Knowledge Bank

Electron transmission $spectroscopy1$ has been used to investigate the through-bond interaction of the $\pi \ast$ molecular orbitals (MD's) of the non-conjugated dienes: [FIGURE] The electron affinities, derived from the electron transmission spectra, of these compounds, their monoene analogues, ethylene, 2-butene, norbornene, and norbornadiene are utilized to determine the interactions of the $\pi \ast$ MO's with the fing o and $o\ast$ MO's. The splittings and shifts in the $\pi \ast$ MO's are compared with those in the filled $\pi \ast$ MO's as determined from photoelectron $spectroscopy2$ and with the results of MO calculations.