Using Fourier transform ion cyclotron resonance mass spectrometry and linear quadrupole ion trap mass spectrometry for the study of polyradicals and the structural elucidation of unknowns in mixtures

Phenyl mono- and biradicals play important roles, for example, in organic synthesis and in the biological activity of certain drugs. The presence of unpaired electrons lends these species unique chemical properties. Many parameters may be involved in controlling their reactivity. A better understanding of these parameters may lead to the ability to alter, or tune, the reactivity of radical species, which would be highly desirable. Therefore, studies leading to an improved understanding of these reactive intermediates are needed. While the chemical properties of many pyridine-based σ-type mono-, bi- and triradicals have been studied, the behavior of pyridine-based tetraradicals is still unknown. There are also many aspects of the effects of substituents on radical reactivity that remain unclear. This thesis describes the generation of a pyridine-based σ,σ,σ,σ-tetraradical, as well as studies on the effects of the hydroxy substituent on the reactivity of σ-monoradicals. Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry was employed for these studies. In addition to aiding fundamental studies, as described above, mass spectrometry is also an extremely valuble tool in the field of mixture analysis and structural elucidation of unknown compounds. Especially, tandem mass spectrometry (MS/MS) coupled with collision-activated dissociation (CAD) provides a wealth of structural information for unknown analytes directly in mixtures. In this thesis, a linear quadrupole ion trap (LQIT) mass spectrometer coupled with high-performance liquid chromatography (HPLC) was demonstrated to allow detailed structural characterization of unknown organic compounds in mixtures