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1. OH, HO ₂ , and RO ₂ radical chemistry in a rural forest environment: measurements, model comparisons, and evidence of a missing radical sink

   https://doi.org/10.5194/acp-23-10287-2023  

   Bottorff, Brandon; Lew, Michelle M.; Woo, Youngjun; Rickly, Pamela; Rollings, Matthew D.; Deming, Benjamin; Anderson, Daniel C.; Wood, Ezra; Alwe, Hariprasad D.; Millet, Dylan B.; et al (September 2024, Atmospheric Chemistry and Physics)

   Abstract. The hydroxyl (OH), hydroperoxy (HO2), and organic peroxy (RO2)radicals play important roles in atmospheric chemistry. In the presence ofnitrogen oxides (NOx), reactions between OH and volatile organiccompounds (VOCs) can initiate a radical propagation cycle that leads to theproduction of ozone and secondary organic aerosols. Previous measurements ofthese radicals under low-NOx conditions in forested environmentscharacterized by emissions of biogenic VOCs, including isoprene andmonoterpenes, have shown discrepancies with modeled concentrations. During the summer of 2016, OH, HO2, and RO2 radical concentrationswere measured as part of the Program for Research on Oxidants:Photochemistry, Emissions, and Transport – Atmospheric Measurements ofOxidants in Summer (PROPHET-AMOS) campaign in a midlatitude deciduousbroadleaf forest. Measurements of OH and HO2 were made by laser-inducedfluorescence–fluorescence assay by gas expansion (LIF-FAGE) techniques,and total peroxy radical (XO2) mixing ratios were measured by the Ethane CHemical AMPlifier (ECHAMP) instrument. Supporting measurements ofphotolysis frequencies, VOCs, NOx, O3, and meteorological datawere used to constrain a zero-dimensional box model utilizing either theRegional Atmospheric Chemical Mechanism (RACM2) or the Master ChemicalMechanism (MCM). Model simulations tested the influence of HOxregeneration reactions within the isoprene oxidation scheme from the LeuvenIsoprene Mechanism (LIM1). On average, the LIM1 models overestimated daytimemaximum measurements by approximately 40 % for OH, 65 % for HO2,and more than a factor of 2 for XO2. Modeled XO2 mixing ratioswere also significantly higher than measured at night. Addition of RO2 + RO2 accretion reactions for terpene-derived RO2 radicals tothe model can partially explain the discrepancy between measurements andmodeled peroxy radical concentrations at night but cannot explain thedaytime discrepancies when OH reactivity is dominated by isoprene. Themodels also overestimated measured concentrations of isoprene-derivedhydroxyhydroperoxides (ISOPOOH) by a factor of 10 during the daytime,consistent with the model overestimation of peroxy radical concentrations.Constraining the model to the measured concentration of peroxy radicalsimproves the agreement with the measured ISOPOOH concentrations, suggestingthat the measured radical concentrations are more consistent with themeasured ISOPOOH concentrations. These results suggest that the models maybe missing an important daytime radical sink and could be overestimating therate of ozone and secondary product formation in this forest. 

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2. Alcohol-alcohol cross-coupling enabled by S _H 2 radical sorting

   https://doi.org/10.1126/science.adl5890  

   Chen, Ruizhe; Intermaggio, Nicholas E.; Xie, Jiaxin; Rossi-Ashton, James A.; Gould, Colin A.; Martin, Robert T.; Alcázar, Jesús; MacMillan, David W. (March 2024, Science)

   Yeston, Jake S. (Ed.)

   Alcohols represent a functional group class with unparalleled abundance and structural diversity. In an era of chemical synthesis that prioritizes reducing time to target and maximizing exploration of chemical space, harnessing these building blocks for carbon-carbon bond-forming reactions is a key goal in organic chemistry. In particular, leveraging a single activation mode to form a new C(sp³)–C(sp³) bond from two alcohol subunits would enable access to an extraordinary level of structural diversity. In this work, we report a nickel radical sorting–mediated cross-alcohol coupling wherein two alcohol fragments are deoxygenated and coupled in one reaction vessel, open to air. 

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3. One-dimensional antiferromagnetic chain in the cation radical salt α-(BEDT-TTF) ₂ Hg(SeCN) ₂ Cl

   https://doi.org/10.1039/D5CE00007F  

   Henderson, A; Razpopov, A; Biswas, S; Valentí, R; Cui, H; Kato, R; Wei, K; van_Tol, J; Siegrist, T; Schlueter, J A (May 2025, CrystEngComm)

   Electrocrystallization of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) with Hg(SeCN)₂Cl⁻results in α-(BEDT-TTF)₂Hg(SeCN)₂Cl crystals that possesses antiferromagnetic spin chains. 

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4. Relative energetics of CH ₃ CH ₂ O, CH ₃ CHOH, and CH ₂ CH ₂ OH radical products from ethanol dehydrogenation

   https://doi.org/10.1063/5.0062809  

   Williams, Ashley E.; Hammer, Nathan I.; Tschumper, Gregory S. (September 2021, The Journal of Chemical Physics)
5. Formation of the Elusive Silylenemethyl Radical (HCSiH ₂ ; X ² B ₂ ) via the Unimolecular Decomposition of Triplet Silaethylene (H ₂ CSiH ₂ ; a ³ A″)

   https://doi.org/10.1021/acs.jpca.2c01853  

   He, Chao; Thomas, Aaron M.; Dangi, Beni B.; Yang, Tao; Kaiser, Ralf I.; Lee, Huan-Cheng; Sun, Bing-Jian; Chang, Agnes H. (June 2022, The Journal of Physical Chemistry A)