Article
Optics
Asaf Farhi, Aristide Dogariu
Summary: The interaction between helical structures and oscillating dipoles can lead to strong and selective responses. The identification of coherent oscillation modes through vibrational and eigenfunction analyses may explain the diverse functionality of cytoskeletal microtubules in the cellular environment.
Article
Chemistry, Multidisciplinary
Motoki Tsuchiya, Hazuki Maeda, Ryo Inoue, Yasuhiro Morisaki
Summary: In this study, optically active conjugated molecules with one-handed helical structures were prepared, showing excellent chiroptical properties such as circularly polarized luminescence. Optical resolution of planar chiral pseudo-meta-disubstituted [2.2]paracyclophane was also achieved on a sub-gram scale.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Wenhao Liu, Xiaomeng Liu, Xianghe Meng, Chunxiao Li, Mengran Sun, Zheshuai Lin, Jiyong Yao
Summary: The spontaneous crystallization method was used to synthesize two non-centrosymmetric scandium borate crystal materials with wide band gaps and good second harmonic generation (SHG) effects. First-principles calculations revealed that the arrangement of [B5O10](5-) groups and the distortion of ScO6 polyhedra were responsible for the SHG response. The materials may have potential applications in UV nonlinear optical devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Cell Biology
Gaoxingyu Huang, Dongliang Liu, Weipeng Wang, Qiurong Wu, Jiaofeng Chen, Xiaojing Pan, Huaizong Shen, Nieng Yan
Summary: This study reports the cryo-EM structure of Na(v)1.7 channel complexed with different subunits, revealing conformational differences and ligand-induced structural changes.
Article
Chemistry, Inorganic & Nuclear
Asif Ahmad, Suvam Saha, Mohammad Zafar, Marie Cordier, Sundargopal Ghosh
Summary: The reactivity of kappa(2)-N,S-chelated ruthenium borate complexes with monoboranes has been explored. Hydrogen-rich complex arachno-[PPh3(kappa(2)-B3H8)Ru{kappa(3)-H,S,S '-H2B(NC7H4S2)(2)}] and isomeric ruthenatetraborane complexes [Ru(PPh3)(kappa(2)-N,S-(B3H8){kappa(3)-H,S,S '-H2B(NC5H4S)(2)}] have been obtained through reactions with [BH3 center dot THF].
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Materials Science, Ceramics
Jan Havlicek, Katerina Rubesova, Vit Jakes, Romana Kucerkova, Alena Beitlerova, Martin Nikl
Summary: This study explores the potential of cerium- or europium-doped LiSrBO3 and LiSr4(BO3)(3) as thermal neutron scintillator materials, which exhibit advantages such as high lithium and boron content, suitable density, and proper environment for luminescent ions. Radioluminescence of these ceramic borates doped with cerium and europium was investigated, showing promising results, especially in response to X-ray excitation.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Review
Chemistry, Multidisciplinary
Yanpeng Zhu, Jiaobing Wang
Summary: This article summarizes the research progress and importance of synthetic nanographene in the field of chemistry. With precise atomic structure and unique molecular properties, nanographene has applications in optoelectronics, nanotechnologies, and biomedicine.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Optics
V. Slavchev, A. Dakova, I. Bojikoliev, D. Dakova, L. Kovachev
Summary: This paper investigates the vortex structures of optical pulses propagating in concave-gradient fiber, with their dynamics governed by a system of amplitude equations for x and y components of the electrical field. New class vortex solutions of these equations are discovered, which exhibit the characteristic feature of generating depolarization of the vector field.
Article
Multidisciplinary Sciences
Sarah B. Nyenhuis, Xufeng Wu, Marie-Paule Strub, Yang-In Yim, Abigail E. Stanton, Valentina Baena, Zulfeqhar A. Syed, Bertram Canagarajah, John A. Hammer, Jenny E. Hinshaw
Summary: It has been found that dominant optic atrophy, a leading cause of childhood blindness, is caused by gene mutations in OPA1. OPA1 encodes a protein that plays a key role in mitochondrial membrane fusion and remodelling. Using cryo-electron microscopy, researchers have been able to solve the helical structures of OPA1 on lipid membrane tubes and have discovered the importance of nucleotide in the dimerization of the GTPase domains. The study also revealed unique secondary structures in OPA1 that enhance its association with membranes. These findings provide insight into the effects of pathogenic mutations on protein folding, inter-protein assembly, and membrane interactions.
Article
Materials Science, Multidisciplinary
Shixuan Hao, Jicheng Wang, Ivan Fanayev, Sergei Khakhomov, Jingwen LI
Summary: This study investigates the super-resolution capability of different types of multilayered graphene-dielectric hyperbolic metamaterials to break the diffraction limit of light. A super-resolution of lambda/10 is achieved and the dispersion and super-resolution performance can be dynamically tuned by adjusting the chemical potential of graphene. The research is important for terahertz imaging systems and the development of hyperbolic metamaterial modulation devices.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Hyeyoon Ko, Minwook Kim, Youngjae Wi, Minwoo Rim, Seok-In Lim, Jahyeon Koo, Dong-Gue Kang, Kwang-Un Jeong
Summary: Circularly polarized freestanding films are prepared with polymerizable cholesteric liquid crystal paints, allowing students to understand circular polarization and molecular chirality. By controlling the helical pitch of the polymerized CLC films, students can achieve brilliant structural colors through selective reflection of visible light. These films can be stabilized through photopolymerization, enabling students to encode secret letters visible only with a specific circular polarizer.
JOURNAL OF CHEMICAL EDUCATION
(2021)
Article
Crystallography
Runqing Liu, Hongping Wu, Hongwei Yu, Zhanggui Hu, Jiyang Wang, Yicheng Wu
Summary: CIBO is a new noncentrosymmetric cadmium indium borate with good optical and thermal properties. Its structure includes distorted InO6 and CdOn polyhedra and exhibits strong second harmonic generation and moderate birefringence due to the approximately parallel arrangement of BO3 triangles.
Article
Physics, Multidisciplinary
M. Labat, O. Chubar, J. Breunlin, A. Andersson
Summary: This study presents a detailed investigation of the intensity distribution of bending magnet synchrotron radiation in a focusing optical system. The measured intensity distribution at the MAX-IV low emittance storage ring is shown to be in excellent agreement with theoretical predictions. The research also derives a closed analytical expression for the intensity distribution of a zero-emittance beam, which allows for the demonstration of the meeting between classical electrodynamics and the Landau and Lifshitz predictions of radiation intensity distribution near a caustic.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
M. Labat, O. Chubar, J. Breunlin, N. Hubert, A. Andersson
Summary: This study presents a profound investigation of the intensity distribution of synchrotron radiation from bending magnets in a storage ring based light source. The measured results at the MAX-IV low emittance storage ring are found to agree excellently with theoretical predictions. The study also suggests the possibility of high resolution emittance diagnostics using visible or near-visible synchrotron radiation in future low-emittance storage ring based light sources.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Suhua Li, Gencheng Li, Bing Gao, Sidharam P. Pujari, Xiaoyan Chen, Hyunseok Kim, Feng Zhou, Liana M. Klivansky, Yi Liu, Hafedh Driss, Dong-Dong Liang, Jianmei Lu, Peng Wu, Han Zuilhof, John Moses, K. Barry Sharpless
Summary: SuFEx is a type of click chemistry that allows covalent linking of modular units through sulfur(vi) connective hubs, leading to the synthesis of structurally diverse copolymers with high efficiency and stable bonds. SuFEx click chemistry offers the potential for post-polymerization modification, enabling the synthesis of materials with control over composition and conformation, making it a powerful tool in polymer chemistry.
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)
