Gerhard J. Fonken

Photoelectron spectra of molecules. Part VII. Cyclopropylallenes

A series of alkyl-substituted cyclopropylallenes have been investigated by p.e. spectroscopy using the HeI resonance line and the MINDO/3 method. In all cases studied the highest occupied MO is thought to be the π-MO adjacent to the three-membered ring. Comparison of the allenes with the corresponding vinylcyclopropanes indicates little, if any, interaction occurs between MOs of the cyclopropyl ring and the nonadjacent double bond. MINDO/3 calculations of the dicyclopropyl compounds, assuming the known bisected conformation, led to accurate predictions of splittings between the double bond and the MO of the cyclopropane possessing π-type symmetry.