Rafat Tahawy, Mohamed Esmat, Hamza El-Hosainy, Fatma E Farghaly, El-Sayed A Abdel-Aal, F I El-Hosiny, Yusuke Ide
Research into TiO2 photocatalysts for solar H2 evolution from water is still growing for environmentally benign and economically valid H2 production. Herein, in contrast to many researches on the modification of TiO2 toward higher photocatalytic activities, we develop a photocatalytically inactive TiO2-based nanostructure and use it, like graphene, as a booster of a benchmark TiO2. A layered potassium titanate with two-dimensional plate-like particle morphology was converted to the corresponding one-dimensional nanowire form via a hydrothermal reaction, after which the layered potassium titanate nanowire was acid-treated to obtain a layered titanate nanowire. This nanowire was completely inactive toward H2 evolution from water containing methanol under solar simulator irradiation. However, when Pt nanoparticle-loaded P25 TiO2 (Pt/P25) was mixed with a considerably smaller amount of the layered titanate nanowire in water, a durable composite was obtained and the composite showed a good photocatalytic activity three times higher than Pt/P25. The apparent quantum efficiency of the reaction at wavelength of 350 nm was 56%, which was higher than or comparable to those of the state-of-the-art TiO2-based photocatalysts. The possible reason for the enhanced photocatalytic activity of the Pt/P25 and layered titanate nanowire composite involved the transfer of photogenerated holes from Pt/P25 to the nanowire to suppress charge recombination and/or disaggregation (improved dispersion) of Pt/P25 particles on the nanowire.
{"title":"A Layered Titanate Nanowire Helps Pt/TiO2 Photocatalyst for Solar Hydrogen Evolution from Water with High Quantum Efficiency","authors":"Rafat Tahawy, Mohamed Esmat, Hamza El-Hosainy, Fatma E Farghaly, El-Sayed A Abdel-Aal, F I El-Hosiny, Yusuke Ide","doi":"10.1093/bulcsj/uoae079","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae079","url":null,"abstract":"Research into TiO2 photocatalysts for solar H2 evolution from water is still growing for environmentally benign and economically valid H2 production. Herein, in contrast to many researches on the modification of TiO2 toward higher photocatalytic activities, we develop a photocatalytically inactive TiO2-based nanostructure and use it, like graphene, as a booster of a benchmark TiO2. A layered potassium titanate with two-dimensional plate-like particle morphology was converted to the corresponding one-dimensional nanowire form via a hydrothermal reaction, after which the layered potassium titanate nanowire was acid-treated to obtain a layered titanate nanowire. This nanowire was completely inactive toward H2 evolution from water containing methanol under solar simulator irradiation. However, when Pt nanoparticle-loaded P25 TiO2 (Pt/P25) was mixed with a considerably smaller amount of the layered titanate nanowire in water, a durable composite was obtained and the composite showed a good photocatalytic activity three times higher than Pt/P25. The apparent quantum efficiency of the reaction at wavelength of 350 nm was 56%, which was higher than or comparable to those of the state-of-the-art TiO2-based photocatalysts. The possible reason for the enhanced photocatalytic activity of the Pt/P25 and layered titanate nanowire composite involved the transfer of photogenerated holes from Pt/P25 to the nanowire to suppress charge recombination and/or disaggregation (improved dispersion) of Pt/P25 particles on the nanowire.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141721366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intermolecular interactions in 1:1 inclusion complexes of cucurbit[7]uril (CB[7]) with phenylalanine derivatives were investigated by density functional theory (B97-D) calculations. For each complex, two optimized geometries were found: conformer C in which a guest molecule resided in the center of CB[7], and conformer E where a guest molecule was present at the edge of CB[7]. The order of energy differences between these conformers agreed well with previously reported differences in the affinity of guest molecules for CB[7]. Molecular dynamics simulations of the complexes showed that the guest molecules in CB[7] had different stabilities, and the calculated binding free energies between them also qualitatively agreed with the experimental results. Pair-interaction energy decomposition analyses of the complexes at FMO-MP2/6-31G(d) and aug-cc-pVDZ level of theory were performed using snapshot structures at 500 ns of simulations. The dispersion interaction characterized the interaction, and the order of total interaction energies between the guest molecules and CB[7] was also associated with the experimental results. A significant difference in electrostatic interaction energies was observed in conformer E, which was correlated with the stability of the guest molecules at the edge of CB[7]. The balance between the stabilities of these conformers was correlated with the affinity of guest molecules for CB[7].
{"title":"Modulation of the Intermolecular Interactions of Cucurbit[7]uril with Phenylalanine Derivatives by the Functional Groups","authors":"Kaori Ueno-Noto, Seina Toyama, Yuki Kono, Keiko Takano","doi":"10.1093/bulcsj/uoae077","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae077","url":null,"abstract":"\u0000 Intermolecular interactions in 1:1 inclusion complexes of cucurbit[7]uril (CB[7]) with phenylalanine derivatives were investigated by density functional theory (B97-D) calculations. For each complex, two optimized geometries were found: conformer C in which a guest molecule resided in the center of CB[7], and conformer E where a guest molecule was present at the edge of CB[7]. The order of energy differences between these conformers agreed well with previously reported differences in the affinity of guest molecules for CB[7]. Molecular dynamics simulations of the complexes showed that the guest molecules in CB[7] had different stabilities, and the calculated binding free energies between them also qualitatively agreed with the experimental results.\u0000 Pair-interaction energy decomposition analyses of the complexes at FMO-MP2/6-31G(d) and aug-cc-pVDZ level of theory were performed using snapshot structures at 500 ns of simulations. The dispersion interaction characterized the interaction, and the order of total interaction energies between the guest molecules and CB[7] was also associated with the experimental results. A significant difference in electrostatic interaction energies was observed in conformer E, which was correlated with the stability of the guest molecules at the edge of CB[7]. The balance between the stabilities of these conformers was correlated with the affinity of guest molecules for CB[7].","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sophisticated control of the spatial arrangement of gold nanorods provides significant advantages in the design of plasmonic systems. However, dynamic modulation of the gold nanorod spatial arrangements remains challenging. Here, we present a novel strategy for dynamic control of thermo-responsive gold nanorods with uniform alignment on a solid substrate using polymer brushes. In this system, cationic-thermo-responsive gold nanorods were immobilized into anionic polymer brushes via moderate electrostatic interactions, providing vertically aligned gold nanorod arrays. Upon heating, the gold nanorods were assembled while maintaining their vertical orientation within the polymer brushes. They returned to the original state upon cooling, indicating reversible assembly/disassembly. It is noticeable that this system exhibits rapid changes in nanostructure arrangement even when immobilized in the polymer brush substrate on a solid substrate rather than those dispersed in solution. Importantly, the gold nanorods showed good adhesion stability in polymer brushes without any significant detachment during washing and thermal cycling processes, but performed assembly formation even at largely separated conditions, indicating the traveling of considerable distances similar to the lateral diffusion of membrane proteins in cell membranes. In addition to providing unprecedented control over gold nanorod spatial configurations, our approach introduces a versatile platform for developing advanced plasmonic devices.
{"title":"Assembly/Disassembly Control of Gold Nanorods with Uniform Orientation on Anionic Polymer Brush Substrates","authors":"Jingyan Yang, Yu Sekizawa, Xu Shi, Kuniharu Ijiro, Hideyuki Mitomo","doi":"10.1093/bulcsj/uoae073","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae073","url":null,"abstract":"Sophisticated control of the spatial arrangement of gold nanorods provides significant advantages in the design of plasmonic systems. However, dynamic modulation of the gold nanorod spatial arrangements remains challenging. Here, we present a novel strategy for dynamic control of thermo-responsive gold nanorods with uniform alignment on a solid substrate using polymer brushes. In this system, cationic-thermo-responsive gold nanorods were immobilized into anionic polymer brushes via moderate electrostatic interactions, providing vertically aligned gold nanorod arrays. Upon heating, the gold nanorods were assembled while maintaining their vertical orientation within the polymer brushes. They returned to the original state upon cooling, indicating reversible assembly/disassembly. It is noticeable that this system exhibits rapid changes in nanostructure arrangement even when immobilized in the polymer brush substrate on a solid substrate rather than those dispersed in solution. Importantly, the gold nanorods showed good adhesion stability in polymer brushes without any significant detachment during washing and thermal cycling processes, but performed assembly formation even at largely separated conditions, indicating the traveling of considerable distances similar to the lateral diffusion of membrane proteins in cell membranes. In addition to providing unprecedented control over gold nanorod spatial configurations, our approach introduces a versatile platform for developing advanced plasmonic devices.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Copper iodide (CuI) is a wide-bandgap (colorless) p-type semiconductor with a high Seebeck coefficient. Although CuI is promising for fabricating transparent thermoelectric devices and hole-transfer layers of solar cells, the insolubility in common solvents due to 3-dimensional coordination networks has been a drawback to constructing low-temperature solution-processed thin films. Moreover, it is challenging to fabricate void-and-crack-free CuI thin films through a convenient spin-coating process. In limited solvents of acetonitrile and diethyl sulfide, CuI is dissolved by forming soluble CuI complexes; however, void-and-crack-free CuI thin films have never been prepared. In this study, we report that CuI-alkanolamine complexes are soluble in alcohols and the spin-coated complexes undergo thermal decomposition to a CuI thin film at moderately low temperatures until 150 °C. We discover that the CuI-alkanolamines show different properties such as solubility and melting/decomposition temperatures depending on their structures. Specifically, by using 1-amino-2-propanol, we obtain void-and-crack-free and transparent CuI thin films with controlled thicknesses of >50 nm. The conductivity, carrier density, mobility, and Seebeck coefficient of the CuI thin film are 9.35 S·cm-1, 6.38×1019 cm-3, 0.96 cm2·V-1·S-1, and 192 µV･K-1, respectively.
碘化铜（CuI）是一种具有高塞贝克系数的宽带隙（无色）p 型半导体。虽然 CuI 有望用于制造透明热电设备和太阳能电池的空穴传输层，但其三维配位网络导致的在普通溶剂中的不溶性一直是构建低温溶液加工薄膜的一个缺点。此外，通过便捷的旋涂工艺制作无空隙和裂缝的 CuI 薄膜也具有挑战性。在乙腈和硫化二乙烷等有限的溶剂中，CuI 通过形成可溶性 CuI 复合物而溶解；然而，无空隙和裂缝的 CuI 薄膜却从未制备出来。在这项研究中，我们发现 CuI-烷醇胺络合物可溶于醇类，并且旋涂络合物在 150 °C 之前的中等低温下会发生热分解，生成 CuI 薄膜。我们发现，CuI-烷醇胺因其结构不同而显示出不同的特性，如溶解度和熔化/分解温度。具体来说，通过使用 1-氨基-2-丙醇，我们获得了无空隙、无裂纹、透明的 CuI 薄膜，厚度控制在 50 nm。CuI 薄膜的电导率、载流子密度、迁移率和塞贝克系数分别为 9.35 S-cm-1、6.38×1019 cm-3、0.96 cm2-V-1-S-1 和 192 µV・K-1。
{"title":"Three-type Precursors for Low-Temperature Solution-Processed Void-and-Crack-Free CuI Films: Comparison of Electrical Conductivities and Optical Transparency","authors":"Manabu Ishizaki, Naoki Koya, Yoshitomo Gotoh, Kodai Muramatsu, Masato Kurihara","doi":"10.1093/bulcsj/uoae071","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae071","url":null,"abstract":"Copper iodide (CuI) is a wide-bandgap (colorless) p-type semiconductor with a high Seebeck coefficient. Although CuI is promising for fabricating transparent thermoelectric devices and hole-transfer layers of solar cells, the insolubility in common solvents due to 3-dimensional coordination networks has been a drawback to constructing low-temperature solution-processed thin films. Moreover, it is challenging to fabricate void-and-crack-free CuI thin films through a convenient spin-coating process. In limited solvents of acetonitrile and diethyl sulfide, CuI is dissolved by forming soluble CuI complexes; however, void-and-crack-free CuI thin films have never been prepared. In this study, we report that CuI-alkanolamine complexes are soluble in alcohols and the spin-coated complexes undergo thermal decomposition to a CuI thin film at moderately low temperatures until 150 °C. We discover that the CuI-alkanolamines show different properties such as solubility and melting/decomposition temperatures depending on their structures. Specifically, by using 1-amino-2-propanol, we obtain void-and-crack-free and transparent CuI thin films with controlled thicknesses of >50 nm. The conductivity, carrier density, mobility, and Seebeck coefficient of the CuI thin film are 9.35 S·cm-1, 6.38×1019 cm-3, 0.96 cm2·V-1·S-1, and 192 µV･K-1, respectively.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review summarizes our development of nitrogen-doped carbon-supported metal catalysts for precise organic synthesis, including asymmetric carbon-carbon bond forming reactions and electrochemical synthesis. These catalysts have been successfully applied to continuous-flow reactions. The nitrogen dopants critically activate and stabilize metal species, enabling unique reactivity and expanding the potential for novel organic reactions in heterogeneous manner.
{"title":"Development of Nitrogen-doped Carbon Supported Metal Catalysts for Green Organic Synthesis","authors":"Tomohiro Yasukawa","doi":"10.1093/bulcsj/uoae076","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae076","url":null,"abstract":"This review summarizes our development of nitrogen-doped carbon-supported metal catalysts for precise organic synthesis, including asymmetric carbon-carbon bond forming reactions and electrochemical synthesis. These catalysts have been successfully applied to continuous-flow reactions. The nitrogen dopants critically activate and stabilize metal species, enabling unique reactivity and expanding the potential for novel organic reactions in heterogeneous manner.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iezoside (1a) is a novel, potent sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) inhibitor from marine cyanobacterium. This paper describes the synthesis of comprehensive iezoside (1a) analogs containing C18/19 diastereomers, simplified analogs without the peptide unit, and aglycones. Evaluations of the antiproliferative activities against cancer cells and SERCA inhibitory activities of the synthesized analogs revealed how the absolute configurations at C18/19, peptide, and the sugar unit contribute to each bioactivity.Ca2+ ATPase (SERCA) inhibitor, Structure-activity relationship, Marine natural products
{"title":"Structure-Activity Relationship Studies on Iezoside, a Highly Potent Ca2+ ATPase Inhibitor","authors":"Naoaki Kurisawa, Kazuya Teranuma, Akari Noto, Arihiro Iwasaki, Yoshiki Kabashima, Rie Nakajima, Chikashi Toyoshima, Kiyotake Suenaga","doi":"10.1093/bulcsj/uoae070","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae070","url":null,"abstract":"Iezoside (1a) is a novel, potent sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) inhibitor from marine cyanobacterium. This paper describes the synthesis of comprehensive iezoside (1a) analogs containing C18/19 diastereomers, simplified analogs without the peptide unit, and aglycones. Evaluations of the antiproliferative activities against cancer cells and SERCA inhibitory activities of the synthesized analogs revealed how the absolute configurations at C18/19, peptide, and the sugar unit contribute to each bioactivity.Ca2+ ATPase (SERCA) inhibitor, Structure-activity relationship, Marine natural products","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present account reviews recent progress in the synthesis, functionalization, and application of discrete polyketones. Whereas most polyketones are synthesized as polydisperse polymers with various molecular chain lengths and sizes, discrete polyketones are obtained in chemically pure forms. This allows precise structural analysis using NMR and X-ray diffraction. Discrete polyketones have been used to determine the critical chain length that distinguishes the crystallization behaviors of small molecules from those of macromolecules. Calix[3]pyrrole, which is a ring-contracted analogue of porphyrinogen, was first obtained from a cyclic hexaketone. The discovery of the strain-induced ring expansion reaction of calix[3]pyrroles has provided an important insight into solving a long-standing enigma in porphyrin synthesis. Chemical derivatization of discrete polyketones using ketone-derived transformations has resulted in the generation of various functional molecules for potential applications. These molecules have been used to develop several materials, including luminescent chromophores, ion adsorbents, drug–drug conjugates, and microfluidic devices for cancer diagnosis.
本报告回顾了离散聚酮化合物在合成、功能化和应用方面的最新进展。大多数聚酮化合物是以分子链长度和大小各异的多分散聚合物形式合成的，而离散聚酮化合物则是以化学纯形式获得的。这样就可以利用核磁共振和 X 射线衍射进行精确的结构分析。离散多酮已被用于确定临界链长，以区分小分子和大分子的结晶行为。钙[3]吡咯是卟啉原的环收缩类似物，最早是从环状六酮中获得的。钙[3]吡咯的应变诱导扩环反应的发现，为解决卟啉合成中一个长期存在的谜团提供了重要的启示。利用酮衍生转化法对离散多酮进行化学衍生，产生了各种具有潜在应用价值的功能分子。这些分子已被用于开发多种材料，包括发光发色团、离子吸附剂、药物共轭物和用于癌症诊断的微流控装置。
{"title":"Discrete Polyketones: Synthesis, Derivatization, and Potential Applications","authors":"Yasuhide Inokuma","doi":"10.1093/bulcsj/uoae072","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae072","url":null,"abstract":"The present account reviews recent progress in the synthesis, functionalization, and application of discrete polyketones. Whereas most polyketones are synthesized as polydisperse polymers with various molecular chain lengths and sizes, discrete polyketones are obtained in chemically pure forms. This allows precise structural analysis using NMR and X-ray diffraction. Discrete polyketones have been used to determine the critical chain length that distinguishes the crystallization behaviors of small molecules from those of macromolecules. Calix[3]pyrrole, which is a ring-contracted analogue of porphyrinogen, was first obtained from a cyclic hexaketone. The discovery of the strain-induced ring expansion reaction of calix[3]pyrroles has provided an important insight into solving a long-standing enigma in porphyrin synthesis. Chemical derivatization of discrete polyketones using ketone-derived transformations has resulted in the generation of various functional molecules for potential applications. These molecules have been used to develop several materials, including luminescent chromophores, ion adsorbents, drug–drug conjugates, and microfluidic devices for cancer diagnosis.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While a variety of functional zeolites have been synthesized using hydrothermal methods with conventional discrete Al and Si sources, control of the composition, structure, and function of the targeted zeolites often involves costly and time-consuming trial-and-error approaches. Despite ongoing efforts to manipulate zeolite formation by adjusting Al and Si sources and reaction conditions, limited attention has been given to studies on zeolite synthesis using molecular precursors (MPs) with pre-organized Al–O–Si bonds. Here, we demonstrate the synthesis of LTA-type zeolites using [TMA]4[Al4Si4O12(OH)8]·13H2O ([MP]; TMA = tetramethylammonium cation) with a double-four-ring (D4R)-type core structure, which is known to be a secondary building unit (SBU) in the LTA-type zeolite, as a MP. Here, we demonstrate the successful synthesis of LTA-type zeolites using [MP] under hydrothermal conditions at 100–200 °C in the presence of 1 equivalent of NaOH or NaCl. Notably, when discrete Al and Si sources were used instead of [MP] under otherwise identical conditions (the same Si/Al ratio, Na+ content, and temperature), GIS-, SOD-, and FAU-type zeolites lacking the D4R structure were obtained in addition to the LTA-type zeolites.
{"title":"Experimental verification of double-four-ring-type aluminosilicate molecule as a single-source precursor for zeolite synthesis","authors":"Akira Imaizumi, Yurika Ohnishi, Akinobu Nakada, Akinori Honda, Takeshi Matsumoto, Kenji Katayama, Ho-Chol Chang","doi":"10.1093/bulcsj/uoae060","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae060","url":null,"abstract":"\u0000 While a variety of functional zeolites have been synthesized using hydrothermal methods with conventional discrete Al and Si sources, control of the composition, structure, and function of the targeted zeolites often involves costly and time-consuming trial-and-error approaches. Despite ongoing efforts to manipulate zeolite formation by adjusting Al and Si sources and reaction conditions, limited attention has been given to studies on zeolite synthesis using molecular precursors (MPs) with pre-organized Al–O–Si bonds. Here, we demonstrate the synthesis of LTA-type zeolites using [TMA]4[Al4Si4O12(OH)8]·13H2O ([MP]; TMA = tetramethylammonium cation) with a double-four-ring (D4R)-type core structure, which is known to be a secondary building unit (SBU) in the LTA-type zeolite, as a MP. Here, we demonstrate the successful synthesis of LTA-type zeolites using [MP] under hydrothermal conditions at 100–200 °C in the presence of 1 equivalent of NaOH or NaCl. Notably, when discrete Al and Si sources were used instead of [MP] under otherwise identical conditions (the same Si/Al ratio, Na+ content, and temperature), GIS-, SOD-, and FAU-type zeolites lacking the D4R structure were obtained in addition to the LTA-type zeolites.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141369582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hayato Narikiyo, Masayuki Gon, Kazuo Tanaka, Y. Chujo
Polyhedral oligomeric silsesquioxane (POSS) is a molecule with an inorganic cubic structure and organic side-chains and has attracted great attention for its application to luminescent materials by modifying luminophores. In this study, pyrenes-integrated POSSs with various lengths of side-chains were synthesized and the effect of the length on luminescent properties was evaluated. In optical measurements, highly efficient excimer emission was observed under dilute solution conditions. The higher value of the intensity ratio of the excimer emission to the monomer one was detected in the shortest side-chains. It is likely that the shorter side-chains of POSS lead to more efficient intramolecular interaction. Interestingly, we also found that the luminescence color was changed in response to metal cations in the dilute solutions. From the mechanistic study, metal cations such as Cu2+ can accelerate hydrolysis at the linker moiety. As a result, highly-sensitive luminescent sensors were obtained. These data represent that POSS can work as a reaction field where chemical reactions are accelerated through the accumulation of reactive species.
{"title":"Enhancement of Excimer Formation Ability by Modulating the Length of Side-Chains in Polyhedral Oligomeric Silsesquioxane (POSS) and Application for Fluorescence Sensors for Metal Cations","authors":"Hayato Narikiyo, Masayuki Gon, Kazuo Tanaka, Y. Chujo","doi":"10.1093/bulcsj/uoae066","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae066","url":null,"abstract":"\u0000 Polyhedral oligomeric silsesquioxane (POSS) is a molecule with an inorganic cubic structure and organic side-chains and has attracted great attention for its application to luminescent materials by modifying luminophores. In this study, pyrenes-integrated POSSs with various lengths of side-chains were synthesized and the effect of the length on luminescent properties was evaluated. In optical measurements, highly efficient excimer emission was observed under dilute solution conditions. The higher value of the intensity ratio of the excimer emission to the monomer one was detected in the shortest side-chains. It is likely that the shorter side-chains of POSS lead to more efficient intramolecular interaction. Interestingly, we also found that the luminescence color was changed in response to metal cations in the dilute solutions. From the mechanistic study, metal cations such as Cu2+ can accelerate hydrolysis at the linker moiety. As a result, highly-sensitive luminescent sensors were obtained. These data represent that POSS can work as a reaction field where chemical reactions are accelerated through the accumulation of reactive species.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141387077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The emerging non-aromatic and non-conjugated clusteroluminogens possess the potential to overcome the common drawbacks of aromatic π-conjugated luminophores such as aggregation-caused quenching, synthetic complexity, bio-toxicity, and environmental pollution. Because of the presence of heteroatoms and carbonyl functional groups, some natural polymers show potential as clusteroluminogens. In this study, co-assembled micro-clusters (MCs) were fabricated using chitosan nanofibers (CSNFs) cross-linked with dialdehyde carboxymethyl cellulose (DACMC). MCs form stable structures under aqueous conditions owing to the formation of cross-links via imine bonds, ionic interactions, and hydrogen bonds between the polysaccharides. These multiple interactions and the heteroatomic nature of both CSNFs and DACMC enable the realization of clusterization-triggered emission (CTE) by through-space conjugation. MCs exhibit stable fluorescence behavior under aqueous conditions. A composite gel of MCs and poly(vinyl alcohol) (PVA) (PVA-MCs) was synthesized using the freeze-thaw method to develop CTE hydrogel. The MCs and PVA-MCs gels demonstrated the detection ability toward specific metal ions such as Cu2+ and Fe3+, by the quenching of the emission. This strategy for the creation of CTE MCs based on cross-linked polysaccharides widens the scope of the practical and sustainable application of water-containing fluorescent materials in the fields of sensing and biomedicines.
{"title":"Clusterization-Triggered Emission of Polysaccharide-based Microclusters induced by the Co-assembly of Chitosan nanofibers and Dialdehyde carboxymethyl cellulose","authors":"Madhurangika Panchabashini Horathal Pedige, Akihide Sugawara, Hiroshi Uyama","doi":"10.1093/bulcsj/uoae065","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae065","url":null,"abstract":"\u0000 The emerging non-aromatic and non-conjugated clusteroluminogens possess the potential to overcome the common drawbacks of aromatic π-conjugated luminophores such as aggregation-caused quenching, synthetic complexity, bio-toxicity, and environmental pollution. Because of the presence of heteroatoms and carbonyl functional groups, some natural polymers show potential as clusteroluminogens. In this study, co-assembled micro-clusters (MCs) were fabricated using chitosan nanofibers (CSNFs) cross-linked with dialdehyde carboxymethyl cellulose (DACMC). MCs form stable structures under aqueous conditions owing to the formation of cross-links via imine bonds, ionic interactions, and hydrogen bonds between the polysaccharides. These multiple interactions and the heteroatomic nature of both CSNFs and DACMC enable the realization of clusterization-triggered emission (CTE) by through-space conjugation. MCs exhibit stable fluorescence behavior under aqueous conditions. A composite gel of MCs and poly(vinyl alcohol) (PVA) (PVA-MCs) was synthesized using the freeze-thaw method to develop CTE hydrogel. The MCs and PVA-MCs gels demonstrated the detection ability toward specific metal ions such as Cu2+ and Fe3+, by the quenching of the emission. This strategy for the creation of CTE MCs based on cross-linked polysaccharides widens the scope of the practical and sustainable application of water-containing fluorescent materials in the fields of sensing and biomedicines.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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