The Infrared and Ultraviolet Spectra of Acrolein

Williamson, Douglas G (1962) The Infrared and Ultraviolet Spectra of Acrolein. PhD thesis, University of Glasgow.

Abstract

The alpha,beta-unsaturated aldehyde acrolein CH2 = CH - CHO and its formyl deuterated derivative acrolein t d1 CH2 = CH- CDO have been synthesised by different methods and their infrared and near ultraviolet spectra recorded. Attempted syntheses of acrolein - d3 CD2 = CD - CHO have resulted in mixtures of isotopic derivatives. With the aid of mass spectroscopic and nuclear magnetic resonance techniques, the compositions of these mixtures have been estimated thereby revealing, in some measure, the mechanistic interpretation of the reaction involved. Measurements of both the infrared and near ultraviolet vapour spectra have enabled frequencies to be assigned to all but two of the eighteen fundamental vibrational modes for each of the two molecules. Two transitions, both of the pi-n type, have been identified in the near ultraviolet region. The lowest energy, a weak triplet system, occurs about 4,061 A. The other transition, characterised by the vibrational analysis. as A"-A', gives rise to a band system having its origin at 3,867 A. Six fundamental vibrations of the upper state. two of them non-totally symmetric, have been identified. The torsional vibration frequencies in the upper state reflect changes in bond order which confirm the diradical nature of the excited state, a concept essential to recent interpretations of photochemical rearrangements.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1962
• Depositing User: Enlighten Team
• Unique ID: glathesis:1962-79469
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Mar 2020 09:18
• Last Modified: 05 Mar 2020 09:18
• URI: https://theses.gla.ac.uk/id/eprint/79469