Rotational isomerism of four amide moieties of the threaded macrocyclic component of [2]rotaxanes featuring mono- and bis-ammonium moieties in dumbbell-shaped axle components were investigated in response to base, and the rotational isomerization of both rotaxanes could be controlled reversibly through the addition of appropriate amounts of base and acids.
{"title":"Rotational Isomerism of Amide Units in the Ring of Rotaxanes in Response to Base/Acid Stimuli","authors":"Takanori Nakamura, Yukari Okuma, Shinobu Miyagawa, Tsuneomi Kawasaki, Masaya Naito, Yuji Tokunaga","doi":"10.1093/chemle/upae143","DOIUrl":"https://doi.org/10.1093/chemle/upae143","url":null,"abstract":"Rotational isomerism of four amide moieties of the threaded macrocyclic component of [2]rotaxanes featuring mono- and bis-ammonium moieties in dumbbell-shaped axle components were investigated in response to base, and the rotational isomerization of both rotaxanes could be controlled reversibly through the addition of appropriate amounts of base and acids.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770582","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}
This highlight review explains advanced structural analysis techniques utilizing electron microscopy to uncover various properties and phenomena in subnanometer clusters that were previously unknown in larger nanoparticles. The discoveries introduced the concept of “subnano alloying,” where different elements mix at the atomic level in arbitrary proportions, leading to enhanced catalytic performance. Additionally, the behavior and dynamics of these clusters were examined to gain insights into their stability and reactivity. These findings have significant implications for the design of advanced materials with tailored properties and improved catalytic applications.
{"title":"Finding Atomic Dynamics in Metal and Alloy Subnanometer Clusters","authors":"Takane Imaoka, Kimihisa Yamamoto","doi":"10.1093/chemle/upae147","DOIUrl":"https://doi.org/10.1093/chemle/upae147","url":null,"abstract":"This highlight review explains advanced structural analysis techniques utilizing electron microscopy to uncover various properties and phenomena in subnanometer clusters that were previously unknown in larger nanoparticles. The discoveries introduced the concept of “subnano alloying,” where different elements mix at the atomic level in arbitrary proportions, leading to enhanced catalytic performance. Additionally, the behavior and dynamics of these clusters were examined to gain insights into their stability and reactivity. These findings have significant implications for the design of advanced materials with tailored properties and improved catalytic applications.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770588","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}
Amorphous materials are very attractive materials because of their unique properties, including high corrosion resistance and catalytic activity. Creating such materials on a nanoscale is very effective in maximizing their performance. However, it is difficult to synthesize amorphous nanomaterials by conventional rapid cooling methods, commonly used for bulk amorphous materials. Therefore, there are not as many reports about amorphous nanomaterials as bulk materials. Herein we report the first synthesis of Pd–Pt–P amorphous nanoparticles by a two-step synthesis method. They were also characterized.
{"title":"Synthesis of Pd–Pt–P amorphous nanoparticles","authors":"Kenta Ikeda, Megumi Mukoyoshi, Kohei Kusada, Tomokazu Yamamoto, Yasukazu Murakami, Hiroshi Kitagawa","doi":"10.1093/chemle/upae144","DOIUrl":"https://doi.org/10.1093/chemle/upae144","url":null,"abstract":"Amorphous materials are very attractive materials because of their unique properties, including high corrosion resistance and catalytic activity. Creating such materials on a nanoscale is very effective in maximizing their performance. However, it is difficult to synthesize amorphous nanomaterials by conventional rapid cooling methods, commonly used for bulk amorphous materials. Therefore, there are not as many reports about amorphous nanomaterials as bulk materials. Herein we report the first synthesis of Pd–Pt–P amorphous nanoparticles by a two-step synthesis method. They were also characterized.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770585","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}
Keiji Yasuda, Takuya Iwata, Yuki Mizuno, Yuta Yamamoto
This paper, for the first time, reports on synthesis of Au@Pd core-shell nanoparticles in the absence of any capping and reducing agents by ultrafine bubbles and ultrasound. The mean diameter of the bimetallic core-shell nanoparticles was controlled by the ultrafine bubble concentration during the synthesis. The Pd shell thickness also varied with the concentration of Pd(II) ions. These Au@Pd core-shell nanoparticles showed excellent catalytic performance due to the pure surface without any capping and reducing agents.
{"title":"Synthesis of Au@Pd core-shell nanoparticles by ultrafine bubbles and ultrasound without capping and reducing agents","authors":"Keiji Yasuda, Takuya Iwata, Yuki Mizuno, Yuta Yamamoto","doi":"10.1093/chemle/upae145","DOIUrl":"https://doi.org/10.1093/chemle/upae145","url":null,"abstract":"This paper, for the first time, reports on synthesis of Au@Pd core-shell nanoparticles in the absence of any capping and reducing agents by ultrafine bubbles and ultrasound. The mean diameter of the bimetallic core-shell nanoparticles was controlled by the ultrafine bubble concentration during the synthesis. The Pd shell thickness also varied with the concentration of Pd(II) ions. These Au@Pd core-shell nanoparticles showed excellent catalytic performance due to the pure surface without any capping and reducing agents.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770589","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}
We investigated the unique aggregation behavior of 3 types of positively charged poly(methyl methacrylate) (PMMA) latex particles in the presence of a trifluoromethanesulfonate (triflate) anion. The particles were prepared based on surfactant-free emulsion polymerization using azo radical initiators. The triflate anion was strongly adsorbed to surfaces of positively charged PMMA latex particles, as confirmed by electrophoresis. Additionally, its presence significantly reduced the critical coagulation concentration of the cationic PMMA latex particles compared with other anions.
{"title":"Aggregation of positively charged poly(methyl methacrylate) latex particles in the presence of trifluoromethanesulfonate anion","authors":"Takashi Yamazaki, Toshikazu Tsuji","doi":"10.1093/chemle/upae136","DOIUrl":"https://doi.org/10.1093/chemle/upae136","url":null,"abstract":"We investigated the unique aggregation behavior of 3 types of positively charged poly(methyl methacrylate) (PMMA) latex particles in the presence of a trifluoromethanesulfonate (triflate) anion. The particles were prepared based on surfactant-free emulsion polymerization using azo radical initiators. The triflate anion was strongly adsorbed to surfaces of positively charged PMMA latex particles, as confirmed by electrophoresis. Additionally, its presence significantly reduced the critical coagulation concentration of the cationic PMMA latex particles compared with other anions.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770586","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}
2-Silylaryl triflates are widely employed as effective aryne precursors in organic synthesis, but their use as substrates for the synthesis of organosilicon compounds by retaining their silicon substituents is another attractive usage of these reagents. In particular, cyclic compounds having a silicon atom in the ring are promising candidates for various biologically active substances and optoelectronic functional materials. In this context, new synthetic methods of silicon-containing cyclic compounds have been actively investigated through the development of palladium-catalyzed reactions of 2-silylaryl triflates without generating aryne intermediates. As a result, selective synthesis of various silacyclic compounds has been achieved via C–H and/or C–Si bond activations as well as intramolecular exchange between these bonds and C–Pd bonds that are formed as reaction intermediates. An overview of this topic is described including the mechanistic insights.
{"title":"Synthesis of cyclic organosilicon compounds by palladium-catalyzed reactions of 2-silylaryl triflates","authors":"Ryo Shintani","doi":"10.1093/chemle/upae132","DOIUrl":"https://doi.org/10.1093/chemle/upae132","url":null,"abstract":"\u0000 2-Silylaryl triflates are widely employed as effective aryne precursors in organic synthesis, but their use as substrates for the synthesis of organosilicon compounds by retaining their silicon substituents is another attractive usage of these reagents. In particular, cyclic compounds having a silicon atom in the ring are promising candidates for various biologically active substances and optoelectronic functional materials. In this context, new synthetic methods of silicon-containing cyclic compounds have been actively investigated through the development of palladium-catalyzed reactions of 2-silylaryl triflates without generating aryne intermediates. As a result, selective synthesis of various silacyclic compounds has been achieved via C–H and/or C–Si bond activations as well as intramolecular exchange between these bonds and C–Pd bonds that are formed as reaction intermediates. An overview of this topic is described including the mechanistic insights.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141640961","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}
Acetaminophen may cause acute liver failure due to overdose. Understanding the processes of adsorption and incorporation of acetaminophen into cell membranes is crucial for elucidating the mechanisms of action and toxicity of acetaminophen. We investigated the interaction between acetaminophen and a model cell membrane (dioleoylphosphatidylcholine) using surface pressure–area isotherms. Acetaminophen was incorporated into the dioleoylphosphatidylcholine membrane under basic conditions, increasing the dioleoylphosphatidylcholine molecular area. The acetaminophen uptake was explained by the adsorption of hydroxide ions onto the lipid membrane and electrostatic interaction between acetaminophen and lipid molecules under basic conditions.
{"title":"pH-dependent interaction between acetaminophen and dioleoylphosphatidylcholine membranes","authors":"Kodai Ishikawa, Hideki Nabika","doi":"10.1093/chemle/upae133","DOIUrl":"https://doi.org/10.1093/chemle/upae133","url":null,"abstract":"Acetaminophen may cause acute liver failure due to overdose. Understanding the processes of adsorption and incorporation of acetaminophen into cell membranes is crucial for elucidating the mechanisms of action and toxicity of acetaminophen. We investigated the interaction between acetaminophen and a model cell membrane (dioleoylphosphatidylcholine) using surface pressure–area isotherms. Acetaminophen was incorporated into the dioleoylphosphatidylcholine membrane under basic conditions, increasing the dioleoylphosphatidylcholine molecular area. The acetaminophen uptake was explained by the adsorption of hydroxide ions onto the lipid membrane and electrostatic interaction between acetaminophen and lipid molecules under basic conditions.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613897","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}
Magnetic properties of N-nonylphenothiazine radical cations were found to vary depending on their counter ions. The radical cations in NTf2– (bis(N-trifluoromethanesulfonyl)imide ion), OTf– (trifluoromethanesulfonate), and BF4– salts formed π-dimer with strong antiferromagnetic interactions. The SbF6– salt exhibited paramagnetic properties with quite weak antiferromagnetic interaction. Interestingly, the NTf2– salt transformed to the paramagnetic liquid state upon heating to 78 oC.
{"title":"Magnetic Properties of N-Nonylphenothiazine Radical Cations Depending on Counter Anions","authors":"Sett Aung Naing, Takeshi Naota, Daisuke Shiomi, Kentaro Matsuda, Kazunobu Sato, Shuichi Suzuki","doi":"10.1093/chemle/upae135","DOIUrl":"https://doi.org/10.1093/chemle/upae135","url":null,"abstract":"Magnetic properties of N-nonylphenothiazine radical cations were found to vary depending on their counter ions. The radical cations in NTf2– (bis(N-trifluoromethanesulfonyl)imide ion), OTf– (trifluoromethanesulfonate), and BF4– salts formed π-dimer with strong antiferromagnetic interactions. The SbF6– salt exhibited paramagnetic properties with quite weak antiferromagnetic interaction. Interestingly, the NTf2– salt transformed to the paramagnetic liquid state upon heating to 78 oC.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613900","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}
We developed a simple and rapid process for synthesizing dithieno[3',2':3,4; 2'',3'':5,6]benzo[1,2-c][1,2,5]thiadiazole (fDTBT) derivatives using crystalline sulfur and internal alkynes, wherein thiophene is cyclized to benzothiadiazole. Cyclized derivatives were synthesized in three or five steps using this reaction, whereas the conventional synthesis methods involved seven steps and hazardous reactions with explosive properties. The absorption spectra of the synthesized fDTBT derivatives in chloroform solution revealed a new absorption band owing to the cyclization. All three compounds exhibited orange-to-red luminescence, and the maximum absolute quantum yield was determined to be 67%, demonstrating excellent luminescence.
{"title":"A Simple Synthesis of Luminescent π-Conjugated Materials having fDTBT Derivatives","authors":"Yuta Nakagawa, Kensyo Miki, Yoshihiro Yamaguchi","doi":"10.1093/chemle/upae141","DOIUrl":"https://doi.org/10.1093/chemle/upae141","url":null,"abstract":"We developed a simple and rapid process for synthesizing dithieno[3',2':3,4; 2'',3'':5,6]benzo[1,2-c][1,2,5]thiadiazole (fDTBT) derivatives using crystalline sulfur and internal alkynes, wherein thiophene is cyclized to benzothiadiazole. Cyclized derivatives were synthesized in three or five steps using this reaction, whereas the conventional synthesis methods involved seven steps and hazardous reactions with explosive properties. The absorption spectra of the synthesized fDTBT derivatives in chloroform solution revealed a new absorption band owing to the cyclization. All three compounds exhibited orange-to-red luminescence, and the maximum absolute quantum yield was determined to be 67%, demonstrating excellent luminescence.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613899","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}
Pingyu Jiang, Alexander S Mikherdov, Hajime Ito, Mingoo Jin
Molecular dynamics in the crystalline solid state, typically constrained by a densely packed crystal environment, may offer opportunities to control the physical properties of solid-state materials. In this work, a neutral crystalline molecular rotor featuring a para-phenylene rotator encapsulated by N-heterocyclic carbene ligands and connected via a C-Au-C rotational axis is presented. Single-crystal X-ray diffraction studies, along with variable-temperature solid-state 2H NMR spin-echo measurements, confirm the presence of 180° 2-fold rotational dynamics of the para-phenylene moiety in the solid state.
{"title":"Solid-state Dynamics of Binuclear N-Heterocyclic Carbene Au(I) Rotor with para-Phenylene Rotator","authors":"Pingyu Jiang, Alexander S Mikherdov, Hajime Ito, Mingoo Jin","doi":"10.1093/chemle/upae139","DOIUrl":"https://doi.org/10.1093/chemle/upae139","url":null,"abstract":"Molecular dynamics in the crystalline solid state, typically constrained by a densely packed crystal environment, may offer opportunities to control the physical properties of solid-state materials. In this work, a neutral crystalline molecular rotor featuring a para-phenylene rotator encapsulated by N-heterocyclic carbene ligands and connected via a C-Au-C rotational axis is presented. Single-crystal X-ray diffraction studies, along with variable-temperature solid-state 2H NMR spin-echo measurements, confirm the presence of 180° 2-fold rotational dynamics of the para-phenylene moiety in the solid state.","PeriodicalId":9862,"journal":{"name":"Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613898","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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