We encapsulated silver nanoplates (AgNPLs) into poly(lactic-co-glycolic) acid (PLGA) nanoparticles. The encapsulation stabilized the AgNPLs in a physiological environment and the antibacterial activity of the AgNPLs against planktonic bacteria was reduced. However, the PLGA nanoparticles encapsulating the AgNPLs were internalized into macrophages and showed antibacterial activity against intracellular bacteria. AgNPL-loaded PLGA nanoparticles are promising for treating intractable infectious diseases caused by bacteria-infecting macrophages.
{"title":"Encapsulation of silver nanoplates into poly(lactic-co-glycolic) acid nanoparticles and the antibacterial activity against intracellular bacteria","authors":"Ryoko Nawata, Sayo Maruyama, Wei Xu, Takuro Niidome","doi":"10.1093/chemle/upae084","DOIUrl":"https://doi.org/10.1093/chemle/upae084","url":null,"abstract":"We encapsulated silver nanoplates (AgNPLs) into poly(lactic-co-glycolic) acid (PLGA) nanoparticles. The encapsulation stabilized the AgNPLs in a physiological environment and the antibacterial activity of the AgNPLs against planktonic bacteria was reduced. However, the PLGA nanoparticles encapsulating the AgNPLs were internalized into macrophages and showed antibacterial activity against intracellular bacteria. AgNPL-loaded PLGA nanoparticles are promising for treating intractable infectious diseases caused by bacteria-infecting macrophages.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein, we report the N-arylation of amides based on the formation of N-centered amidyl radicals via proton-coupled electron transfer (PCET) using a nickel–photoredox dual catalyst. The reaction achieved arylation of sterically hindered linear secondary amides under mild conditions. Control experiments with radical inhibitors suggested the formation of amidyl radicals via the PCET mechanism.
{"title":"Ni-photoredox-catalyzed amide arylation reaction using amidyl radical formation via PCET","authors":"Sodai Nishino, Takuya Kurahashi","doi":"10.1093/chemle/upae088","DOIUrl":"https://doi.org/10.1093/chemle/upae088","url":null,"abstract":"Herein, we report the N-arylation of amides based on the formation of N-centered amidyl radicals via proton-coupled electron transfer (PCET) using a nickel–photoredox dual catalyst. The reaction achieved arylation of sterically hindered linear secondary amides under mild conditions. Control experiments with radical inhibitors suggested the formation of amidyl radicals via the PCET mechanism.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Derivatives of a 1,3-dithiole[6]dendralene analog with two thiophene spacers inserted (2) have been successfully synthesized. Cyclic voltammetry and spectroelectrochemistry revealed that their redox behavior, based on the distribution of the positive charges, differed depending on the position and the electronic effect of substituents on the 1,3-dithiole rings.
{"title":"Synthesis and Properties of 1,3-Dithiole[6]dendralene Analogs with Two Thiophene Spacers Inserted","authors":"Tomoya Misaki, Masataka Nishiwaki, Toshiki Ito, Masafumi Ueda, Masahiro Fujisaki, Aya Yoshimura, Takashi Shirahata, Minoru Hayashi, Yohji Misaki","doi":"10.1093/chemle/upae104","DOIUrl":"https://doi.org/10.1093/chemle/upae104","url":null,"abstract":"Derivatives of a 1,3-dithiole[6]dendralene analog with two thiophene spacers inserted (2) have been successfully synthesized. Cyclic voltammetry and spectroelectrochemistry revealed that their redox behavior, based on the distribution of the positive charges, differed depending on the position and the electronic effect of substituents on the 1,3-dithiole rings.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Materials science research benefits from the powerful machine-learning (ML) surrogate models, but it is also limited by the implicit requirement for sufficiently big and balanced data distribution for ML. In this paper, we propose a model to obtain more credible results for small and imbalanced materials data sets as well as chemical knowledge. Taking 2 bandgaps imbalanced data sets as instances, we demonstrate the usability and performance of our model compared with common ML models with normal sampling and resampling methods.
材料科学研究得益于强大的机器学习（ML）代用模型，但也受限于 ML 对足够大且均衡的数据分布的隐性要求。在本文中，我们提出了一种模型，以获得更可信的结果，适用于小而不平衡的材料数据集以及化学知识。以 2 个带隙不平衡数据集为例，我们展示了我们的模型与采用正常采样和重采样方法的普通 ML 模型相比的可用性和性能。
{"title":"CSIML: a cost-sensitive and iterative machine-learning method for small and imbalanced materials data sets","authors":"Shengzhou Li, Ayako Nakata","doi":"10.1093/chemle/upae090","DOIUrl":"https://doi.org/10.1093/chemle/upae090","url":null,"abstract":"Materials science research benefits from the powerful machine-learning (ML) surrogate models, but it is also limited by the implicit requirement for sufficiently big and balanced data distribution for ML. In this paper, we propose a model to obtain more credible results for small and imbalanced materials data sets as well as chemical knowledge. Taking 2 bandgaps imbalanced data sets as instances, we demonstrate the usability and performance of our model compared with common ML models with normal sampling and resampling methods.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141256668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To predict the lifetime of metal-organic frameworks (MOFs) with high water capacity/stability as water harvesters and adsorption heat pumps, a simple accelerated water stability test was developed using liquid water and water vapor in an autoclave. The function obtained from Bnlnauer-Emmett-Teller (BET) surface area loss analysis of MOF-801-P was applied to lifetime prediction, and a long-term stability test of MOF-801-P with liquid water at 65 °C agreed well with the values predicted using the developed test.
为了预测具有高水容量/稳定性的金属有机框架（MOFs）作为水收集器和吸附热泵的寿命，开发了一种在高压釜中使用液态水和水蒸气的简单加速水稳定性试验。从 MOF-801-P 的 Bnlnauer-Emmett-Teller (BET) 表面积损失分析中获得的函数被应用于寿命预测，MOF-801-P 在 65 °C 下与液态水进行的长期稳定性测试与使用所开发的测试预测的值非常吻合。
{"title":"Accelerated water stability test and lifetime prediction of metal-organic frameworks","authors":"Tetsushi Ohmura, Yusuke Mukae, Yoichi Hosokawa, Hiroshi Nakamura, Takafumi Yamauchi","doi":"10.1093/chemle/upae093","DOIUrl":"https://doi.org/10.1093/chemle/upae093","url":null,"abstract":"To predict the lifetime of metal-organic frameworks (MOFs) with high water capacity/stability as water harvesters and adsorption heat pumps, a simple accelerated water stability test was developed using liquid water and water vapor in an autoclave. The function obtained from Bnlnauer-Emmett-Teller (BET) surface area loss analysis of MOF-801-P was applied to lifetime prediction, and a long-term stability test of MOF-801-P with liquid water at 65 °C agreed well with the values predicted using the developed test.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141256666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Since the properties of sulfur-containing compounds depend on the sulfur number contained in the compound, it is desirable to develop a method to control the sulfur number. A common method for synthesizing sulfur-containing compounds is to mix sulfur with a base to form linear sulfur, which is then reacted with an organic compound to obtain a sulfur-containing compound. In this study, we systematically investigated the relationship between the type of base, equivalent amount of the base, and the reaction solvent and the sulfur number in the resulting sulfur-containing compound. The sulfur number of sulfur-containing compounds prepared in water was controlled by the equivalent ratio of elemental sulfur (S8) and base. Sulfur-containing compound with high sulfur values was obtained using solvents with low dielectric constants and with lower base equivalents compared to S8.
{"title":"Control of sulfur number in sulfur-containing compounds: The effect of base type, equivalent of the base, and reaction solvent in synthesizing linear sulfur","authors":"Ryuto Nishimura, Yuichiro Kobayashi, Ryunosuke Kamioka, Shun Hashimoto, Hiroyasu Yamaguchi","doi":"10.1093/chemle/upae105","DOIUrl":"https://doi.org/10.1093/chemle/upae105","url":null,"abstract":"<jats:title>Abstract</jats:title> Since the properties of sulfur-containing compounds depend on the sulfur number contained in the compound, it is desirable to develop a method to control the sulfur number. A common method for synthesizing sulfur-containing compounds is to mix sulfur with a base to form linear sulfur, which is then reacted with an organic compound to obtain a sulfur-containing compound. In this study, we systematically investigated the relationship between the type of base, equivalent amount of the base, and the reaction solvent and the sulfur number in the resulting sulfur-containing compound. The sulfur number of sulfur-containing compounds prepared in water was controlled by the equivalent ratio of elemental sulfur (S8) and base. Sulfur-containing compound with high sulfur values was obtained using solvents with low dielectric constants and with lower base equivalents compared to S8.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141256766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract 1,2-Bis((cholesteryloxy)octyloxy)-4-nitrobenzene was synthesized as a chiral dopant that exhibited electroresponsiveness in nematic liquid crystal (LC) phases. Even in a nonelectroresponsive host nematic LC, the helical pitch of the chiral nematic phase, generated by doping the chiral dopant molecules, could be altered in response to an external electric field, thus controlling the selective reflection color.
{"title":"Structural color control by remote electrical manipulation of chiral dopant molecules in a chiral nematic phase","authors":"Keiki Kishikawa, Daiki Fukuda, Kazuto Takayashiki, Michinari Kohri","doi":"10.1093/chemle/upae098","DOIUrl":"https://doi.org/10.1093/chemle/upae098","url":null,"abstract":"<jats:title>Abstract</jats:title> 1,2-Bis((cholesteryloxy)octyloxy)-4-nitrobenzene was synthesized as a chiral dopant that exhibited electroresponsiveness in nematic liquid crystal (LC) phases. Even in a nonelectroresponsive host nematic LC, the helical pitch of the chiral nematic phase, generated by doping the chiral dopant molecules, could be altered in response to an external electric field, thus controlling the selective reflection color.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Radical chemistry, a rapidly growing field in organic synthesis, offers numerous innovative approaches for the cleavage and construction of challenging chemical bonds. Recent findings have underscored the pivotal contributions of alkali metal ions in radical-driven reactions, where they play a crucial role in lowering the energy barriers required to initiate these processes and in stabilizing vital transient radical species. These properties contribute significantly to the advancement of next-generation synthetic techniques. This article offers a concise yet thorough examination of the roles alkali metal ions assume within radical chemistry, with a specific focus on their diverse modes of activation and the associated mechanistic contexts. Our objective is to encourage and expand their strategic use across various facets of organic synthesis, catalysis, and environmentally conscious green chemistry applications.
{"title":"Influence of Alkali Metal Ions on the Mechanisms and Outcomes of Radical-Mediated Organic Reactions","authors":"Ziqi Ye, Jia-Bin Liao, Lei Gong","doi":"10.1093/chemle/upae103","DOIUrl":"https://doi.org/10.1093/chemle/upae103","url":null,"abstract":"\u0000 Radical chemistry, a rapidly growing field in organic synthesis, offers numerous innovative approaches for the cleavage and construction of challenging chemical bonds. Recent findings have underscored the pivotal contributions of alkali metal ions in radical-driven reactions, where they play a crucial role in lowering the energy barriers required to initiate these processes and in stabilizing vital transient radical species. These properties contribute significantly to the advancement of next-generation synthetic techniques. This article offers a concise yet thorough examination of the roles alkali metal ions assume within radical chemistry, with a specific focus on their diverse modes of activation and the associated mechanistic contexts. Our objective is to encourage and expand their strategic use across various facets of organic synthesis, catalysis, and environmentally conscious green chemistry applications.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141100535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Formose reaction facilitates the synthesis of sugars from HCHO, yet the valuable sugars constitute only a small portion of the total products. This necessitates the need for a chemical scavenger capable of selectively capturing only valuable sugars. With over 600,000 potential combinations of boronic acid-based scavengers available, pursuing a deductive search approach is unfeasible. This study aims to derive guidelines for designing scavengers that readily bind with target sugars while avoiding non-target ones, via machine learning informed by DFT calculations.
{"title":"Developing a Design Guideline of Boronic Acid Derivatives to Scavenge Targeted Sugars in the Formose Reaction Products using DFT-based Machine Learning","authors":"Nanako Ishihara, Genta Chikatani, Hiroaki Nishijima, Hiro Tabata, Yoko Hase, Y. Mukouyama, Shuji Nakanishi, Shiho Mukaida","doi":"10.1093/chemle/upae087","DOIUrl":"https://doi.org/10.1093/chemle/upae087","url":null,"abstract":"\u0000 Formose reaction facilitates the synthesis of sugars from HCHO, yet the valuable sugars constitute only a small portion of the total products. This necessitates the need for a chemical scavenger capable of selectively capturing only valuable sugars. With over 600,000 potential combinations of boronic acid-based scavengers available, pursuing a deductive search approach is unfeasible. This study aims to derive guidelines for designing scavengers that readily bind with target sugars while avoiding non-target ones, via machine learning informed by DFT calculations.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141103351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cyclic anthraquinodimethane (AQD) dimer with a highly constrained structure was synthesized by using the Au-templated method. X-ray diffraction analysis and UV-Vis spectroscopy revealed that the AQD skeleton adopts a deeply folded structure and exhibits red-shifted absorptions in the dimer compared to those in non-cyclized monomeric AQD. Due to the rigid and constrained structure, both enantiomers of the cyclic AQD dimer with planar chirality can be isolated and show strong circular dichroism signals. It is demonstrated that the Au-templated method is a valuable way to access a highly constrained cyclic structure with AQD skeletons.
{"title":"Synthesis and Chiroptical Properties of Cyclic Anthraquinodimethane Dimer Using Au-Templated Method","authors":"Soichiro Sugiyama, Kazuharu Murotani, Fumitaka Ishiwari, Akinori Saeki, Hidetoshi Kawai, Takanori Suzuki, Yoshitaka Tsuchido, Yusuke Ishigaki","doi":"10.1093/chemle/upae102","DOIUrl":"https://doi.org/10.1093/chemle/upae102","url":null,"abstract":"\u0000 Cyclic anthraquinodimethane (AQD) dimer with a highly constrained structure was synthesized by using the Au-templated method. X-ray diffraction analysis and UV-Vis spectroscopy revealed that the AQD skeleton adopts a deeply folded structure and exhibits red-shifted absorptions in the dimer compared to those in non-cyclized monomeric AQD. Due to the rigid and constrained structure, both enantiomers of the cyclic AQD dimer with planar chirality can be isolated and show strong circular dichroism signals. It is demonstrated that the Au-templated method is a valuable way to access a highly constrained cyclic structure with AQD skeletons.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141103549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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