Marco Bertolini, Kohei Iijima, Utsa Karmakar, Lucia González Pico, Emma Martin, Valentina Giai, Marc Vendrell
Oxygen availability is a key regulator of immune cell function, particularly in B lymphocytes, because they are highly sensitive to hypoxia signaling. However, current hypoxia-sensing probes lack the specificity to distinguish B cells from other leukocytes and lymphocytes in biosamples. Here, we present hCXCL13-6 as an AND-gate activatable probe for the fluorescence detection and live imaging of hypoxic human B cells. The probe hCXCL13-6 combines a site-specifically labeled analog of the human chemokine CXCL13─for selective internalization in B cells─and a bioconjugable azo-containing rhodamine fluorophore─for hypoxia sensing. Notably, hCXCL13-6 displays both CXCR5 receptor-mediated endocytosis in B cells and hypoxia-mediated enzymatic activation, which results in bright fluorescence signals being exclusively found in hypoxic B cells but not in normoxic B cells or in other immune cells. Notably, we demonstrated that hCXCL13-6 enables direct identification of hypoxic B cells in cell mixtures derived from human blood biosamples. The combination of ‘clickable’ fluorogenic reporters with nonperturbative ligation to chemokine proteins will create new avenues for the rational design of targeted B cell probes to study inflammatory diseases and hematological malignancies.
{"title":"Enzyme-Activatable CXCL13 Chemokine Probes Enable Direct Fluorescence Detection of Hypoxic Subpopulations of Human B Cells","authors":"Marco Bertolini, Kohei Iijima, Utsa Karmakar, Lucia González Pico, Emma Martin, Valentina Giai, Marc Vendrell","doi":"10.1021/jacs.5c18237","DOIUrl":"https://doi.org/10.1021/jacs.5c18237","url":null,"abstract":"Oxygen availability is a key regulator of immune cell function, particularly in B lymphocytes, because they are highly sensitive to hypoxia signaling. However, current hypoxia-sensing probes lack the specificity to distinguish B cells from other leukocytes and lymphocytes in biosamples. Here, we present hCXCL13-6 as an AND-gate activatable probe for the fluorescence detection and live imaging of hypoxic human B cells. The probe hCXCL13-6 combines a site-specifically labeled analog of the human chemokine CXCL13─for selective internalization in B cells─and a bioconjugable azo-containing rhodamine fluorophore─for hypoxia sensing. Notably, hCXCL13-6 displays both CXCR5 receptor-mediated endocytosis in B cells and hypoxia-mediated enzymatic activation, which results in bright fluorescence signals being exclusively found in hypoxic B cells but not in normoxic B cells or in other immune cells. Notably, we demonstrated that hCXCL13-6 enables direct identification of hypoxic B cells in cell mixtures derived from human blood biosamples. The combination of ‘clickable’ fluorogenic reporters with nonperturbative ligation to chemokine proteins will create new avenues for the rational design of targeted B cell probes to study inflammatory diseases and hematological malignancies.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"40 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718063","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}
Muhammad Abdullah Khan, Zhen Xu, Muhammad Muzammil, Samuel Bird, Monica Munawar, Fariah Salam, Niamh A. Hartley, Jack Taylor, Kamran Amin, Jianheng Ling, Henry R. N. B. Enninful, Naveed Zafar Ali, Kai Hetze, Sijia Cao, Yan Lu, Zhixiang Wei, Martin Oschatz, Phillip J. Milner, Alexander C. Forse
Electrochemical CO2 capture is an emerging technology that promises to be more energy-efficient than traditional thermal or pressure-swing processes. Herein, the first evidence of electrochemical capture of CO2 using a covalent organic framework (COF) is presented. We hypothesized that the assembly of anthraquinone units into a well-defined porous framework electrode would lead to enhanced electrochemical CO2 capture compared to previous approaches that grafted anthraquinones on carbon supports and suffered from low CO2 capacities and stabilities. To test this, an anthraquinone-based COF is employed, and it is found that the quinones are electrochemically accessible for reversible CO2 capture in an ionic liquid electrolyte. The system achieves a high electrochemical CO2 uptake capacity >2.6 mmol g–1 COF, reaching half of the theoretical CO2 capacity of the material and surpassing the capacities of anthraquinone-functionalized carbons. The stability and CO2 uptake rate issues encountered with the ionic liquid system are also addressed by using aqueous electrolytes where we attained stable carbon capture for 500 cycles with a 99.6% Coulombic efficiency and an electrical energy consumption of 31 kJ molCO2–1. The use of covalent organic framework electrodes can become a general strategy for understanding and enhancing the electrochemical CO2 capture.
{"title":"Electrochemical CO2 Capture by a Quinone-Based Covalent Organic Framework","authors":"Muhammad Abdullah Khan, Zhen Xu, Muhammad Muzammil, Samuel Bird, Monica Munawar, Fariah Salam, Niamh A. Hartley, Jack Taylor, Kamran Amin, Jianheng Ling, Henry R. N. B. Enninful, Naveed Zafar Ali, Kai Hetze, Sijia Cao, Yan Lu, Zhixiang Wei, Martin Oschatz, Phillip J. Milner, Alexander C. Forse","doi":"10.1021/jacs.5c12304","DOIUrl":"https://doi.org/10.1021/jacs.5c12304","url":null,"abstract":"Electrochemical CO<sub>2</sub> capture is an emerging technology that promises to be more energy-efficient than traditional thermal or pressure-swing processes. Herein, the first evidence of electrochemical capture of CO<sub>2</sub> using a covalent organic framework (COF) is presented. We hypothesized that the assembly of anthraquinone units into a well-defined porous framework electrode would lead to enhanced electrochemical CO<sub>2</sub> capture compared to previous approaches that grafted anthraquinones on carbon supports and suffered from low CO<sub>2</sub> capacities and stabilities. To test this, an anthraquinone-based COF is employed, and it is found that the quinones are electrochemically accessible for reversible CO<sub>2</sub> capture in an ionic liquid electrolyte. The system achieves a high electrochemical CO<sub>2</sub> uptake capacity >2.6 mmol g<sup>–1</sup> COF, reaching half of the theoretical CO<sub>2</sub> capacity of the material and surpassing the capacities of anthraquinone-functionalized carbons. The stability and CO<sub>2</sub> uptake rate issues encountered with the ionic liquid system are also addressed by using aqueous electrolytes where we attained stable carbon capture for 500 cycles with a 99.6% Coulombic efficiency and an electrical energy consumption of 31 kJ mol<sub>CO<sub>2</sub></sub><sup>–1</sup>. The use of covalent organic framework electrodes can become a general strategy for understanding and enhancing the electrochemical CO<sub>2</sub> capture.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"115 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704746","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}
Detao Gao, Khuraijam Dhanachandra Singh, Sadashiva Karnik, Tatiana V. Byzova, Eugene A. Podrez
CD36 is a multifunctional receptor widely expressed in immune and nonimmune cells, known for its role in lipid transport and inflammatory signaling. Oxidized phospholipids (oxPLs), a class of prominent lipid oxidation products generated under oxidative stress, bind CD36 with high affinity, contributing to the development of atherogenesis and thrombosis and potentially influencing other CD36-dependent biological events. The molecular basis for the oxPL-CD36 interaction is poorly understood. Here, we used cutting-edge enrichment-mass spectrometry to identify lysine residues of CD36 that directly interact with oxPLs. These residues are located along a putative ligand translocation path─spanning from the apex of the extracellular domain to the entrance, interior, and around the exit of the lipid transport tunnel. Molecular docking revealed two sets of oxPL binding poses: one within a tunnel and the other on a surface loop cluster spanning the top to midsection, including the tallest loop containing oxPL-modified K398/K403. These findings support the selective oxPL binding observed in the LC–MS/MS analysis. Molecular dynamics (MD) simulation demonstrated that the sn-1 chain and headgroup of oxPLs engage distinct CD36 residues through hydrophobic, hydrogen-bonding, and ionic interactions, optimally positioning the reactive sn-2 group for lysine modification. MD and metadynamics simulations further demonstrated oxPL translocation through the tunnel, beginning with sn-1 chain insertion, followed by reorientation at the tunnel midsection, where the sn-2 chain and sn-3 headgroup lead the molecule toward the exit. Together, these studies indicate that CD36 may serve as a transporter of individual oxPL molecules into the cell and outline a translocation pathway, key residues and binding forces involved.
{"title":"Structural Insights into Recognition and Translocation of Oxidized Phospholipid by CD36 Using Mass Spectrometry, Molecular Docking, Dynamics, and Metadynamics Simulations","authors":"Detao Gao, Khuraijam Dhanachandra Singh, Sadashiva Karnik, Tatiana V. Byzova, Eugene A. Podrez","doi":"10.1021/jacs.5c07761","DOIUrl":"https://doi.org/10.1021/jacs.5c07761","url":null,"abstract":"CD36 is a multifunctional receptor widely expressed in immune and nonimmune cells, known for its role in lipid transport and inflammatory signaling. Oxidized phospholipids (oxPLs), a class of prominent lipid oxidation products generated under oxidative stress, bind CD36 with high affinity, contributing to the development of atherogenesis and thrombosis and potentially influencing other CD36-dependent biological events. The molecular basis for the oxPL-CD36 interaction is poorly understood. Here, we used cutting-edge enrichment-mass spectrometry to identify lysine residues of CD36 that directly interact with oxPLs. These residues are located along a putative ligand translocation path─spanning from the apex of the extracellular domain to the entrance, interior, and around the exit of the lipid transport tunnel. Molecular docking revealed two sets of oxPL binding poses: one within a tunnel and the other on a surface loop cluster spanning the top to midsection, including the tallest loop containing oxPL-modified K398/K403. These findings support the selective oxPL binding observed in the LC–MS/MS analysis. Molecular dynamics (MD) simulation demonstrated that the sn-1 chain and headgroup of oxPLs engage distinct CD36 residues through hydrophobic, hydrogen-bonding, and ionic interactions, optimally positioning the reactive sn-2 group for lysine modification. MD and metadynamics simulations further demonstrated oxPL translocation through the tunnel, beginning with sn-1 chain insertion, followed by reorientation at the tunnel midsection, where the sn-2 chain and sn-3 headgroup lead the molecule toward the exit. Together, these studies indicate that CD36 may serve as a transporter of individual oxPL molecules into the cell and outline a translocation pathway, key residues and binding forces involved.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"6 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704772","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}
Meng Lei, Decheng Li, Keyi Chen, Zhe Han, Guyue Li, Xianhui Nie, Jingxian Zhang, Chilin Li
Due to the ultrahigh theoretical energy density, no dendrite issue, and abundant resources, fluoride ion batteries (FIBs) have received a lot of attention. Regarding the issue of dissolving inorganic salt CsF in aprotic organic solvents, some anion acceptor (AA) strategies have been proposed. However, the strong binding force greatly constrains F– ion desolvation, resulting in short lifespan, low specific capacity, and poor reversibility of FIBs. Herein, we propose a concept of steric hindrance-driven closed-loop acceptor to address these problems, by using tetraphenylphosphonium chloride (Ph4PCl) with appropriate Lewis acidity to dissolve CsF and prepare a dynamic fluoride ion electrolyte based on the F–Cl exchange reaction, with a high ionic conductivity of 4.1 mS/cm at room temperature. The steric hindrance effects of chlorine and phenyl can accelerate the desolvation kinetics of F– ions. The excellent kinetics of the Ph4PCl-based electrolyte endows FIBs with long-term cycling stability, and the Sn@SnF2 symmetric cells can cycle for 500 h at 100 μA/cm2 and tolerate a critical current density as high as 1250 μA/cm2. Due to the potential dissociation ability of five-coordinated acceptor central phosphorus for fluorides and the closed-loop conversion effect of chlorine, the fluorination and defluorination reaction proceeds in a dissolution-deposition mode. The CuF2//Sn@SnF2 cell (under a high cathode loading of 4.2 mg/cm2) exhibits the highest reversible capacity up to 717.7 mAh/g and remains 316 mAh/g after 65 cycles with a small voltage polarization of only 11 mV. This work points out the novel design concept of AAs for developing high capacity and long lifespan FIBs.
{"title":"Steric Hindrance-Driven Closed-Loop Conversion of Acceptor Enables Long-Life and High-Capacity Fluoride-Ion Batteries","authors":"Meng Lei, Decheng Li, Keyi Chen, Zhe Han, Guyue Li, Xianhui Nie, Jingxian Zhang, Chilin Li","doi":"10.1021/jacs.5c11916","DOIUrl":"https://doi.org/10.1021/jacs.5c11916","url":null,"abstract":"Due to the ultrahigh theoretical energy density, no dendrite issue, and abundant resources, fluoride ion batteries (FIBs) have received a lot of attention. Regarding the issue of dissolving inorganic salt CsF in aprotic organic solvents, some anion acceptor (AA) strategies have been proposed. However, the strong binding force greatly constrains F<sup>–</sup> ion desolvation, resulting in short lifespan, low specific capacity, and poor reversibility of FIBs. Herein, we propose a concept of steric hindrance-driven closed-loop acceptor to address these problems, by using tetraphenylphosphonium chloride (Ph<sub>4</sub>PCl) with appropriate Lewis acidity to dissolve CsF and prepare a dynamic fluoride ion electrolyte based on the F–Cl exchange reaction, with a high ionic conductivity of 4.1 mS/cm at room temperature. The steric hindrance effects of chlorine and phenyl can accelerate the desolvation kinetics of F<sup>–</sup> ions. The excellent kinetics of the Ph<sub>4</sub>PCl-based electrolyte endows FIBs with long-term cycling stability, and the Sn@SnF<sub>2</sub> symmetric cells can cycle for 500 h at 100 μA/cm<sup>2</sup> and tolerate a critical current density as high as 1250 μA/cm<sup>2</sup>. Due to the potential dissociation ability of five-coordinated acceptor central phosphorus for fluorides and the closed-loop conversion effect of chlorine, the fluorination and defluorination reaction proceeds in a dissolution-deposition mode. The CuF<sub>2</sub>//Sn@SnF<sub>2</sub> cell (under a high cathode loading of 4.2 mg/cm<sup>2</sup>) exhibits the highest reversible capacity up to 717.7 mAh/g and remains 316 mAh/g after 65 cycles with a small voltage polarization of only 11 mV. This work points out the novel design concept of AAs for developing high capacity and long lifespan FIBs.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711479","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}
Response properties of molecules and crystals are naturally described by tensors that obey specific equivariance and symmetry constraints. However, directly predicting these tensorial quantities remains challenging for machine learning models. We present a general-purpose output module for equivariant graph neural networks that enables end-to-end prediction of tensors of arbitrary order with prescribed permutation (fundamental) symmetry. Coupled with the SE(3)-equivariant XPaiNN architecture, our framework attains accuracy comparable to that of first-principles calculations. It also supports atomic-level properties─such as chemical shielding tensors and Born effective charges─in an all-in-one model. Moreover, the method handles higher-order tensors, including molecular hyperpolarizability and the elastic tensor (stiffness matrix) of crystalline materials, thereby enabling the derivation and analysis of rich anisotropic information and facilitating AI-assisted discovery and design of functional molecules and materials.
{"title":"General Framework for Geometric Deep Learning on Tensorial Properties of Molecules and Crystals","authors":"Wenjie Yan, Xinming Lai, Yicheng Chen, Wenhao Zhang, Jianming Wu, Xin Xu","doi":"10.1021/jacs.5c12428","DOIUrl":"https://doi.org/10.1021/jacs.5c12428","url":null,"abstract":"Response properties of molecules and crystals are naturally described by tensors that obey specific equivariance and symmetry constraints. However, directly predicting these tensorial quantities remains challenging for machine learning models. We present a general-purpose output module for equivariant graph neural networks that enables end-to-end prediction of tensors of arbitrary order with prescribed permutation (fundamental) symmetry. Coupled with the <i>SE</i>(3)-equivariant XPaiNN architecture, our framework attains accuracy comparable to that of first-principles calculations. It also supports atomic-level properties─such as chemical shielding tensors and Born effective charges─in an all-in-one model. Moreover, the method handles higher-order tensors, including molecular hyperpolarizability and the elastic tensor (stiffness matrix) of crystalline materials, thereby enabling the derivation and analysis of rich anisotropic information and facilitating AI-assisted discovery and design of functional molecules and materials.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"26 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704747","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}
Miaomiao Zhang, Junjie Cheng, Wen Yu, Zenghao Wang, Weijian Chen, Shengpeng Xia, Yan Zhao, Yiming Huang, Fengting Lv, Haotian Bai, Shu Wang
Rapid and reliable communication with photosynthetic organisms is essential for monitoring their physiological states, which would reflect their endogenous bioelectric signals. However, these signals are inherently weak and challenging to detect due to the low efficiency of bioelectronic generation and transmission. In this work, we constructed a Syne/PFP/PPy biohybrid system by integrating the photosynthetic cyanobacterial cells of Synechococcus sp. PCC7942 (Syne) with cationic poly(fluorene-co-phenylene) derivative (PFP) and polypyrrole (PPy). Leveraging the superior light-harvesting ability of PFP and the excellent electrical conducting properties of PPy, the Syne/PFP/PPy system can enhance the acquisition of in situ bioelectronic signals from Syne. Compared to single Syne cells, the intensity of bioelectronic signals collected by Syne/PFP/PPy increased over 14 times (from 3.4 to 47.9 nA cm–2). By incorporating machine learning models, we successfully correlated these bioelectronic signals with key physiological conditions, including variations in temperature, light intensity, pH, and nutrient availability (nitrogen and phosphorus). Furthermore, a wireless device was also designed for a simulation application of this system to realize wireless monitoring of Syne cells. This strategy offers a promising platform for decoding intrinsic bioelectronic signals of photosynthetic organisms and providing an efficient method for timely tracking their life status.
与光合生物快速、可靠的通信是监测其生理状态、反映其内源生物电信号的必要条件。然而，由于生物电子的产生和传输效率较低，这些信号本身就很弱，难以检测。本研究将聚藻球菌PCC7942 （Syne）光合蓝藻细胞与阳离子聚芴-共苯衍生物（PFP）和聚吡咯（PPy）结合，构建了Syne/PFP/PPy生物杂交体系。利用PFP优越的光收集能力和PPy优异的导电性能，Syne/PFP/PPy系统可以增强Syne的原位生物电子信号的采集。与单个Syne细胞相比，Syne/PFP/PPy收集的生物电子信号强度增加了14倍以上（从3.4 nA cm-2增加到47.9 nA cm-2）。通过结合机器学习模型，我们成功地将这些生物电子信号与关键的生理条件联系起来，包括温度、光照强度、pH值和养分有效性（氮和磷）的变化。此外，针对该系统的仿真应用，设计了无线设备，实现了对Syne小区的无线监测。该策略为解码光合生物的内在生物电子信号提供了一个有前景的平台，并为及时跟踪其生命状态提供了有效的方法。
{"title":"Machine Learning-Guided Decoding Bioelectronic Signals of Photosynthetic Cyanobacterial Cells by Conducting Polymers","authors":"Miaomiao Zhang, Junjie Cheng, Wen Yu, Zenghao Wang, Weijian Chen, Shengpeng Xia, Yan Zhao, Yiming Huang, Fengting Lv, Haotian Bai, Shu Wang","doi":"10.1021/jacs.5c13150","DOIUrl":"https://doi.org/10.1021/jacs.5c13150","url":null,"abstract":"Rapid and reliable communication with photosynthetic organisms is essential for monitoring their physiological states, which would reflect their endogenous bioelectric signals. However, these signals are inherently weak and challenging to detect due to the low efficiency of bioelectronic generation and transmission. In this work, we constructed a <i>Syne</i>/PFP/PPy biohybrid system by integrating the photosynthetic cyanobacterial cells of <i>Synechococcus</i> sp. <i>PCC7942</i> (<i>Syne</i>) with cationic poly(fluorene-<i>co</i>-phenylene) derivative (PFP) and polypyrrole (PPy). Leveraging the superior light-harvesting ability of PFP and the excellent electrical conducting properties of PPy, the <i>Syne</i>/PFP/PPy system can enhance the acquisition of in situ bioelectronic signals from <i>Syne</i>. Compared to single <i>Syne</i> cells, the intensity of bioelectronic signals collected by <i>Syne</i>/PFP/PPy increased over 14 times (from 3.4 to 47.9 nA cm<sup>–2</sup>). By incorporating machine learning models, we successfully correlated these bioelectronic signals with key physiological conditions, including variations in temperature, light intensity, pH, and nutrient availability (nitrogen and phosphorus). Furthermore, a wireless device was also designed for a simulation application of this system to realize wireless monitoring of <i>Syne</i> cells. This strategy offers a promising platform for decoding intrinsic bioelectronic signals of photosynthetic organisms and providing an efficient method for timely tracking their life status.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"55 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711398","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}
Florian Benner, Saroshan Deshapriya, Jakub Hrubý, Stephen Hill, Selvan Demir
Magnetic exchange coupling is difficult to foster in polynuclear lanthanide (Ln) complexes and poorly understood. While coupling Ln ions through closed-shell ligands is inherently weak due to the contracted 4f orbitals, placing open-shell ligands instead has proven to promote orders of magnitude stronger coupling, giving rise to single-molecule magnets (SMMs) innate to real magnetic memory effect in the case of the anisotropic Ln ions. Notably, the impact of radical bridges with differing oxidation states on magnetic blocking remains unexplored due to lack of Ln SMMs with radicals in two distinct charge states. Herein, the first dilanthanide complexes (Ln = Gd, Dy) containing fluoflavine (flv) bridges, [(Cp*2Ln)2(μ-flvz)]X, (where X = [Al(OC{CF3}3)4]− (z = 1–•), 1-Ln; X = 0 (z = 2−), 2-Ln; X =[K(crypt-222)]+ (z = 3–•), 3-Ln) are reported. 1-Ln and 3-Ln, comprising the flv1–• and flv3–• radical bridges, were investigated via single-crystal X-ray diffraction (SCXRD), ultraviolet–visible (UV–vis) spectroscopy, Superconducting Quantum Interference Device (SQUID) magnetometry, high-field electron paramagnetic resonance (HF-EPR) spectroscopy and broken-symmetry density functional theory (BS-DFT) calculations. 1-Dy and 3-Dy constitute the first SMMs innate to radicals in two differing oxidation states. 1-Dy exhibits a spin-reversal barrier Ueff of 28.36 cm–1 and open magnetic hysteresis loops below 3 K. By contrast, 3-Dy displays a much higher Ueff of 143(2) cm–1 and open hysteresis loops until 9.5 K, representing a record for dilanthanide SMMs containing an organic radical bridge. The boost in SMM properties in 3-Dy is attributed to spin-phonon coupling and improved frontier orbital structure. This study paves the way for advanced design strategies of polynuclear Ln SMMs.
{"title":"Magnetic Blocking in Fluoflavine Radical-Bridged Dilanthanide Complexes","authors":"Florian Benner, Saroshan Deshapriya, Jakub Hrubý, Stephen Hill, Selvan Demir","doi":"10.1021/jacs.5c14158","DOIUrl":"https://doi.org/10.1021/jacs.5c14158","url":null,"abstract":"Magnetic exchange coupling is difficult to foster in polynuclear lanthanide (Ln) complexes and poorly understood. While coupling Ln ions through closed-shell ligands is inherently weak due to the contracted 4f orbitals, placing open-shell ligands instead has proven to promote orders of magnitude stronger coupling, giving rise to single-molecule magnets (SMMs) innate to real magnetic memory effect in the case of the anisotropic Ln ions. Notably, the impact of radical bridges with differing oxidation states on magnetic blocking remains unexplored due to lack of Ln SMMs with radicals in two distinct charge states. Herein, the first dilanthanide complexes (Ln = Gd, Dy) containing fluoflavine (flv) bridges, [(Cp*<sub>2</sub>Ln)<sub>2</sub>(μ-flv<sup>z</sup>)]X, (where X = [Al(OC{CF<sub>3</sub>}<sub>3</sub>)<sub>4</sub>]<sup>−</sup> (<i>z</i> = 1–•), <b>1-Ln</b>; X = 0 (<i>z</i> = 2−), <b>2-Ln</b>; X =[K(crypt-222)]<sup>+</sup> (<i>z</i> = 3–•), <b>3-Ln</b>) are reported. <b>1-Ln</b> and <b>3-Ln</b>, comprising the flv<sup>1–•</sup> and flv<sup>3–•</sup> radical bridges, were investigated via single-crystal X-ray diffraction (SCXRD), ultraviolet–visible (UV–vis) spectroscopy, Superconducting Quantum Interference Device (SQUID) magnetometry, high-field electron paramagnetic resonance (HF-EPR) spectroscopy and broken-symmetry density functional theory (BS-DFT) calculations. <b>1-Dy</b> and <b>3-Dy</b> constitute the first SMMs innate to radicals in two differing oxidation states. <b>1-Dy</b> exhibits a spin-reversal barrier <i>U</i><sub>eff</sub> of 28.36 cm<sup>–1</sup> and open magnetic hysteresis loops below 3 K. By contrast, <b>3-Dy</b> displays a much higher <i>U</i><sub>eff</sub> of 143(2) cm<sup>–1</sup> and open hysteresis loops until 9.5 K, representing a record for dilanthanide SMMs containing an organic radical bridge. The boost in SMM properties in <b>3-Dy</b> is attributed to spin-phonon coupling and improved frontier orbital structure. This study paves the way for advanced design strategies of polynuclear Ln SMMs.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"144 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711429","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}
Ion transport in metal-organic frameworks (MOFs) is attracting increasing attention, as ions can be easily incorporated into porous MOF structures as guest species, promising a variety of possible applications. While electronically insulating but ionically conductive MOFs show great potential as solid electrolytes, the precise structure and tunability of MOFs also enable a rational combination of electronic and ionic conductivity to create intrinsic mixed conductors. In this perspective, we discuss structure-function relationships in ionically conductive MOFs, pointing toward fundamental research opportunities, and lay out strategies to enable and characterize mixed ionic-electronic transport properties.
{"title":"Mixed Ionic-Electronic Transport in Metal-Organic Frameworks.","authors":"Alice Yue Su, Mircea Dincă","doi":"10.1021/jacs.5c14871","DOIUrl":"https://doi.org/10.1021/jacs.5c14871","url":null,"abstract":"<p><p>Ion transport in metal-organic frameworks (MOFs) is attracting increasing attention, as ions can be easily incorporated into porous MOF structures as guest species, promising a variety of possible applications. While electronically insulating but ionically conductive MOFs show great potential as solid electrolytes, the precise structure and tunability of MOFs also enable a rational combination of electronic and ionic conductivity to create intrinsic mixed conductors. In this perspective, we discuss structure-function relationships in ionically conductive MOFs, pointing toward fundamental research opportunities, and lay out strategies to enable and characterize mixed ionic-electronic transport properties.</p>","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712670","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}
Mengying Ye, Xinyin Li, Lu Huang, Xinru Mei, Huahang Yu, Ke Cao, Feng Chen, Yongxi Zhao
Recording biophysical processes is crucial to understanding the cellular history and stimuli-responsive behaviors. The construction of memory machines for continuous membrane fluidity, however, remain challenging. Here, we report a biophysical-to-DNA catalytic cumulative birecorder (BioDIMER) for making individual recordings of continuous membrane fluidity events into both fluorescent signals and DNA unique molecular identifiers (UMIs) sequencing. We do this through engineered DNAzyme probe sets that accumulate bimodal signals responsive to each transient encounter on cell membrane. This in situ imaging captures spatiotemporal information, and the UMIs sequencing counts the number of transient encounters over time by digital quantification. The DNA catalytic bimodal signals enable continuous records of new events without corrupting the records of older events and achieve multidimensional interpretation of membrane fluidity timing. Using this proof-of-concept method, we recorded and deciphered differential cell membrane dynamics across diverse cell types and states, including cell cycle phases, cardiac hypertrophy, myotube differentiation, and cellular senescence. We found the first decreased and then increased change of membrane fluidity during the cell circle phases. In cardiac hypertrophy, we visualized an enhanced membrane fluidity. Oppositely, cellular senescence caused a significant reduction in membrane fluidity. They implied a highly dynamic organization of cell membrane components.
{"title":"Biophysical-to-DNA Catalytic Cumulative Birecorder for Measuring Continuous Membrane Fluidity","authors":"Mengying Ye, Xinyin Li, Lu Huang, Xinru Mei, Huahang Yu, Ke Cao, Feng Chen, Yongxi Zhao","doi":"10.1021/jacs.5c16545","DOIUrl":"https://doi.org/10.1021/jacs.5c16545","url":null,"abstract":"Recording biophysical processes is crucial to understanding the cellular history and stimuli-responsive behaviors. The construction of memory machines for continuous membrane fluidity, however, remain challenging. Here, we report a biophysical-to-DNA catalytic cumulative birecorder (BioDIMER) for making individual recordings of continuous membrane fluidity events into both fluorescent signals and DNA unique molecular identifiers (UMIs) sequencing. We do this through engineered DNAzyme probe sets that accumulate bimodal signals responsive to each transient encounter on cell membrane. This in situ imaging captures spatiotemporal information, and the UMIs sequencing counts the number of transient encounters over time by digital quantification. The DNA catalytic bimodal signals enable continuous records of new events without corrupting the records of older events and achieve multidimensional interpretation of membrane fluidity timing. Using this proof-of-concept method, we recorded and deciphered differential cell membrane dynamics across diverse cell types and states, including cell cycle phases, cardiac hypertrophy, myotube differentiation, and cellular senescence. We found the first decreased and then increased change of membrane fluidity during the cell circle phases. In cardiac hypertrophy, we visualized an enhanced membrane fluidity. Oppositely, cellular senescence caused a significant reduction in membrane fluidity. They implied a highly dynamic organization of cell membrane components.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"139 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704837","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 electric double layer (EDL) at solid-liquid interfaces governs electrochemical processes from plating to catalysis, yet its atomistic dynamics remain poorly defined. Using operando atomic-resolution transmission electron microscopy, we directly visualize EDL formation, growth, and collapse during zinc electroplating on copper in an ionic liquid electrolyte. Under galvanostatic conditions, the EDL appears as a dense amorphous layer that grows via charge accumulation, and dynamic surface erosion of the substrate releases surface atoms that nucleate transient metallic nanoparticles within the EDL. Enlargement of these particles locally short-circuits the capacitive layer, leading to abrupt dielectric breakdown, heat generation, and alloy deposition. Recurrent growth-breakdown cycles (240-520 s) produce ∼2 nm Cu/Zn alloy layers, with an activation free energy of ∼86 kJ mol-1. Strikingly, brass nanoparticles form spontaneously at room temperature despite requiring ∼1000 °C in bulk, reflecting the large interfacial energy of nanoscale species. This breakdown-driven mechanism reframes electroplating as a discontinuous, chemically reactive, and electrostatically unstable process, providing a unifying explanation for the rough morphologies often observed in plated films. More broadly, our findings suggest that the dielectric breakdown of chemically active EDLs is a general phenomenon relevant to plating, energy storage, catalysis, and other interfacial transformations.
{"title":"Zinc Plating on Copper Proceeds via Breakdown of a Capacitive Electric Double Layer.","authors":"Haoxiang Sun,Shulin Ding,Jinkai Zhang,Yujie Chen,Xinyao Wu,Zhao Zhang,Tong Zhou,Zhenhua Yan,Kai Zhang,Qing Zhao,Wei Xie,Ke Yang,Guang Feng,Eiichi Nakamura,Jun Chen,Wei Zhang","doi":"10.1021/jacs.5c17948","DOIUrl":"https://doi.org/10.1021/jacs.5c17948","url":null,"abstract":"The electric double layer (EDL) at solid-liquid interfaces governs electrochemical processes from plating to catalysis, yet its atomistic dynamics remain poorly defined. Using operando atomic-resolution transmission electron microscopy, we directly visualize EDL formation, growth, and collapse during zinc electroplating on copper in an ionic liquid electrolyte. Under galvanostatic conditions, the EDL appears as a dense amorphous layer that grows via charge accumulation, and dynamic surface erosion of the substrate releases surface atoms that nucleate transient metallic nanoparticles within the EDL. Enlargement of these particles locally short-circuits the capacitive layer, leading to abrupt dielectric breakdown, heat generation, and alloy deposition. Recurrent growth-breakdown cycles (240-520 s) produce ∼2 nm Cu/Zn alloy layers, with an activation free energy of ∼86 kJ mol-1. Strikingly, brass nanoparticles form spontaneously at room temperature despite requiring ∼1000 °C in bulk, reflecting the large interfacial energy of nanoscale species. This breakdown-driven mechanism reframes electroplating as a discontinuous, chemically reactive, and electrostatically unstable process, providing a unifying explanation for the rough morphologies often observed in plated films. More broadly, our findings suggest that the dielectric breakdown of chemically active EDLs is a general phenomenon relevant to plating, energy storage, catalysis, and other interfacial transformations.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"35 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704639","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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