Article
Chemistry, Organic
Shota Miwa, Ryunosuke Senda, Kazuya Saito, Azusa Sato, Yuko Nakamura, Osamu Kitagawa
Summary: N-C axially chiral quinazolinone derivatives were prepared with high enantio- and diastereomeric purities (98% ee). These derivatives are isotopic atropisomers based on orthoCH3/CD3 discrimination and exhibit slight optical rotation and high rotational stability.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Shota Miwa, Ryunosuke Senda, Kazuya Saito, Azusa Sato, Yuko Nakamura, Osamu Kitagawa
Summary: High enantiomeric and diastereomeric purities (98% ee) were achieved in the preparation of N-C axially chiral quinazolinone derivatives. These derivatives, characterized by ortho- CH3/CD3 discrimination, display slight optical rotation and high rotational stability.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Y. Zou, C. Lin, G. Luo, H. Li, H. Hu, P. Lin, P. Wang, L. Xu, X. Wu, C. Cui
Summary: The structure instability of perovskite solar cells (PSCs) can be limited by stabilizing the perovskite structure through partial replacement of A-site ions with larger and non-polar ions.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Nadezhda B. Tamm, Vitaliy Yu. Markov, Sergey I. Troyanov
Summary: The research demonstrates the transformation of buckminsterfullerene I-h-C-60 to non-IPR CF3 derivatives through high-temperature chlorination and trifluoromethylation reactions. X-ray diffraction studies reveal the preferential occupation of CF3 groups at the sites of pentagon-pentagon fusions on the carbon cage.
DALTON TRANSACTIONS
(2021)
Article
Computer Science, Artificial Intelligence
Hanlin Mo, Hongxiang Hao, Hua Li
Summary: This paper focuses on deriving blur moment invariants and proposes a new method to determine the invariance of existing moment invariants to N-fold symmetric blur. It is found that five Hu moment invariants are naturally invariant to N-fold symmetric blur. The experiments show that these five Hu moment invariants outperform some widely used blur moment invariants and non-moment image features in image retrieval, classification, and template matching.
PATTERN RECOGNITION
(2021)
Article
Energy & Fuels
Xin Zhang, Yiming Zhao, Wenjuan Li, Yun Zhang, Siyu Xu, Sen Xu, Wen Zhou, Yizheng Fu, Yongan Feng, Weiguo Cao
Summary: Higher fatty alcohols are important in industry, but the risk of dust explosion cannot be ignored. Through ignition tests and molecular dynamics simulations, the combustion characteristics of three linear monohydric alcohols CH3(CH2)n-1OH (n = 16, 18, 22) were explored. The results showed that the flame propagation height of alcohol dust increased with the increase in dust concentration, and the flame propagation velocity had two peaks. The volatility of alcohols was the key factor determining the difference in flame propagation behavior.
Article
Physics, Multidisciplinary
Hiroyuki Kitahata, Yuki Koyano
Summary: A camphor particle at a water surface exhibits self-propulsion and its shape affects its mode of motion. By studying the bifurcation structure of camphor floats with different rotational symmetries, it was found that shape alteration leads to changes in the direction of motion.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Organic
Jia Cao, Liuzhou Gao, Guoqiang Wang, Shuhua Li
Summary: Here, we present a metal-free method for constructing C-X (X=S, Se) bonds using readily available N-hydroxyphthalimide esters and disulfides/diselenides (Ar2X2, X=S or Se) with bis(pinacolato)diboron as the reductant. Computational and experimental studies reveal that this C-X bond formation process involves reductive decarboxylation mediated by a pyridine-boryl radical to generate alkyl or aryl radicals. The resulting carbon radical then undergoes bimolecular homolytic substitution (S(H)2) with disulfides or diselenides to give the corresponding sulfides or selenides. This method exhibits excellent functional group tolerance and broad substrate applicability.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jianyang Dong, Jianhua Liu, Hongjian Song, Yuxiu Liu, Qingmin Wang
Summary: A mild and operationally simple method using vinyl ethers as acetyl sources for Minisci C-H acetylation of N-heteroarenes is reported. This method does not require conventional photocatalysis, electrocatalysis, metal catalysis, light activation, or high temperature, making it more sustainable in terms of cost, reagent toxicity, and waste generation compared to previous methods. It is expected to obtain medically relevant molecules from abundant feedstock materials.
Article
Materials Science, Multidisciplinary
L. Herviou, S. Capponi, P. Lecheminant
Summary: The zero-temperature phase diagram of the J1-J2 SU(N) antiferromagnetic Heisenberg spin chain is studied for general N using field theory and numerical methods. A fully gapped SU(N) valence bond solid is formed for all N above a critical value of J2/J1. The extension of this N-merized phase for larger J2 strongly depends on the parity of N. For odd N, a gapless phase in the SU(N)1 universality class is stabilized for larger J2, while for even N, the phase smoothly interpolates to a zigzag SU(N) two-leg spin ladder phase.
Article
Multidisciplinary Sciences
Zhiqi He, Jose Antonio Moreno, Manisha Swain, Jason Wu, Ohyun Kwon
Summary: In this study, the authors report a cross-coupling reaction that enables the rupture of alkene C(sp(3))-C(sp(2)) bonds using ozonolysis and copper catalysis. This method was used for the construction of new C(sp(3))-N bonds in hormones, pharmaceutical reagents, peptides, and nucleosides. Additionally, the authors demonstrate the synthesis of artificial terpenoid alkaloids and complex chiral amines using abundantly available terpenes and terpenoids.
Article
Physics, Particles & Fields
Ioseph Buchbinder, Evgeny Ivanov, Nikita Zaigraev
Summary: In this study, manifestly 4D, N = 2 supersymmetric and gauge invariant off-shell cubic couplings were constructed for matter hypermultiplets to the higher integer spin gauge multiplets. The cubic coupling structure was q(+)(H) over cap (++ )((s))q(+), and for odd integer spins, the gauge group generators and couplings were proportional to internal symmetry generators, while for even integer spins, the inclusion of internal symmetry generators was not necessary.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Ruguang Wang, Lifu Zhang, Jieqiong Shan, Yuanyuan Yang, Jyh-Fu Lee, Tsan-Yao Chen, Jing Mao, Yang Zhao, Liujing Yang, Zhenpeng Hu, Tao Ling
Summary: In this work, the authors report for the first time the introduction of chalcogen oxygen groups as polar functional groups to break the symmetry of the FeN4 active center in Fe-N-C catalysts, thereby enhancing their oxygen reduction reaction activity. The study provides a new strategy for tuning the local coordination and electronic structure of single-atom catalysts.
Article
Chemistry, Physical
Li Zhang, Xin Cheng, Xiang-Hui Li, Jing-Hua Chen, Wei-Ming Sun
Summary: The adsorption behavior of antiviral drug Favipiravir on BnNn surface has been investigated, and it is found that the drug tends to combine with the boron atoms of BnNn, forming strong polar covalent bonds. The strength of these bonds and the adsorption energy gradually decrease with the increasing size of BnNn. The study provides guidance for the design of drug delivery systems based on BnNn nanocages.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Computer Science, Theory & Methods
Jarkko Kari, Victor H. Lutfalla
Summary: This study focuses on substitution tilings that are also discrete plane tilings. We prove that the Sub Rosa substitution tilings with a 2n-fold rotational symmetry are not discrete planes, and then define new Planar Rosa substitution tilings that satisfy the discrete plane condition. Our methods involve using the lift operator to adjust the tilings and substitutions, and applying linear algebra, properties of circulant matrices, and trigonometric sums to study the planarity of substitution tilings in R-n. The construction of the Planar Rosa substitutions also utilizes the Kenyon criterion and a result on De Bruijn multigrid dual tilings.
DISCRETE & COMPUTATIONAL GEOMETRY
(2023)
Article
Chemistry, Multidisciplinary
Santiago Alonso-Gil, Kamil Parkan, Jakub Kaminsky, Radek Pohl, Takatsugu Miyazaki
Summary: Understanding the conformational changes in sugar moieties is important for studying glycoside hydrolase mechanisms and designing inhibitors. In this study, the conformational pathway of GH92 enzymes was predicted using computational methods and confirmed with experiments. The study also demonstrated the potential of a new type of C-disaccharides for biochemical applications.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Denise-Liu' Leone, Radek Pohl, Martin Hubalek, Marta Kaderabkova, Matous Kromer, Veronika Sykorova, Michal Hocek
Summary: Glyoxal-linked nucleotides were synthesized and used for efficient bioconjugations and crosslinking with arginine-containing peptides or proteins. The reactive glyoxal modification in DNA was found to be more reactive than previously reported 1,3-diketone-linked DNA probes.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Medicine, Research & Experimental
Deniz Genc, Burcu Gunaydin, Serhat Sezgin, Akin Aladag, Emine Figen Tarhan
Summary: The study showed the regenerative potential of dental mesenchymal stem cells in the synovial fluid microenvironment of patients with rheumatoid arthritis, with differentiation into osteogenic and chondrogenic lineage. They may be candidates for tissue regeneration, especially in patients with RA with bone or cartilage erosions.
CYPRUS JOURNAL OF MEDICAL SCIENCES
(2022)
Article
Chemistry, Organic
Perihan Ozturk, Akin Akdag
Summary: This study investigates the chirality induction in the third position of benzo[f]coumarin molecules, and analyzes the spectroscopic properties and chiroptical signals influenced by solvents and hydrogen bonding. The water solubility and ordered aggregations of compounds are enhanced through functional group modification. The results demonstrate that coumarin is sensitive to both the attached chiral unit and conformational changes in the side chain.
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Bengi Senturk, Akin Akdag
Summary: Among photo-switchable compounds, spiropyrans have attracted significant attention due to their multi-responsiveness to changes in pH, solvent polarity, temperature, and light. This study successfully incorporated D and L amino acid derivatives onto a spiropyran with a hydroxyl group to obtain optically active spiropyrans. The results also showed that the benzyl group significantly affects the ring closure rate of merocyanines.
Article
Chemistry, Multidisciplinary
Jacopo Perego, Charl X. Bezuidenhout, Silvia Bracco, Sergio Piva, Giacomo Prando, Cristian Aloisi, Pietro Carretta, Jiri Kaleta, Thi Phuong Le, Piero Sozzani, Andrea Daolio, Angiolina Comotti
Summary: Fluorinated metal-organic frameworks exhibit benchmark mobility of correlated dipolar rotors at low temperatures, with practically zero activation energy. Through various experiments and calculations, the dynamic characteristics and cascade mechanism of dipole configurations have been revealed. It has also been shown that the dipole configurations in the crystal can be changed by chemical stimuli such as CO2.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Adela Krizkova, Guillaume Bastien, Igor Roncevic, Ivana Cisarova, Jiri Rybacek, Vaclav Kasicka, Jiri Kaleta
Summary: In this study, a radical chlorination reaction of cubane-1,4-dicarboxylic acid was reported, resulting in the preferential formation of a monochlorinated derivative (approximately 70%) along with four dichlorinated derivatives (approximately 20% in total). The positions of the chlorine atoms were confirmed by X-ray diffraction analysis. The acidity constants of the different chlorinated cubane dicarboxylates were determined, and their thermal stability was evaluated using differential scanning calorimetry. The reaction pathways and strain energies of the derivatives were investigated through computational calculations.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Vaclav Houska, Egor Ukraintsev, Jaroslav Vacek, Jiri Rybacek, Lucie Bednarova, Radek Pohl, Irena G. Stara, Bohuslav Rezek, Ivo Stary
Summary: The synthesis of helically chiral macrocycles composed of dibenzo[5]helicene units and trans-stilbene-4,4'-diyl linkers is reported. Different stereoisomers of these macrocycles were obtained through chiral resolution. The self-assembly of these macrocycles into long 1D molecular stripes in ordered 2D nanocrystals was studied using AFM.
Article
Chemistry, Organic
Jiri Kaleta, Miroslav Dudic, Lucie Ludvikova, Alan Liska, Alexandr Zaykov, Igor Roncevic, Milan Masat, Lucie Bednarova, Paul I. Dron, Simon J. Teat, Josef Michl
Summary: Three symmetrically and three unsymmetrically substituted cibalackrot dyes have been synthesized and studied for their potential use in molecular electronics and singlet fission. Solution measurements and computational analysis revealed the molecular properties to be close to ideal for singlet fission. However, the crystal structures obtained through XRD showed competition from charge separation, intersystem crossing, and excimer formation. Calculations indicated the difficulty of changing the crystal packing in a desirable direction. Preparation of deuteriated versions of the dyes was also discussed to further investigate the mechanism of fast intersystem crossing.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Kristyna Jelinkova, Aneta Zavodna, Jiri Kaleta, Petr Janovsky, Filip Zatloukal, Marek Necas, Zdenka Pruckova, Lenka Dastychova, Michal Rouchal, Robert Vicha
Summary: Novel binding motifs suitable for the construction of multitopic molecular devices are needed in supramolecular chemistry. In this study, we prepared three model guests and investigated their binding properties towards cucurbit[6]uril (CB6)/7 and alpha-/beta-CD. The new binding motifs showed high selectivity and stability, indicating promising potential in the construction of multitopic supramolecular components.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Vladimir Motornov, Radek Pohl, Blanka Klepetarova, Petr Beier
Summary: Elusive N-acyl-1,2,3-triazoles formed by direct acylation of NH-1,2,3-triazoles were isolated and characterized. Thermodynamic N2 isomers were found to be preferred. Direct evidence of interconversion between N1- and N2-acyltriazoles confirmed their usefulness in denitrogenative transformations. An efficient synthesis of enamido triflates from NH-triazoles via N2-acyl-1,2,3-triazole intermediates was developed.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
David Kodr, Erika Kuzmova, Radek Pohl, Tomas Kraus, Michal Hocek
Summary: We designed and synthesized lipid-modified dNTPs, which served as substrates for DNA polymerase and could be incorporated simultaneously into the DNA strand. These lipid-ON probes showed enhanced membrane anchoring efficiency and better stability in the cell membrane compared to commonly studied ON analogues. The probes were detected at the cell surface even after 24 hours, indicating their long-lasting effect.
Article
Chemistry, Multidisciplinary
Eylul Calikyilmaz, Gozde Karaoglu, Mete Demir, Onur Sahin, Burak Ulgut, Akin Akdag, Yunus Emre Turkmen
Summary: The new scaffold demonstrates efficient intramolecular through-space charge transfer, with electron-rich benzofuran and electron-deficient ynone groups strategically placed in proximity via a naphthalene spacer. The charge transfer is supported by distinct CT bands in the visible region (>500 nm) in their UV-vis absorption and emission spectra.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Anna Kovalova, Vit Prouza, Martin Zavrel, Miroslav Hajek, Rastislav Dzijak, Alzbeta Magdolenova, Radek Pohl, Zdenek Voburka, Kamil Parkan, Milan Vrabel
Summary: This study presents a method for identifying lectin-binding ligands with low micromolar affinity by screening synthetic click glycopeptide libraries. The selected glycopeptides showed enhanced binding potency to the target lectins compared to the starting sugar moieties. This approach offers a promising alternative means of discovering ligands for galectins and other carbohydrate-binding proteins.
Article
Chemistry, Multidisciplinary
Carina Santos Hurtado, Guillaume Bastien, Igor Roncevic, Martin Dracinsky, Teddy Tortorici, Charles T. Rogers, Josef Michl, Jiri Kaleta
Summary: Dielectric spectroscopy was employed to calculate the barriers of rotation for surface-mounted fullerenes. A C-60 derivative with an anchoring group was synthesized to form a surface inclusion with TPP. Solid-state NMR analysis revealed different chemical environments for approximately 50% of the surface-mounted molecules, indicating two distinct insertion modes.
CHEMICAL COMMUNICATIONS
(2023)
