Article
Chemistry, Organic
Daisuke Taura, Xiang Wang, Masaki Ito, Eiji Yashima
Summary: Novel ortho-linked tetraphenol strands with electron-deficient naphthalene (NDI) and perylene (PDI) diimide linkers formed double-stranded homo-helicates bridged by spiroborate groups in the presence of NaBH4. The reaction of an electron-rich porphyrin-linked tetraphenol strand with the NDI-strand quantitatively afforded the double-stranded hetero-helicate, while that with the longer PDI strand gave a mixture of homo- and hetero-helicates. The isolated homo- and hetero-helicates were successfully resolved into enantiomers by chiral HPLC.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Naoki Ousaka, Manabu Itakura, Akira Nagasaka, Masaki Ito, Tomonari Hattori, Daisuke Taura, Tomoyuki Ikai, Eiji Yashima
Summary: This study presents a unique water-mediated reversible transformation among three distinct dinuclear titanium(IV) helicates, linked by an oxo or hydroxo bridge, through dehydration/hydration or water-mediated dynamic cleavage/re-formation reactions. These transformations can be accelerated under different conditions, ultimately successfully generating different helicates in a controllable manner.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Inorganic & Nuclear
Christian Mevissen, David Sommer, Sabarina Vasanthakumar, Khai-Nghi Truong, Kari Rissanen, Markus Albrecht
Summary: A series of compressed and expanded helicates have been obtained in this study, with cesium cations adopting the expanded structure while sodium and rubidium cations adopting the compressed structure. This represents an example of cation-translocation based isomerism.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Organic
Naoki Ousaka, Shinya Yamamoto, Hiroki Iida, Takuya Iwata, Shingo Ito, Rafael Souza, Yuh Hijikata, Stephan Irle, Eiji Yashima
Summary: This study systematically investigated the factors influencing the formation of inclusion complexes within a bisporphyrin, revealing that the size, electron density, and substituents of the aromatic guests all play a role. The ability of the helicate to encapsulate guests increased with larger core sizes but decreased with bulkier and more substituted guests. In addition, a new mechanism for the formation of inclusion complexes was discovered in specific naphthalenediimide derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Astronomy & Astrophysics
Vitek Vesely, Martin Zofka
Summary: A toy relativistic model is proposed to study oscillatory behavior and motion in gravitational fields without the pitfalls of superluminal motion. The system only involves local interaction and satisfies energy-momentum conservation locally, making it a useful tool for studying extended objects falling freely in a background gravitational field.
Article
Chemistry, Multidisciplinary
Malavika G. Kalarikkal, Christoph Drechsler, Gers Tusha, Lars V. Schaefer, David Van Craen
Summary: Chirality analysis of small molecules can be efficiently performed through streamlined chromatographic methods or with the use of chiroptical probes relying on host-guest interactions. In this study, metal-based containers known as helicates are explored for their potential in recognizing anions and conducting chirality analysis. The helicates contain triazole units that exhibit rotational freedom and can form either a meso-structure or a racemic mixture, resulting in a chiroptical response upon recognition of chiral carboxylates. This receptor-based approach offers a non-invasive and waste-free solution for high-throughput screenings.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Wang-Chuan Xiao, Qing-Bin Nie, Geng-Geng Luo
Summary: We synthesized a new tripyridine dipyrrolide pincer ligand and used it to prepare a subnanometric chiral silver cluster. The cluster exhibited a double-stranded helicate structure. Interestingly, through hierarchical intercluster interactions, the cluster helicates evolved into complex secondary structures resembling protein secondary structures.
DALTON TRANSACTIONS
(2023)
Article
Multidisciplinary Sciences
Zhe Lian, Jing He, Lin Liu, Yanqing Fan, Xuebo Chen, Hua Jiang
Summary: The authors report the non-covalent syntheses of double helicates by metalcoordination interaction and their applications in artificial light-harvesting systems (ALHSs) and white light-emitting diode (LED) device. The aggregated double helicates can be used to construct efficient ALHSs with high energy transfer efficiency. Furthermore, the double helicates can produce white light emission in different forms, such as a PMMA film and a blue LED bulb.
NATURE COMMUNICATIONS
(2023)
Article
Instruments & Instrumentation
Xiao Han, Mengjing Fan, Xinyan Yue, Xiaoman Zhao, Yongkun Liu, Jianhan Hong, Leigen Liu
Summary: In this study, polyamide 6 nanofibers were coated on the surface of a silver-coated nylon core yarn using a multi-needle water-bath electrospinning method. The resulting linear flexible capacitive sensors showed good performance in human motion monitoring.
SMART MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Saikat Pahan, Sanjit Dey, Gijo George, Souvik Panda Mahapatra, DRGKoppalu R. Puneeth Kumar, Hosahudya. N. Gopi
Summary: In this study, chiral beta-double helices constructed from specific amino acids were observed in both single crystals and in solution. These structures can transport ions across membranes, suggesting their potential applications in designing functional foldamers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Marcel Schlottmann, Tobias Krueckel, Markus Albrecht
Summary: The competition among different chiral ligands in controlling the stereochemistry of hierarchically formed helical coordination compounds is investigated. It is found that sterically demanding chiral units can dominate the chiral induction of the helix even if they are present as a minor species. Thus, the relative strength of stereoinduction of different chiral units can be evaluated.
CHEMICAL COMMUNICATIONS
(2022)
Article
Polymer Science
Yu Lu, Xin-Yue Liu, Guo-Hui Hu
Summary: This study numerically investigates the diffusion of nanoparticles in an unentangled polymer network using single-particle dissipative particle dynamics (DPD). The results show that the deformation due to junction deviation significantly affects the diffusion of nanoparticles. Based on the theory of continuum mechanics, a nonlinear spring is proposed to describe the relationship between the deformed energy and the junction deviation. A double-spring model is suggested to characterize the diffusivity of nanoparticles in the ordered network, taking into account both loop stretching and junction deviation effects. The theoretical prediction is in good agreement with numerical simulations and previous theoretical studies.
Article
Chemistry, Multidisciplinary
Chunmei Zhao, Zhiying Ma, Chunli Li, Li Xu, Hua Wang
Summary: A novel racemate and enantiomer of binaphthylcyclooctaterthiophene (BN-COTh) were synthesized and investigated for their crystal structures, spectroscopic behaviors, chiral resolution, and characteristics. The enantiomer of (R,R, R)-BN-COTh exhibited unique intermolecular interactions in crystal, forming a larger and extended assembly packing along the b-axis.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Irene Regeni, Bin Chen, Marina Frank, Ananya Baksi, Julian J. Holstein, Guido H. Clever
Summary: This study introduces a strategy to incorporate four members of the classic coal-tar dye family into [Pd2L4] self-assemblies, investigating their performance in different ligands and color ranges, showing potential applications in chiroptical recognition, photo-redox catalysis, and optical materials. The results demonstrate different behaviors of the self-assemblies based on this new ligand class, such as chiral induction, binding modes distinction, and rearrangement to new structures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jiangbin Wu, Nan Wang, Ya-Ru Xie, Hefei Liu, Xinghao Huang, Xin Cong, Hung-Yu Chen, Jiahui Ma, Fanxin Liu, Hangbo Zhao, Jun Zhang, Ping-Heng Tan, Han Wang
Summary: This research reports the extraordinary mechanical properties of the newly discovered inorganic double helical semiconductor tin indium phosphate, which has the lowest Young's modulus and large elastic and plastic bending strains. These results are of great significance for understanding the mechanical properties of the material and its potential applications in flexible electronics and nanomedicine.
Article
Chemistry, Multidisciplinary
Tomoyuki Ikai, Tomoyuki Kurake, Shogo Okuda, Katsuhiro Maeda, Eiji Yashima
Summary: The racemic monomer-based optically inactive polyacetylene can fold into a one-handed helix with the assistance of a nonracemic alcohol, serving as a chiral stationary phase in chromatography to separate enantiomers effectively. The polymer shows auto-evolution of helical handedness over time and enhanced optical purity of the nonracemic alcohol adsorbed on the helical polyacetylene due to chiral filter effect, contributing to increased helix-sense-excess.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Medicinal
Tomoyuki Ikai, Shogo Okuda, Eiji Yashima
Summary: Two novel poly(biphenylylacetylene)s containing asymmetric alkylphenyl groups were synthesized, and their effects on macromolecular helicity induction and static helicity memory were investigated. The polymers exhibited high chiral recognition ability in high-performance liquid chromatography experiments.
Article
Chemistry, Multidisciplinary
Shogo Okuda, Naoki Ousaka, Takuya Iwata, Riku Ishida, Akio Urushima, Nozomu Suzuki, Shusaku Nagano, Tomoyuki Ikai, Eiji Yashima
Summary: In this study, unique coordination-driven supramolecular helical assemblies were reported using specific dirhodium complexes and auxiliary materials to form helical polymers in solvents. These structures are stabilized by hydrogen bonding networks and exhibit specific chirality and helical sense inversion properties during formation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Editorial Material
Chemistry, Medicinal
Eiji Yashima, Katsuhiro Maeda, Oliver Trapp, Nina Berova, Simona Collina, Gennaro Pescitelli
Article
Polymer Science
Tomoyuki Ikai, Shoki Takeda, Eiji Yashima
Summary: In this study, a dynamically racemic helical copolymer was discovered to fold into an excess one-handed helix in the presence of a small amount of optically active amines, and the induced helicity was retained after removal of the chiral amines. The copolymer showed high sensitivity for detecting the chirality of chiral amines, even in the presence of a very low amount, and exhibited Cotton effects.
Article
Polymer Science
Tomoyuki Ikai, Shogo Okuda, Motoki Aizawa, Eiji Yashima
Summary: The one-handed helix induction and chiral recognition abilities of cis-poly(biphenylylacetylene) derivatives with chiral and achiral pendant groups were investigated. The chiral recognition abilities were significantly influenced by the types of pendant residues.
Article
Chemistry, Multidisciplinary
Wei Zheng, Kosuke Oki, Ranajit Saha, Yuh Hijikata, Eiji Yashima, Tomoyuki Ikai
Summary: Defect-free one-handed contracted helical tubular ladder polymers with a pi-electron-rich cylindrical helical cavity were synthesized and exhibited high enantioseparation abilities. The formation of the pi-electron-rich cylindrical helical cavity is key to the highly-enantioseparation ability. Molecular dynamics simulations suggested that chiral aromatics can be encapsulated by specific pi-pi and/or hydrophobic interactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Tomoyuki Ikai, Shun Anzai, Kosuke Oki, Eiji Yashima
Summary: In this study, a series of novel chiral/achiral copolymers with configurationally labile optically active helicene pendants were synthesized. It was found that the copolymers could maintain their preferred helicity even after the pendant helicene units were completely racemized, thanks to the static memory of the main-chain helicity. On the other hand, the helicity memory of the helicene-free homopolymer was lost rapidly.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Tomoyuki Ikai, Koshi Nakamura, Kosuke Mizumoto, Kosuke Oki, Eiji Yashima
Summary: In this study, we report a novel way to remotely control the helicity of chiral/achiral biphenylylacetylene copolymers with amphiphilic oligo(ethylene glycol) (OEG) side chains. By introducing a small amount of chiral binaphthyl residues (<= 10 mol %) at the terminal of achiral OEG spacers, a complete one-handed helix can be induced in water. The helix-sense can be inverted at a specific spacer length. The superiority of this covalent-bond driven remote helicity control over noncovalent helicity induction is demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tomoyuki Ikai, Kosuke Oki, Shoya Yamakawa, Eiji Yashima
Summary: Enantiopure [6]helicene and carbo[7]helicene with opposite helicity were synthesized simultaneously and quantitatively (>99 %) through stepwise acid-promoted intramolecular alkyne annulations. The stereocontrol of helical handedness of the [6]- and [7]helicenes was achieved by the doubly axial chirality of the precursors. The cyclizations proceeded in a stepwise manner, resulting in the production of enantiopure circularly polarized luminescent [6]- and [7]helicenes with opposite helicity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tomoyuki Ikai, Masaki Ito, Kosuke Oki, Nozomu Suzuki, Eiji Yashima
Summary: A series of poly(biarylylacetylene)s (PBAs) with axially-chiral pyridyl-N-oxide residues and different substituents were synthesized. Despite having the same twist-sense, all PBAs formed a preferred-handed helix with the helical sense preference depending on the substituents. Among them, the propoxy-bound helical PBA showed exceptional chiral recognition ability as a CSP in HPLC, efficiently resolving various chiral aromatic and aliphatic alcohols, which are difficult to separate using commercially-available CSPs. These practical CSPs can be produced from racemic PBA through deracemization of the biaryl units using a chiral alcohol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tomoyuki Ikai, Sayaka Miyoshi, Kosuke Oki, Ranajit Saha, Yuh Hijikata, Eiji Yashima
Summary: We report the synthesis and resolution of a fully p-conjugated helical ladder polymer with a rigid helical cavity, composed of achiral units. The isolated excess one-handed helical ladder polymer showed strong circular dichroism and thermal stability, maintaining its optical activity in solution.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Nanoscience & Nanotechnology
Li-Bo Huang, Fumihiko Mamiya, Marc Baaden, Eiji Yashima, Mihail Barboiu
Summary: By self-assembly, we have successfully constructed a self-assembled peptide-bound Ni2+ metallomacrocycle 1, which achieves high selective single-channel water permeability. Compared to aquaporins, compound 1 has lower single-channel permeability and negligible ion transport. Molecular simulations reveal the formation of spongelike aggregates, generating transient cluster water pathways through the bilayer. Overall, adaptive metallosupramolecular self-assembly is an efficient and simple way to construct selective channel superstructures.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Kosuke Oki, Wei Zheng, Eiji Yashima, Tomoyuki Ikai
Summary: Optically-pure triptycene-based metallomacrocycles were synthesized for the first time through the coordination-driven self-assembly of enantiopure triptycene-derived ligands. Additionally, a pair of enantiomeric homochiral metallomacrocycles were also produced through the coordination-driven homochiral self-sorting of racemic ligands, demonstrating the shape-persistent nature of the ladder-structured ligands.
CHEMICAL COMMUNICATIONS
(2023)
Review
Multidisciplinary Sciences
Eiji Yashima
Summary: This review focuses on our research in the past decade on the synthesis of one-handed helical polymers through noncovalent helicity induction and subsequent memory. Our method allows for the immediate retention and amplification of an excess one-handed helical conformation even after the removal of nonracemic molecules, providing novel switchable chiral materials.
PROCEEDINGS OF THE JAPAN ACADEMY SERIES B-PHYSICAL AND BIOLOGICAL SCIENCES
(2023)
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.