Postprint version. Published in Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, Volume 73, Issue 6, January 1, 1977, pages 829-843.
NOTE: At the time of publication, the author Robert D. Koob was not yet affiliated with Cal Poly.
The definitive version is available at https://doi.org/10.1039/F29777300829.
The molecular structures and bond energies in the low-lying excited states of n-alkanes from methane to n-pentane are investigated using the semi-empirical INDO method with configuration interaction. In general the calculated geometries and bond energies are consistent with the known threshold photochemistry of these molecules, the only exception being the prediction of vicinal (rather than geminal) elimination of H2 in ethane. It appears that INDO overestimates the amount of angular distortion in these excited states.