modulation strategies remain limited and poor. Here, we design a series of D-A COFs with isomeric imine linkage to promote the IEF and redox activity. The orientation of imine linkages on D/A centers could effectively adjust dipole moment of COFs, which is increased by ~50%, thereby enhancing the IEF. The charge separation efficiency is also elevated through the enhancement of IEF, leading to exciton binding energy reduced by ~30% and charge-separated state lifetime prolonged by 7-fold. Accordingly, the optimal COF exhibits impressive photocatalytic redox activities (5-fold promoted), achieving a remarkable tetrahydroquinoline dehydrogenation rate of 10.02 mmol/g/h, far exceeding reported metal-free photocatalysts and even comparative with metal photocatalysts, along with a H2O2 production rate over 20.01 mmol/g/h. Our findings establish a universal strategy to modulate the IEF which contributes to designing high-performance COF photocatalysts.
{"title":"Directing Robust Built-in Electric Fields via Imine Linkage Orientation in COFs for Efficient Dehydrogenative Organic Transformation Coupled with H2O2 Photosynthesis","authors":"Chang He, Enwei Zhu, Weixu Liu, Yongfa Zhu, Chen Chen","doi":"10.1039/d5sc08299d","DOIUrl":"https://doi.org/10.1039/d5sc08299d","url":null,"abstract":"The built-in electric field (IEF) could be improved via developing donor-acceptor (D-A) type COF photocatalysts, yet available modulation strategies remain limited and poor. Here, we design a series of D-A COFs with isomeric imine linkage to promote the IEF and redox activity. The orientation of imine linkages on D/A centers could effectively adjust dipole moment of COFs, which is increased by ~50%, thereby enhancing the IEF. The charge separation efficiency is also elevated through the enhancement of IEF, leading to exciton binding energy reduced by ~30% and charge-separated state lifetime prolonged by 7-fold. Accordingly, the optimal COF exhibits impressive photocatalytic redox activities (5-fold promoted), achieving a remarkable tetrahydroquinoline dehydrogenation rate of 10.02 mmol/g/h, far exceeding reported metal-free photocatalysts and even comparative with metal photocatalysts, along with a H2O2 production rate over 20.01 mmol/g/h. Our findings establish a universal strategy to modulate the IEF which contributes to designing high-performance COF photocatalysts.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"34 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732558","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}
Alexander Karr, Hye Joon Lee, A. Talim G. Khan, Chloe Ramsperger, Cesar Reyes, Kelly Biv, Elias Picazo
Donor–acceptor Stenhouse adducts (DASAs) are molecular photoswitches with applications spanning materials to molecular machines. Although structural modularity has enabled seminal DASA studies, sulfonyl substituents in amino DASAs remain unexplored. Evaluation of sulfonyl substituents reveals a distinct photoswitching pathway between acyclic isomers about the C3–C4 bond, as evidenced by UV-vis spectroscopy and low-temperature NMR spectroscopy. This discovery was achieved by significantly improving DASA structural stability under irradiation, which in turn enables the creation of a compound that sets the record for amino DASA isomer distribution at the photostationary state. Thermal reversion is rapid with little to no fatigue in dichloromethane and solvent versatility is demonstrated with photoswitching and full recovery in toluene, albeit with slower thermal recovery rates. Sulfonyl substituents are also found to modulate molar absorption coefficients and structural charge distribution in a manner that broadly follows Hammett substituent constants with modest correlations, thereby providing qualitative guidance for molecular design. These findings enable the greater DASA photoswitch class to selectively access multiple isomers through structural design, offering opportunities for further developments in responsive materials, soft robotics, and selective reactivity.
{"title":"Sulfonyl-tuned amino DASAs for targeted photophysical and photoswitching control","authors":"Alexander Karr, Hye Joon Lee, A. Talim G. Khan, Chloe Ramsperger, Cesar Reyes, Kelly Biv, Elias Picazo","doi":"10.1039/d5sc07740k","DOIUrl":"https://doi.org/10.1039/d5sc07740k","url":null,"abstract":"Donor–acceptor Stenhouse adducts (DASAs) are molecular photoswitches with applications spanning materials to molecular machines. Although structural modularity has enabled seminal DASA studies, sulfonyl substituents in amino DASAs remain unexplored. Evaluation of sulfonyl substituents reveals a distinct photoswitching pathway between acyclic isomers about the C3–C4 bond, as evidenced by UV-vis spectroscopy and low-temperature NMR spectroscopy. This discovery was achieved by significantly improving DASA structural stability under irradiation, which in turn enables the creation of a compound that sets the record for amino DASA isomer distribution at the photostationary state. Thermal reversion is rapid with little to no fatigue in dichloromethane and solvent versatility is demonstrated with photoswitching and full recovery in toluene, albeit with slower thermal recovery rates. Sulfonyl substituents are also found to modulate molar absorption coefficients and structural charge distribution in a manner that broadly follows Hammett substituent constants with modest correlations, thereby providing qualitative guidance for molecular design. These findings enable the greater DASA photoswitch class to selectively access multiple isomers through structural design, offering opportunities for further developments in responsive materials, soft robotics, and selective reactivity.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"15 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732560","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}
Cyclopropyl sulfoxides, merging two privileged motifs in medicinal chemistry, remain synthetically challenging despite their pharmaceutical potential. Herein, we report a mild, metal-free hydrosulfenation strategy that enables their direct synthesis, achieving exceptional diastereoselectivity (dr up to >20:1) in systems with up to eight possible diastereomers. Chiral sulfoxides with 4 to 7 stereogenic centers were also synthesized in high dr. The methodology provides direct access to medicinally relevant architectures, including cyclopropyl sulfones, sulfoximines, and drug-conjugated hybrids. Mechanistic studies reveal stereochemical control via collective spatial factors including endo/exo, facial and side selectivities during the cycloaddition step
{"title":"Diastereoselective Synthesis of Cyclopropyl Sulfoxides via Hydrosulfenation","authors":"Liyan Yuwen, Jiazhong Tang, Yayu Qi, Tianyi Zou, Shaotong Zhang, Ya-Qian Zhang, Qingwei Zhang","doi":"10.1039/d5sc08731g","DOIUrl":"https://doi.org/10.1039/d5sc08731g","url":null,"abstract":"Cyclopropyl sulfoxides, merging two privileged motifs in medicinal chemistry, remain synthetically challenging despite their pharmaceutical potential. Herein, we report a mild, metal-free hydrosulfenation strategy that enables their direct synthesis, achieving exceptional diastereoselectivity (dr up to >20:1) in systems with up to eight possible diastereomers. Chiral sulfoxides with 4 to 7 stereogenic centers were also synthesized in high dr. The methodology provides direct access to medicinally relevant architectures, including cyclopropyl sulfones, sulfoximines, and drug-conjugated hybrids. Mechanistic studies reveal stereochemical control via collective spatial factors including endo/exo, facial and side selectivities during the cycloaddition step","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"1 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729156","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}
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