Article
Chemistry, Multidisciplinary
Longhui Duan, Xiaoping Xue, Biqiong Hong, Zhenhua Gu
Summary: A class of highly stable hydrocarbon radicals with helical chirality have been synthesized and their structures, optoelectronic properties, and stability have been investigated through experimental and computational methods.
Article
Chemistry, Physical
Nikki Cecil M. Magdaong, Haoyu Jing, James R. Diers, Christine Kirmaier, Jonathan S. Lindsey, David F. Bocian, Dewey Holten
Summary: This study examines the impact of vibrational-electronic resonances on the rate of excited-state energy transfer and observes ultrafast energy transfer in bacteriochlorin dyads.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Huaiyu Zhang, Yating Wang, Qingrui Lu, Jinshuai Song, Yandong Duan, Yanli Zeng, Yirong Mo
Summary: In the past two decades, boron compounds have attracted increasing attention due to their extraordinary versatility in chemical reactions and applications. One of the notable advancements is the unprecedented preparation of unsaturated boron species. This study focuses on the role of thiol substituents in (CAAC)2B2(SR)2 and identifies the co-planarity of thiol groups and the captodative effect as the reason for its 90 degrees-twisted diradical form. Computational analyses reveal two forces contributing to the pi electron movements, including the push effect of lone pairs on sulfur atoms and the pi electron delocalization within each (CAAC)B(SR) fragment.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Samantha J. Kruse, Harindu Rajapaksha, Leonard R. Macgillivray, Jay A. Laverne, Tori Z. Forbes
Summary: This study evaluates the atomistic-level effects of gamma radiation on organic crystalline materials and explores the relationship between specific noncovalent interactions and structural stability. The results highlight the crucial role of noncovalent interactions in maintaining the structural integrity of these materials.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Fang Zhang, Jianhua Zhou, Hui Liu
Summary: Preferential solvation behavior of rimsulfuron varies in different solvent composition regions, with methanol/ethanol preferentially solvating rimsulfuron and water preferentially solvating in water-rich regions; Analysis using Hansen solubility parameter and linear solvation energy relationships reveals the influence of solvent-solvent and solute-solvent molecule interactions on rimsulfuron solubility variation.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Organic
Kun-Quan Chen, Bei-Bei Zhang, Zhi-Xiang Wang, Xiang-Yu Chen
Summary: In this study, the catalytic ability of N-Heterocyclic nitrenium salts (NHN salts) is explored. It is found that NHN salts can act as catalytic electron acceptors in charge transfer complex photoactivations, facilitating the generation of aryl radicals from aryl halides under blue light irradiation.
Article
Chemistry, Inorganic & Nuclear
Younis Ahmad Pandit, Syed Jehanger Shah, Mohammad Usman, Sabyasachi Sarkar, Eugenio Garribba, Sankar Prasad Rath
Summary: Dinickel(II) and dicopper(II) porphyrin dimers with a long unconjugated dipyrrole bridge were synthesized. The bridge can be oxidized to form a fully pi-conjugated structure, leading to one- and two-electron-oxidized species with long-range charge/radical delocalization. This results in intense absorptions in the near-infrared region and electron paramagnetic resonance signals of a triplet state. Despite the large physical separation, the two metal centers behave as a single unit and efficiently share electrons between them.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Mohammad Rashedul Hasan, Bart-Jan Niebuur, Martin Siebrecht, Bjorn Kuttich, Ralf Schweins, Asaph Widmer-Cooper, Tobias Kraus
Summary: Solvent engineering provides a powerful method to control the colloidal stability of nanoparticles. In this study, the molecular structure of ligand shells on gold nanoparticles was found to affect their stability in solvent mixtures. The agglomeration temperature of the nanoparticles depended on the solvent composition and exhibited different trends in different solvent mixtures. Molecular dynamics simulations revealed that temperature-dependent ligand order played a dominant role in the agglomeration process, while the solvent composition near the ligands significantly influenced the ligand shell ordering. The results highlight the importance of ligand-solvent and solvent-solvent interactions in determining the colloidal stability of nanoparticles in solvent mixtures.
Article
Agricultural Engineering
Giulia Ischia, Jillian L. Goldfarb, Antonio Miotello, Luca Fiori
Summary: This study investigates the enhancement of hydrochars through solvent extraction to improve their potential applications. The results show that solvent washing effectively removes highly volatile species adsorbed on the hydrochar surface.
BIORESOURCE TECHNOLOGY
(2023)
Article
Chemistry, Physical
Yao Xiao, Collin Dominique, Gavat Odile, Carvalho Alain, Moulin Emilie, Giuseppone Nicolas, Guenet Jean-Michel
Summary: The gelation properties of tri-aryl amine (TATA) in two isomers of dichlorobenzene, ortho-dichlorobenzene (o-DCB) and meta-dichlorobenzene (m-DCB), have been studied. The results show that both systems have different behaviors and can form molecular compounds. X-ray and electron microscopy observations reveal differences in morphology between the two gel systems. These findings are significant in understanding the role of the solvent.
Article
Chemistry, Applied
Xiu-min Liu, Ya Liu, Chun-hui Shan, Xin-quan Yang, Qin Zhang, Na Xu, Li-ying Xu, Wen Song
Summary: This study investigated the effects of different extraction methods on flavonoids in jujube, and found that DES-UAE was an efficient method for preserving flavonoid content and stability.
Article
Astronomy & Astrophysics
J. M. Joel Ong, Lisa Bugnet, Sarbani Basu
Summary: This article investigates the effects of rotation on the splitting of internal vibrational modes in stars and the resulting resonance phenomena. Using new developments in the theory of mixed-mode coupling, the researchers discover that near-degenerate mixed-mode pairs can exhibit asymmetric rotational splitting, particularly when pure p-modes and pure g-modes are in resonance. They explore the observational consequences of this asymmetrical splitting and propose improved measurement techniques for rotational characterization.
ASTROPHYSICAL JOURNAL
(2022)
Article
Chemistry, Physical
Feng Bao, Jianhua Han, Da Huang, Chunming Yang, Jianxiao Wang, Xichang Bao, Xigao Jian, Jinyan Wang
Summary: Insulating polymers as the third functional component for organic solar cells have shown potential to enhance power conversion efficiencies, stabilize morphology, and improve device stretchability. Through a ternary copolymerization strategy, PEK-DZ with fine-tuned aggregation behavior and good miscibility with photovoltaic molecules was synthesized, leading to optimized morphological properties and improved device performance through a Forster resonance energy transfer effect. The introduction of PEK-DZ25 in the active layer achieved a high PCE of 17.24%, demonstrating the potential of insulating polymers to be a rational strategy for efficient and stable organic electronics.
CHEMISTRY OF MATERIALS
(2022)
Article
Astronomy & Astrophysics
C. Adam, P. Dorey, A. Garcia Martin-Caro, M. Huidobro, K. Oles, T. Romanczukiewicz, Y. Shnir, A. Wereszczynski
Summary: Antikink-kink collisions in the 06 model exhibit resonant scattering, transferring energy to a collective bound mode of the full over bar KK configuration instead of any bound states. Further evidence is presented for this conjecture, and a collective coordinate model based on this collective bound mode is constructed to accurately reproduce the dynamics of over bar KK scattering. The role of radiation in kink-antikink scattering is also discovered.
Article
Chemistry, Inorganic & Nuclear
Jin-Hyoung Kim, So-Yoen Kim, Sunghan Choi, Ho-Jin Son, Sang Ook Kang
Summary: The study evaluated the impact of bulky substituents on the photophysical properties and efficiency of iridium complexes, revealing that the introduction of a diMePh group in a sterically demanding side-branch can enhance radiative quantum yield and improve efficiency in film form. Through X-ray structural studies and quantum calculations, it was found that the diMePh group maximizes the peripheral effect.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Yunfan Qin, Arthur H. Winter
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Joshua P. Peterson, Arkady Ellern, Arthur H. Winter
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Organic
Julie A. Peterson, Logan J. Fischer, Elizabeth J. Gehrmann, Pradeep Shrestha, Ding Yuan, Chamari S. Wijesooriya, Emily A. Smith, Arthur H. Winter
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Pradeep Shrestha, Komadhie C. Dissanayake, Elizabeth J. Gehrmann, Chamari S. Wijesooriya, Atreyee Mukhopadhyay, Emily A. Smith, Arthur H. Winter
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Organic
Joshua P. Peterson, Arthur H. Winter
Article
Chemistry, Multidisciplinary
Rui Zhang, Arkady Ellern, Arthur H. Winter
Summary: By conjugating formally antiaromatic substituents to the free radical, a new strategy to stabilize free radicals electronically has been described. This strategy successfully stabilizes radicals by providing antiaromaticity relief to the substituent, but only if the antiaromatic substituent is constrained to be planar by synthetically imposed conformational restraints. This work leads to the counterintuitive finding that increasing the antiaromaticity of the radical substituent leads to greater radical stability, providing proof of concept for a new stereoelectronic approach for stabilizing free radicals.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Julie A. Peterson, Ding Yuan, Arthur H. Winter
Summary: By mixing different photoremovable protecting groups, independent optical control over a mixture of photocaged substrates can be achieved through wavelength-selective activation using long-wavelength light.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Rui Zhang, Arkady Ellern, Arthur H. Winter
Summary: This study found that steric hindrance at the para position causes julolidine-derived dicyanomethyl radicals to form sigma dimers rather than pi dimers, contrary to other carbon-centered radicals. This change in dimerization mode can be attributed to weaker London dispersion forces and decreased orbital overlap in the sterically hindered dicyanomethyl radical pi dimers, while the bulky groups have relatively little effect on the energy of the sigma dimer.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Pharmacology & Pharmacy
Elena Contreras-Garcia, Carmen Lozano, Cristina Garcia-Iriepa, Marco Marazzi, Arthur H. Winter, Carmen Torres, Diego Sampedro
Summary: Controlling the activity of pharmaceutical agents using light has the potential to enhance selectivity, reduce adverse effects, and minimize environmental impact. This study presents photoreleasable quinolones that can be activated by visible/NIR light, protected by BODIPY photocages, and regain antimicrobial activity upon light irradiation. A computational study reveals the importance of explicit solvent molecules in the reaction mechanism and the role of solvent-assisted photodissociation. The light-controlled activity of these compounds has been evaluated on quinolone-susceptible E. coli, demonstrating a significant change in antimicrobial activity.
Article
Multidisciplinary Sciences
Lili Du, Juanjuan Wang, Yunfan Qiu, Runhui Liang, Penglin Lu, Xuebo Chen, David Lee Phillips, Arthur H. Winter
Summary: This study reports the detection of a triplet nitrenium ion using spectroscopic methods and calculations, providing insights into the properties and behavior of this important intermediate. Nitrenium ions play crucial roles in chemistry and biology, and the triplet state of nitrenium ions has never been directly observed before.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Antoine Juneau, Iannick Lepage, Sami G. Sabbah, Arthur H. Winter, Mathieu Frenette
Summary: This study reports the unambiguous detection of a free phenoxenium intermediate in the reaction of an electron-rich phenol, 2,4,6-trimethoxyphenol, with (diacetoxyiodo)benzene. It is concluded that the often-postulated free phenoxenium intermediate is unlikely to be a general mechanistic pathway in the reaction of typical phenols with hypervalent iodine reagents. The use of polar solvents or more strongly oxidizing hypervalent iodine reagents can help reduce the formation of radical byproducts and favors the formation of phenoxenium intermediates.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Pradeep Shrestha, Atreyee Mukhopadhyay, Komadhie C. Dissanayake, Arthur H. Winter
Summary: The recent developments in more efficient BODIPY photocages have led to higher photosensitivity and better chemical yields. These photocages can release amines, alcohols, phenols, phosphates, halides, and carboxylic acid derivatives with high quantum yields. The quantum yield of photorelease is related to the quality of the leaving group and the color of the absorbing light.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Medicinal
Elyse M. Digby, Seylan Ayan, Pradeep Shrestha, Elizabeth J. Gehrmann, Arthur H. Winter, Andrew A. Beharry
Summary: A new photosensitizer probe has been designed to enhance the efficacy of photodynamic therapy (PDT) by localizing in the nucleus or cytosol and producing reactive oxygen species (ROS) under light illumination.
JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Pradeep Shrestha, Dnyaneshwar Kand, Roy Weinstain, Arthur H. Winter
Summary: Meso-methyl BODIPY photocages are a novel type of photoremovable protecting groups (PPGs) that release leaving groups upon absorbing visible to near-infrared light.The development of these PPGs, along with their photochemical properties and applications, is summarized in this Perspective. The absorption properties, structure-photoreactivity studies, photoreaction mechanism, range of functional groups that can be caged, chemical synthesis, and the influence of substituents on water solubility and subcellular localization of the PPG are discussed. Applications that utilize the unique optical and photochemical properties of BODIPY PPGs, such as wavelength-selective photoactivation, biological studies, and photomedicine, are also explored.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Sabrina Leichnitz, Komadhie C. Dissanayake, Arthur H. Winter, Peter H. Seeberger
Summary: Protective groups that can be selectively removed under mild conditions are important in carbohydrate chemistry. This study explores different BODIPY protecting groups for their usefulness in glycan synthesis. A BODIPY group with a boron difluoride unit is stable during glycosylations but can be cleaved with green light, as demonstrated by the assembly of a trisaccharide.
CHEMICAL COMMUNICATIONS
(2022)