Herein, a novel chromatic reaction based on the oxidative self-coupling of tertiary aromatic amines and driven by a redox reaction with gold(III) or cerium(IV) is developed. The dimers resulting from the oxidation of tertiary aromatic amines with gold(III) or cerium(IV) show colors depending on their chemical structures. Substituting a hydrogen atom on the aromatic ring with a methyl or methoxy group induces a bathochromic shift in the color developed via oxidation. This redox reaction is highly selective for gold(III) and cerium(IV) because of their high redox potentials and complexation abilities with tertiary aromatic amines, thus suggesting the development of a selective analytical method for gold(III) and cerium(IV). Cyclic voltammograms and ultraviolet–visible light absorption spectra confirm that the oxidative coupling of tertiary aromatic amines develops color. The addition of reductants, such as L-ascorbic acid, degrades the color of the resultant colored species, thus indicating that the quinoid structure of the colored species caused color development. Thus, the developed redox reaction of tertiary aromatic amines with gold(III) or cerium(IV) provides a new chromogenic platform for determining gold(III), cerium(IV), and ascorbic acid.
{"title":"Novel Chromatic Reaction Based on the Redox Reaction between Tertiary Aromatic Amines and Gold(Ⅲ) or Cerium(Ⅳ)","authors":"Kento Inoue, Arinori Inagawa, Sachio Yoshihara, Nobuo Uehara","doi":"10.1093/bulcsj/uoae021","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae021","url":null,"abstract":"\u0000 Herein, a novel chromatic reaction based on the oxidative self-coupling of tertiary aromatic amines and driven by a redox reaction with gold(III) or cerium(IV) is developed. The dimers resulting from the oxidation of tertiary aromatic amines with gold(III) or cerium(IV) show colors depending on their chemical structures. Substituting a hydrogen atom on the aromatic ring with a methyl or methoxy group induces a bathochromic shift in the color developed via oxidation. This redox reaction is highly selective for gold(III) and cerium(IV) because of their high redox potentials and complexation abilities with tertiary aromatic amines, thus suggesting the development of a selective analytical method for gold(III) and cerium(IV). Cyclic voltammograms and ultraviolet–visible light absorption spectra confirm that the oxidative coupling of tertiary aromatic amines develops color. The addition of reductants, such as L-ascorbic acid, degrades the color of the resultant colored species, thus indicating that the quinoid structure of the colored species caused color development. Thus, the developed redox reaction of tertiary aromatic amines with gold(III) or cerium(IV) provides a new chromogenic platform for determining gold(III), cerium(IV), and ascorbic acid.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140089760","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 precise molecular design of functional dendritic polymers enables the accumulation of multiple metals within the molecular cage. We have established the synthesizing methodology of metallodendrimers where the number of constituent atoms, the choice of elements, and the composition ratio were precisely controlled through the intramolecular Lewis acid-base interaction at each branch part of phenylazomethine dendrons. Chemical reduction of metallodendrimers, due to their inherent capsule effect, generates homogeneous subnanoparticles with a particle size of about 1 nm in diameter within the dendrimer cage. Fabricated subnanoparticles show amorphous crystal structures with distorted and fluctuated surface atoms and, with such a unique atomic structure, induce peculiar electronic states, surpassing unique and discrete physical and chemical properties of conventional nanoparticles and bulk metals. In this paper, we review the dendrimer-derived synthesis of atomic hybrid subnanoparticles and their application researches established in our laboratory.
{"title":"Dendrimer-induced Synthesis of Subnano Materials and their Characterization: Establishing Atom Hybrid Science","authors":"A. Kuzume, Kimihisa Yamamoto","doi":"10.1093/bulcsj/uoae022","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae022","url":null,"abstract":"\u0000 The precise molecular design of functional dendritic polymers enables the accumulation of multiple metals within the molecular cage. We have established the synthesizing methodology of metallodendrimers where the number of constituent atoms, the choice of elements, and the composition ratio were precisely controlled through the intramolecular Lewis acid-base interaction at each branch part of phenylazomethine dendrons. Chemical reduction of metallodendrimers, due to their inherent capsule effect, generates homogeneous subnanoparticles with a particle size of about 1 nm in diameter within the dendrimer cage. Fabricated subnanoparticles show amorphous crystal structures with distorted and fluctuated surface atoms and, with such a unique atomic structure, induce peculiar electronic states, surpassing unique and discrete physical and chemical properties of conventional nanoparticles and bulk metals. In this paper, we review the dendrimer-derived synthesis of atomic hybrid subnanoparticles and their application researches established in our laboratory.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140409649","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 herein report the development of a novel hybrid complex containing gold(I) and a chiral phosphoric acid moiety to generate a multifunctional catalyst. While the use of chiral phosphoric acid as a bifunctional catalyst is a common strategy in asymmetric organic synthesis, the investigation of chiral phosphoric acid–transition metal hybrid complexes as multifunctional catalysts remains unknown. Thus, we designed and synthesized a novel gold(I) hybrid complex as a multifunctional catalyst that promotes asymmetric catalytic reactions through multipoint nonclassical noncovalent interactions in substrates that lack classical hydrogen-bond donors. In addition, we demonstrate its usefulness as a multifunctional catalyst by successfully developing the first catalytic asymmetric synthesis of dihydrocyclohepta[b]indoles. Experimental and theoretical studies revealed that this asymmetric catalytic reaction involves the kinetic resolution of the reaction intermediate, and the favored diastereomeric transition state for yielding enantiomeric products is formed through multipoint nonclassical noncovalent interactions originating from the acid–base nature of the chiral phosphoric acid moiety.
{"title":"Asymmetric Cyclization Catalyzed by a Chiral Phosphoric Acid–Gold(I) Hybrid Complex as a Multifunctional Catalyst","authors":"Naoya Taniguchi, Mitsuhiro Ueda, Kenichi Michigami, Seiji Mori, Masato Ohashi","doi":"10.1093/bulcsj/uoae026","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae026","url":null,"abstract":"\u0000 We herein report the development of a novel hybrid complex containing gold(I) and a chiral phosphoric acid moiety to generate a multifunctional catalyst. While the use of chiral phosphoric acid as a bifunctional catalyst is a common strategy in asymmetric organic synthesis, the investigation of chiral phosphoric acid–transition metal hybrid complexes as multifunctional catalysts remains unknown. Thus, we designed and synthesized a novel gold(I) hybrid complex as a multifunctional catalyst that promotes asymmetric catalytic reactions through multipoint nonclassical noncovalent interactions in substrates that lack classical hydrogen-bond donors. In addition, we demonstrate its usefulness as a multifunctional catalyst by successfully developing the first catalytic asymmetric synthesis of dihydrocyclohepta[b]indoles. Experimental and theoretical studies revealed that this asymmetric catalytic reaction involves the kinetic resolution of the reaction intermediate, and the favored diastereomeric transition state for yielding enantiomeric products is formed through multipoint nonclassical noncovalent interactions originating from the acid–base nature of the chiral phosphoric acid moiety.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140415264","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}
M. Akiyama, Yuka Yasuda, Daiki Kisoi, Y. Kusakabe, H. Kaji, Hiroshi Imahori
The present paper reports development of new thermally activated delayed fluorescence (TADF) molecules with the acridan–triazine structure substituted by the perfluoroadamantyl (AdF) groups. The AdF group was prepared by perfluorination using fluorine gas, and introduced into the molecules via nucleophilic aromatic substitution. The bulky AdF group made the emitters highly soluble in organic solvents. Furthermore, their LUMOs were stabilized by the electron induction from the AdF groups, leading to small HOMO–LUMO energy gaps. As a result, both emitters showed red-shifted TADF compared to the non-fluorinated analogue.
{"title":"Perfluoroadamantyl Group: Bulky and Highly Electron-Withdrawing Substituent in Thermally Activated Delayed Fluorescence Materials","authors":"M. Akiyama, Yuka Yasuda, Daiki Kisoi, Y. Kusakabe, H. Kaji, Hiroshi Imahori","doi":"10.1093/bulcsj/uoae025","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae025","url":null,"abstract":"\u0000 The present paper reports development of new thermally activated delayed fluorescence (TADF) molecules with the acridan–triazine structure substituted by the perfluoroadamantyl (AdF) groups. The AdF group was prepared by perfluorination using fluorine gas, and introduced into the molecules via nucleophilic aromatic substitution. The bulky AdF group made the emitters highly soluble in organic solvents. Furthermore, their LUMOs were stabilized by the electron induction from the AdF groups, leading to small HOMO–LUMO energy gaps. As a result, both emitters showed red-shifted TADF compared to the non-fluorinated analogue.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140427418","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}
Luminescence from terbium(III) species is typically weak due to its low absorption coefficient and slow radiative process despite its advantageous color purity. Hybridizing with a photosensitizer(s) is one of the most popular strategy to obtain intense luminescence from terbium(III) species. We have developed a novel photosensitizing system in which terbium(III) ion is hybridized with the ionic nanosphere, a class of spherical ion-exchange resins with a diameter being <300 nm. Terbium(III)-doped ionic nanospheres successfully exhibited obvious green luminescence upon the photoexcitation of the nanosphere at 260 nm. The terbium(III)–nanosphere hybrids can be prepared by a simple methodology, and sample conditions are controllable facilely.
{"title":"Ionic Nanosphere as A Novel Sensitizer for Luminescence from Terbium(III) Ion Hybridized by Facile Ion-Exchange Process","authors":"Nikita Madhukar, Taizo Misato, A. Ito","doi":"10.1093/bulcsj/uoae023","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae023","url":null,"abstract":"\u0000 Luminescence from terbium(III) species is typically weak due to its low absorption coefficient and slow radiative process despite its advantageous color purity. Hybridizing with a photosensitizer(s) is one of the most popular strategy to obtain intense luminescence from terbium(III) species. We have developed a novel photosensitizing system in which terbium(III) ion is hybridized with the ionic nanosphere, a class of spherical ion-exchange resins with a diameter being <300 nm. Terbium(III)-doped ionic nanospheres successfully exhibited obvious green luminescence upon the photoexcitation of the nanosphere at 260 nm. The terbium(III)–nanosphere hybrids can be prepared by a simple methodology, and sample conditions are controllable facilely.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437776","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}
Stable compositions and H2O desorption processes of SinO2n+iH2i+1+ (nominally, (SiO2)n(H2O)iH+ ; n = 3–10) clusters have been studied by gas-phase thermal desorption spectrometry coupled with density functional theory (DFT) calculations. Five or six H2O molecules were found to be stored (i = 5, 6) mainly in the clusters at room temperature. The clusters sequentially released H2O molecules upon heating to form the species with i = 2 (n = 3–5, 8) and 3 (n = 6, 7, 9, 10) as the most prominent compositions at 1000 K. The desorption energies of H2O molecules from the clusters were evaluated from the temperature dependence data for n = 3–5. The experimental and theoretical results suggest that (SiO2)n(H2O)iH+ clusters with higher i (e.g., i ≥ 4 for n = 3) involve H2O molecules bound with hydrogen bonds and can easily release the H2O molecules (ΔE < ∼0.5 eV); species with lower i (e.g., i = 2 and 3 for n = 3) form H2O molecules from two hydroxide groups, whose desorption requires higher energies (ca. 1–2 eV); and H2O release is hampered if the product species does not maintain the structure with tetrahedrally coordinated Si atoms.
{"title":"Water Storage Capacity of Closed-Shell Silicon Oxyhydroxide Cluster Cations in the Gas Phase","authors":"Toshiaki Nagata, K. Miyajima, F. Mafuné","doi":"10.1093/bulcsj/uoae020","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae020","url":null,"abstract":"\u0000 Stable compositions and H2O desorption processes of SinO2n+iH2i+1+ (nominally, (SiO2)n(H2O)iH+ ; n = 3–10) clusters have been studied by gas-phase thermal desorption spectrometry coupled with density functional theory (DFT) calculations. Five or six H2O molecules were found to be stored (i = 5, 6) mainly in the clusters at room temperature. The clusters sequentially released H2O molecules upon heating to form the species with i = 2 (n = 3–5, 8) and 3 (n = 6, 7, 9, 10) as the most prominent compositions at 1000 K. The desorption energies of H2O molecules from the clusters were evaluated from the temperature dependence data for n = 3–5. The experimental and theoretical results suggest that (SiO2)n(H2O)iH+ clusters with higher i (e.g., i ≥ 4 for n = 3) involve H2O molecules bound with hydrogen bonds and can easily release the H2O molecules (ΔE < ∼0.5 eV); species with lower i (e.g., i = 2 and 3 for n = 3) form H2O molecules from two hydroxide groups, whose desorption requires higher energies (ca. 1–2 eV); and H2O release is hampered if the product species does not maintain the structure with tetrahedrally coordinated Si atoms.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140448522","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}
Several synthetic compounds bind to proteins of interest and inhibit the protein-protein interactions. To develop a detection method for the interactions between the synthetic compounds and the target proteins, we applied an engineered split intein derived from Npu DnaE and TEM-1 β-lactamase as reporter tags. We constructed the synthetic ligands bearing 6-residue C-terminal peptide from Npu DnaE and Cys-Trp as the C-extein, and the target proteins bearing the N-terminal region of the engineered Npu DnaE and residues 24-284 of β-lactamase. The specific ligand-protein interactions such as phosphopeptide-Src SH2 and imatinib-NQO2 increased the protein trans-splicing (PTS) reaction rates and yields. The PTS product showed the enhanced β-lactamase activity compared with the starting materials. The PTS-based β-lactamase activity assay was used for the quantitative analysis of the ligand-protein interactions. The signal sequence and 9-residue N-terminal sequence of Escherichia coli (E. coli) lipoprotein (Lpp) and residues 46-159 of outer membrane protein OmpA (Lpp-OmpA) were conjugated with the target proteins bearing split intein and β-lactamase to display them on the live E. coli cell surfaces. PTS on live E. coli surfaces provided enhanced resistance to carbenicillin.
一些合成化合物会与相关蛋白质结合，并抑制蛋白质与蛋白质之间的相互作用。为了开发一种检测合成化合物与目标蛋白之间相互作用的方法，我们使用了源自 Npu DnaE 和 TEM-1 β-内酰胺酶的工程化分裂内含子作为报告标签。我们构建了带有来自 Npu DnaE 的 6 位元 C 端肽的合成配体和 Cys-Trp 作为 C 外蛋白，以及带有工程化 Npu DnaE 的 N 端区域和 β-内酰胺酶的 24-284 位残基的靶蛋白。磷酸肽-Src SH2和伊马替尼-NQO2等特定配体与蛋白质的相互作用提高了蛋白质转接（PTS）反应的速率和产量。与起始材料相比，PTS 产物显示出更强的β-内酰胺酶活性。基于 PTS 的 β-内酰胺酶活性测定被用于配体与蛋白质相互作用的定量分析。将大肠杆菌脂蛋白（Lpp）的信号序列和 9 个残基的 N 端序列以及外膜蛋白 OmpA（Lpp-OmpA）的残基 46-159 与带有分裂内含素和 β-内酰胺酶的目标蛋白连接，使其显示在活的大肠杆菌细胞表面。活大肠杆菌表面的 PTS 增强了对羧苄青霉素的耐药性。
{"title":"Development of a β-lactamase activity assay for detecting ligand-protein interactions using an engineered split intein and β-lactamase","authors":"Hiroaki Hagiwara, Eriho Fujii, Taisei Iwabuchi, Tsuyoshi Takahashi","doi":"10.1093/bulcsj/uoae019","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae019","url":null,"abstract":"\u0000 Several synthetic compounds bind to proteins of interest and inhibit the protein-protein interactions. To develop a detection method for the interactions between the synthetic compounds and the target proteins, we applied an engineered split intein derived from Npu DnaE and TEM-1 β-lactamase as reporter tags. We constructed the synthetic ligands bearing 6-residue C-terminal peptide from Npu DnaE and Cys-Trp as the C-extein, and the target proteins bearing the N-terminal region of the engineered Npu DnaE and residues 24-284 of β-lactamase. The specific ligand-protein interactions such as phosphopeptide-Src SH2 and imatinib-NQO2 increased the protein trans-splicing (PTS) reaction rates and yields. The PTS product showed the enhanced β-lactamase activity compared with the starting materials. The PTS-based β-lactamase activity assay was used for the quantitative analysis of the ligand-protein interactions. The signal sequence and 9-residue N-terminal sequence of Escherichia coli (E. coli) lipoprotein (Lpp) and residues 46-159 of outer membrane protein OmpA (Lpp-OmpA) were conjugated with the target proteins bearing split intein and β-lactamase to display them on the live E. coli cell surfaces. PTS on live E. coli surfaces provided enhanced resistance to carbenicillin.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140454752","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}
Kanyaporn Adpakpang, Panyapat Ponchai, Ladawan Pukdeejorhor, K. Faungnawakij, S. Bureekaew
Enantioselective production of lactic acid from xylose sugar in constrained pore space of Ni-triazole MOF is demonstrated. Robust hydrophilic structure with confined nano-pocket is constructed from {Ni3(µ3-OH)(Tz)3(OH)2(H2O)4}n secondary building unit (SBU). At elevated temperature, the de-coordination of water and hydroxide species on Ni-node can generate accessible open-metal site (OMS) possessing Lewis acidicity, acting as catalytic center for the catalysis of xylose to lactic acid. DFT calculation suggests that enantiospecific yield of lactic acid is realizable by a preferential interaction between any pair of SBUs and the interlocked trans-pyruvaldehyde intermediate. This work highlights the unique spatial and chemical environment of MOFs as the advantageous platform for specific process in catalysis.
{"title":"Confined space of nickel-triazole metal-organic framework responsible for high product selectivity and enantiospecific yield of lactic acid converted from sugar in water-based system","authors":"Kanyaporn Adpakpang, Panyapat Ponchai, Ladawan Pukdeejorhor, K. Faungnawakij, S. Bureekaew","doi":"10.1093/bulcsj/uoae016","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae016","url":null,"abstract":"\u0000 Enantioselective production of lactic acid from xylose sugar in constrained pore space of Ni-triazole MOF is demonstrated. Robust hydrophilic structure with confined nano-pocket is constructed from {Ni3(µ3-OH)(Tz)3(OH)2(H2O)4}n secondary building unit (SBU). At elevated temperature, the de-coordination of water and hydroxide species on Ni-node can generate accessible open-metal site (OMS) possessing Lewis acidicity, acting as catalytic center for the catalysis of xylose to lactic acid. DFT calculation suggests that enantiospecific yield of lactic acid is realizable by a preferential interaction between any pair of SBUs and the interlocked trans-pyruvaldehyde intermediate. This work highlights the unique spatial and chemical environment of MOFs as the advantageous platform for specific process in catalysis.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139844662","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}
Kanyaporn Adpakpang, Panyapat Ponchai, Ladawan Pukdeejorhor, K. Faungnawakij, S. Bureekaew
Enantioselective production of lactic acid from xylose sugar in constrained pore space of Ni-triazole MOF is demonstrated. Robust hydrophilic structure with confined nano-pocket is constructed from {Ni3(µ3-OH)(Tz)3(OH)2(H2O)4}n secondary building unit (SBU). At elevated temperature, the de-coordination of water and hydroxide species on Ni-node can generate accessible open-metal site (OMS) possessing Lewis acidicity, acting as catalytic center for the catalysis of xylose to lactic acid. DFT calculation suggests that enantiospecific yield of lactic acid is realizable by a preferential interaction between any pair of SBUs and the interlocked trans-pyruvaldehyde intermediate. This work highlights the unique spatial and chemical environment of MOFs as the advantageous platform for specific process in catalysis.
{"title":"Confined space of nickel-triazole metal-organic framework responsible for high product selectivity and enantiospecific yield of lactic acid converted from sugar in water-based system","authors":"Kanyaporn Adpakpang, Panyapat Ponchai, Ladawan Pukdeejorhor, K. Faungnawakij, S. Bureekaew","doi":"10.1093/bulcsj/uoae016","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae016","url":null,"abstract":"\u0000 Enantioselective production of lactic acid from xylose sugar in constrained pore space of Ni-triazole MOF is demonstrated. Robust hydrophilic structure with confined nano-pocket is constructed from {Ni3(µ3-OH)(Tz)3(OH)2(H2O)4}n secondary building unit (SBU). At elevated temperature, the de-coordination of water and hydroxide species on Ni-node can generate accessible open-metal site (OMS) possessing Lewis acidicity, acting as catalytic center for the catalysis of xylose to lactic acid. DFT calculation suggests that enantiospecific yield of lactic acid is realizable by a preferential interaction between any pair of SBUs and the interlocked trans-pyruvaldehyde intermediate. This work highlights the unique spatial and chemical environment of MOFs as the advantageous platform for specific process in catalysis.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139784668","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}
Molecular rotors are one of the building blocks of molecular machines and are nano-sized machines with mechanically rotating moieties. Among them, intermeshing triptycenes with a gear-like skeleton allows the construction of a molecular rotor that transmits rotational motion. For triptycenes to mesh with each other without loss of rotation, intermeshing them in parallel and adjusting the distance between their axis to 8.1 Å are required. However, with conventional methods, because of the restrictions on bond lengths and atomic radius, achieving an ideal arrangement in which the triptycenes mesh in parallel at 8.1 Å has been difficult. In this work, we synthesized disulfonic acid containing a triptycene as a rotator, and combining it with amines of two different steric factors (normal-amylamine (nAmA) and guanidine (Gu)) allowed us to prepare organic salts with varying arrangements of triptycene. In the organic salt with the planar amine (Gu), the crystal structure was close to the ideal intermeshing arrangement of triptycene, and the distance between their axis was 7.7 Å. The T1ρ 13C spin-lattice relaxation time by solid-state NMR demonstrated that triptycene rotates efficiently at 24 kHz at 313 K with a low rotational barrier (10.9 kcal/mol) compared to non-intermeshing structures.
分子转子是分子机器的组成部分之一，是具有机械旋转分子的纳米级机器。其中，将具有齿轮状骨架的三庚烯相互啮合，可以构建一个传递旋转运动的分子转子。要使三庚烯相互啮合而不损失旋转，需要将它们平行啮合，并将它们的轴间距调整到 8.1 Å。然而，在传统方法中，由于键长和原子半径的限制，很难实现三庚烯平行啮合在 8.1 Å 的理想排列。在这项工作中，我们合成了含有三庚烯作为旋转剂的二磺酸，并将其与两种不同立体因子的胺（正氨胺（nAmA）和胍胺（Gu））结合，制备出了具有不同三庚烯排列的有机盐。固态核磁共振的 T1ρ 13C 自旋晶格弛豫时间表明，与非啮合结构相比，三庚烯在 313 K 下以 24 kHz 的频率高效旋转，旋转势垒较低（10.9 kcal/mol）。
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