Regioselective γ-polyhaloalkylation is achieved using tetrahalomethanes or α,α,α-trihaloalkyl compounds and siloxydienes via Fe(II) catalysis. A range of siloxydienes are functionalized in good yield and high stereoselectivity under mild reaction conditions. Structural divergence is observed as either haloalkylated or haloalkenylated products are formed based on substitution pattern of the siloxydiene. The halogenated products show utility in further synthetic transformations selec- tive reduction and cross coupling reactions.
{"title":"Fe-Catalyzed Structurally Divergent γ-Polyhaloalkylation of Si- loxydienes","authors":"Justin, Mohr, Douglas, Yarbrough, Brian, Osei-Badu, Cole, Wagner, Kayla, Storme, Sebastian, Marquez R.","doi":"10.26434/chemrxiv-2024-78vqn","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-78vqn","url":null,"abstract":"Regioselective γ-polyhaloalkylation is achieved using tetrahalomethanes or α,α,α-trihaloalkyl compounds and siloxydienes via Fe(II) catalysis. A range of siloxydienes are functionalized in good yield and high stereoselectivity under mild reaction conditions. Structural divergence is observed as either haloalkylated or haloalkenylated products are formed based on substitution pattern of the siloxydiene. The halogenated products show utility in further synthetic transformations selec- tive reduction and cross coupling reactions.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Immunogenic cell death (ICD), which converts tumor cells into their own vaccine, plays a pivotal role in the development of novel anti-cancer therapies. Here, a small series of osmium(II) polypyridyl complexes were synthesized and their biological activity in the dark and upon light irradiation against various cancer cell lines was studied. The compound Os2 (bearing two 4,7-diphenyl-1,10-phenanthrolines and one substituted bipyridine ligand) was discovered to be the most effective photosensitizer (PS) for photodynamic therapy (PDT) of this series through the photogeneration of 1O2 and •OH. In addition, Os2 was found to exhibit promising toxicity upon near-infrared (NIR) irradiation under both normoxia and hypoxia. These observations indicate that this PS is working through a mixture of Type-I and Type-II mechanisms. More interestingly, upon 740 nm irradiation, Os2 can stimulate a strong ICD response both in vitro and in vivo. A comprehensive immune analysis showed that mice vaccinated with Os2-treated CT26-luc cells boosted the systemic specific adaptive immune responses, including the activation of CD8+ T cells and reprograming of macrophages, leading to effective inhibition of tumor growth. Os2 is, to the best of our knowledge, the first photoactive osmium-based complex inducing ICD.
免疫性细胞死亡（ICD）可将肿瘤细胞转化为自身疫苗，在新型抗癌疗法的开发中发挥着关键作用。在此，我们合成了一小系列锇（II）多吡啶配合物，并研究了它们在暗处和光照下对各种癌细胞株的生物活性。研究发现，化合物 Os2（含有两个 4,7-二苯基-1,10-菲罗啉和一个取代的联吡啶配体）通过光生成 1O2 和-OH，成为该系列中最有效的光敏剂（PS），可用于光动力疗法（PDT）。此外，研究还发现 Os2 在正常缺氧和缺氧条件下经近红外（NIR）照射后均表现出良好的毒性。这些观察结果表明，这种 PS 是通过 I 型和 II 型机制混合发挥作用的。更有趣的是，在 740 纳米波长的照射下，Os2 在体外和体内都能激发强烈的 ICD 反应。一项全面的免疫分析表明，用 Os2 处理过的 CT26-luc 细胞接种小鼠，可增强全身特异性适应性免疫反应，包括激活 CD8+ T 细胞和重编程巨噬细胞，从而有效抑制肿瘤生长。据我们所知，Os2 是第一个诱导 ICD 的光活性锇基复合物。
{"title":"A Near-Infrared-Absorbing Osmium(II) Complex as a Photosensitizer for Photodynamic Therapy inducing Immunogenic Cell Death","authors":"Gilles, Gasser, Yiyi, Zhang, Pierre, Mesdom, Eduardo, Izquierdo-García, João, António, Bruno, Saubamea, Johanne, Seguin, Morgane , Moinard, Philippe, Arnoux, Céline, Frochot, Kevin, Cariou, Bich-Thuy, Doan","doi":"10.26434/chemrxiv-2024-6dnl2","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-6dnl2","url":null,"abstract":"Immunogenic cell death (ICD), which converts tumor cells into their own vaccine, plays a pivotal role in the development of novel anti-cancer therapies. Here, a small series of osmium(II) polypyridyl complexes were synthesized and their biological activity in the dark and upon light irradiation against various cancer cell lines was studied. The compound Os2 (bearing two 4,7-diphenyl-1,10-phenanthrolines and one substituted bipyridine ligand) was discovered to be the most effective photosensitizer (PS) for photodynamic therapy (PDT) of this series through the photogeneration of 1O2 and •OH. In addition, Os2 was found to exhibit promising toxicity upon near-infrared (NIR) irradiation under both normoxia and hypoxia. These observations indicate that this PS is working through a mixture of Type-I and Type-II mechanisms. More interestingly, upon 740 nm irradiation, Os2 can stimulate a strong ICD response both in vitro and in vivo. A comprehensive immune analysis showed that mice vaccinated with Os2-treated CT26-luc cells boosted the systemic specific adaptive immune responses, including the activation of CD8+ T cells and reprograming of macrophages, leading to effective inhibition of tumor growth. Os2 is, to the best of our knowledge, the first photoactive osmium-based complex inducing ICD.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.26434/chemrxiv-2024-j0sdf
Mami, Isobe, Daichi, Kitagawa, Seiya, Kobatake
We report patterned growth of crystals of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (1a) on the glass substrate with convex guides by sublimation methods. The lower supersaturation of substrate surfaces with higher temperatures can facilitate the vapor-to-melt process rather than the vapor-to-crystal process in the early stage of the sublimation. Micro-droplets of melts of 1a are generated on the sidewalls of the convex guides, then crystallized into the micro-crystals, accompanied by the reconstructions of the crystallographic in-plane orientations. Moreover, the crystalline patterns fringed with the rod crystals are colored in red upon irradiation with ultraviolet light. This well-controllability of crystal morphologies in a simple use of sublimation methods will pave the way for large-sized photomechanical materials with the desired morphologies.
{"title":"Patterning of photochromic diarylethene crystals by sublimation for morphological controls","authors":"Mami, Isobe, Daichi, Kitagawa, Seiya, Kobatake","doi":"10.26434/chemrxiv-2024-j0sdf","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-j0sdf","url":null,"abstract":"We report patterned growth of crystals of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (1a) on the glass substrate with convex guides by sublimation methods. The lower supersaturation of substrate surfaces with higher temperatures can facilitate the vapor-to-melt process rather than the vapor-to-crystal process in the early stage of the sublimation. Micro-droplets of melts of 1a are generated on the sidewalls of the convex guides, then crystallized into the micro-crystals, accompanied by the reconstructions of the crystallographic in-plane orientations. Moreover, the crystalline patterns fringed with the rod crystals are colored in red upon irradiation with ultraviolet light. This well-controllability of crystal morphologies in a simple use of sublimation methods will pave the way for large-sized photomechanical materials with the desired morphologies.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Similar to macroscopic woven fabrics, molecularly woven polymers constructed from identical molecular strands but different weaving architectures are anticipated to display diverse physical and mechanical characteristics. Nonetheless, identifying these distinctions and comprehending the underlying mechanisms poses a significant challenge. Herein, we evaluate the impacts of different weaving patterns—plain, mix, and basket—on the characteristics of two-dimensional (2D) organic woven polymers through systematic all-atom simulation. Three weaves, consisting of the same molecular strands, are produced by adjusting the connections of the enantiomers of an inherently chiral 2×2 interwoven grid. Among the tested patterns, the plain weave exhibits superior stability, minimal structural deformation, and the most consistent pore size compared to others. The maintenance of the weaves in kinetically stable high-energy states is attributed to both aromatic stacking and hydrogen bonding interactions between warp and weft strands, while the alteration of weaving patterns leads to variations in the type and strength of these weak interactions. Despite the differences on the weaving pattern, the mechanical stress tends to localize at the contact field. Further analysis on impact resistance and in-plane stretchability highlights how weaving architectures influence the energy dissipation pathways and reinforce the mechanical properties of individual molecular chains. Simulation outcomes indicate that the disparities resulting from various weave patterns primarily stem from the total number and density of entanglements, as well as the interstrand non-covalent interactions. This research highlights the critical influence of weaving architecture on molecularly interlacing material properties, providing valuable insights for future invention and engineering of molecular-level weaving.
{"title":"Implications of weaving pattern on the material properties of two-dimensional molecularly woven fabrics","authors":"Zhi-Hui, Zhang, Shiwei, Chen, Yuntao, Li, Yijing, Chen, Jinrong, Yang, Xiao, He, Liang, Zhang","doi":"10.26434/chemrxiv-2024-x07sq","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-x07sq","url":null,"abstract":"Similar to macroscopic woven fabrics, molecularly woven polymers constructed from identical molecular strands but different weaving architectures are anticipated to display diverse physical and mechanical characteristics. Nonetheless, identifying these distinctions and comprehending the underlying mechanisms poses a significant challenge. Herein, we evaluate the impacts of different weaving patterns—plain, mix, and basket—on the characteristics of two-dimensional (2D) organic woven polymers through systematic all-atom simulation. Three weaves, consisting of the same molecular strands, are produced by adjusting the connections of the enantiomers of an inherently chiral 2×2 interwoven grid. Among the tested patterns, the plain weave exhibits superior stability, minimal structural deformation, and the most consistent pore size compared to others. The maintenance of the weaves in kinetically stable high-energy states is attributed to both aromatic stacking and hydrogen bonding interactions between warp and weft strands, while the alteration of weaving patterns leads to variations in the type and strength of these weak interactions. Despite the differences on the weaving pattern, the mechanical stress tends to localize at the contact field. Further analysis on impact resistance and in-plane stretchability highlights how weaving architectures influence the energy dissipation pathways and reinforce the mechanical properties of individual molecular chains. Simulation outcomes indicate that the disparities resulting from various weave patterns primarily stem from the total number and density of entanglements, as well as the interstrand non-covalent interactions. This research highlights the critical influence of weaving architecture on molecularly interlacing material properties, providing valuable insights for future invention and engineering of molecular-level weaving.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The controlled translational motion displayed by nature’s motor proteins underpins a wealth of processes integral to life, from organelle transport to muscle contraction. The motor proteins move along one dimensional cytoskeletal tracks, with their motion characterised by high association of the enzyme to the biopolymer combined with highly dynamic motion along the track. Efforts to mimic this dynamic association and control translational motion in fully synthetic systems have been dominated by rotaxane-based systems, where the properties of the mechanical bond ensure complete association between the moving component (the macrocycle) and the track it encircles, while allowing high rates of translation through shuttling of the moving component under Brownian motion. In addition to the dynamic association displayed by many rotaxane systems, by careful design of the track and macrocyclic component, elegant strategies have been employed to further control the motion in these mechanically interlocked systems, with both energy and information ratchet mechanisms allowing directional translational motion to be achieved. Other than mechanical bonds, alternative platforms for achieving controlled translational motion in fully synthetic systems have had more limited success, with bipedal walker systems that exhibit dynamic association lacking mechanisms to achieve inherent directionality, and bipedal systems that do display high levels of directionality requiring stepwise intervention of an experimentalist (i.e., they lack the dynamic autonomous behaviour that underpins nature’s walkers). Here we introduce carbon-to-carbon metal migration as a new platform for dynamic association and show how such migrations, in combination with the incorporation of a simple hydrocarbon fuel, can be harnessed to achieve autonomous directional translational motion of a metal centre along the length of a polyaromatic thread.
{"title":"[1,n]-Metal migrations for directional translational motion at the molecular level","authors":"Beatrice, Collins, Emma, Hollis, Michael, Chronias, Carlijn, van Beek, Paul, Gates","doi":"10.26434/chemrxiv-2024-nkrd8-v2","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-nkrd8-v2","url":null,"abstract":"The controlled translational motion displayed by nature’s motor proteins underpins a wealth of processes integral to life, from organelle transport to muscle contraction. The motor proteins move along one dimensional cytoskeletal tracks, with their motion characterised by high association of the enzyme to the biopolymer combined with highly dynamic motion along the track. Efforts to mimic this dynamic association and control translational motion in fully synthetic systems have been dominated by rotaxane-based systems, where the properties of the mechanical bond ensure complete association between the moving component (the macrocycle) and the track it encircles, while allowing high rates of translation through shuttling of the moving component under Brownian motion. In addition to the dynamic association displayed by many rotaxane systems, by careful design of the track and macrocyclic component, elegant strategies have been employed to further control the motion in these mechanically interlocked systems, with both energy and information ratchet mechanisms allowing directional translational motion to be achieved. Other than mechanical bonds, alternative platforms for achieving controlled translational motion in fully synthetic systems have had more limited success, with bipedal walker systems that exhibit dynamic association lacking mechanisms to achieve inherent directionality, and bipedal systems that do display high levels of directionality requiring stepwise intervention of an experimentalist (i.e., they lack the dynamic autonomous behaviour that underpins nature’s walkers). Here we introduce carbon-to-carbon metal migration as a new platform for dynamic association and show how such migrations, in combination with the incorporation of a simple hydrocarbon fuel, can be harnessed to achieve autonomous directional translational motion of a metal centre along the length of a polyaromatic thread.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work the behavior of two Huntingtin (Htt) peptides in mixtures with water and either sucrose or trehalose were investigated by classical molecular dynamics (MD) simulations. Structures of those peptides are listed in the Protein Databank as 2LD2 (Biophys. J., 2013, 105, 699-710) and 6N8C (Proc. Natl. Acad. Sci., 2019, 116, 9, 3562-3571). The principal difference between those peptides is in their C- and N-terminals. Since Huntington’s disease is related to the aggregation of proteins containing consecutive polyglutamine in their amino acid chains, the aim was to investigate if smaller amounts of disaccharides could reduce aggregation of two peptides from the Htt protein. Computational results revealed that both sugars alter the secondary structures of peptides and decrease the total number of contacts (the sum of hydrophobic contacts and hydrogen bonds) between these biomolecules. However, regarding only the number of hydrogen bonds, the disaccharides reduced this value for peptide-peptide interactions for 6N8C, while for 2LD2 sucrose and trehalose instead promoted an increase of this number. Such a difference in behaviors of peptides could be related to dissimilarities in their sequences, pointing out the importance to consider amino-acid residues in C- and N-terminal when developing drugs. Furthermore, both disaccharides demonstrated abilities to slow down the dynamics of simulated mixtures, which was concluded from rotational correlation and self-intermediate scattering functions. Amino-acid residues MET(1), GLU(5), LYS(6), LYS(9), GLU(12), LYS(15), PHE(17) and GLN(18) are identified as the main candidate amino acids involved in interpeptide binding and binding to disaccharides, where the glutamic acid residues (GLU(5) and GLU(12)) had the highest number of hydrogen bonds with sucrose and trehalose.
在这项工作中，我们通过经典分子动力学（MD）模拟研究了两种亨廷汀（Htt）多肽在与水、蔗糖或曲哈葡萄糖的混合物中的行为。这些多肽的结构已被列入蛋白质数据库，分别为 2LD2 (Biophys. J., 2013, 105, 699-710) 和 6N8C (Proc. Natl. Acad. Sci., 2019, 116, 9, 3562-3571)。这些肽的主要区别在于它们的 C 端和 N 端。由于亨廷顿氏病与氨基酸链中含有连续多聚谷氨酰胺的蛋白质的聚集有关，因此我们的目的是研究较少量的二糖是否能减少 Htt 蛋白中两种肽的聚集。计算结果显示，这两种糖都会改变肽的二级结构，并减少这些生物大分子之间的接触总数（疏水接触和氢键的总和）。然而，仅就氢键的数量而言，对于 6N8C 而言，二糖降低了肽与肽之间相互作用的这一数值，而对于 2LD2 而言，蔗糖和曲哈糖反而促进了这一数值的增加。肽的这种行为差异可能与它们的序列不同有关，这表明在开发药物时考虑 C 端和 N 端氨基酸残基的重要性。此外，两种二糖都显示出减缓模拟混合物动力学的能力，这是从旋转相关性和自中间散射函数得出的结论。氨基酸残基 MET(1)、GLU(5)、LYS(6)、LYS(9)、GLU(12)、LYS(15)、PHE(17) 和 GLN(18) 被确定为参与肽间结合和与二糖结合的主要候选氨基酸，其中谷氨酸残基（GLU(5) 和 GLU(12)）与蔗糖和树海糖的氢键数量最多。
{"title":"Effect of minor differences in sequences of huntingtin peptides on their interactions with sucrose and trehalose: in silico investigation","authors":"Inna, Ermilova, Linnea, Ögren, Olivia, Borg, Maria, Weber, Elinor, Einarsson, Erik, Podda Grahn, Jan, Swenson","doi":"10.26434/chemrxiv-2024-5dk2f","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-5dk2f","url":null,"abstract":"In this work the behavior of two Huntingtin (Htt) peptides in mixtures with water and either sucrose or trehalose were investigated by classical molecular dynamics (MD) simulations. Structures of those peptides are listed in the Protein Databank as 2LD2 (Biophys. J., 2013, 105, 699-710) and 6N8C (Proc. Natl. Acad. Sci., 2019, 116, 9, 3562-3571). The principal difference between those peptides is in their C- and N-terminals. Since Huntington’s disease is related to the aggregation of proteins containing consecutive polyglutamine in their amino acid chains, the aim was to investigate if smaller amounts of disaccharides could reduce aggregation of two peptides from the Htt protein. Computational results revealed that both sugars alter the secondary structures of peptides and decrease the total number of contacts (the sum of hydrophobic contacts and hydrogen bonds) between these biomolecules. However, regarding only the number of hydrogen bonds, the disaccharides reduced this value for peptide-peptide interactions for 6N8C, while for 2LD2 sucrose and trehalose instead promoted an increase of this number. Such a difference in behaviors of peptides could be related to dissimilarities in their sequences, pointing out the importance to consider amino-acid residues in C- and N-terminal when developing drugs. Furthermore, both disaccharides demonstrated abilities to slow down the dynamics of simulated mixtures, which was concluded from rotational correlation and self-intermediate scattering functions. Amino-acid residues MET(1), GLU(5), LYS(6), LYS(9), GLU(12), LYS(15), PHE(17) and GLN(18) are identified as the main candidate amino acids involved in interpeptide binding and binding to disaccharides, where the glutamic acid residues (GLU(5) and GLU(12)) had the highest number of hydrogen bonds with sucrose and trehalose.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.26434/chemrxiv-2024-1gxgq
Franz Philipp, Bereck, Christian Hippolyt, Bartsch, Limei, Jin, Andreas, Mertens, Rüdiger-Albert, Eichel, Christoph, Scheurer, Josef, Granwehr
Electrochemical impedance spectroscopy (EIS) is one of the most widely deployed methods to characterise electrochemical systems such as batteries, fuel cells or electrolyzers. The distribution of relaxation times (DRT) represents a technique to simplify EIS data by deconvolution with a suitable kernel, while with equivalent circuit modelling (ECM) a user-selected function is fitted to characterize the investigated system. Ideally, the residuals of a DRT fit should represent random white noise without systematic residuals, hence no useful data is lost by this analysis step. Thereby DRT can provide the number of distinguishable features based solely on the EIS data, without a priori knowledge of the response of the investigated system. It is demonstrated that such a 'lossless' DRT inversion is possible if the local noise amplitude is considered, which requires a weighted DRT procedure and a method to estimate the frequency dependent noise amplitude. A noise estimate to determine the necessary weights was obtained using multiple EIS acquisitions of the same battery at identical state-of-charge. Alternatively, it is shown that Gaussian process regression (GPR) is capable of estimating an equivalent weighting matrix from a single data set as a prerequisite for automatized weighted DRT inversion without user intervention. The obtained DRT spectrum is then used for the selection of an equivalent circuit model, its initial parametrization, and setting of constraints. The robustness and reliability of this technique is tested numerically using a simple digital twin model. Eventually, by means of the investigated battery it is discussed that using a combination of DRT and ECM, a more physically relevant description of processes in an electrochemical system can be achieved.
电化学阻抗光谱法（EIS）是表征电池、燃料电池或电解槽等电化学系统最广泛使用的方法之一。弛豫时间分布（DRT）是一种通过使用合适的核进行解卷积来简化 EIS 数据的技术，而等效电路建模（ECM）则是通过拟合用户选择的函数来表征所研究的系统。理想情况下，DRT 拟合的残差应代表无系统残差的随机白噪声，因此这一分析步骤不会丢失任何有用数据。因此，DRT 可以仅根据 EIS 数据提供可区分特征的数量，而无需先验地了解所研究系统的响应。研究表明，如果考虑到局部噪声振幅，这种 "无损" DRT 反演是可能的，这就需要一个加权 DRT 程序和一种估算与频率相关的噪声振幅的方法。通过在相同充电状态下对同一电池进行多次 EIS 采集，获得了用于确定必要权重的噪声估计值。另外，研究还表明，高斯过程回归 (GPR) 能够从单个数据集中估算出等效加权矩阵，这是自动加权 DRT 反演的先决条件，无需用户干预。获得的 DRT 频谱可用于选择等效电路模型、初始参数化和设置约束条件。该技术的稳健性和可靠性通过一个简单的数字孪生模型进行了数值测试。最后，通过所研究的电池，讨论了将 DRT 和 ECM 结合使用，可以实现对电化学系统过程更贴近物理的描述。
{"title":"Weighted distribution of relaxation time analysis of battery impedance spectra using Gaussian process regression for noise estimation","authors":"Franz Philipp, Bereck, Christian Hippolyt, Bartsch, Limei, Jin, Andreas, Mertens, Rüdiger-Albert, Eichel, Christoph, Scheurer, Josef, Granwehr","doi":"10.26434/chemrxiv-2024-1gxgq","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-1gxgq","url":null,"abstract":"Electrochemical impedance spectroscopy (EIS) is one of the most widely deployed methods to characterise electrochemical systems such as batteries, fuel cells or electrolyzers. The distribution of relaxation times (DRT) represents a technique to simplify EIS data by deconvolution with a suitable kernel, while with equivalent circuit modelling (ECM) a user-selected function is fitted to characterize the investigated system. Ideally, the residuals of a DRT fit should represent random white noise without systematic residuals, hence no useful data is lost by this analysis step. Thereby DRT can provide the number of distinguishable features based solely on the EIS data, without a priori knowledge of the response of the investigated system. It is demonstrated that such a 'lossless' DRT inversion is possible if the local noise amplitude is considered, which requires a weighted DRT procedure and a method to estimate the frequency dependent noise amplitude. A noise estimate to determine the necessary weights was obtained using multiple EIS acquisitions of the same battery at identical state-of-charge. Alternatively, it is shown that Gaussian process regression (GPR) is capable of estimating an equivalent weighting matrix from a single data set as a prerequisite for automatized weighted DRT inversion without user intervention. The obtained DRT spectrum is then used for the selection of an equivalent circuit model, its initial parametrization, and setting of constraints. The robustness and reliability of this technique is tested numerically using a simple digital twin model. Eventually, by means of the investigated battery it is discussed that using a combination of DRT and ECM, a more physically relevant description of processes in an electrochemical system can be achieved.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"119 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A suitable host material is pivotal for efficient and stable deep-blue phosphorescent organic light-emitting diodes (PhOLEDs). Here, we firstly construct a deuterated exciplex-forming host in literature and demonstrate that, besides enhancing molecular stability, deuteration could also reduce molecular reorganization energy and enhance molecular packing density of the host, not only improving its charge transport ability but also reducing shoulder emissions of dopant and accelerating the radiative decay for blue-shifted colour with higher photoluminescence efficiency. The corresponding deep-blue PhOLEDs simultaneously achieve a lower operation voltage and higher maximum external quantum efficiency of 27.4% and power efficiency of 41.2 lm/W. Moreover, a lifetime of 370 h to reach 90% of the initial luminance of 1000 cd/m2 with Commission Internationale de l'Eclairage coordinates of (0.148, 0.165) is achieved, a 1.6-fold enhancement with even blue-shifted colour compared to the protonated counterpart and representing the longest lifetime for deep-blue PhOLEDs at this specific colour.
{"title":"High-efficiency and long-lifetime deep-blue phosphorescent OLEDs using deuterated exciplex-forming host","authors":"Wenbo, Yuan, Tianyu, Huang, Jianping, Zhou, Man-Chung, Tang, Dongdong, Zhang, Lian, Duan","doi":"10.26434/chemrxiv-2024-8bn7g","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-8bn7g","url":null,"abstract":"A suitable host material is pivotal for efficient and stable deep-blue phosphorescent organic light-emitting diodes (PhOLEDs). Here, we firstly construct a deuterated exciplex-forming host in literature and demonstrate that, besides enhancing molecular stability, deuteration could also reduce molecular reorganization energy and enhance molecular packing density of the host, not only improving its charge transport ability but also reducing shoulder emissions of dopant and accelerating the radiative decay for blue-shifted colour with higher photoluminescence efficiency. The corresponding deep-blue PhOLEDs simultaneously achieve a lower operation voltage and higher maximum external quantum efficiency of 27.4% and power efficiency of 41.2 lm/W. Moreover, a lifetime of 370 h to reach 90% of the initial luminance of 1000 cd/m2 with Commission Internationale de l'Eclairage coordinates of (0.148, 0.165) is achieved, a 1.6-fold enhancement with even blue-shifted colour compared to the protonated counterpart and representing the longest lifetime for deep-blue PhOLEDs at this specific colour.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Since ether moieties are often found not only in petrochemical products but also in natural organic molecules, the development of methods for manipulating C–O bonds of ethers is important for expanding the range of compound libraries synthesized from biomass resources, which should contribute to the goal of carbon neutrality. We report herein that gold nanoparticles supported on Lewis acidic metal oxides, namely α-Fe2O3, showed excellent catalytic activity for the reaction of dialkyl ethers and diborons, which enables the conversion of unactivated C(sp3)–O bonds to C(sp3)–B bonds at around room temperature. Various acyclic and cyclic ethers as well as a series of diborons participated in the heterogeneous gold-catalyzed borylation of unactivated C(sp3)–O bonds, to give a series of alkylboronates in high yields. Mechanistic studies corroborated that the present borylation of C(sp3)–O bonds of dialkyl ethers proceeded at the interface between gold nanoparticles and Lewis acidic metal oxides. Furthermore, adsorption IR measurements supported the notion that strong Lewis acid sites were generated at the boron atom of diborons adsorbed at the interface between Lewis acidic metal oxides and gold nanoparticles, which enabled us to ensure that the cooperation of gold nanoparticles and Lewis acidic metal oxides was responsible for the efficient transformation of unactivated C(sp3)–O bonds in ethers under mild conditions. This novel reaction technology which is specific to heterogeneous catalysts enables the activation of stable C(sp3)–O bonds of oxygenated chemical feedstock, which is beneficial for the sustainable synthesis of value-added organoboron compounds.
{"title":"Low-Temperature Borylation of C(sp3)–O Bonds of Alkyl Ethers by Gold-Metal Oxide Cooperative Catalysis","authors":"Hiroki, Miura, Hidenori, Nishio, Tetsuya, Shishido","doi":"10.26434/chemrxiv-2024-h6mw9","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-h6mw9","url":null,"abstract":"Since ether moieties are often found not only in petrochemical products but also in natural organic molecules, the development of methods for manipulating C–O bonds of ethers is important for expanding the range of compound libraries synthesized from biomass resources, which should contribute to the goal of carbon neutrality. We report herein that gold nanoparticles supported on Lewis acidic metal oxides, namely α-Fe2O3, showed excellent catalytic activity for the reaction of dialkyl ethers and diborons, which enables the conversion of unactivated C(sp3)–O bonds to C(sp3)–B bonds at around room temperature. Various acyclic and cyclic ethers as well as a series of diborons participated in the heterogeneous gold-catalyzed borylation of unactivated C(sp3)–O bonds, to give a series of alkylboronates in high yields. Mechanistic studies corroborated that the present borylation of C(sp3)–O bonds of dialkyl ethers proceeded at the interface between gold nanoparticles and Lewis acidic metal oxides. Furthermore, adsorption IR measurements supported the notion that strong Lewis acid sites were generated at the boron atom of diborons adsorbed at the interface between Lewis acidic metal oxides and gold nanoparticles, which enabled us to ensure that the cooperation of gold nanoparticles and Lewis acidic metal oxides was responsible for the efficient transformation of unactivated C(sp3)–O bonds in ethers under mild conditions. This novel reaction technology which is specific to heterogeneous catalysts enables the activation of stable C(sp3)–O bonds of oxygenated chemical feedstock, which is beneficial for the sustainable synthesis of value-added organoboron compounds.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Substances of misuse are becoming increasingly difficult to analyze as unique methods of smuggling are adopted and due to the rapid emergence of new psychoactive substances, increasing the pool of compounds to characterize and identify. Technologies such as gas chromatography and liquid chromatography coupled to mass spectrometry (MS) represent the gold standard for accurate and robust analysis, with on-site ambient- and portable-MS systems providing rapid methods of drug screening and testing. For many samples containing residual analyte quantities, methods to improve sensitivity through chemical derivatization are critical for accurate determination. Herein, we demonstrate for the first time the use of trimethylation enhancement using diazomethane (TrEnDi) to improve the MS-based sensitivity of 13 different drugs of misuse. All analytes were successfully permethylated, with 11 demonstrating improved analytical characteristics from TrEnDi with MS sensitivity enhancements of 1.2–24.2-fold and increases in reversed-phase chromatographic retention. Derivatization using 13C-isotopically labelled TrEnDi reagents were used to successfully resolve isobaric interference issues between three pairs of controlled substances. The sensitivity of a TrEnDi-modified analyte was increased several orders of magnitude using an unconventional aprotic solvent system for electrospray ionization. Finally, TrEnDi was employed to boost the sensitivity of morphine in a real urine matrix. Our results demonstrate a percent recovery of 103.1% and a sensitivity enhancement of 2.4-fold, demonstrating versatility and applicability of TrEnDi to pre-existing analytical workflows for trace analysis.
{"title":"Improved LC-MS detection of opioids, amphetamines, and psychedelics using TrEnDi","authors":"Jeffrey, Smith, Christian, Rosales, Noah, Lepinsky, Wondewossen, Gebeyehu, Karl, Wasslen, Benjamin, Warnes, Jasmine, Chihabi, Jeffrey, Manthorpe","doi":"10.26434/chemrxiv-2024-7gb0p","DOIUrl":"https://doi.org/10.26434/chemrxiv-2024-7gb0p","url":null,"abstract":"Substances of misuse are becoming increasingly difficult to analyze as unique methods of smuggling are adopted and due to the rapid emergence of new psychoactive substances, increasing the pool of compounds to characterize and identify. Technologies such as gas chromatography and liquid chromatography coupled to mass spectrometry (MS) represent the gold standard for accurate and robust analysis, with on-site ambient- and portable-MS systems providing rapid methods of drug screening and testing. For many samples containing residual analyte quantities, methods to improve sensitivity through chemical derivatization are critical for accurate determination. Herein, we demonstrate for the first time the use of trimethylation enhancement using diazomethane (TrEnDi) to improve the MS-based sensitivity of 13 different drugs of misuse. All analytes were successfully permethylated, with 11 demonstrating improved analytical characteristics from TrEnDi with MS sensitivity enhancements of 1.2–24.2-fold and increases in reversed-phase chromatographic retention. Derivatization using 13C-isotopically labelled TrEnDi reagents were used to successfully resolve isobaric interference issues between three pairs of controlled substances. The sensitivity of a TrEnDi-modified analyte was increased several orders of magnitude using an unconventional aprotic solvent system for electrospray ionization. Finally, TrEnDi was employed to boost the sensitivity of morphine in a real urine matrix. Our results demonstrate a percent recovery of 103.1% and a sensitivity enhancement of 2.4-fold, demonstrating versatility and applicability of TrEnDi to pre-existing analytical workflows for trace analysis.","PeriodicalId":9813,"journal":{"name":"ChemRxiv","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：