Radical cations of cyclopropanes

RADICAL CATIONS OF CYCLOPROPANE SYSTEMS CONJUGATION AND HOMOCONJUGATION WITH ALKENE FUNCTIONS... 

The DCA-sensitized photooxygenation of less electron-rich cyclopropanes in the absence of Mg(C104)2 does not afford 1,2-dioxolanes. However, the photoreaction in the presence of MgfClOJj gives 1,2-dioxolanes in moderate yields [157], In this photoreaction, Mg(C104)2 suppresses not only a back electron transfer from DCA to the radical cations of cyclopropanes, but also the decomposition of the 1,2-dioxolanes produced. 

V. THE RADICAL CATIONS OF CYCLOPROPANES WITH ADDITIONAL STRAIN. 

The radical cations of cyclopropanes are of interest for numerous reasons. The first reason is that because Koopmans theorem equates (to within a sign) the various ionization potentials of a molecule to its various orbital energies, the ionization process thus gives direct information about the electronic (i.e. orbital) interactions in the molecule (see, for example. Ref. 62). Photoelectron spectroscopy on gas phase species is the method of choice for these investigations. We refer the reader to Chapter 5 by Ballard for a more complete discussion of the method and will quote only a few results. 

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