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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Transactinide studies with sulfur macrocyclic extractant using mercury

Mercury extraction has been studied in nitric and hydrochloric acids with hexathia-18-crown-6 dissolved in carbon tetrachloride. Batch study experiments have been performed to determine the best conditions for maximum extraction. In both acids, Hg(II) was best extracted at low molarity while almost no extraction was observed above 2 M. Furthermore, speciation studies were carried out in an attempt to describe the extraction mechanism, but the exact composition of the extracted species was not determined. The extraction kinetics were studied to assess the feasibility of this crown ether for extracting Cn and/or Fl in a future online experiment.

197mHg↗
DOE OSTI2022

Quantum Chemical Treatment of Strongly Correlated Magnetic Systems Based on Heavy Elements. Final Report

The objective of this project over the years has been to develop novel quantum chemical methods and employ them to study the chemistry of systems containing actinides, and transactinides. We have focused on their electronic and spectroscopic properties, their reactivity and utilization as single molecule magnets. We have developed wave-function based methods that are optimal to treat strongly correlated systems, namely systems with many electronic configurations that are all important and should be treated on an equal foot. Moreover, relativistic effects have to be included in the model, with special focus on spin-orbit coupling. We have derived our theories and developed our codes and made them available to the community as parts of open source packages. We have modelled systems in collaboration with experimentalists in the program, so that we could address some of the questions that are relevant to this community. We have also worked in collaboration with people at Lawrence Livermore National Laboratories on a project on super-heavy atoms. We hope that our theoretical predictions will inspire novel experiments. We have trained about 10 students/postdocs during this period, which are now faculty, researchers at national laboratories and in companies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Assessment of the Second-Ionization Potential of Lawrencium: Investigating the End of the Actinide Series with a One-Atom-at-a-Time Gas-Phase Ion Chemistry Technique

Experiments were performed at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron facility to investigate the electron-transfer reduction reaction of dipositive Lr ( Z = 103) with O 2 gas. Ions of 255 Lr were produced in the fusion-evaporation reaction 209 Bi( 48 Ca,2n) 255 Lr and were studied with a novel gas-phase ion chemistry technique. The produced 255 Lr 2+ ions were trapped and O 2 gas was introduced, such that the charge-exchange reaction to reduce 255 Lr 2+ to 255 Lr 1+ was observed and the reaction rate constant was determined to be k = 1.5(7) × 10 -10 cm 3 /mol/s. The observation that this reaction proceeds establishes the lower limit on the second ionization potential of Lr to be 13.3(3) eV. This gives further support that the actinide series terminates with Lr. Additionally, this result can be used to better interpret the situation concerning the placement of Lu and Lr on the periodic table within the current framework of the actinide hypothesis. The success of this experimental approach now identifies unique opportunities for future gas-phase reaction studies on actinide and super heavy elements.

36 MATERIALS SCIENCE↗