Article
Chemistry, Physical
Tomasz Gierczak, Dimitrios K. Papanastasiou, James B. Burkholder
Summary: This study investigated the gas-phase reactions of the Cl atom with c-C5F8 and c-C5HF7 under various temperature and pressure conditions, determining the rate coefficients and product formation. The degradation pathways of c-C5F8 and c-C5HF7 initiated by Cl atom were discussed, revealing their potential atmospheric implications based on experimental and theoretical analyses.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Barbara Noziere, Fabienne Fache
Summary: This study investigated the reactions of organic peroxy radicals with alkenes at room temperature, showing rate coefficients larger than expected from previous combustion studies. The reactions may not be negligible for some substituted RO2, potentially accounting for a significant portion of their sinks in biogenic-rich regions of the atmosphere.
Article
Chemistry, Physical
Kai Song, Huilin Hou, Dongdong Zhang, Fang He, Weiyou Yang
Summary: We have developed an in-situ gas-phase cation exchange strategy to engineer single-atomic Co on the surface of TiO2 photoanode for solar water splitting. The atomically-dispersed Co with Co-O coordination can optimize the surface electronic structures, enhance light absorption, promote photoinduced charge transfer, lower the reaction barrier and accelerate reaction kinetics, leading to improved photoelectrochemical (PEC) behaviors. The TiO2-based photoanodes constructed in this study demonstrate robust stability up to 100 h and a photocurrent density up to 1.47 mA cm-2 at 1.23 V vs. RHE, surpassing pristine TiO2 and showing significant potential for applications.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Engineering, Environmental
Longgang Chu, Long Cang, Guodong Fang, Zhaoyue Sun, Xinghao Wang, Dongmei Zhou, Juan Gao
Summary: The EK-Fenton/CMK3-GDE-CEM system demonstrates promising efficiency in the remediation of PAHs polluted soil, providing a sustainable, eco-friendly, and cost-effective strategy. The modified CMK3-gas diffusion electrode allows continuous H2O2 generation, while the utilization of cation exchange membranes effectively prevents H2O2 decomposition and soil alkalization near the cathode.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Chemistry, Physical
Mitchell W. Alton, Virginia L. Johnson, Sandeep Sharma, Eleanor C. Browne
Summary: Despite investigations, the oxidation chemistry of cyclic volatile methyl siloxanes (VMS) and their environmental fate remains poorly understood. This study uses theoretical calculations to explore the formation of siloxanol from a reaction between a siloxy radical and gas-phase water, investigate the differences in reaction rates between hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4) oxidation, and explain the experimentally observed products. The study finds that the reaction of the siloxy radical with water is too slow to compete with other reactions and cannot fully explain the observed siloxanol formation.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Dylan E. Holst, Diana J. Wang, Min Ji Kim, Ilia A. Guzei, Zachary K. Wickens
Summary: In summary, this study introduces a new synthetic strategy for electrochemically transforming unactivated alkenes into N-alkyl aziridines, expanding the scope of accessible products compared to existing methods.
Article
Chemistry, Physical
Aparajeo Chattopadhyay, Tomasz Gierczak, Paul Marshall, Vassileios C. Papadimitriou, James B. Burkholder
Summary: The rate coefficients for the reaction between Cl and Furan-2,5-dione were measured at various temperatures and pressures, with a proposed atmospheric degradation mechanism based on product yields and theoretical calculations. Experimental and theoretical approaches were used to deduce the reaction mechanism and intermediate products.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Katharina A. E. Meyer, Kathleen A. A. Nickson, Etienne Garand
Summary: Using infrared predissociation spectroscopy, this study revisits the vibrational spectra of alkali metal ion and glycine complexes and finds that the electric field of the metal ion plays a significant role in spectral shifts.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Yuri Ito, Yuji Nakashima, Kenichi Okutsu, Motoyoshi Nakano, Fuminori Misaizu
Summary: The ultraviolet photodissociation processes of gas phase Mg+-NO complex were studied using both experiments and theoretical calculations. The experimental results showed the formation of Mg+ and NO+ ions, and the theoretical calculations explained the origin of these dissociation channels. The NO+ channel exhibited high anisotropy and a larger fraction of translational energy, while the Mg+ channel showed more isotropic angular distribution and less translational energy release.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Review
Chemistry, Multidisciplinary
Agnieszka Mikus, Beata Lopuszynska
Summary: This review discusses nitration reactions of porphyrin derivatives and their importance in providing valuable intermediates for further transformations. The introduction of NO2 group increases the electrophilic character of porphyrins, leading to a broad spectrum of subsequent reactions. This approach allows synthesizing complex porphyrin-like compounds, with nitration substitutions possible at various positions in the porphyrin systems.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Biochemical Research Methods
Guilherme L. Tripodi, Jana Roithova
Summary: This study investigates the application of ArIO as an oxidant for FeII species, revealing its oxidation mechanism and reaction properties, providing theoretical guidance for the design and synthesis of related reactions.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2022)
Article
Chemistry, Multidisciplinary
Pengju Li, Alexander M. Deetz, Jiaming Hu, Gerald J. Meyer, Ke Hu
Summary: This study presents two photocatalytic pathways for chloride oxidation, which generate different oxidation products through different excitation modes. By these pathways, chlorination of unactivated C(sp(3))-H bonds in organic compounds can be achieved.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Xiaoxu Qi, Subramanian Jambu, Yining Ji, Kevin M. Belyk, Nihar R. Panigrahi, Paramjit S. Arora, Neil A. Strotman, Tianning Diao
Summary: Chiral nickel catalysts are used to control the stereoselectivity of radical addition to Dha in oligopeptides, allowing the introduction of various side chains for modification of short peptides.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Mrittika Roy, Wen Fu, Lilia M. Baldauf, James C. Fettinger, R. David Britt, Alan L. Balch
Summary: The oxidation of thianthrene and 10-phenylphenothiazine into cation radicals or coordination complexes has been studied using redox-active Lewis acids. Different redox reactions and crystalline formations were observed depending on the Lewis acid used and the solvent system employed.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Xiaoqing Wu, Can Huang, Jiajue Chai, Feng Zhang
Summary: The study reveals that the weak tertiary C-H bonds in 3-methyl-1-hexene (3-MH) and 2-methylpentanal (2-MP) can react through direct consumption or indirect destruction pathways. The yields of pathways producing precursors of ROO radicals are less than 10% for both reactions.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Biochemical Research Methods
Muhammad A. Zenaidee, Benqian Wei, Carter Lantz, Hoi Ting Wu, Tyler R. Lambeth, Jolene K. Diedrich, Rachel R. Ogorzalek Loo, Ryan R. Julian, Joseph A. Loo
Summary: Analysis of internal fragments in TD-MS experiments can complement terminal fragments, increase protein sequence coverage, and enable more reliable localization of modification sites.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2021)
Article
Chemistry, Analytical
Halle M. Edwards, Hoi-Ting Wu, Ryan R. Julian, Glen P. Jackson
Summary: Understanding a protein's function relies on its detailed structure, with even small changes in the primary structure potentially disrupting function. Long-lived proteins are especially vulnerable to alterations in primary sequence, leading to diseases. Charge transfer dissociation (CTD) can differentiate between isomeric and epimeric forms of Asp in peptides, offering a robust and statistically significant method for analysis.
Article
Chemistry, Multidisciplinary
Courtney Ngai, Hoi-Ting Wu, Bryce Camara, Christopher G. Williams, Leonard J. Mueller, Ryan R. Julian, Richard J. Hooley
Summary: A self-assembled cage structure was synthesized by controlling the self-assembly of internal amines. Despite carrying a positive charge, the structure can extract protons from water in solution. The internal amines have lower basicity compared to their counterparts in free solution. This moderation is a hallmark of enzymatic catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Biochemical Research Methods
Tyler R. Lambeth, Ryan R. Julian
Summary: Radical-directed dissociation (RDD) is a powerful technique for structural characterization of peptides in mass spectrometry experiments. This study explores the use of a radical precursor that can be easily attached in a single step, modifying peptides through a click reaction with iodophenyl isothiocyanate. The results show that the 4-iodo isomer has the highest photodissociation yields and favorable losses of the tag during fragmentation, while 4-iodobenzoic acid, 4-iodophenylthiourea, and 3-iodotyrosine yield similar fragmentation patterns for a given peptide.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2022)
Article
Biochemical Research Methods
Jacob W. Silzel, Tyler R. Lambeth, Ryan R. Julian
Summary: Isomerization of individual residues in long-lived proteins (LLPs) is a growing research topic in age-related diseases. This study presents a novel labeling technique using protein L-isoaspartyl methyltransferase (PIMT) and Tris to rapidly identify L-isoAsp, simplifying the identification process.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2022)
Article
Chemistry, Analytical
Jacob W. Silzel, Gili Ben-Nissan, Jin Tang, Michal Sharon, Ryan R. Julian
Summary: Long-lived proteins (LLPs) play important roles in age-related diseases. Isomerization in LLPs can interfere with protein turnover and digestion. This study examines the effect of isomerization on proteolysis by trypsin and chymotrypsin, and finds that trypsin is relatively tolerant of isomerization while chymotrypsin digestion is less predictable.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Bryce da Camara, Noa Bar Ziv, Veronica Carta, Gabriela A. Mota A. Orozco, Hoi-Ting Wu, Ryan R. Julian, Richard J. Hooley
Summary: Appending functional groups onto Zn4L4 cages can control anion binding by creating a doorstop that slows down guest exchange. The effects on anion exchange depend on factors such as anion size, nature of the leaving anion, and the properties of the pendant groups. The bulky external groups can selectively affect anion ingress and egress, resulting in significant variations in affinity even for similar anions within identically sized cavities.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Analytical
Hoi-Ting Wu, Dylan L. Riggs, Yana A. Lyon, Ryan R. Julian
Summary: Isomeric molecules pose challenges for many analytical methods, including mass spectrometry. In this study, a framework is presented for comparing mass spectra that differ only in terms of peak intensity, allowing for confident identification of peptide isomers. The method can accommodate changes in instrumental settings and enable quantification of isomeric mixtures using calibration curves. This framework may also prove useful in other contexts where similar mass spectra are generated.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Maike Lettow, Kim Greis, Eike Mucha, Tyler R. Lambeth, Murat Yaman, Vasilis Kontodimas, Christian Manz, Waldemar Hoffmann, Gerard Meijer, Ryan R. Julian, Gert von Helden, Mateusz Marianski, Kevin Pagel
Summary: Fucose is a signaling carbohydrate attached to the end of glycan processing. It has various roles in processes like leukocyte adhesion and pathogen-receptor interactions. However, the presence of fucose-containing chimeric fragments in mass-spectrometric analysis has complicated the determination of glycans' structure. In this study, various techniques were used to deduce the rearrangement product of fucose in model trisaccharides Lewis x and blood group H2, with the most likely product being fucose attached to galactose through an alpha(1 -> 6) glycosidic bond.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemical Research Methods
Jacob W. Silzel, Ryan R. Julian
Summary: This study explores the use of higher-energy collisional dissociation (HCD) in radical-directed dissociation (RDD) experiments. The results show that RDD-HCD spectra vary considerably as a function of activation energy, with lower energies favoring RDD and higher energies favoring cleavage directed by mobile protons. It is confirmed that RDD generally proceeds via lower-energy barriers relative to mobile-proton-driven dissociation, and the difference between HCD and CID spectra is due to multiple dissociation events.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2023)
Article
Chemistry, Multidisciplinary
Bryce da Camara, Connor Z. Woods, Komal Sharma, Hoi-Ting Wu, Naira S. Farooqi, Changwei Chen, Ryan R. Julian, Douglas A. Vander Griend, Richard J. Hooley
Summary: Spacious M4L6 tetrahedra can act as catalytic inhibitors for base-mediated reactions by increasing the acidity of the reaction solvent, resulting in a reduced conversion rate of the conjugate addition reaction.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemical Research Methods
Thomas A. Shoff, Ryan R. Julian
Summary: Top-down mass spectrometry (MS), a versatile tool for investigating protein sequence and structure, faces challenges in quantifying differences between spectra generated by different fragmentation methods. This study demonstrates that subtle differences in spectra can reveal protein structure and/or charge localization, even in unfolded proteins observed in high charge states. Additionally, differences in fragmentation shed light on the mechanisms underlying dissociation methods. The results also highlight the impact of experimental parameters on structural changes and the ability to distinguish identical charge states using different ion manipulation techniques.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Connor Z. Woods, Hoi-Ting Wu, Courtney Ngai, Bryce da Camara, Ryan R. Julian, Richard J. Hooley
Summary: Different internal functions can be synthesized with self-assembled Fe4L6 cage complexes by varying the ligand backbone; these cages show differences in guest binding properties and fluorescent emission; structural design variations can affect the affinities and stoichiometries of the cages towards neutral organic substrates.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Analytical
Gaurav Pandey, Ryan R. Julian
Summary: Defects in autophagy are implicated in neurodegenerative diseases, and the isomerization of aspartic acid affects lysosomal degradation, leading to autophagic malfunction.
ANALYSIS & SENSING
(2022)
Article
Biochemistry & Molecular Biology
Tyler R. Lambeth, Zhefu Dai, Yong Zhang, Ryan R. Julian
Summary: Cathepsin B is an important protease in lysosomes, responsible for protein recycling. Recent research has shown that it can also act as a ligase, synthesizing novel peptides through a two-step mechanism involving proteolysis and ligation separately. This dual functionality is dependent on the active site of the enzyme.
RSC CHEMICAL BIOLOGY
(2021)
