Date of Award

5-2018

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Committee Chair

Hilkka I. Kenttämaa

Committee Member 1

Chittaranjan Das

Committee Member 2

Kavita Shah

Committee Member 3

Julia Laskin

Abstract

Mass spectrometry (MS) is a versatile analytical tool for the characterization of unknown compounds in complex mixtures. MS separates the ionized components of a mixture based on their m/z values and provides accurate molecular weight information and elemental compositions for the ionized analytes. Tandem mass spectrometry (MS/MS) based on collision-activated dissociation or ion-molecule reactions can be used for structural characterization of the ionized analytes. MS/MS can also be used to probe the intrinsic properties of highly reactive intermediates that are difficult to study in solution. The experiments described in this thesis focus on the examination of various gas-phase reactions. A functional group-selective ion-molecule reaction for the identification of carboxylic acid functionalities in protonated drug metabolites was studied in a linear quadrupole ion trap mass spectrometer. This MS/MS method was combined with high-performance liquid chromatography to demonstrate its applicability to high-throughput screening of mixtures. Further, MS/MS was used to study the reactivity of protonated meta-pyridynes toward methanol and the reactivity of two interesting pentaradicals, the 1,2,4,5,7-pentadehydroquinolinium cation and the 1,2,4,6,8pentadehydroquinolinium cation, toward cyclohexane. Gas-phase reaction mechanisms of three charged ortho-pyridynes with furan, tetrahydrofuran and allyl iodide reported in the dissertation of Dr. Bartlomiej J. Jankiewicz were also investigated.

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