Date of Award
Master of Science in Chemical Engineering - (M.S.)
Chemical Engineering and Chemistry
William H. Snyder
Howard S. Kimmel
Cis,cis-dipropenyl ether was prepared by potassium t-butoxide catalyzed rearrangement of diallyl ether in diglyme solution. Pyrolysis was used in an attempt to produce an isomeric dipropenyl ether mixture with a high percentage of the less stable trans,trans isomer; 21.6% trans,trans-dipropenyl ether was produced by pyrolysis at 395°C, but formation of an azeotropic byproduct in significant quantities negated the feasibility of this synthesis. A mixture of 45.7% cis,cis-, 43.6% cis,trans-, and 10.7% trans,trans-dipropenyl ether was produced by mercuric acetate catalyzed isomerization at 80°C, and the mixture was separated on a Nester/Faust spinning band column of two hundred theoretical plates.
Physical properties, including boiling point, density, index of refraction, and proton and carbon-13 chemical shifts were determined for all three isomers. Liquid-phase Raman spectra and liquid-phase, vapor-phase, and CCl4 solution infrared spectra were taken on the three dipropenyl ethers and vibrational frequency assignments were made. Conformations have been established based on the vibrational and NMR spectra.
The most stable conformation for cis,cis-dipropenyl ether is the planar C2v form, but a non-planar conformer exists at higher temperatures, in the liquid-phase, and in solution. Trans,trans-dipropenyl ether is slightly more stable in the planar Cs conformation with the planar C2v conformer present at a slightly lower population level. Two Cs conformations are found for cis,trans-dipropenyl ether; the linear coupled Cs planar form is more stable than the bent Cs planar conformation.
Hollein, Helen C., "The preparation, spectra, and conformations of cis, cis-, cis, trans-, and trans, trans- dipropenyl ethers" (1979). Theses. 2059.