Novel cyclobutene-fused aromatic systems

dc.contributor.advisorThummel, Randolph Paul
dc.contributor.committeeMemberWelch, Steven C.
dc.contributor.committeeMemberDeming, Stanley N.
dc.contributor.committeeMemberAlbright, Thomas A.
dc.contributor.committeeMemberWeinheimer, Alfred J.
dc.creatorChayangkoon, Paochai
dc.description.abstractThe insertion of methylene into the aromatic ring of benzocyclobutene leads to a mixture of cyclobutene-fused cyclOheptatrienes. Treatment of this mixture with a trityl salt affords the cyclobutene-fused tropylium salt in essentially pure form. If this same synthetic approach is applied to other annelated benzenes, bis- and tris-annelated salts can be prepared. The proton and carbon-13 nmr spectra of a series of annelated tropylium salts have been analyzed and interpreted in terms of a rehybridization theory. With decreasing size of the annelated rings the chemical shift of the carbon ortho to the bridgehead moves upfield and the chemical shift of the bridgehead carbons moves downfield. The aromatic proton chemical shift of the annelated tropylium salts shows anomalous behavior but the aromatic C-H coupling constant increases with the decreasing size of the annelated rings. A shift to longer wavelength absorption in the UV is observed upon increasing annelation. The molar absorptivity (extinction coefficient) is found to increase as the size of the fused rings is decreased. [...]
dc.description.departmentChemistry, Department of
dc.format.digitalOriginreformatted digital
dc.rightsThis item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. Section 107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder.
dc.subjectAromatic compounds
dc.subjectAlicyclic compounds
dc.titleNovel cyclobutene-fused aromatic systems
dc.type.genreThesis of Natural Sciences and Mathematics, Department of of Houston of Philosophy


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