The Vibrational Spectra and Structures of Organic Acids and Their Derivatives. Volume III. Dimethyl Carbonate and Methyl Cyanoacetate.
Final rept. 1 Jan 73-1 Jan 75,
MIAMI UNIV OXFORD OHIO DEPT OF CHEMISTRY
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The infrared spectra of dimethyl carbonate in the liquid and solid phases and the Raman spectrum of the liquid phase are reported. It is shown that dimethyl carbonate exists an equilibrium mixture of at least two two conformers in the liquid state. An experimental value for the enthalpy difference of the two conformers is obtained from the temperature dependency of the infrared spectrum. Dimethyl carbonate crystallizes as an oriented polycrystalline film and polarized infrared spectra of the solid have been obtained. These have been used, along with the liquid phase data to obtain an improved vibrational assignment. The infrared spectra of methyl cyanoacetate in both liquid and solid phases and of methyl cyanoacetate-d3 in the liquid phase have been recorded in the region 4000-250cm. The Raman spectra of both the compounds in the liquid phase have also been recorded. A tentative vibrational assignment has been made both for the liquid and the heavy ester. Evidence is presented for the existence of conformational isomers in the liquid phase.
- Organic Chemistry