Gas-phase studies of distonic meta-benzyne and carbon-nitrogen ortho-benzyne analogues in a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer and in a flowing-afterglow-triple quadrupole (FA-QqQ) apparatus
Abstract
Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry was employed for the majority of the work discussed in this thesis due to its powerful capabilities. Distonic benzyne ions’ reactivities were examined in the gas phase utilizing the FT-ICR, thereby avoiding difficulties associated with the short-lived nature of these highly reactive species in the condensed phase. High-level molecular orbital calculations were employed to help rationalize experimental results. It has been discovered in our laboratories that some benzyne precursor molecules yield a carbon-nitrogen (CN) ortho-benzyne instead of the desired benzyne. Therefore, a flowing-afterglow-triple quadrupole (FA-QqQ) apparatus was employed to determine the energy thresholds for formation of several CN ortho-benzynes. The results of this study help to rationalize the facile formation of the CN ortho-benzyne moiety. This understanding can be applied to prevent or exploit the formation of the CN ortho-benzyne moiety in the gas phase. Lastly, an investigation into the gas-phase reactivity of metal ion nitrene adducts was conducted. The reactions of the Mg+ and Cu + nitrene adducts with varying substrates involve radical and nonradical pathways, respectively, yielding characteristic reaction products for each adduct. This preliminary result suggests that the reactivity of metal ion nitrene adducts is strongly influenced by the type of the metal ion.
Degree
Ph.D.
Advisors
Kenttamaa, Purdue University.
Subject Area
Analytical chemistry
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