Article
Chemistry, Physical
Zhuoer Wang, Aiyou Hao, Pengyao Xing
Summary: The researchers successfully realized chiroptical properties in the near-infrared (NIR) region using a charge-transfer strategy and applied it to photothermal agents. They self-assembled pyrene-conjugated amino acid derivatives into helical structures with supramolecular tilt chirality. By manipulating the amino acid domains, they achieved chiroptical activity evolution in the NIR region and controlled the photothermal performance using circularly polarized NIR light.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Takaya Fujie, Takeshi Yamamoto, Michinori Suginome
Summary: A single-handed poly(quinoxaline-2,3-diyl) (PQX) has been discovered as a new type of chiral shift reagent (CSR) for determining enantiomeric ratio by NMR spectroscopy. Without specific binding site, PQX interacts nonbondingly with chiral analytes, resulting in significant shift of NMR chemical shift and enabling quantification of enantiomeric ratios. This new CSR offers advantages such as wide analyte scope, including ethers, haloalkanes, and alkanes, easy tunability of chemical shifts with temperature, and erasability of proton signals due to short T-2 relaxation of the macromolecular scaffold.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Damian Pociecha, Rebecca Walker, Ewan Cruickshank, Jadwiga Szydlowska, Paulina Rybak, Anna Makal, Joanna Matraszek, Joanna M. Wolska, John M. D. Storey, Corrie T. Imrie, Ewa Gorecka
Summary: In this study, strongly dipolar mesogenic compounds with a chiral center located in a lateral alkyl chain were synthesized and found to exhibit the ferroelectric nematic phase. The presence of molecular chirality induced helical structures in both the N* and N-F* phases, but with opposite helix sense. The relaxation frequency of polar fluctuations was only weakly influenced by the helical structure.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Review
Chemistry, Multidisciplinary
Biao Zhao, Shenghua Yang, Jianping Deng, Kai Pan
Summary: Chirality and graphene have become important research subjects with the potential to create unique functional materials and discoveries when combined. This overview paper aims to fill the gap in summarizing developments in chiral materials developed from graphene and their derivatives, while also discussing future directions and challenges.
Article
Chemistry, Multidisciplinary
Tian Li, Jinzhe Li, Zhengkan Xu, YingRui Tian, Jiatong Li, Jiani Du, Fanbin Meng
Summary: Nowadays, advanced antidetection technology requires microwave absorption materials (MAMs) to have wider bandwidth, thinner thickness, and lower density. Adding magnetic medium for broadband absorption may reduce service performance and cause corrosion. Chiral MAMs can produce magnetic loss without magnetic medium due to the electromagnetic cross polarization effect. Efforts should be made to further improve the bandwidth and understand the attenuation mode and modulation method of chiral structure.
Article
Chemistry, Multidisciplinary
Nithin Suryadevara, Ansgar Pausch, Eufemio Moreno-Pineda, Asato Mizuno, Jochen Buerck, Ananya Baksi, Tim Hochdoerffer, Ivan Salitros, Anne S. Ulrich, Manfred M. Kappes, Volker Schuenemann, Wim Klopper, Mario Ruben
Summary: Enantiomerically pure Fe(II) grid complexes were successfully prepared by designing novel chiral ligands, allowing for the fabrication of magneto-chiral molecular devices. The chiral resolution of these complexes enables controlled programmable separation before synthesis. The experimental and calculated CD spectra showed good agreement, confirming the enantiomeric purity of the complexes.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Mechanics
Yuchen Han, Huadong Yong, Xingyi Zhang, Youhe Zhou
Summary: In this paper, a theoretical model is established to study the local contact characteristics of multilevel chiral helical structures and their effects on fretting wear. The load-bearing capacity is described by the ratio of axial total moment to force. Two contact force models, 1D-explicit and 2D-iteration, are developed and verified using finite element method. The Pareto sets of optimal designs with strong load-bearing capacity and high fretting wear resistance are obtained using Non-dominated Sorting Genetic Algorithm-II (NSGA-II), providing guidance for the design of multilevel chiral helical structures.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Chemistry, Organic
Vadivel Arjun, Masilamani Jeganmohan
Summary: In this study, the atroposelective synthesis of axially chiral biaryls with unactivated olefins was achieved through a palladium-catalyzed C-H olefination using a chiral transient directing group strategy. The protocol showed compatibility with a diverse range of biaryl-2-aldehydes as well as various olefins, such as allyl sulfonamides and allyl sulfones, resulting in synthetically useful yields of atroposelective olefinated products with excellent enantioselectivities up to >99% ee. Furthermore, a wide number of axially chiral biaryl alcohols were synthesized by the simple diversification of the products with excellent enantioselectivity.
Review
Chemistry, Multidisciplinary
Himanshi Singh, Freya E. L. Berggoetz, Wenhao Sun, Melanie Schnell
Summary: Microwave three-wave mixing is a novel approach for studying chiral molecules in the gas phase, providing a non-linear and coherent method using resonant microwave pulses. It can differentiate between enantiomers and determine the enantiomeric excess, even in complex chiral mixtures. Furthermore, tailored microwave pulses enable control and manipulation of chirality at the molecular level. Recent developments include enantiomer-selective population transfer and achieving high enantiomeric excess using microwave pulses alone.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Alla E. Sidorova, Ekaterina V. Malyshko, Aleksey O. Lutsenko, Denis K. Shpigun, Olga E. Bagrova
Summary: This paper proposes methods for quantitative analysis of the chirality of protein helical and superhelical structures, revealing common and specific features among different protein classes. The data obtained can likely reflect considerations about molecular machines as chiral formations.
Article
Chemistry, Multidisciplinary
Mitchell D. Mills, Reilly E. Sonstrom, Zoua Pa Vang, Justin L. Neill, Haley N. Scolati, Channing T. West, Brooks H. Pate, Joseph R. Clark
Summary: The article discusses a novel method for synthesizing isotopically chiral molecules as well as a general spectroscopic technique for determining their absolute configuration and enantiomeric excess, with a focus on the application of chiral tag rotational spectroscopy.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Yuxia Zhang, Zhongxing Geng, Yu Zhang, Zhaoran Xu, Hang Li, Yixiang Cheng, Yiwu Quan
Summary: The study synthesized three achiral pyrene derivatives and found that only the chiral co-assembly could form regular and orderly helical nanofibers, emitting a strong deep blue circularly polarized luminescence signal.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Lenka Pallova, Laura Abella, Marion Jean, Nicolas Vanthuyne, Cecile Barthes, Laure Vendier, Jochen Autschbach, Jeanne Crassous, Stephanie Bastin, Vincent Cesar
Summary: The first efficient chiral helicene-NHC gold(I) complexes for enantioselective catalysis have been synthesized. Their structural and stereochemical characterization confirms their potential in asymmetric catalysis, demonstrated by the benchmark cycloisomerization reaction with high enantiomeric excess.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Jianjian Zhao, Aiyou Hao, Pengyao Xing
Summary: This study presents a simple folding protocol to construct chiral benzimidazole skeleton with propeller chirality, which exhibits high selectivity to chloroform as a solvent. Chloroform can invert the propeller chirality by replacing the original hydrogen bonds between the diamino acid arms. This work demonstrates that the active participation of solvent, not only its polarity, can change the chirality and optical activities of small folded molecules.
Article
Chemistry, Multidisciplinary
Rafael Rodriguez, Elena Rivadulla-Cendal, Manuel Fernandez-Miguez, Berta Fernandez, Katsuhiro Maeda, Emilio Quinoa, Felix Freire
Summary: This study induced different helical structures with different helical senses in a helical polymer by controlling the conformation of two different chiral residues in a pendant group.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Yusuke Kawasaki, Showkat Rashid, Katsuhiko Ikeyatsu, Yuichiro Mutoh, Yusukc Yoshigoe, Simko Kikkawa, Isao Azumaya, Shoichi Hosoya, Shinichi Saito
Summary: In this study, a series of [2]rotaxanes with various functional groups in the axle component were synthesized through the oxidativedimerization of alkynes mediated by a macrocyclic phenanthroline-Cu complex. The rotaxanes were fully characterized and the structure of one rotaxane was determined by X-ray crystallographic analysis. The interaction between the ring component and the axle component was studied in detail, revealing that the presence of a hydrogen bond between the phenanthroline moiety in the macrocyclic component and the acidic proton in the axle component influenced the conformation of the rotaxane.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Keisuke Takahashi, Shunya Kudo, Kiharu Kawamura, Taichi Kusakabe, Shoko Kikkawa, Isao Azumaya, Keisuke Kato
Summary: The proposed structure of mohangic acid C (3) was synthesized through a series of reactions, which selectively introduced specific functional groups and constructed the overall framework of the molecule.
Correction
Chemistry, Organic
Keisuke Takahashi, Shunya Kudo, Kiharu Kawamura, Taichi Kusakabe, Shoko Kikkawa, Isao Azumaya, Keisuke Kato
Article
Chemistry, Multidisciplinary
Shunsuke Yanagi, Akihisa Matsumoto, Naoyuki Toriumi, Yusuke Tanaka, Kazunori Miyamoto, Atsuya Muranaka, Masanobu Uchiyama
Summary: In this study, two bench-stable BzTAPs with 18 pi- and 20 pi-electron structures were designed and synthesized. It was found that the NIR-inert BzTAP can be converted to the NIR-active form in the presence of mild reducing agents. This finding is significant for the development of activatable NIR probes in reductive environments.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hajime Sugita, Yi Lu, Daisuke Aoki, Hideyuki Otsuka, Koichiro Mikami
Summary: Radical-type mechanophores (RMs) can undergo homolytic cleavage of their central C-C bonds upon exposure to mechanical forces, which affords radical species. Understanding the characteristics of these radical species allows bespoke mechanoresponsive materials to be designed and developed. In this paper, the synthesis and characterization of arylfluorene-based RM derivatives, and the importance of thermodynamic stability and oxygen tolerance for their functions and applicability, are reported. Furthermore, the mechanochromism of a BTAF-centered polymer synthesized by ATRP was demonstrated.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Plant Sciences
Lingjian Tan, Kouharu Otsuki, Mi Zhang, Takashi Kikuchi, Misaki Okayasu, Isao Azumaya, Di Zhou, Ning Li, Li Huang, Chin-Ho Chen, Wei Li
Summary: Twelve macrocyclic daphnane diterpenoids, including six new compounds, were isolated from the whole plant of Daphne pedunculata. Their structures were determined using various methods, and their anti-HIV activity was evaluated. The compounds showed significant activity against HIV, providing further insights into the structure-activity relationships of macrocyclic daphnane diterpenoids.
JOURNAL OF NATURAL PRODUCTS
(2022)
Article
Chemistry, Multidisciplinary
Hajime Sugita, Yi Lu, Daisuke Aoki, Hideyuki Otsuka, Koichiro Mikami
Summary: In this study, the synthesis and characterization of two series of arylfluorene-based mechanophores were reported. Density functional theory (DFT) calculations revealed the importance of thermodynamic stability and oxygen tolerance for the functions and applicability of these materials. Furthermore, the mechanochromism of a polymer containing one of the mechanophores was demonstrated through ball-milling.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Polymer Science
Hiroyuki Taniyama, Koji Takagi
Summary: This study focused on the structural control and surface functionalization of a cellulose nanocrystal (CNC) film by modifying it with silane coupling reagents. Silane compounds containing glycidyl groups were chemically bonded to the CNC surface, resulting in changes in surface roughness and hydrophilicity. The adhesion strength of the silane-modified CNC film with chitosan cast film was found to be strong, suggesting successful reactions between glycidyl groups and amino groups.
Article
Neurosciences
Takashi Ozaki, Koichiro Mikami, Atsuhito Toyomaki, Naoki Hashimoto, Yoichi M. Ito, Ichiro Kusumi
Summary: This study examined the association between the effects of antipsychotic monotherapy on quantitative EEG and the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy. The results showed a weak positive correlation between HOMO energy of antipsychotic drugs and delta-and gamma band power in EEG. This suggests that the effect of antipsychotic drugs on EEG may be related to their antioxidant actions.
NEUROPSYCHOPHARMACOLOGY REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Masataka Ito, Yuriko Iwata, Hiroyasu Iwasaki, Kyu Hayashi, Taku Nakayama, Hidemasa Hikawa, Isao Azumaya, Hironori Suzuki, Shuji Noguchi
Summary: This finding suggests that deep eutectic solvents (DESs) can be utilized for the crystallization of cocrystals or salts from active pharmaceutical ingredients. In this study, DESs were employed as environmentally friendly solvents for crystal formation. The results revealed the formation of five different cocrystals or salts, including two that were identified for the first time.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Physical
Abhijit Sen, Valerii Bukhanko, Heeyoel Baek, Aya Ohno, Atsuya Muranaka, Yoichi M. A. Yamada
Summary: The amination of aryl chlorides was achieved using polymeric nickel and iridium catalysts under microwave and visible-light irradiation, with a high reaction efficiency and recyclability. This approach offers a wide range of substrate compatibility and can be used for the synthesis of biologically active molecules.
Article
Polymer Science
Tomoki Hasegawa, Koji Takagi
Summary: The cationic polymerization of p-methoxystyrene (pMOS) was successfully achieved using pMOS·HCl and Sb(C6F5)3 as catalysts. The catalytic activity increased in the order of Sb(C6F5)3 > Te(C6F5)2 > IC6F5. The molecular weight distribution of the polymer was narrowed when nBu4NCl was used as an additive. [MeSbPh3][TEPB] showed better molecular weight controllability as a catalyst. [SbPh4][TEPB] and [SbPh4][OTf] exhibited lower catalytic activity. [EtOCOCH2SbPh3][TEPB] with an electron-withdrawing group showed the highest reactivity.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Polymer Science
Koji Takagi, Hiroto Murakata, Tomoki Hasegawa
Summary: In this study, cationic polymerization of isobutyl vinyl ether (IBVE) was investigated using Schreiner's thiourea (STU) combined with Im-TEPB cocatalysts. The results show that STU/Im-TEPB displayed higher activity and better control over the molecular weight compared to other systems studied.
Article
Chemistry, Multidisciplinary
Koji Takagi, Asuka Maeda, Ryotaro Tsunekawa
Summary: In this study, the palladium-catalyzed intramolecular direct arylation of three aromatic tertiary amide compounds was investigated. The C-H activation of the benzene ring required temperatures above 120 degrees C and the presence of specific reagents, and the formation of regioisomers could not be suppressed. In contrast, the C-H activation of the pyridine ring proceeded even at lower temperatures, and the desired compound was obtained quantitatively.
RESULTS IN CHEMISTRY
(2022)
Correction
Chemistry, Organic
Keisuke Takahashi, Shunya Kudo, Kiharu Kawamura, Taichi Kusakabe, Shoko Kikkawa, Isao Azumaya, Keisuke Kato
