Date of Award

1981

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Abstract

Methyl-substituted piperidines, oxanes, 1,3-dioxanes, and cyclohexanones were studied by photoelectron spectroscopy (pes) to determine the mechanism by which alkyl groups stabilize radical cations. Hyperconjugation was found to be the dominant mechanism, while inductive effects and charge-induced polarization were indicated to be less effective. N-Arylazacycloalkanes were studied by pes to correlate solution basicities with ionization potentials (IPs). Conformational analysis of these compounds indicated that aryl-substituted aziridines are coplanar (conjugating) in all cases studied, while ortho substituent(s) may cause rotation and loss of conjugation between the lone pair and the phenyl ring as the amine ring size is increased. N-Phenylpiperidine was indicated to be non-coplanar, despite the lack of ortho substituents. Pes studies of phencyclidine and a number of its analogs demonstrate that the amine lone pair IP changes predictably, depending on the nature and location of the substituent. The phencyclidine analogs which have the lowest IPs are the most reactive in rat behavioral studies and binding studies. Some exocyclic alkenes were studied by pes to try to correlate the IP with the observed reactivity and regioselectivity in 1,3-dipolar cycloadditions. Cumenes and cyclopropylbenzenes were studied in an attempt to correlate IPs with photochemical reactivity studies. Both of these sets of compounds also showed normal substituent effects on the IPs as substituents were added. Three different classes of quinones were studied by semi-empirical and ab initio methods to predict their stabilities and reactivities. The MINDO/3 results are genuine predictions of the thermodynamic stabilities and reactivities of the little known quinones of azulene. 1,5- and 1,7-azuloquinone are predicted to be the most stable and the least susceptible to nucleophilic attack. Benzoquinones and naphthoquinones were studied for comparison to the azuloquinones. STO-3G studies of substituted benzoquinones and naphthoquinones using frontier molecular orbital theory correctly indicate the preferred site(s) of reaction with nucleophiles.

Pages

208

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