Degree Type

Dissertation

Date of Award

1985

Degree Name

Doctor of Philosophy

Department

Chemistry

Abstract

The flash vacuum pyrolysis of 4-methylbenzocyclobutene and benzocyclobutene-1,1-d(,2) affords labeled styrenes which require the intermediacy of substituted arylcarbenes and cycloheptatetraenes. A deuterium isotope effect of 2.2 is found for the C-H insertion reac- tion of one of the intermediate carbenes. Methyl substituents on the aromatic ring of the arylcarbenes influenced the direction of the migration of the carbene towards the closest methyl substituent;The liquid phase pyrolysis of benzocyclobutene in a high pressure atmosphere of hydrogen gas produces ortho-xylene. The pyrolysis of cyclopentadiene in hydrogen gas produces cyclopentene and cyclopentane. The pyrolysis of benzocyclobutene in deuterium gas produces ortho-xylene with greater than 90% d(,2) incorporation. We interpret the evidence as indicating that hydrogen is adding in a unimolecular fashion across the diene system of ortho-xylylene in a 4+2 manner;Results from the pyrolysis of 1,2-dihydronaphthalene and ortho-divinylbenzene indicate that the ortho-quinodimethane, 2,3-dihydro- naphthalene, cannot be trapped via intra- or inter-molecular Diels-Alder reactions. The presence of 1,2-dihydronaphthalene in the pyrolyzate resulting from the pyrolysis of ortho-divinylbenzene offers possible evidence for 2,3-dihydronaphthalene;The pyrolysis of simple hydroaromatic compounds over active packings such as oxidized copper, zeolite, charcoal and carbon pellets leads to dehydrogenated products and in most cases, fully aromatized ones. It was concluded that quartz chips which were;cleaned by flowing O(,2) gas over the heated chips provided a satisfactorily inert surface; *DOE Report IS-T-1185. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy.

DOI

https://doi.org/10.31274/rtd-180813-12209

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Michael Eugene Scribner

Language

en

Proquest ID

AAI8604518

File Format

application/pdf

File Size

225 pages

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