Chemical Science最新文献

{"title":"Aromatic-Aromatic Interactions Drive Fold Switch of GA95 and GB95 with Three Residue Difference","authors":"Chen Chen, Zeting Zhang, Mojie Duan, Qiong Wu, Minghui Yang, Ling Jiang, Maili Liu, Conggang Li","doi":"10.1039/d4sc04951a","DOIUrl":"https://doi.org/10.1039/d4sc04951a","url":null,"abstract":"Proteins typically adopt a single fold to carry out their function, but metamorphic proteins, with multiple folding states, defy this norm. Deciphering the mechanism of conformational interconversion of metamorphic proteins is challenging. Herein, we employed nuclear magnetic resonance (NMR), circular dichroism (CD), and all-atom molecular dynamics (MD) simulations to elucidate the mechanism of fold switching in proteins GA95 and GB95, which share 95% sequence homology. The results reveal that long-range interactions, especially aromatic π-π interactions involving residues F52, Y45, F30, and Y29, are critical for the protein switching from a 3α to a 4β+α fold. This study contributes to understanding how proteins with highly similar sequences fold into distinct conformations and may provide valuable insights into the protein folding code.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"4 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841665","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}

{"title":"570 nm-/770 nm Light-Excited Deep-Red Fluorescence Switch Based on Dithienylethene Derived from BF2-Curcuminoid","authors":"Ziyong Li, Xiaoxie Ma, Jinzhao Song, Qilian Wang, Yongliang Feng, Haining Liu, Pei Zhang, Hui Guo, Jun Yin","doi":"10.1039/d4sc05473c","DOIUrl":"https://doi.org/10.1039/d4sc05473c","url":null,"abstract":"Developing dithienylethene (DTE)-based fluorescence switches triggered by biocompatible visible light has always been a long-term goal in view of their potential in numerous biological scenarios. However, their practical availability is severely limited by the short visible light (generally less than 500 nm) required for photocyclization, their inability to achieve red or near-infrared emission, and their short fluorescence lifetimes. Herein, we present a novel DTE derivative featuring a dimethylamine-functionalized BF2-curcuminoid moiety (NBDC) by using an “acceptor synergistic conjugation system” strategy. The dimethylamine group not only enables a red shift in the absorption and emission wavelengths of the open isomer but also endows NBDC with unique acid/base-gated photochromism. As expected, as-prepared NBDC presents 570 nm-/770 nm light-driven photochromic properties, red-emissive fluorescence, and thermally activated delayed fluorescence (TADF) switching in toluene. To our knowledge, this represents the first instance of a yellow-green- and NIR light-controlled red fluorescence DTE switch with the longer fluorescence lifetime. Specifically, NBDC, which shows almost no photochromic activity in CHCl3, demonstrates enhanced photochromic performance when gated by TFA/TEA. Ultimately, this non-toxic deep-red fluorescence switch has been successfully applied for photoswitchable imaging in vivo of living cells and zebrafish, further proving its versatility in life sciences.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"256 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841682","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}

{"title":"Unveiling the Enzymatic Pathway of UMG-SP2 Urethanase: Insights into Polyurethane Degradation at the Atomic Level","authors":"Pedro Paiva, Luís Miguel Correia Teixeira, Wei Ren, Weidong Liu, Gert Weber, Jens Preben Morth, Peter Westh, Allan R. Petersen, Martin Johansen, Andreas Sommerfeldt, Alexander Sandahl, Daniel Otzen, Pedro Alexandrino Fernandes, Maria Joao Joao Ramos","doi":"10.1039/d4sc06688j","DOIUrl":"https://doi.org/10.1039/d4sc06688j","url":null,"abstract":"The recently discovered metagenomic urethanases UMG-SP1, UMG-SP2, and UMG-SP3 have emerged as promising tools to establish a bio-based recycling approach for polyurethane (PU) waste. These enzymes are capable of hydrolyzing urethane bonds in low molecular weight dicarbamates as well as in thermoplastic PU and the amide bond in polyamide employing a Ser-Sercis-Lys triad for catalysis, similar to members of the amidase signature protein superfamily. Understanding the catalytic mechanism of these urethanases is crucial for enhancing their enzymatic activity and improving PU bio-recycling processes. In this study, we employed hybrid quantum mechanics/molecular mechanics methods to delve into the catalytic machinery of the UMG-SP2 urethanase in breaking down a model PU substrate. Our results indicate that the reaction proceeds in two stages: STAGE 1 - acylation, in which the enzyme becomes covalently bound to the PU substrate, releasing an alcohol-leaving group; STAGE 2 - deacylation, in which a catalytic water hydrolyzes the enzyme:ligand covalent adduct, releasing the product in the form of a highly unstable carbamic acid, expected to rapidly decompose into an amine and carbon dioxide. We found that STAGE 1 comprises the rate-limiting step of the overall reaction, consisting of the cleavage of the substrate’s urethane bond by its ester moiety and the release of the alcohol-leaving group (overall Gibbs activation energy of 20.8 kcal·mol-1). Lastly, we identified point mutations that are expected to enhance the enzyme's turnover for the hydrolysis of urethane bonds by stabilizing the macrodipole of the rate-limiting transition state. These findings expand our current knowledge of urethanases and homolog enzymes from the amidase signature superfamily, paving the way for future research on improving the enzymatic depolymerization of PU plastic materials.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"56 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841660","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}

{"title":"Enhancing Electrocatalytic Hydrogen Evolution via Engineering Unsaturated Electronic Structures in MoS₂","authors":"Qingqing Zhou, Hao Hu, Zhijie Chen, xiao ren, Ding Ma","doi":"10.1039/d4sc07309f","DOIUrl":"https://doi.org/10.1039/d4sc07309f","url":null,"abstract":"The search for efficient, earth-abundant electrocatalysts for the hydrogen evolution reaction (HER) has identified unsaturated molybdenum disulfide (MoS₂) as a leading candidate. This review synthesis recent advancements in the engineering of MoS₂ to enhance its electrocatalytic properties. It focuses on strategies for designing an unsaturated electronic structure on metal catalytic centers and their role in boosting the efficiency of the hydrogen evolution reaction (HER). It also considers how to optimize the electronic structures of unsaturated MoS₂ for enhanced catalytic performance. This review commences with an examination of the fundamental crystal structure of MoS₂; it elucidates the classical unsaturated electron configurations and the intrinsic factors that contribute to such electronic structures. Furthermore, it introduces popular strategies for constructing unsaturated electronic structures at the atomic level, such as nanostructure engineering, surface chemical modification and interlayer coupling engineering. It also discusses the challenges and future research directions in the study of MoS₂ electronic structures, with the aim of broadening their application in sustainable hydrogen production.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"115 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841685","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}

{"title":"Interplay between A-site and oxygen-vacancy ordering, and mixed electron/oxide-ion conductivity in n = 1 Ruddlesden−Popper perovskite Sr2Nd2Zn2O7","authors":"Danhe Li, Guangxiang Lu, Zien Cheng, Maxim Avdeev, Jungu Xu, Zhengyang Zhou, Rihong Cong, Tao Yang, Pengfei Jiang","doi":"10.1039/d4sc05323k","DOIUrl":"https://doi.org/10.1039/d4sc05323k","url":null,"abstract":"Oxygen vacancies in Ruddlesden−Popper (RP) perovskites (PV) [AO][ABO3]n play a pivotal role in engineering functional properties and thus understanding the relationship between oxygen-vacancy distribution and physical properties can open up new strategies for fine manipulation of structure-driven functionalities. However, the structural origin of preferential distribution for oxygen vacancies in RP structures is not well understood, notably in the single-layer (n =1) RP-structure. Herein, the n = 1 RP phase Sr2Nd2Zn2O7 was rationally designed and structurally characterized by combining three-dimensional (3D) electron diffraction and neutron powder diffraction. Sr2Nd2Zn2O7 adopts a novel 2-fold n = 1 RP-type Pmmn-superstructure due to the concurrence of A-site column ordering and oxygen-vacancy array ordering. These two ordering models are inextricably linked, and disrupting one would thus destroy the other. Oxygen vacancies are structurally confined to occupy the equatorial sites of “BO6”-octahedra, in stark contrast to the preferential occupation of the inner apical sites in n ≥ 2 structures. Such a layer-dependent oxygen-vacancy distribution in RP structures is in fact dictated by the reduction of the cationic A−A/B repulsion. Moreover, the intrinsic oxygen vacancies can capture atmospheric O2, consequently resulting in a mixed oxide ion and p-type electrical conductivity of 1.0 × 10-4 S cm-1 at temperatures > 800 °C. This value could be further enhanced to > 1.0 × 10-3 S cm-1 by creating additional oxygen vacancies on the equatorial sites through acceptor doping. Bond valence site energy analysis indicates that the oxide ion conduction in Sr2Nd2Zn2O7 is predominated by the one-dimensional pathways along the [Zn2O7] ladders and is triggered by the gate-control-like migration of the equatorial bridging oxygens to the oxygen-vacant sites. Our results demonstrate that control of anion and cation ordering in RP perovskites opens a new path toward innovative structure-driven property design.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"48 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841667","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}

{"title":"Buried Interface Management toward High-Performance Perovskite Solar Cells","authors":"Bin Du, Yuexin Lin, Jintao Ma, Weidan Gu, Fei Liu, Yijun Yao, Lin Song","doi":"10.1039/d4sc06932c","DOIUrl":"https://doi.org/10.1039/d4sc06932c","url":null,"abstract":"The interface between the perovskite layer and the electron transport layer is an extremely important factor that cannot be ignored in achieving high-performance perovskite photovoltaic technology. However, the void defects of the interface pose a serious challenge for high performance perovskite solar cells (PSCs). To address this, we report a polydentate ligand reinforced chelating strategy to strengthen the stability of buried interface by managing interfacial defects and stress. The gelatin-coupled cellulose (GCC) is employed to manipulate the buried interface. The unique functional groups in GCC synergistically passivate the defects from the surface of SnO2 and the bottom surface of the perovskite layer. Our work demonstrates that by implementing the GCC as a buried interface strategy, it is possible to prepare devices with reduced vacancy states, non-radiative recombination suppression, and excellent optoelectronic performance. At the same time, this work improves the efficiency and stability of PSCs, and provides greater space for device manufacturing.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"79 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841668","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}

{"title":"Inverse design of copolymers including stoichiometry and chain architecture","authors":"Gabriel Vogel, Jana M. Weber","doi":"10.1039/d4sc05900j","DOIUrl":"https://doi.org/10.1039/d4sc05900j","url":null,"abstract":"The demand for innovative synthetic polymers with improved properties is high, but their structural complexity and vast design space hinder rapid discovery. Machine learning-guided molecular design is a promising approach to accelerate polymer discovery. However, the scarcity of labeled polymer data and the complex hierarchical structure of synthetic polymers make generative design particularly challenging. We advance the current state-of-the-art approaches to generate not only repeating units, but monomer ensembles including their stoichiometry and chain architecture. We build upon a recent polymer representation that includes stoichiometries and chain architectures of monomer ensembles and develop a novel variational autoencoder (VAE) architecture encoding a graph and decoding a string. Using a semi-supervised setup, we enable the handling of partly labelled datasets which can be beneficial for domains with a small corpus of labelled data. Our model learns a continuous, well organized latent space (LS) that enables <em>de novo</em> generation of copolymer structures including different monomer stoichiometries and chain architectures. In an inverse design case study, we demonstrate our model for <em>in silico</em> discovery of novel conjugated copolymer photocatalysts for hydrogen production using optimization of the polymer's electron affinity and ionization potential in the latent space.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"77 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142831935","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}

{"title":"Metal-organic frameworks generated from oligomeric ligands with functionalized tethers","authors":"Hyunyong Kim, Seth M Cohen","doi":"10.1039/d4sc06666a","DOIUrl":"https://doi.org/10.1039/d4sc06666a","url":null,"abstract":"Metal-organic frameworks (MOFs) can be prepared from oligomeric organic ligands to prepare materials referred to as oligoMOFs. Studies of oligoMOFs are relatively limited, with most existing reports focused on fundamental structure-property relationships. In this report, functional groups, such as terminal alkynes and pyridine groups, are installed on the tether between 1,4-benzene dicarboxylic acid (H2bdc) groups of the dimer ligands. It was found that the position of the pyridine donor atom had pronounced effects on the synthesis and structure of Zn(II)-based isoreticular MOFs (IRMOF-1 analog, oligoIRMOF). Importantly, simple H2bdc ligands with pendant pyridine groups (i.e., not part of an dimeric ligand), were unable to produce crystalline phases or produced new MOF phases, showing the importance of the oligomeric ligand in directing structure. Dimeric ligands with two H2bdc groups and a terminal alkyne produced a crystalline and porous oligoIRMOF that enables postsynthetic modification (PSM) via ‘click’ chemistry to introduce other functional groups into the pores of the material. This oligoIRMOF could be cross-linked using reagents containing multiple azide functional sites. Taken together, these studies are among the first examples of oligoMOFs with functionalized tethers and demonstrate the versatility, utility, and unique opportunities for new chemistry provided by oligoMOFs.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"23 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841683","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}

{"title":"Intrinsically Chiral Thermoresponsive Assemblies from Achiral Clusters: Enhanced Luminescence and Optical Activity through Tailor-made Chiral Additives","authors":"Camelia Dutta, Ragul Vivaz Nataraajan, Jatish Kumar","doi":"10.1039/d4sc07227h","DOIUrl":"https://doi.org/10.1039/d4sc07227h","url":null,"abstract":"Chiral metal clusters, due to their intriguing optical properties and unique resemblance in size with biomolecules, have gained vast attention in recent times as potential candidates for application in bio-detection and therapy. While several strategies are reported for the synthesis of optically active clusters, a facile approach that enhances multitude of properties has remained a challenge. Herein, we report a simple strategy wherein the use of chiral cationic surfactant, during the synthesis of achiral clusters, lead to the fabrication of chiral assemblies possessing enhanced luminescence and optical activity. The structural resemblance of the capping ligand, mercaptoundecanoic acid (MUA) with the co-surfactant, (+/−)-N-dodecyl-N-methylephedrinium bromide (DMEB), assisted specific interactions that led to the formation of chiral assemblies exhibiting unique thermoresponsive behavior and tunable optical activity. The symmetry breaking in the aggregates driven by the electrostatic interaction between the positively charged chiral surfactant and negatively charged clusters led to enhanced luminescence through aggregation induced enhanced emission (AIEE). The work highlighting the generation and tuning of cluster chirality provides newer insights into the fundamental understanding of nanocluster optical activity thereby opening newer avenues for the development of materials for application in the field of chiral biosensing and enantioselective catalysis.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"11 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142831936","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}

{"title":"Unravelling complex mechanisms in materials processes with cryogenic electron microscopy","authors":"Minyoung Lee, Yonggoon Jeon, Sungin Kim, Ihnkyung Jung, Sungsu Kang, Seol-Ha Jeong, Jungwon Park","doi":"10.1039/d4sc05188b","DOIUrl":"https://doi.org/10.1039/d4sc05188b","url":null,"abstract":"Investigating nanoscale structural variations, including heterogeneities, defects, and interfacial characteristics, is crucial for gaining insight into material properties and functionalities. Cryogenic electron microscopy (cryo-EM) is developing as a powerful tool in materials science particularly for non-invasively understanding nanoscale structures of materials. These advancements bring us closer to the ultimate goal of correlating nanoscale structures to bulk functional outcomes. However, while understanding mechanisms from structural information requires analysis that closely mimics operation conditions, current challenges in cryo-EM imaging and sample preparation hinder the extraction of detailed mechanistic insights. In this Perspective, we discuss the innovative strategies and the potential for using cryo-EM for revealing mechanisms in materials science, with examples from high-resolution imaging, correlative elemental analysis, and three-dimensional and time-resolved analysis. Furthermore, we propose improvements in cryo-sample preparation, optimized instrumentation setup for imaging, and data interpretation techniques to enable the wider use of cryo-EM and achieve deeper context into materials to bridge structural observations with mechanistic understanding.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"28 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841684","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}