SPECTROSCOPIC STUDIES OF SOME AROMATIC DECOMPOSITION INTERMEDIATES

A number of aromatic radicals have been produced and identified. A re-examination has been made of spectra from discharges through toluene and toluene-alpha-d, In each case a vibrational frequency analysis has been carried out on the bands: to the violet of the (0,0) band. The fundamental frequencies derived for the benzyl radical have been used to interpret the visible region absorption spectrum of the radical and to show that the furthermost red band is the (0,0) band. An analysis has also been made of the benzyl radical emission spectrum recorded by Schuler and Kusjakow. Electronic emission spectra in the visible region have been recorded from mild radio-frequency discharges through paradisubstituted benzenes and alkylnaphthalenes. Vibrational analyses were performed on the spectra having sufficient bands: to merit this. A comparison of fundamentals and assignments with those of the parent molecule has aided the determination of the structure of the emitter. Use has been made of isotopic substitution in an examination of aromatic aldehydes and ketones to show that the emitter of a spectrum associated with the presence of benzaldehyde in a discharge is the original molecule. Electronic absorption spectra in the ultra-violet region have been obtained from radicals formed by photolysis- of paradisubstituted benzenes in methylcyclohexane-isopentane or ether- isopentane-ethanol solvent mixtures at 77°K« The structures of the radicals have been deduced by consideration of the furthermost red band in the spectrum and by the application of the generalizations of Porter and Strachan2 concerning the relative probabilities of dissociation at a 3-bond. Radicals of the general formulae RC6H4CH2 and RC6H4CHCH3 where R represents an alkyl group, and XCH2C6H4CH2 where X represents Cl or COOH, have been identified. Evidence has also been found for the formation of permanent products. These were probably disubstituted hexat- rienes.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

1963

Author dc:creator

• Watts, Alan Thomas

Licence

• https://dora.dmu.ac.uk/bitstreams/cc4937f3-7e26-453f-9411-2a42ee40dfb7/download