THE MICROWAVE SPECTRUM OF PIVALALDEHYDE,

Abstract

The microwave spectrum of pivalaldehyde ((CH3)3CCHO) was investigated in the frequency region 9-40 kMc/sec. The ground state, first and second excited states of the t-butyl torsion, and the first excited state of each of the three methyl torsions were assigned. The barrier to internal rotation of the t-butyl top was calculated from the splittings in the first excited state to be 1186 cal/mole, from the splittings in the second excited state to be 1176 cal/mole, and from the intensities of the first excited state relative to the ground state to be 1100 cal/mole. The excited states of the methyl torsions show no splittings, but the relative intensities yield barrier estimates of 2600 cal/mole, 3500 cal/mole, and 3800 cal/mole, if one assumes that the three tops are independent. On the basis of certain analogies with previously investigated molecules the lowest of these barriers is very tentatively assigned to a methyl group which is eclipsed with respect to the oxygen atom. The dipole moment components were computed from Stark effect measurements to be mu-a = 2.56 D and mu-b = 0.76 D. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 14, 1966
Accession Number
AD0645777

Entities

People

  • A. M. Ronn
  • R. C. Woods

Organizations

  • Harvard University

Tags

DTIC Thesaurus Topics

  • Atoms
  • Diffraction
  • Dipole Moments
  • Electromagnetic Spectra
  • Frequency
  • Ground State
  • Intensity
  • Measurement
  • Microwaves
  • Molecules
  • Rotation
  • Spectra
  • Splitting
  • Stark Effect
  • Wave Phenomena

Readers

  • Chemistry (specifically Chemical Fluorescence)
  • Materials Science and Engineering.