Hyperfine interactions of a muoniated ethyl radical in supercritical CO2

Abstract

Abstract A muoniated ethyl radical was studied in supercritical carbon dioxide. The muon and the proton hyperfine coupling constants were measured over temperatures ranging from 305 to 475 K, and a density range from 0.2 to 0.7 (g cm−3). A decrease was found in the muon hyperfine coupling constants as a function of the density, which can be attributed to the interaction between the CO2 molecule and the p-orbital of the ethyl radical. The changes to the α-proton and β-proton hyperfine coupling constants with density are attributed to changes in the overall geometry in the formed radical. This system was modeled using quantum calculations.