Chemical Science最新文献_第10页

On the nature of high-spin forms in the S2 state of the oxygen-evolving complex

IF 8.4 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/d4sc07818g

Markella Aliki Mermigki, Maria Drosou, Dimitrios A. Pantazis

{"title":"On the nature of high-spin forms in the S2 state of the oxygen-evolving complex","authors":"Markella Aliki Mermigki, Maria Drosou, Dimitrios A. Pantazis","doi":"10.1039/d4sc07818g","DOIUrl":"https://doi.org/10.1039/d4sc07818g","url":null,"abstract":"The Mn4CaOx cluster of the oxygen-evolving complex (OEC) in photosystem II, the site of biological water oxidation, adopts different forms as it progresses through the catalytic cycle of Si states (i = 0–4) and within each Si state itself. This has been amply documented by spectroscopy, but the structural basis of spectroscopic polymorphism remains debated. The S2 state is extensively studied by magnetic resonance spectroscopies. In addition to the common type of g ≈ 2 multiline EPR signal attributed to a low-spin (S = 1/2) form of the manganese cluster, other signals at lower fields (g ≥ 4) associated with the S2 state arise from higher-spin forms. Resolving the structural identity of the high-spin species is paramount for a microscopic understanding of the catalytic mechanism. Hypotheses explored by theoretical studies implicate valence isomerism, proton tautomerism, or coordination change with respect to the low-spin form. Here we analyze structure–property correlations for multiple formulations employing a common high-level protocol based on multiscale models that combine a converged quantum mechanics region embedded within a large protein region treated semiempirically with an extended tight-binding method (DFT/xTB), surpassing conventional quantum mechanics/molecular mechanics (QM/MM) approaches. Our results provide a comprehensive comparison of magnetic topologies, spin states and energetics in relation to experimental observations. Crucial predictions are made about 14N hyperfine coupling constants and X-ray absorption Mn K-pre-edge features as criteria for discriminating between different models. This study updates our view on a persistent mystery of biological water oxidation, while providing a refined and transferable computational platform for future theoretical studies of the OEC.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"25 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072170","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}

引用次数: 0

The role of cytosine methylation in regulating the topology and liquid-liquid phase separation of DNA G-quadruplexes

IF 8.4 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/d4sc06959e

Mitsuki Tsuruta, Sumit Shil, Shinya Taniguchi, Keiko Kawauchi, Daisuke Miyoshi

引用次数: 0

Thermal-responsive luminescence/dielectric responses with reversibly shifted light emissions

IF 8.4 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/d4sc06631f

Ming Zhu, Pei-Zhi Huang, Lin-Mei Li, Yi-Xuan Yang, Lei Pan, Zhi-Jie Wang, Hao-Fei Ni, Feng-Wen Zhang, Gele Teri, Zhi-Xu Zhang, Zunqi Liu, Da-Wei Fu, Yi Zhang

{"title":"Thermal-responsive luminescence/dielectric responses with reversibly shifted light emissions","authors":"Ming Zhu, Pei-Zhi Huang, Lin-Mei Li, Yi-Xuan Yang, Lei Pan, Zhi-Jie Wang, Hao-Fei Ni, Feng-Wen Zhang, Gele Teri, Zhi-Xu Zhang, Zunqi Liu, Da-Wei Fu, Yi Zhang","doi":"10.1039/d4sc06631f","DOIUrl":"https://doi.org/10.1039/d4sc06631f","url":null,"abstract":"Molecular-rotor-type crystals dominated by crown ethers have garnered significant attention for their applications in sensing, optoelectronics, information encryption and other diverse fields. However, the role of crown ethers in regulating photoluminescent properties has long been overlooked in such structural systems. Here, by inserting 18-crown-6 molecules into the ionic crystal (4-pyridinemethaneaminum)PF6 (PP-1), we constructed a molecular-rotor-type crystal [(4-pyridinemethaneaminum)(18-crown-6)][PF6] (PCP-1), exhibiting sensitively thermal-driven, unusual PL/dielectric responses. Notably, the introduction of the 18-crown-6 molecule changed the dynamic thermal motion and exerted a confinement effect through rich hydrogen bonding interactions, thereby inducing structural phase transitions and modulating energy transfer processes. These not only brought about switchable dielectric responses but also resulted in a comprehensive improvement of PL properties, encompassing extended lifetime, doubled quantum yield and temperature-controllable luminescent color. This study offers novel insights into the role of crown ethers in developing smart luminescent materials, holding promising prospects for intelligent recognition and information encryption.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"77 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072917","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}

引用次数: 0

Celebrating 10 years of #RSCPoster

IF 7.6 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/D5SC90028J

Natalie Cotterell, Patrick A. J. M. de Jongh, Timothy Noël, Tanja Junkers, C. Malla Reddy, Athina Anastasaki and Edward Randviir

引用次数: 0

Correction: Peptide macrocyclisation via intramolecular interception of visible-light-mediated desulfurisation

IF 7.6 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/D5SC90021B

Frances R. Smith, Declan Meehan, Rhys C. Griffiths, Harriet J. Knowles, Peiyu Zhang, Huw E. L. Williams, Andrew J. Wilson and Nicholas J. Mitchell

引用次数: 0

Thorium metal–organic framework crystallization for efficient recovery from rare earth element mixtures

IF 8.4 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/d4sc07652d

Madeleine A. Gaidimas, Courtney S. Smoljan, Zi-Ming Ye, Charlotte L. Stern, Christos D. Malliakas, Kent O. Kirlikovali, Omar K. Farha

{"title":"Thorium metal–organic framework crystallization for efficient recovery from rare earth element mixtures","authors":"Madeleine A. Gaidimas, Courtney S. Smoljan, Zi-Ming Ye, Charlotte L. Stern, Christos D. Malliakas, Kent O. Kirlikovali, Omar K. Farha","doi":"10.1039/d4sc07652d","DOIUrl":"https://doi.org/10.1039/d4sc07652d","url":null,"abstract":"Rare earth (RE) elements are critical materials that underpin many modern technologies, particularly in the clean energy industry. Despite their importance, these vital resources are difficult to obtain due to the presence of numerous metals and radioactive contaminants, such as thorium, that are present in RE ores. Current processing methods, which are dominated by homogeneous solvent extraction, are inefficient and produce substantial hazardous waste. In this work, we describe an alternative strategy to separate thorium from REs through metal–organic framework (MOF) crystallization. Starting from a mixture of thorium and rare earth ions in solution, we utilize the simple carboxylate ligand trimesic acid to selectively crystallize a novel thorium MOF, NU-2500, leaving the remaining rare earth ions in solution. By leveraging the increased oxophilicity of Th(IV) compared to RE(III) ions, we observe the exclusive formation of the thermodynamically preferred Th-MOF product. This valence-selective crystallization strategy occurs rapidly (within 30 minutes) at mild temperatures (80 °C) with an environmentally-friendly ethanol/water solvent system to produce phase-pure NU-2500 containing >98% molar fraction of thorium. Sequestering the radioactive Th(IV) ions within a solid framework enables facile separation of REs through simple filtration. We demonstrate that our selective crystallization platform retains its high selectivity for Th crystallization even at low initial Th concentrations and in complex mixtures with multiple different REs. We anticipate that further insights into the kinetics and thermodynamics of MOF crystallization can be applied to additional challenging industrial separations.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"53 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072174","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}

引用次数: 0

MOSAEC-DB: a comprehensive database of experimental metal–organic frameworks with verified chemical accuracy suitable for molecular simulations

IF 8.4 1区化学

Chemical Science Pub Date : 2025-01-31 DOI: 10.1039/d4sc07438f

Marco Gibaldi, Anna Kapeliukha, Andrew White, Jun Luo, Robert Alex Mayo, Jake Burner, Tom K. Woo

{"title":"MOSAEC-DB: a comprehensive database of experimental metal–organic frameworks with verified chemical accuracy suitable for molecular simulations","authors":"Marco Gibaldi, Anna Kapeliukha, Andrew White, Jun Luo, Robert Alex Mayo, Jake Burner, Tom K. Woo","doi":"10.1039/d4sc07438f","DOIUrl":"https://doi.org/10.1039/d4sc07438f","url":null,"abstract":"Ongoing developments in computational databases seek to improve the accessibility and breadth of high-throughput screening and materials discovery efforts. Their reliance on experimental crystal structures necessitates significant processing prior to computation in order to resolve any crystallographic disorder or partial occupancies and remove any residual solvent molecules in the case of activated porous materials. Contemporary investigations revealed that deficiencies in the experimental characterization and computational preprocessing methods generated considerable occurrence of structural errors in metal–organic framework (MOF) databases. The MOSAEC MOF database (MOSAEC-DB) tackles these structural reliability concerns through utilization of innovative preprocessing and error analysis protocols applying the concepts of oxidation state and formal charge to exclude erroneous crystal structures. Comprising more than 124k crystal structures, this work maintains the largest and most accurate dataset of experimental MOFs ready for immediate deployment in molecular simulations. The databases' comparative diversity is demonstrated through its enhanced coverage of the periodic table, expansive quantity of structures, and balance of chemical properties relative to existing MOF databases. Chemical and geometric descriptors, as well as DFT electrostatic potential-fitted charges, are included to facilitate subsequent atomistic simulation and machine-learning (ML) studies. Curated subsets—sampled according to their chemical properties and structural uniqueness—are also provided to further enable ML studies in recognition of the strict demand for duplicate structure elimination and dataset diversity in such applications.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"37 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072171","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}

引用次数: 0

Characterization of a C-methyltransferase from Streptomyces griseoviridis - crystal structure, mechanism, and substrate scope.

IF 7.6 1区化学

Chemical Science Pub Date : 2025-01-30 DOI: 10.1039/d4sc07300b

Mona Haase, Oliver H Weiergräber, Benoit David, Elias L Pfirmann, Beatrix Paschold, Holger Gohlke, Jörg Pietruszka

{"title":"Characterization of a C-methyltransferase from Streptomyces griseoviridis - crystal structure, mechanism, and substrate scope.","authors":"Mona Haase, Oliver H Weiergräber, Benoit David, Elias L Pfirmann, Beatrix Paschold, Holger Gohlke, Jörg Pietruszka","doi":"10.1039/d4sc07300b","DOIUrl":"10.1039/d4sc07300b","url":null,"abstract":"Despite the presence of pyrroloindoles in many natural products with diverse biological activities, their synthesis remains challenging in terms of stereoselectivity, especially with respect to methylation at the indole C3 position. In the present study, the pyrroloindole motif in tryptophan-based diketopiperazines (DKPs) is synthesized using the SAM-dependent methyltransferase SgMT from Streptomyces griseoviridis. The three-dimensional structure of this indole C3-methyltransferase was determined by X-ray crystallography, providing insights into the enzyme. The complex active site was explored by site-directed mutagenesis, highlighting an intriguing network of tyrosine side chains that is involved in catalytic activity. The enzyme's precise substrate requirements were characterized using a broad panel of methylation educts, while molecular docking and molecular dynamics simulations revealed the catalytic binding mode of the cyclo-(ll)-ditryptophan substrate. This study provides an in-depth account of the structure and catalytic properties of SgMT, which may apply to other diketopiperazine-targeting indole C3-methyltransferases, thus paving the way for their optimization as biocatalysts.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":" ","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11804793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143381314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A coordination polymer with a silylene-supported Pd₆ core as an efficient heterogeneous hydrogenation catalyst.

IF 7.6 1区化学

Chemical Science Pub Date : 2025-01-30 DOI: 10.1039/d4sc05663a

Taiga Mitomo, Yoshimasa Wada, Tetsuro Suda, Atsushi Tamura, Shunsuke Yagi, Soichi Kikkawa, Seiji Yamazoe, Yusuke Sunada

引用次数: 0

A focus on a complex abiotic tertiary structure

IF 7.6 1区化学

Chemical Science Pub Date : 2025-01-30 DOI: 10.1039/D5SC90011E

Yulong Zhong and Bing Gong

引用次数: 0