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PART I: STRUCTURE OF FURAN RADICAL CATION AND THE MECHANISM OF ITS REACTION WITH 1,3-BUTADIENE. PART II: THE UNUSUALLY SLOW LOSS OF A HYDROGEN ATOM IN UNIMOLECULAR DISSOCIATION. PART III: ION-MOLECULE REACTIONS OF UNSATURATED ALCOHOLS
Abstract
Part I. We have investigated the ion-molecule reactions of C(,4)H(,4)O radical cations from furan, 2-, and 4-pyrone utilizing the technique of ion-cyclotron resonance spectrometry (ICR). The C(,4)H(,4)O radical cation from furan reacts with 1,3-butadiene to form a {4 + 2} cycloadduct. The furan radical cation serves as the dienophile in this ionic analogue of a Diels-Alder reaction. The intermediate then undergoes a loss of a methyl group involving principally the terminal carbon atom of butadiene. The M-CO ion from both pyrones partly reacts with 1,3-butadiene in the same fashion as that of furan. We conclude, based on this phenomenon, that the structure of M-CO ions from both pyrones possess in part the furan-like structure. Part II. The time-dependence of the decomposition of the diyne compounds (C(,5)-C(,9)), benzonitrile, bibenzyl, m-, and p-aminobibenzyl has been studied using conventional mass spectrometry and ion-cyclotron resonance spectrometry. We have found that the unusually slow loss of a hydrogen atom with respect to residence time was significant in the non-conjugated diyne with six carbons or less. Part III. The ion-molecule reaction of the major fragment ions of unsaturated alcohols and their neutral parents were studied using the ion-cyclotron resonance spectrometry technique. The reactions are significantly different for various isomeric butenols and pentenols and those differences permit each to be identified. The major reaction pathways involve the fragment ion reacting with the neutral alcohol to form intermediate complexes that fragment by loss of water or unsaturated hydrocarbons to give distinctive ion products.
Subject Area
Analytical chemistry
Recommended Citation
PHONGBETCHARA, RUCHA, "PART I: STRUCTURE OF FURAN RADICAL CATION AND THE MECHANISM OF ITS REACTION WITH 1,3-BUTADIENE. PART II: THE UNUSUALLY SLOW LOSS OF A HYDROGEN ATOM IN UNIMOLECULAR DISSOCIATION. PART III: ION-MOLECULE REACTIONS OF UNSATURATED ALCOHOLS" (1981). ETD collection for University of Nebraska-Lincoln. AAI8201038.
https://digitalcommons.unl.edu/dissertations/AAI8201038