Radiochemistry Commons^™

Compact 1 Ghz Electron Paramagnetic Resonance Spectrometers For Preclinical Imaging Studies, Tanden A. Hovey

Electronic Theses and Dissertations

Magnetic resonance is one of the most generally useful scientific techniques. New horizons of understanding are revealed as technological advances make possible explorations of nuclear spins and electron spins at higher and lower magnetic fields and electromagnetic frequencies. While the greatest current effort is on ever higher magnetic fields and microwave frequencies, both in nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR), the Eaton lab focusses on developing high signal-to-noise performance EPR at low microwave frequencies. EPR provides information about O2, pH, viscosity, glutathione concentrations, and reactive oxygen species in living organisms that MRI cannot. To yield clinically or …

Intrinsic Gas-Phase Behavior Of Uranium Species: A Comprehensive Reactivity Study Of [O=U≡Ch]+ And [Uh]+, Justin Terhorst

Electronic Theses and Dissertations

The intrinsic chemistry of actinide elements, particularly uranium, remains a key challenge in understanding f-block reactivity due to the complexity introduced by solvent interactions, counter-ions, and complex equilibria in the condensed phase. In this dissertation, a systematic gas-phase study utilizing preparative tandem ion-trap mass spectrometry (PTMSⁿ) is presented, focusing on the reactivity of uranium-centered species, specifically [OUCH]⁺, an oxy uranium methylidyne species, and [UH]⁺ ions. By stripping away solvent effects and isolating the ions, PTMSⁿ provides a powerful platform to probe the fundamental chemical behavior of uranium species in their intrinsic state.

The …

Electron Spin Relaxation Of Nitroxide Spin Labels And Relaxation Processes, Thacien Ngendahimana

Electronic Theses and Dissertations

MTSL is the nitroxide spin label that is most commonly used in site-directed spin labeling. However, due to rotation of its gem-dimethyl groups that average anisotropic interactions, T_m becomes short above about 70 K and this makes DEER experiments difficult at these temperatures. Strategies for decreasing spin echo dephasing and electron spin lattice relaxation rates are important for design of nitroxide spin labels and molecular qubits.

In searching for labels with longer T_m, new nitroxide spin labels devoid of gemdimethyl groups or with more rigid structures were synthesized at the University of Nebraska and pulsed EPR measurements …