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1. Homogeneous Catalytic Reduction of O 2 to H 2 O by a Terpyridine-Based FeN 3 O Complex

   https://doi.org/10.1021/acs.inorgchem.2c00524  

   Cook, Emma N. ; Hooe, Shelby L. ; Dickie, Diane A. ; Machan, Charles W. ( May 2022 , Inorganic Chemistry)

   We report a new terpyridine-based FeN3O catalyst, Fe(tpytbupho)Cl2, which reduces O2 to H2O. Variable concentration and variable temperature spectrochemical studies with decamethylferrocene as a chemical reductant in acetonitrile solution enabled the elucidation of key reaction parameters for the catalytic reduction of O2 to H2O by Fe(tpytbupho)Cl2. These mechanistic studies suggest that a 2 + 2 mechanism is operative, where hydrogen peroxide is produced as a discrete intermediate, prior to further reduction to H2O. Consistent with this proposal, the spectrochemically measured first-order rate constant k (s−1) value for H2O2 reduction is larger than that for O2 reduction. Further, significant H2O2 production is observed under hydrodynamic conditions in rotating ring-disk electrode measurements, where the product can be swept away from the cathode surface before further reduction occurs. 

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2. The non-covalently bound SO⋯H 2 O system, including an interpretation of the differences between SO⋯H 2 O and O 2 ⋯H 2 O

   https://doi.org/10.1039/C8CP05749D  

   Misiewicz, Jonathon P. ; Noonan, Julia A. ; Turney, Justin M. ; Schaefer, Henry F. ( November 2018 , Physical Chemistry Chemical Physics)

   Despite the interest in sulfur monoxide (SO) among astrochemists, spectroscopists, inorganic chemists, and organic chemists, its interaction with water remains largely unexplored. We report the first high level theoretical geometries for the two minimum energy complexes formed by sulfur monoxide and water, and we report energies using basis sets as large as aug-cc-pV(Q+d)Z and correlation effects through perturbative quadruple excitations. One structure of SO⋯H 2 O is hydrogen bonded and the other chalcogen bonded. The hydrogen bonded complex has an electronic energy of −2.71 kcal mol −1 and a zero kelvin enthalpy of −1.67 kcal mol −1 , while the chalcogen bonded complex has an electronic energy of −2.64 kcal mol −1 and a zero kelvin enthalpy of −2.00 kcal mol −1 . We also report the transition state between the two structures, which lies below the SO⋯H 2 O dissociation limit, with an electronic energy of −1.26 kcal mol −1 and an enthalpy of −0.81 kcal mol −1 . These features are much sharper than for the isovalent complex of O 2 and H 2 O, which only possesses one weakly bound minimum, so we further analyze the structures with open-shell SAPT0. We find that the interactions between O 2 and H 2 O are uniformly weak, but the SO⋯H 2 O complex surface is governed by the superior polarity and polarizability of SO, as well as the diffuse electron density provided by sulfur's extra valence shell. 

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3. Reactivity of O 2 versus H 2 O 2 with polysaccharide monooxygenases

   https://doi.org/10.1073/pnas.1801153115  

   Hangasky, John A. ; Iavarone, Anthony T. ; Marletta, Michael A. ( May 2018 , Proceedings of the National Academy of Sciences)
4. The dual role of bismuth in Li 2 O–Bi 2 O 3 –B 2 O 3 glasses along the orthoborate join

   https://doi.org/10.1111/jace.18699  

   Topper, Brian ; Tsekrekas, Elizabeth M. ; Greiner, Lucas ; Youngman, Randall E. ; Kamitsos, Efstratios I. ; Möncke, Doris ( August 2022 , Journal of the American Ceramic Society)

   The structures of glasses in the lithium–bismuth orthoborate composition range deviate significantly from the short‐range order structure of the two crystalline end‐members. Although binary Li₃BO₃and BiBO₃are solely of comprised trigonal orthoborate anions, all glasses formed by their combination contain four‐coordinated borate tetrahedra. We analyze the structure of (75−1.5x)Li₂O–xBi₂O₃–(25+0.5x)B₂O₃glasses in increments ofx = 5, with¹¹B magic‐angle spinning nuclear magnetic resonance (NMR), infrared (IR), and Raman spectroscopy. For the full series, the oxygen‐to‐boron ratio remains constant at O/B = 3:1. NMR quantifies an increase in the fraction of tetrahedral boron with increasing bismuth oxide content. Evolution of the mid‐IR profile suggests multiple types of tetrahedral boron sites. Raman spectroscopy reveals that Bi₂O₃tends to cluster within the lithium borate matrix when initially introduced and that this behavior transforms into a bismuthate network with increasing bismuth oxide content. In all cases, mixed Bi–O–B linkages are observed. The dual role of bismuth as network modifier and network former is likewise observed in the far IR. The glass transition temperature continuously increases with bismuth oxide content; however, the glass stability displays a maximum in the multicomponent glass ofx = 40.

    

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5. Physical, structural, optical and gamma‐ray shielding properties of Na 2 O‐CdO‐Bi 2 O 3 ‐B 2 O 3 glasses

   https://doi.org/10.1111/ijag.15859  

   Alajerami, Yasser S. ; Drabold, David A. ; Thapa, Rajendra ; Sayyed, M. I. ; Mhareb, M. H. A. ( November 2020 , International Journal of Applied Glass Science)

   The current study shows a new attempt to develop gamma‐ray shielding glasses. The proposed glass is a borate‐base composition modified with sodium and cadmium oxides and different concentrations of bismuth oxide. Based on the melt‐quenching technique, we prepared four glass compositions of 20NaO‐15CdO‐ (65−x)B₂O₃‐xBi₂O₃, wherex = 0, 10, 20, and 30 mol%. The amorphous nature of the prepared samples was confirmed by XRD. To get more details about the structure, FTIR and UV‐Vis‐NIR were performed to characterize the prepared glasses. Moreover, we used ab initio molecular dynamics simulations to create the possible structures of the new compositions, and compared with the experimental measurements. A series of shielding parameters was investigated based on the gamma‐ray emission in the range of 0.01‐10 MeV. The results revealed an improvement of the shielding parameters with increasing of Bi₂O₃content. The sample with the highest Bi₂O₃(S4) has the highestZ_effand least HVL, while S1 (with no Bi₂O₃content) has the lowestZ_effat all energy levels. The gamma‐ray transmission factor of the prepared glasses was compared with some commercial concretes. Finally, the new glasses especially with highest Bi₂O₃are recommended to use in gamma radiation shielding facilities.

    

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