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1. Uranium Isotope Fractionation in Non‐sulfidic Anoxic Settings and the Global Uranium Isotope Mass Balance

   https://doi.org/10.1029/2020GB006649  

   Cole, Devon B.; Planavsky, Noah J.; Longley, Martha; Böning, Philipp; Wilkes, Daniel; Wang, Xiangli; Swanner, Elizabeth D.; Wittkop, Chad; Loydell, David K.; Busigny, Vincent; et al (August 2020, Global Biogeochemical Cycles)

   Abstract Uranium isotopes (²³⁸U/²³⁵U) have been used widely over the last decade as a global proxy for marine redox conditions. The largest isotopic fractionations in the system occur during U reduction, removal, and burial. Applying this basic framework, global U isotope mass balance models have been used to predict the extent of ocean floor anoxia during key intervals throughout Earth's history. However, there are currently minimal constraints on the isotopic fractionation that occurs during reduction and burial in anoxic and iron‐rich (ferruginous) aquatic systems, despite the consensus that ferruginous conditions are thought to have been widespread through the majority of our planet's history. Here we provide the first exploration of δ²³⁸U values in natural ferruginous settings. We measured δ²³⁸U in sediments from two modern ferruginous lakes (Brownie Lake and Lake Pavin), the water column of Brownie Lake, and sedimentary rocks from the Silurian‐Devonian boundary that were deposited under ferruginous conditions. Additionally, we provide new δ²³⁸U data from core top sediments from anoxic but nonsulfidic settings in the Peru Margin oxygen minimum zone. We find that δ²³⁸U values from sediments deposited in all of these localities are highly variable but on average are indistinguishable from adjacent oxic sediments. This forces a reevaluation of the global U isotope mass balance and how U isotope values are used to reconstruct the evolution of the marine redox landscape. 

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2. Convenient Syntheses of Trivalent Uranium Halide Starting Materials without Uranium Metal

   https://doi.org/10.1021/acs.inorgchem.1c00598  

   Fetrow, Taylor V.; Grabow, J. Peter; Leddy, Johna; Daly, Scott R. (June 2021, Inorganic Chemistry)

   null (Ed.)
3. Synthesis and Structure of Uranium‐Silylene Complexes

   https://doi.org/10.1002/chem.202000214  

   Brackbill, I. Joseph; Douair, Iskander; Lussier, Daniel J.; Boreen, Michael A.; Maron, Laurent; Arnold, John (February 2020, Chemistry – A European Journal)
4. Uranium: The Nuclear Fuel Cycle and Beyond

   https://doi.org/10.3390/ijms23094655  

   Costa Peluzo, Bárbara Maria; Kraka, Elfi (May 2022, International Journal of Molecular Sciences)

   This review summarizes the recent developments regarding the use of uranium as nuclear fuel, including recycling and health aspects, elucidated from a chemical point of view, i.e., emphasizing the rich uranium coordination chemistry, which has also raised interest in using uranium compounds in synthesis and catalysis. A number of novel uranium coordination features are addressed, such the emerging number of U(II) complexes and uranium nitride complexes as a promising class of materials for more efficient and safer nuclear fuels. The current discussion about uranium triple bonds is addressed by quantum chemical investigations using local vibrational mode force constants as quantitative bond strength descriptors based on vibrational spectroscopy. The local mode analysis of selected uranium nitrides, N≡U≡N, U≡N, N≡U=NH and N≡U=O, could confirm and quantify, for the first time, that these molecules exhibit a UN triple bond as hypothesized in the literature. We hope that this review will inspire the community interested in uranium chemistry and will serve as an incubator for fruitful collaborations between theory and experimentation in exploring the wealth of uranium chemistry. 

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5. Conversion of Trivalent Uranium Anilido to Tetravalent Uranium Imido Species via Oxidative Deprotonation

   https://doi.org/10.1021/acs.inorgchem.0c01704  

   Perales, Diana; Ford, Shannon A.; Salpage, Sahan R.; Collins, Tyler S.; Zeller, Matthias; Hanson, Kenneth; Bart, Suzanne C. (September 2020, Inorganic Chemistry)

   null (Ed.)