Enzymes with well-defined three-dimensional structure have in-built information for molecular organization in the near vicinity of the active sites – popularly known as enzyme architecture. Over the past few years, molecular assembly has been exploited in creating artificial enzyme or catalyst architectures. Emergent spatiotemporal structure and catalytic activity can be achieved through controlled assembly of suitable molecular building blocks. The programmed molecular assembly governed by the scheme of molecule architectonics can generate enzyme-mimetic catalyst assembly-architecture. Apart from the conventional ligand-metal interaction in the first coordination sphere of a catalyst, second coordination sphere play key role in the catalytic activity of enzymes. This review attempts to unravel the balancing act between molecular architectonics and second coordination sphere in catalyst assembly-architectures development. Judicious design and exploitation of the state-of-the-art biomimetic catalyst architectures derived from small molecules, sugars, nucleic acids, peptides, and proteins are discussed under the above-mentioned framework. Metal-coordinated molecular assembly-architectures of specific catalytic property are considered with respect to the nature of molecular assembly and experimental conditions. The concise and critical discussion provide a holistic view on the enzyme-mimetic architectures and their second coordination sphere through reductionistic approach-based on the molecular architectonics of simple and modular molecular building blocks. This review highlights the contribution of molecular architectonics and second coordination sphere theory in designing state-of-the-art catalyst assembly-architectures as enzyme-mimetics.
{"title":"Enzyme-mimetic Catalyst Architectures: The Role of Second Coordination Sphere in Catalytic Activity","authors":"Bappaditya Roy, Thimmaiah Govindaraju","doi":"10.1246/bcsj.20230224","DOIUrl":"https://doi.org/10.1246/bcsj.20230224","url":null,"abstract":"Enzymes with well-defined three-dimensional structure have in-built information for molecular organization in the near vicinity of the active sites – popularly known as enzyme architecture. Over the past few years, molecular assembly has been exploited in creating artificial enzyme or catalyst architectures. Emergent spatiotemporal structure and catalytic activity can be achieved through controlled assembly of suitable molecular building blocks. The programmed molecular assembly governed by the scheme of molecule architectonics can generate enzyme-mimetic catalyst assembly-architecture. Apart from the conventional ligand-metal interaction in the first coordination sphere of a catalyst, second coordination sphere play key role in the catalytic activity of enzymes. This review attempts to unravel the balancing act between molecular architectonics and second coordination sphere in catalyst assembly-architectures development. Judicious design and exploitation of the state-of-the-art biomimetic catalyst architectures derived from small molecules, sugars, nucleic acids, peptides, and proteins are discussed under the above-mentioned framework. Metal-coordinated molecular assembly-architectures of specific catalytic property are considered with respect to the nature of molecular assembly and experimental conditions. The concise and critical discussion provide a holistic view on the enzyme-mimetic architectures and their second coordination sphere through reductionistic approach-based on the molecular architectonics of simple and modular molecular building blocks. This review highlights the contribution of molecular architectonics and second coordination sphere theory in designing state-of-the-art catalyst assembly-architectures as enzyme-mimetics.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135252068","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}
Novel 2-substituted 1,3-bis[bis(3’,5’-di-tert-butyl phenyl)phosphino]propanes (SciPROP-R; 1-R), as well as their iron complexes FeCl2(SciPROP-R) 2-R, are synthesized. Single-crystal X-ray analysis and solution-phase Fe K- and L-edge XAS of 2-R reveals that these complexes maintain tetrahedral geometry and hence of paramagnetic high-spin properties both in the solid state and in the solution phase. 31P NMR results demonstrate that the superior coordination ability of SciPROP-TB (1-TB) is due to the bulky tert-butyl group at position 2 of the propane-1,3-diyl linker of the ligand. These novel iron-complexes catalyze Suzuki–Miyaura-type cross coupling under mild conditions. Notably, Iron(II) chloride–1-TB complex (2-TB) exhibits excellent catalytic activity owing to the high coordination ability and electron-donating nature of 1-TB, being effective for chemoselective cross coupling between various alkyl chlorides and arylboron compounds. A series of 2-R-substituted 1,3-bis[bis(3’,5’-di-tert-butyl phenyl)phosphino]propane SciPROP-R are designed and synthesized. Their iron complexes, especially FeCl2(SciPROP-TB), are effective catalysts for the highly chemoselective iron-catalyzed Suzuki–Miyaura-type cross-coupling reaction of alkyl chlorides with arylboron compounds.
{"title":"SciPROP-R: An Effective Bisphosphine Ligand for the Chemo-selective Iron-Catalyzed Suzuki–Miyaura Coupling of Alkyl Chlorides","authors":"Sho Nakajima, Toru Hashimoto, Siming Lu, Daisuke Hashizume, Hiroshi Matsuda, Takuji Hatakeyama, Katsuhiro Isozaki, Hikaru Takaya, Masaharu Nakamura","doi":"10.1246/bcsj.20230180","DOIUrl":"https://doi.org/10.1246/bcsj.20230180","url":null,"abstract":"Novel 2-substituted 1,3-bis[bis(3’,5’-di-tert-butyl phenyl)phosphino]propanes (SciPROP-R; 1-R), as well as their iron complexes FeCl2(SciPROP-R) 2-R, are synthesized. Single-crystal X-ray analysis and solution-phase Fe K- and L-edge XAS of 2-R reveals that these complexes maintain tetrahedral geometry and hence of paramagnetic high-spin properties both in the solid state and in the solution phase. 31P NMR results demonstrate that the superior coordination ability of SciPROP-TB (1-TB) is due to the bulky tert-butyl group at position 2 of the propane-1,3-diyl linker of the ligand. These novel iron-complexes catalyze Suzuki–Miyaura-type cross coupling under mild conditions. Notably, Iron(II) chloride–1-TB complex (2-TB) exhibits excellent catalytic activity owing to the high coordination ability and electron-donating nature of 1-TB, being effective for chemoselective cross coupling between various alkyl chlorides and arylboron compounds. A series of 2-R-substituted 1,3-bis[bis(3’,5’-di-tert-butyl phenyl)phosphino]propane SciPROP-R are designed and synthesized. Their iron complexes, especially FeCl2(SciPROP-TB), are effective catalysts for the highly chemoselective iron-catalyzed Suzuki–Miyaura-type cross-coupling reaction of alkyl chlorides with arylboron compounds.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135252066","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}
Porphycene, a constitutional isomer of porphyrin, is an attractive ligand, and its metal complexes have been investigated as alternative metal cofactors for hemoproteins such as myoglobin. Iron, cobalt and manganese complexes of porphycene are smoothly inserted into apomyoglobin after removal of native heme b, resulting in stable reconstituted proteins. Myoglobin reconstituted with iron porphycene exhibits extremely high O2 affinity compared to native myoglobin (nMb). In addition, the reconstituted protein also shows catalytic activity toward one-electron oxidation of phenol derivatives and sulfoxidation of thioanisole, although the natural function of nMb is O2 storage. Furthermore, myoglobin reconstituted with manganese porphycene can promote H2O2-dependent hydroxylation of inert alkane species as seen with cytochrome P450s. Myoglobin reconstituted with iron porphycene can act as a catalyst for an abiological reaction such as cyclopropanation with ethyl diazoacetate. These results clearly indicate that replacement of heme with metalloporphycenes can dramatically alter the function of hemoproteins. Myoglobin reconstituted with iron porphycene, a constitutional isomer of iron porphyrin, exhibits significantly higher O2 affinity with unique O2/CO discrimination ability compared to native myoglobin. Furthermore, myoglobin, an O2 storage protein, can be converted to artificial metalloenzymes with catalytic activities such as peroxidase, hydroxylase and carbene transferase, by replacing the native heme cofactor with iron porphycene or manganese porphycene.
{"title":"Metalloporphycene is an Attractive Cofactor for Hemoproteins","authors":"Takashi Hayashi","doi":"10.1246/bcsj.20230222","DOIUrl":"https://doi.org/10.1246/bcsj.20230222","url":null,"abstract":"Porphycene, a constitutional isomer of porphyrin, is an attractive ligand, and its metal complexes have been investigated as alternative metal cofactors for hemoproteins such as myoglobin. Iron, cobalt and manganese complexes of porphycene are smoothly inserted into apomyoglobin after removal of native heme b, resulting in stable reconstituted proteins. Myoglobin reconstituted with iron porphycene exhibits extremely high O2 affinity compared to native myoglobin (nMb). In addition, the reconstituted protein also shows catalytic activity toward one-electron oxidation of phenol derivatives and sulfoxidation of thioanisole, although the natural function of nMb is O2 storage. Furthermore, myoglobin reconstituted with manganese porphycene can promote H2O2-dependent hydroxylation of inert alkane species as seen with cytochrome P450s. Myoglobin reconstituted with iron porphycene can act as a catalyst for an abiological reaction such as cyclopropanation with ethyl diazoacetate. These results clearly indicate that replacement of heme with metalloporphycenes can dramatically alter the function of hemoproteins. Myoglobin reconstituted with iron porphycene, a constitutional isomer of iron porphyrin, exhibits significantly higher O2 affinity with unique O2/CO discrimination ability compared to native myoglobin. Furthermore, myoglobin, an O2 storage protein, can be converted to artificial metalloenzymes with catalytic activities such as peroxidase, hydroxylase and carbene transferase, by replacing the native heme cofactor with iron porphycene or manganese porphycene.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135251921","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}
Yuji Nishii, Koji Hirano, Tetsuya Satoh, Masahiro Miura
Transition metal-catalyzed aromatic functionalization reactions are highly important for the construction of various organic fine chemicals. In particular, the direct C(sp2)-H bond transformation of (hetero)aromatics is currently recognized to be highly useful in organic synthesis, as it can realize short-step sequences leading to target molecules. We have been studying on aromatic cross-coupling reactions through C-H bond activation/cleavage leading to new C-C and C-heteroatom bonds. The research strategies involve directing group control and utilization of unique properties of reaction substrates and catalysts, which enable efficient regioselective direct coupling reactions. In this account, our recent work is briefly summarized, mainly focused on the synthetic methods of benzo-fused multi-ring heterocyclic compounds of potent interest in pharmaceutical and material chemistry. We have been studying on aromatic cross-coupling reactions through C-H bond activation/cleavage leading to new C-C and C-heteroatom bonds. In this account, our recent work is briefly summarized, mainly focused on the development of synthetic methods of multi-ring benzo-fused heterocyclic compounds of potent interest in pharmaceutical and material chemistry.
{"title":"Construction of Multi-ring Molecules through Direct C-H Bond Transformation","authors":"Yuji Nishii, Koji Hirano, Tetsuya Satoh, Masahiro Miura","doi":"10.1246/bcsj.20230225","DOIUrl":"https://doi.org/10.1246/bcsj.20230225","url":null,"abstract":"Transition metal-catalyzed aromatic functionalization reactions are highly important for the construction of various organic fine chemicals. In particular, the direct C(sp2)-H bond transformation of (hetero)aromatics is currently recognized to be highly useful in organic synthesis, as it can realize short-step sequences leading to target molecules. We have been studying on aromatic cross-coupling reactions through C-H bond activation/cleavage leading to new C-C and C-heteroatom bonds. The research strategies involve directing group control and utilization of unique properties of reaction substrates and catalysts, which enable efficient regioselective direct coupling reactions. In this account, our recent work is briefly summarized, mainly focused on the synthetic methods of benzo-fused multi-ring heterocyclic compounds of potent interest in pharmaceutical and material chemistry. We have been studying on aromatic cross-coupling reactions through C-H bond activation/cleavage leading to new C-C and C-heteroatom bonds. In this account, our recent work is briefly summarized, mainly focused on the development of synthetic methods of multi-ring benzo-fused heterocyclic compounds of potent interest in pharmaceutical and material chemistry.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"298 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135303642","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 efficient synthesis of siladenoserinol analogs possessing a diastereomeric 6,8-dioxabicyclo[3.2.1]octane (6,8-DOBCO) skeleton has been achieved from commercially available carbohydrates as a chiral source. In this synthesis, we successfully determined the reaction conditions for the one-pot transformation using (PPh3)AuCl/AgSbF6/2,6-di-tert-butylpyridine (2,6-DTBP), leading to the desired bicycloketal without losing the TBS group. Elongation of two side chains by the Julia–Kocienski olefination and Horner–Wadsworth–Emmons reaction and subsequent chemoselective sulfamation furnished the two desired diastereomers from the corresponding carbohydrates, respectively. The inhibitory activities of the synthetic diastereomeric analogs against the p53–Hdm2 interaction were slightly weaker than that of natural siladenoserinol A, resulting in the fact that the stereochemistry on the 6,8-DOBCO skeleton would be one of the fundamental factors to control the potency of inhibition of the p53–Hdm2 interaction but not an essential one. We successfully achieved the synthesis of siladenoserinol A analogs through one-pot bicycloketal formation using a catalytic amount of (PPh3)AuCl/AgSbF6 and AlCl3. Biological evaluation of the natural product and synthetic analogs revealed that the stereochemistry on the 6,8-DOBCO skeleton would be one of the fundamental factors to control the potency of inhibition of the p53–Hdm2 interaction but not an essential one.
{"title":"Synthesis and Biological Evaluation of Siladenoserinol A Analogs Possessing a Diastereomeric 6,8-Dioxabicyclo[3.2.1]octane Skeleton","authors":"Masahito Yoshida, Kohei Sasaoka, Kohei Hano, Yoshiyuki Sugiyama, Yuki Hitora, Takayuki Doi, Sachiko Tsukamoto, Hideo Kigoshi","doi":"10.1246/bcsj.20230197","DOIUrl":"https://doi.org/10.1246/bcsj.20230197","url":null,"abstract":"The efficient synthesis of siladenoserinol analogs possessing a diastereomeric 6,8-dioxabicyclo[3.2.1]octane (6,8-DOBCO) skeleton has been achieved from commercially available carbohydrates as a chiral source. In this synthesis, we successfully determined the reaction conditions for the one-pot transformation using (PPh3)AuCl/AgSbF6/2,6-di-tert-butylpyridine (2,6-DTBP), leading to the desired bicycloketal without losing the TBS group. Elongation of two side chains by the Julia–Kocienski olefination and Horner–Wadsworth–Emmons reaction and subsequent chemoselective sulfamation furnished the two desired diastereomers from the corresponding carbohydrates, respectively. The inhibitory activities of the synthetic diastereomeric analogs against the p53–Hdm2 interaction were slightly weaker than that of natural siladenoserinol A, resulting in the fact that the stereochemistry on the 6,8-DOBCO skeleton would be one of the fundamental factors to control the potency of inhibition of the p53–Hdm2 interaction but not an essential one. We successfully achieved the synthesis of siladenoserinol A analogs through one-pot bicycloketal formation using a catalytic amount of (PPh3)AuCl/AgSbF6 and AlCl3. Biological evaluation of the natural product and synthetic analogs revealed that the stereochemistry on the 6,8-DOBCO skeleton would be one of the fundamental factors to control the potency of inhibition of the p53–Hdm2 interaction but not an essential one.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135303643","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}
As a new entry of heteroatom-heteroatom bond species, λ3,λ3-phosphanylalumanes, having an unperturbed P–Al single-bond species are expected to show high reactivity due to the separation of Lewis acid/base moieties, which can be extended to develop novel small molecule activation reactions using single-bond and saturated-compounds. We have designed novel λ3,λ3-phosphanylalumanes, which have all-carbon protecting groups on the λ3-P and λ3-Al moieties, respectively. This account highlights the synthesis and availability of phosphanylalumane derivatives. We demonstrate the addition reactions of phosphanylalumanes toward alkynes to give unique unsaturated C2-vicinal P/Al-based frustrated Lewis pairs and the resulting alkyne-adducts are found to undergo transformation into unique ring-compounds. Furthermore, reversible addition reactions of a λ3,λ3-phosphanylalumane toward alkenes will also be described together with the results obtained with other small molecules. As a new entry of interelement bond species, novel λ3,λ3-phosphanylalumanes are designed. Addition reactions of phosphanylalumanes toward alkynes are found to give unique unsaturated C2-vicinal P/Al-based FLPs and the resulting alkyne-adducts undergo transformation into unique ring-compounds. Furthermore, reversible addition reactions of a λ3,λ3-phosphanylalumane toward alkenes are also investigated.
{"title":"Small Molecule Activation Based on Novel Heavier Group 13/15 Interelement Compounds, λ<sup>3</sup>,λ<sup>3</sup>-Phosphanylalumanes","authors":"Tatsuya Yanagisawa, Yoshiyuki Mizuhata, Norihiro Tokitoh","doi":"10.1246/bcsj.20230186","DOIUrl":"https://doi.org/10.1246/bcsj.20230186","url":null,"abstract":"As a new entry of heteroatom-heteroatom bond species, λ3,λ3-phosphanylalumanes, having an unperturbed P–Al single-bond species are expected to show high reactivity due to the separation of Lewis acid/base moieties, which can be extended to develop novel small molecule activation reactions using single-bond and saturated-compounds. We have designed novel λ3,λ3-phosphanylalumanes, which have all-carbon protecting groups on the λ3-P and λ3-Al moieties, respectively. This account highlights the synthesis and availability of phosphanylalumane derivatives. We demonstrate the addition reactions of phosphanylalumanes toward alkynes to give unique unsaturated C2-vicinal P/Al-based frustrated Lewis pairs and the resulting alkyne-adducts are found to undergo transformation into unique ring-compounds. Furthermore, reversible addition reactions of a λ3,λ3-phosphanylalumane toward alkenes will also be described together with the results obtained with other small molecules. As a new entry of interelement bond species, novel λ3,λ3-phosphanylalumanes are designed. Addition reactions of phosphanylalumanes toward alkynes are found to give unique unsaturated C2-vicinal P/Al-based FLPs and the resulting alkyne-adducts undergo transformation into unique ring-compounds. Furthermore, reversible addition reactions of a λ3,λ3-phosphanylalumane toward alkenes are also investigated.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135303641","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}
Azobenzene (1,2-diphenyldiazene in IUPAC name) is a widely studied simple rodlike photochromic molecule. The trans- (E) to cis- (Z) photoisomerization of this molecule was discovered long time (nearly 90 years) ago. Nevertheless, the allure and utilities of this molecule never get faded and does not surrender a leading position among many other organic photochromic molecules. New applications for photoswitching molecular and macromolecular systems are still being proposed extensively. When the azobenzene molecule is linked with liquid crystals (LCs) and polymer systems, a number of fascinating motility functions have been newly realized. This article overviews our research activities using azobenzene-containing monolayers and LC polymer films. The topics range surface photoalignment of LCs both from solid surface and free surface, photoalignment of hierarchical structures such as mesohybrids and block copolymers, photomechanical motions and morphological switching in block copolymer monolayers, high-density brushes of azobenzene side chain LC polymers (SCLCPs), photo-triggered mass migrations in azobenzene SCLCP films and polymer motions via Marangoni flow etc. Demonstrations of these dynamic photofunctions are expected to provide great opportunities toward practical smart applications. This account overviews our research activities using azobenzene-containing polymer monolayers and liquid crystalline (LC) materials undertaken over 35 years. The topics cover the surface photoalignment of LC materials both from solid surface and free surface, photoalignment of hierarchical structures, photomechanical motions and morphological switching in monolayers, phototriggered mass migrations etc. Dynamic photoresponsive systems are expected to provide wide opportunities toward practical smart applications.
{"title":"Surface-mediated dynamic cooperative motions in azobenzene polymer films","authors":"Takahiro Seki","doi":"10.1246/bcsj.20230219","DOIUrl":"https://doi.org/10.1246/bcsj.20230219","url":null,"abstract":"Azobenzene (1,2-diphenyldiazene in IUPAC name) is a widely studied simple rodlike photochromic molecule. The trans- (E) to cis- (Z) photoisomerization of this molecule was discovered long time (nearly 90 years) ago. Nevertheless, the allure and utilities of this molecule never get faded and does not surrender a leading position among many other organic photochromic molecules. New applications for photoswitching molecular and macromolecular systems are still being proposed extensively. When the azobenzene molecule is linked with liquid crystals (LCs) and polymer systems, a number of fascinating motility functions have been newly realized. This article overviews our research activities using azobenzene-containing monolayers and LC polymer films. The topics range surface photoalignment of LCs both from solid surface and free surface, photoalignment of hierarchical structures such as mesohybrids and block copolymers, photomechanical motions and morphological switching in block copolymer monolayers, high-density brushes of azobenzene side chain LC polymers (SCLCPs), photo-triggered mass migrations in azobenzene SCLCP films and polymer motions via Marangoni flow etc. Demonstrations of these dynamic photofunctions are expected to provide great opportunities toward practical smart applications. This account overviews our research activities using azobenzene-containing polymer monolayers and liquid crystalline (LC) materials undertaken over 35 years. The topics cover the surface photoalignment of LC materials both from solid surface and free surface, photoalignment of hierarchical structures, photomechanical motions and morphological switching in monolayers, phototriggered mass migrations etc. Dynamic photoresponsive systems are expected to provide wide opportunities toward practical smart applications.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135132674","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}
Metastable solid electrolytes exhibit superior conductivity compared to stable ones, making them a subject of considerable interest. However, their synthesis of the metastable phase is affected by multiple thermodynamic and kinetic parameters, leading to ambiguity in the organization of stability and metastability. In this study, we organized remnant and intermediate metastability based on temperature. The intermediate metastable phase, which is less stable than the temperature-independent stable phase, typically transforms into the stable phase(s) at high temperatures. In contrast, the remnant metastable phase is formed by first obtaining most stable phase at specific temperatures and then “trapping” it by rapidly changing the temperature. By investigating Li+ conducting chlorides, Li3MCl6 (M = Y and Ho), we demonstrated that heating starting materials to approximately 600 K produced low-temperature Li3MCl6 phase with one formula unit while further heating resulted in high-temperature Li3MCl6 phase with three formula units. Annealing of quenched Li3MCl6 at 573 K resulted in a phase transition from the high-temperature to low-temperature phase, indicating that the high-temperature phase was remnant metastable at low temperatures. This study organizes remnant and intermediate metastability. The intermediate metastable phase, which is less stable than the thermodynamically independent stable phase, typically transforms into the stable phase(s) at high temperatures. In contrast, the remnant metastable phase once becomes the most stable phase under specific thermodynamic conditions, like such as ice in a freezer, and is then trapped by upon changing the conditions rapidly.
{"title":"Stability and Metastability of Li<sub>3</sub>YCl<sub>6</sub> and Li<sub>3</sub>HoCl<sub>6</sub>","authors":"Hiroaki Ito, Yuki Nakahira, Naoki Ishimatsu, Yosuke Goto, Aichi Yamashita, Yoshikazu Mizuguchi, Chikako Moriyoshi, Takashi Toyao, Ken-ichi Shimizu, Hiroshi Oike, Masanori Enoki, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga","doi":"10.1246/bcsj.20230132","DOIUrl":"https://doi.org/10.1246/bcsj.20230132","url":null,"abstract":"Metastable solid electrolytes exhibit superior conductivity compared to stable ones, making them a subject of considerable interest. However, their synthesis of the metastable phase is affected by multiple thermodynamic and kinetic parameters, leading to ambiguity in the organization of stability and metastability. In this study, we organized remnant and intermediate metastability based on temperature. The intermediate metastable phase, which is less stable than the temperature-independent stable phase, typically transforms into the stable phase(s) at high temperatures. In contrast, the remnant metastable phase is formed by first obtaining most stable phase at specific temperatures and then “trapping” it by rapidly changing the temperature. By investigating Li+ conducting chlorides, Li3MCl6 (M = Y and Ho), we demonstrated that heating starting materials to approximately 600 K produced low-temperature Li3MCl6 phase with one formula unit while further heating resulted in high-temperature Li3MCl6 phase with three formula units. Annealing of quenched Li3MCl6 at 573 K resulted in a phase transition from the high-temperature to low-temperature phase, indicating that the high-temperature phase was remnant metastable at low temperatures. This study organizes remnant and intermediate metastability. The intermediate metastable phase, which is less stable than the thermodynamically independent stable phase, typically transforms into the stable phase(s) at high temperatures. In contrast, the remnant metastable phase once becomes the most stable phase under specific thermodynamic conditions, like such as ice in a freezer, and is then trapped by upon changing the conditions rapidly.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135477193","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}
Infectious diseases mortality decreased due to effective drugs and healthcare. However, global health remains threatened by infectious diseases. New methods to rapid and accurate bacterial detection have attracted considerable attention. Fluorescence detection of whole bacterial cells offers high sensitivity, quantitative analysis, and simple operation. A highly fluorescent bioconjugated probe improves sensitivity and selectivity. This study presents a novel, bright fluorescent probe comprising a bacteriophage and a fluorescent nanoemulsion (fNE) as biorecognition and signal transduction elements, respectively. We demonstrate that fluorescence microscopy imaging using the S. aureus-specific phage, S13’-fNE (phage-fNE), detects S. aureus in the presence of E. coli or S. pseudintermedius, another closely related Staphylococci, in a highly selective manner. Furthermore, fNEs with high dye loadings exhibit considerably greater brightness compared to the fluorescent dye alone, making them suitable for sensitive fluorescence imaging. Phage-fNEs can quantitatively detect S. aureus at 104–108 colony-forming units per milliliter (CFU mL−1), with a limit of detection of 8 × 104 CFU mL−1. This result is comparable to the lowest value achieved by microscopic bacterial detection, with no preconcentration or enzymatic signal enhancement methods used. Bioconjugated fNEs open new avenues for highly selective and sensitive fluorescent detection of bacteria. This study presents a novel, bright fluorescent probe comprising a bacteriophage and a fluorescent nanoemulsion (fNE) as biorecognition and signal transduction elements, respectively. We demonstrate that fluorescence microscopy imaging using the S. aureus-specific phage, S13’-fNE (phage-fNE), detects S. aureus in the presence of E. coli or S. pseudintermedius, another closely related Staphylococci, in a highly selective manner.
由于有效的药物和保健，传染病死亡率下降。然而，全球健康仍然受到传染病的威胁。快速、准确的细菌检测新方法引起了人们的广泛关注。荧光检测整个细菌细胞灵敏度高，定量分析，操作简单。高荧光生物偶联探针提高了灵敏度和选择性。本研究提出了一种新型的、明亮的荧光探针，分别由噬菌体和荧光纳米乳(fNE)作为生物识别和信号转导元件。我们证明，使用金黄色葡萄球菌特异性噬菌体S13′-fNE(噬菌体-fNE)的荧光显微镜成像，以高度选择性的方式检测大肠杆菌或另一种密切相关的葡萄球菌假中间葡萄球菌存在的金黄色葡萄球菌。此外，与单独的荧光染料相比，具有高染料负载的fNEs表现出相当大的亮度，使它们适合于敏感的荧光成像。噬菌体fnes可定量检测金黄色葡萄球菌，检测限为每毫升104 - 108个菌落形成单位(CFU mL - 1)，检出限为8 × 104 CFU mL - 1。该结果与显微镜下细菌检测获得的最低值相当，不使用预浓缩或酶信号增强方法。生物偶联fNEs为高选择性、高灵敏度的细菌荧光检测开辟了新的途径。本研究提出了一种新型的、明亮的荧光探针，分别由噬菌体和荧光纳米乳(fNE)作为生物识别和信号转导元件。我们证明，使用金黄色葡萄球菌特异性噬菌体S13′-fNE(噬菌体-fNE)的荧光显微镜成像，以高度选择性的方式检测大肠杆菌或另一种密切相关的葡萄球菌假中间葡萄球菌存在的金黄色葡萄球菌。
{"title":"Bacteriophage-Conjugated Fluorescent Nanoemulsion as a Novel Optical Probe for Highly Selective Bacterial Detection","authors":"Shin-ya Sekida, Takatoshi Chisaka, Jumpei Uchiyama, Iyo Takemura-Uchiyama, Shigenobu Matsuzaki, Yosuke Niko, Shingo Hadano, Shigeru Watanabe","doi":"10.1246/bcsj.20230200","DOIUrl":"https://doi.org/10.1246/bcsj.20230200","url":null,"abstract":"Infectious diseases mortality decreased due to effective drugs and healthcare. However, global health remains threatened by infectious diseases. New methods to rapid and accurate bacterial detection have attracted considerable attention. Fluorescence detection of whole bacterial cells offers high sensitivity, quantitative analysis, and simple operation. A highly fluorescent bioconjugated probe improves sensitivity and selectivity. This study presents a novel, bright fluorescent probe comprising a bacteriophage and a fluorescent nanoemulsion (fNE) as biorecognition and signal transduction elements, respectively. We demonstrate that fluorescence microscopy imaging using the S. aureus-specific phage, S13’-fNE (phage-fNE), detects S. aureus in the presence of E. coli or S. pseudintermedius, another closely related Staphylococci, in a highly selective manner. Furthermore, fNEs with high dye loadings exhibit considerably greater brightness compared to the fluorescent dye alone, making them suitable for sensitive fluorescence imaging. Phage-fNEs can quantitatively detect S. aureus at 104–108 colony-forming units per milliliter (CFU mL−1), with a limit of detection of 8 × 104 CFU mL−1. This result is comparable to the lowest value achieved by microscopic bacterial detection, with no preconcentration or enzymatic signal enhancement methods used. Bioconjugated fNEs open new avenues for highly selective and sensitive fluorescent detection of bacteria. This study presents a novel, bright fluorescent probe comprising a bacteriophage and a fluorescent nanoemulsion (fNE) as biorecognition and signal transduction elements, respectively. We demonstrate that fluorescence microscopy imaging using the S. aureus-specific phage, S13’-fNE (phage-fNE), detects S. aureus in the presence of E. coli or S. pseudintermedius, another closely related Staphylococci, in a highly selective manner.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135959849","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}
We investigated the dielectric properties of three hydrocarbon liquids (benzene, diphenylmethane, and c-hexane) using molecular dynamics simulations with a newly developed polarizable force field [DREIDING-UT(D)]. The calculated dielectric constants agree well with the experimental ones. The difference in dielectric constant between liquid diphenylmethane and benzene was due to the difference in liquid structure, whereas the difference in dielectric constant between liquid c-hexane and benzene was mainly due to the difference in atomic polarizability. Molecular dynamics simulations using a new polarizable force field were employed to study the dielectric properties of three hydrocarbon liquids: benzene, diphenylmethane, and c-hexane. The calculated dielectric constants matched well with experimental ones. The difference in dielectric constant between diphenylmethane and benzene was attributed to the difference in liquid structure, while the difference between c-hexane and benzene was mainly due to differences in atomic polarizability.
我们利用新开发的极化力场[dreding - ut (D)]进行分子动力学模拟，研究了三种碳氢化合物液体(苯、二苯甲烷和c-己烷)的介电性质。计算得到的介电常数与实验值吻合较好。液体二苯甲烷和苯之间介电常数的差异主要是由于液体结构的差异，而液体c-己烷和苯之间介电常数的差异主要是由于原子极化率的差异。采用一种新的极化力场进行分子动力学模拟，研究了苯、二苯甲烷和正己烷三种碳氢化合物液体的介电性质。计算得到的介电常数与实验值吻合较好。二苯甲烷和苯之间介电常数的差异主要是由于液体结构的不同，而正己烷和苯之间介电常数的差异主要是由于原子极化率的差异。
{"title":"Structural effect on the dielectric constant of hydrocarbon liquids: A molecular dynamics study using the Drude polarizable force field","authors":"Kohei Sasaki, Takefumi Yamashita","doi":"10.1246/bcsj.20230100","DOIUrl":"https://doi.org/10.1246/bcsj.20230100","url":null,"abstract":"We investigated the dielectric properties of three hydrocarbon liquids (benzene, diphenylmethane, and c-hexane) using molecular dynamics simulations with a newly developed polarizable force field [DREIDING-UT(D)]. The calculated dielectric constants agree well with the experimental ones. The difference in dielectric constant between liquid diphenylmethane and benzene was due to the difference in liquid structure, whereas the difference in dielectric constant between liquid c-hexane and benzene was mainly due to the difference in atomic polarizability. Molecular dynamics simulations using a new polarizable force field were employed to study the dielectric properties of three hydrocarbon liquids: benzene, diphenylmethane, and c-hexane. The calculated dielectric constants matched well with experimental ones. The difference in dielectric constant between diphenylmethane and benzene was attributed to the difference in liquid structure, while the difference between c-hexane and benzene was mainly due to differences in atomic polarizability.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135959848","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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