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1. UV Study of the Fourth Positive Band System of CO and O i 135.6 nm From Electron Impact on CO and CO 2

   https://doi.org/10.1029/2018JA026308  

   Ajello, J. M. ; Malone, C. P. ; Evans, J. S. ; Holsclaw, G. M. ; Hoskins, A. C. ; Jain, S. K. ; McClintock, W. E. ; Liu, X. ; Veibell, V. ; Deighan, J. ; et al ( April 2019 , Journal of Geophysical Research: Space Physics)

   We have measured the 30 and 100 eV far ultraviolet (FUV) emission cross sections of the optically allowed Fourth Positive Group (4PG) band system (A¹Π → X¹Σ⁺) of CO and the optically forbidden O (⁵S^o → ³P) 135.6 nm atomic transition by electron‐impact‐induced‐fluorescence of CO and CO₂. We present a model excitation cross section from threshold to high energy for theA¹Π state, including cascade by electron impact on CO. TheA¹Π state is perturbed by triplet states leading to an extended FUV glow from electron excitation of CO. We derive a model FUV spectrum of the 4PG band system from dissociative excitation of CO₂, an important process observed on Mars and Venus. Our unique experimental setup consists of a large vacuum chamber housing an electron gun system and the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission Imaging Ultraviolet Spectrograph optical engineering unit, operating in the FUV (110–170 nm). The determination of the total Oi(⁵S^o) at 135.6 nm emission cross section is accomplished by measuring the cylindrical glow pattern of the metastable emission from electron impact by imaging the glow intensity about the electron beam from nominally zero to ~400 mm distance from the electron beam. The study of the glow pattern of Oi(135.6 nm) from dissociative excitation of CO and CO₂indicates that the Oi(⁵S^o) state has a kinetic energy of ~1 eV by modeling the radial glow pattern with the published lifetime of 180 μs for the Oi(⁵S^o) state.

    

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2. 1,2-Azolylamidino ruthenium( ii ) complexes with DMSO ligands: electro- and photocatalysts for CO 2 reduction

   https://doi.org/10.1039/D3DT01122D  

   Jennings, Murphy ; Cuéllar, Elena ; Rojo, Ariadna ; Ferrero, Sergio ; García-Herbosa, Gabriel ; Nganga, John ; Angeles-Boza, Alfredo M. ; Martín-Alvarez, Jose M. ; Miguel, Daniel ; Villafañe, Fernando ( November 2023 , Dalton Transactions)

   Ru(ii) 1,2-azolylamidino-DMSO complexes are herein described. Their electrochemical behavior in CO₂media is consistent with CO₂electrocatalyzed reduction, whereas photocatalytic CO₂reduction experiments lead to CO and trace amounts of formate.

    

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3. Optimized small‐molecule pull‐downs define MLBP 1 as an acyl‐lipid‐binding protein

   https://doi.org/10.1111/tpj.14272  

   Sterlin, Yelena ; Pri‐Tal, Oded ; Zimran, Gil ; Park, Sang‐Youl ; Ben‐Ari, Julius ; Kourelis, Jiorgos ; Verstraeten, Inge ; Gal, Maayan ; Cutler, Sean R. ; Mosquna, Assaf ( March 2019 , The Plant Journal)

   Abscisic acid (ABA) receptors belong to theSTARTdomain superfamily, which encompasses ligand‐binding proteins present in all kingdoms of life.STARTdomain proteins contain a central binding pocket that, depending on the protein, can couple ligand binding to catalytic, transport or signaling functions. In Arabidopsis, the best characterizedSTARTdomain proteins are the 14PYR/PYL/RCAR ABAreceptors, while the other members of the superfamily do not have assigned ligands. To address this, we used affinity purification of biotinylated proteins expressed transiently inNicotiana benthamianacoupled to untargetedLC‐MSto identify candidate binding ligands. We optimized this method usingABA–PYLinteractions and show thatABAco‐purifies with wild‐typePYL5 but not a binding site mutant. TheK_dofPYL5 forABAis 1.1 μm, which suggests that the method has sufficient sensitivity for many ligand–protein interactions. Using this method, we surveyed a set of 37STARTdomain‐related proteins, which resulted in the identification of ligands that co‐purified withMLBP1 (At4G01883) orMLP165 (At1G35260). Metabolite identification and the use of authentic standards revealed thatMLBP1 binds to monolinolenin, which we confirmed using recombinantMLBP1. Monolinolenin also co‐purified withMLBP1 purified from transgenic Arabidopsis, demonstrating that the interaction occurs in a native context. Thus, deployment of this relatively simple method allowed us to define a protein–metabolite interaction and better understand protein–ligand interactions in plants.

    

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4. Light-induced O 2 -dependent aliphatic carbon–carbon (C–C) bond cleavage in bipyridine-ligated Co( ii ) chlorodiketonate complexes

   https://doi.org/10.1039/D2DT03727K  

   Anderson, Stephen N. ; Elsberg, Josiah G. ; Berreau, Lisa M. ( March 2023 , Dalton Transactions)

   Illumination of aerobic acetonitrile solutions of bipyridine-ligated Co(ii) chlorodiketonate complexes results in O₂-dependent aliphatic C–C bond cleavage with high¹⁸O incorporation.

    

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5. Characterization of the Slow Molecular Dynamics of Poly( l ‐Lactic Acid) in α and α′ Phases, in a Glassy State, and in a Complex with Poly( d ‐Lactic Acid) by Solid‐State NMR

   https://doi.org/10.1002/macp.201700451  

   Chen, Wei ; Zhou, Wenxuan ; Makita, Yuta ; Wang, Shijun ; Yuan, Shichen ; Konishi, Takashi ; Miyoshi, Toshikazu ( January 2018 , Macromolecular Chemistry and Physics)

   Recently, slow molecular dynamics of poly(l‐lactic acid) (PLLA) by using 1D and 2D exchange NMR are investigated. In this work, slow molecular dynamics of PLLA chains in the α′, a stereocomplex (SC) with poly(d‐lactic acid), and glassy states are investigated in terms of centerband‐only detection of exchange (CODEX) NMR. The mixing‐time dependence of the CODEX data demonstrates that the molecular dynamics of stems become slower in the order of α′, α, and SC. The temperature dependence of the correlation time 〈τ_c〉 of the helical jump motions in the α and SC phases simply exhibits Arrhenius behaviors, with activation energy,E_a, values of 91 ± 1 and 97 ± 1 kJ mol⁻¹, respectively. In contrast, the temperature dependence of 〈τ_c〉 in the α′ sample exhibits two Arrhenius lines with substantially differentE_avalues of 273 ± 12 and 16 ± 14 kJ mol⁻¹at temperatures below and above 84 °C. The obtained kinetics of molecular dynamics not only establish the relationship between packing structure and dynamics in PLLA polymorphs and in the SC, but also allow for an understanding of the coupled dynamics between the crystalline and amorphous regions at approximatelyT_g.

    

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