Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 1, 1975 | Published
Journal Article Open

Electronic spectroscopy of trans-azomethane by electron impact


The electron impact excitation of trans-azomethane (i.e., trans-dimethyl diazine CH3–N–N–CH3) has been studied by both trapped electron (TE) and differential electron scattering (DES) techniques. The nature of the excited state in each of several transitions has been identified by the energy and angular dependences of the excitation cross section. Two previously unreported singlet-->triplet transitions are observed with maxima at 2.75 and 4.84 eV. Theoretical calculations on the parent compound, trans-diimide (H–N=N–H), suggest that these are the χ 1Ag-->1 3Bg (produced by excitation of an electron from an n + molecular orbital to a pi* molecular orbital) and the χ 1Ag-->1 3Bu (pi-->pi*) transitions, respectively. The χ 1Ag-->1 1Bg (n + -->pi*) transition is observed with a peak at 3.50 eV in the DES studies. A strong peak at 6.01 eV in the TE spectra appears as a weak shoulder in the DES studies and is interpreted as either a symmetry-forbidden or Rydberg-like singlet-->singlet transition. Allowed singlet-->singlet features overlap each other in the transition energy range from 6 to 10 eV. Peaks are seen in the DES spectra at 6.71, 7.8, and 9.5 eV and in the TE spectrum at 8.0 eV. Several significant differences between the TE and the DES spectra are analyzed on the basis of the different nature of the two experiments.

Additional Information

© 1975 American Institute of Physics. (Received 22 April 1974) We thank Dr. M.B. Robin, Dr. N.W. Winter, and Dr. W.A. Goddard III for several helpful discussions. We also thank Dr. Winter for communication of his theoretical results prior to their publication. Work supported in part by the United States Atomic Energy Commission under Grant Numbers AT(04-3)-767 PA No. 4 and AT(04-3)-767-8 awarded to A. Kuppermann and J.L. Beauchamp, respectively. Report Code CALT-767P4-131. Work performed [by O.A.M. and M.S.F. (http://resolver.caltech.edu/CaltechETD:etd-09202007-08024)] in partial fulfillment of the requirements for the Ph.D. degree in Chemistry at the California Institute of Technology. Arthur Amos Noyes Laboratory of Chemical Physics, Contribution No. 4870.

Attached Files

Published - MOSjcp75b.pdf


Files (539.6 kB)
Name Size Download all
539.6 kB Preview Download

Additional details

August 22, 2023
October 16, 2023