James M. Macoun

Smith, Harlan I.

doi:10.1126/science.51.1324.478

Cited by 3 publications

(3 citation statements)

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“…It is well-known that such a redistribution reaction can be observed in heavy-main-group chemistry such as antimony and organobismuth in group 15 elements . On the other hand, there are few reports about the redistribution reaction with arsenic . Therefore, we considered that AsBr 3 could be converted to bromoarsine derivatives (R 2 AsBr) through redistribution reactions with AsR 3 .…”

Section: Resultsmentioning

confidence: 99%

Fundamental Study on Arsenic(III) Halides (AsX₃; X = Br, I) toward the Construction ofC₃-Symmetrical Monodentate Arsenic Ligands

et al. 2020

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Arsenic ligands have attracted considerable attention in coordination chemistry. Arsenic(III) halides are the most important starting materials in the preparation of monodentate arsenic ligands. In this work, we optimized the synthetic methodologies of arsenic(III) halides (AsX 3 ; X = Br, I) and examined the difference of their physical properties such as solubility to organic solvent and reactivity to nucleophiles. In addition, a wide variety of monodentate arsenic ligands were prepared with the obtained AsX 3 . Finally, the obtained monodentate arsenic ligands were utilized for copper-free Sonogashira cross-coupling reaction in the reaction system with porphyrin. The results showed that monodentate arsenic ligands have higher catalytic activity compared with triphenylphosphine because of the difference of the electronic features of lone pairs between arsenic and phosphorus atoms.

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Section: Resultsmentioning

confidence: 99%

Fundamental Study on Arsenic(III) Halides (AsX₃; X = Br, I) toward the Construction ofC₃-Symmetrical Monodentate Arsenic Ligands

et al. 2020

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“…New protein sequences can be generated by e. g . directed evolution [116–118] or site directed mutagenesis techniques [119,120] and selected on functionality, [121] leading to acceptance of new substrates, [122,123] new‐to‐nature reactions, [123–126] or enhanced properties such as thermal stability or resistance against solvent denaturation [127,128] …”

Section: Proteinsmentioning

confidence: 99%

Protein‐Inspired Control over Synthetic Polymer Folding for Structured Functional Nanoparticles in Water

Wijker

Palmans

2023

ChemPlusChem

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The folding of proteins into functional nanoparticles with defined 3D structures has inspired chemists to create simple synthetic systems mimicking protein properties. The folding of polymers into nanoparticles in water proceeds via different strategies, resulting in the global compaction of the polymer chain. Herein, we review the different methods available to control the conformation of synthetic polymers and collapse/fold them into structured, functional nanoparticles, such as hydrophobic collapse, supramolecular self‐assembly, and covalent cross‐linking. A comparison is made between the design principles of protein folding to synthetic polymer folding and the formation of structured nanocompartments in water, highlighting similarities and differences in design and function. We also focus on the importance of structure for functional stability and diverse applications in complex media and cellular environments.

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“…DNA is a prime biological molecule because it contains genetic instructions for the growth and function of the cells that constitute all living organisms . Alterations to the genetic integrity affect normal life processes .…”

mentioning

confidence: 99%

Photoexcitation Dynamics of Thymine in Acetonitrile and an Ionic Liquid Probed by Time‐resolved Infrared Spectroscopy

Manna

Park

Lee

et al. 2016

Bulletin Korean Chem Soc

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Femtosecond transient IR absorption spectroscopy was used to probe the decay mechanism of electronically excited thymine (a naturally occurring pyrimidine base in DNA) dissolved in an ionic liquid ([Bmim][BF 4 ]) or CD 3 CN after the absorption of UV light (267 nm). In both solvents, an absorption band grew on a picosecond timescale, along with decaying bleach and evolving red-shifted absorption signals. A population analysis of the observed kinetic data suggested that most of the photoexcited thymine underwent a sub-picosecond non-radiative relaxation to the vibrationally hot ground electronic state. About 4% (16%) of the excited thymine in the ionic liquid (CD 3 CN) relaxed to an intermediate electronic state, which relaxed into a low-lying triplet state by intersystem crossing (ISC) (ISC did not relax to the ground electronic state within the experimental period (1 ns)). The low ISC yield for thymine in an ionic liquid was correlated with molecular properties of the solvent. This observation is significant because the ISC to triplet state transition for excited thymine has been considered as a precursor to cyclobutane-pyrimidine dimer formation, which led to functional damage of the base after UV absorption. This finding may shed light on the photostability of DNA in ionic liquids. Keywords: Femtosecond infrared spectroscopy, Thermal relaxation, Cyclobutane-pyrimidine dimer,Ionic liquid, Photostability of thymine DNA is a prime biological molecule because it contains genetic instructions for the growth and function of the cells that constitute all living organisms. 1,2 Alterations to the genetic integrity affect normal life processes. 2 In addition to its biological significance, DNA is increasingly used as a powerful nanotechnology tool due to its conformational polymorphism (e.g., as a hybrid catalyst in the synthesis of highly enantioselective and asymmetric molecules). 3-6 DNA structure and stability preservation is hindered by a lack of appropriate media. 7,8 Aqueous solutions are considered an important DNA preserver for short-and long-term applications 8,9 ; however, the low solubility of organic reactants in water hinders further efficient use of aqueous solutions.In this context, ionic liquids (ILs) have been established as a unique non-aqueous solvent to preserve DNA for longterm use at ambient temperatures. 10,11 ILs contain an organic cation and an inorganic or organic anion with minimal symmetry; they remain liquid below 373 K. 12-15 ILs possess unique green solvent characteristics, such as a negligible vapor pressure, low flammability, wide solubility range, chemical inertness, and wide electrochemical window. 13,16,17 Electrostatic interactions among the IL cation and DNA (i.e., hydrophobic interactions between the hydrocarbon chains of the IL and the bases of DNA) and intermolecular hydrogen bonding between the anion of the IL and the bases of DNA have been established as the main causes for the high stability of DNA in ILs. 11,18-21 So far, examinations of the interactions between DNA and ILs ...

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James M. Macoun

Cited by 3 publications

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Fundamental Study on Arsenic(III) Halides (AsX₃; X = Br, I) toward the Construction ofC₃-Symmetrical Monodentate Arsenic Ligands

Fundamental Study on Arsenic(III) Halides (AsX₃; X = Br, I) toward the Construction ofC₃-Symmetrical Monodentate Arsenic Ligands

Protein‐Inspired Control over Synthetic Polymer Folding for Structured Functional Nanoparticles in Water

Photoexcitation Dynamics of Thymine in Acetonitrile and an Ionic Liquid Probed by Time‐resolved Infrared Spectroscopy

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James M. Macoun

Cited by 3 publications

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Fundamental Study on Arsenic(III) Halides (AsX3; X = Br, I) toward the Construction ofC3-Symmetrical Monodentate Arsenic Ligands

Fundamental Study on Arsenic(III) Halides (AsX3; X = Br, I) toward the Construction ofC3-Symmetrical Monodentate Arsenic Ligands

Protein‐Inspired Control over Synthetic Polymer Folding for Structured Functional Nanoparticles in Water

Photoexcitation Dynamics of Thymine in Acetonitrile and an Ionic Liquid Probed by Time‐resolved Infrared Spectroscopy

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Fundamental Study on Arsenic(III) Halides (AsX₃; X = Br, I) toward the Construction ofC₃-Symmetrical Monodentate Arsenic Ligands

Fundamental Study on Arsenic(III) Halides (AsX₃; X = Br, I) toward the Construction ofC₃-Symmetrical Monodentate Arsenic Ligands