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1. Monitoring dendrimer conformational transition using 19 F and 1 H 2 O NMR

   https://doi.org/10.1002/mrc.4849  

   Taraban, Marc B. ; Deredge, Daniel J. ; Smith, Margaret E. ; Briggs, Katharine T. ; Li, Yu ; Jiang, Zhong‐Xing ; Wintrode, Patrick L. ; Yu, Yihua Bruce ( March 2019 , Magnetic Resonance in Chemistry)

   The conformational transition of a fluorinated amphiphilic dendrimer is monitored by the¹H signal from water, alongside the¹⁹F signal from the dendrimer. High‐field NMR data (chemical shiftδ, self‐diffusion coefficientD, longitudinal relaxation rateR₁, and transverse relaxation rateR₂) for both dendrimer (¹⁹F) and water (¹H) match each other in detecting the conformational transition. Among all parameters for both nuclei, the water proton transverse‐relaxation rateR₂(¹H₂O) displays the highest relative scale of change upon conformational transition of the dendrimer. Hydrogen/deuterium‐exchange mass spectrometry reveals that the compact form of the dendrimer has slower proton exchange with water than the extended form. This result suggests that the sensitivity ofR₂(¹H₂O) toward dendrimer conformation originates, at least partially, from the difference in proton exchange efficiency between different dendrimer conformations. Finally, we also demonstrated that this conformational transition could be conveniently monitored using a low‐field benchtop NMR spectrometer viaR₂(¹H₂O). The¹H₂O signal thus offers a simple way to monitor structural changes of macromolecules using benchtop time‐domain NMR.

    

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2. Anion Photoelectron Imaging Spectroscopy of C 6 HF 5 – , C 6 F 6 – , and the Absence of C 6 H 2 F 4 –

   https://doi.org/10.1021/acs.jpca.3c04016  

   McGee, Conor J. ; McGinnis, Kristen Rose ; Jarrold, Caroline Chick ( October 2023 , The Journal of Physical Chemistry A)
3. Sensitized Photooxidation of Ortho ‐Prenyl Phenol: Biomimetic Dihydrobenzofuran Synthesis and Total 1O2 Quenching †

   https://doi.org/10.1111/php.13689  

   Jabeen, Shakeela ; Ghosh, Goutam ; Lapoot, Lloyd ; Durantini, Andrés M. ; Greer, Alexander ( September 2022 , Photochemistry and Photobiology)

   The sensitized photooxidation ofortho‐prenyl phenol is described with evidence that solvent aproticity favors the formation of a dihydrobenzofuran [2‐(prop‐1‐en‐2‐yl)‐2,3‐dihydrobenzofuran], a moiety commonly found in natural products. Benzene solvent increased the total quenching rate constant (k_T) of singlet oxygen with prenyl phenol by ~10‐fold compared to methanol. A mechanism is proposed with preferential addition of singlet oxygen to prenyl site due to hydrogen bonding with the phenol OH group, which causes a divergence away from the singlet oxygen ‘ene’ reaction toward the dihydrobenzofuran as the major product. The reaction is a mixed photooxidized system since an epoxide arises by a type I sensitized photooxidation.

    

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4. Luminescence and Scintillation of [Nb 2 O 2 F 9 ] 3– -Dimer-Containing Oxide–Fluorides: Cs 10 (Nb 2 O 2 F 9 ) 3 F, Cs 9.4 K 0.6 (Nb 2 O 2 F 9 ) 3 F, and Cs 10 (Nb 2 O 2 F 9 ) 3 Cl

   https://doi.org/10.1021/acs.inorgchem.1c03787  

   Ayer, Gyanendra B. ; Morrison, Gregory ; Smith, Mark D. ; Jacobsohn, Luiz G. ; zur Loye, Hans-Conrad ( February 2022 , Inorganic Chemistry)
5. Climate warming and tree carbon use efficiency in a whole‐tree 13 CO 2 tracer study

   https://doi.org/10.1111/nph.15721  

   Drake, John E. ; Furze, Morgan E. ; Tjoelker, Mark G. ; Carrillo, Yolima ; Barton, Craig V. M. ; Pendall, Elise ( March 2019 , New Phytologist)

   Autotrophic respiration is a major driver of the global C cycle and may contribute a positive climate warming feedback through increased atmospheric concentrations ofCO₂. The extent of this feedback depends on plants' ability to acclimate respiration to maintain a constant carbon use efficiency (CUE).

   We quantified respiratory partitioning of gross primary production (GPP) andCUEof field‐grown trees in a long‐term warming experiment (+3°C). We delivered a¹³C–CO₂pulse to whole tree crowns and chased that pulse in the respiration of leaves, whole crowns, roots, and soil. We also measured the isotopic composition of soil microbial biomass and the respiration rates of leaves and whole crowns.

   We documented homeostatic respiratory acclimation of foliar and whole‐crown respiration rates; the trees adjusted to experimental warming such that leaf‐level respiration rates were not increased. Experimental warming had no detectable impact on respiratory partitioning or mean residence times. Of the¹³C label acquired by the trees, aboveground respiration consumed 10%, belowground respiration consumed 40%, and the remaining 50% was retained.

   Experimental warming of +3°C did not alter respiratory partitioning at the scale of entire trees, suggesting that complete acclimation of respiration to warming is likely to dampen a positive climate warming feedback.

    

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