Anomalous V/sub 1/reverse arrowN vibrational band intensities in the low energy electron impact spectra of trans-dienes
A detailed examination of the extremely broad and diffuse vibrational structure of the V/sub 1/reverse arrowN allowed valence transition in trans-1,3-butadiene, three related trans-dienes (cis-1,3-pentadiene, trans, trans-2,4-hexadiene, and 2,3-dimethyl-1,3-butadiene), and the cis-diene 1,3-cyclohexadiene has shown that the effect observed previously by Doering, in which the lower vibrational bands of the transition are enhanced in intensity relative to the higher bands at low incident electron energies, occurs in all the trans-dienes studied. This result shows that the effect cannot be due to an underlying, forbidden electronic transition. It appears that in these trans-dienes, the configurational composition of the V/sub 1/ ''state'' depends on the geometry of the molecule and that the configurational components of the excited state that are important in the vertical transition have different electron impact excitation cross sections than those that are important in the adiabatic transition. These results suggest that electron energy loss spectroscopy is a unique tool for probing the configurational composition of certain highly distorted excited states.
- Research Organization:
- Laboratory of Chemical Physics, National Institute of Arthritis, Metabolism and Digestive Diseases, National Institutes of Health, Bethesda, Maryland 20205
- OSTI ID:
- 7053785
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:9; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sulfonated polymeric dispersant compositions for subterranean well drilling, completion, and cementing
Differentiating geometric isomers by laser-ion beam photodissociation
Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
BUTADIENE
COLLISIONS
DATA
DIENES
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
MOLECULE COLLISIONS
NUMERICAL DATA
ORGANIC COMPOUNDS
PENTADIENES
POLYENES
VIBRATIONAL STATES