Adamantylidene cations

If so, one may expect products to result from chemical bond formation between the cation-radical-anion-radical pair, which are both paramagnetic and of opposite charge. In the latter route, there is a precedent for the formation of dioxetane intermediates of stable olefin cation radicals [51], as in the characterization by Nelsen and coworkers of a dioxetane cation radical from adamantylidene cation radical [52]. If a dioxetane is formed, either in neutral form or as a cation radical, the Ti02 surface can function in an additional role, that is, as a Lewis acid catalyst, to induce decomposition of the dioxetane. Since no chemiluminescence could be observed in these reactions, apparently Lewis acid catalysis provides a nonradiative route for cleavage of this high-energy intermediate. That Ti02 can indeed function in this way can be demonstrated by independent synthesis of the dioxetane derived from 1,1-diphenylethylene, which does indeed decompose to benzophenone when it is stirred in the dark on titanium dioxide. 

Recently, in attempts to prepare hindered allyl cations, 2-adamantylidene-l,l-dicyclo-propylethyl cation 47 has been prepared by the ionization of the corresponding 1,3-diol with FS03H or SbF5-FS03H (equation 35)77. The 13C spectrum of the cation at -80 °C... 

The nature of the intermediate cations formed by reaction of adamantylidene-adamantane with electrophiles has also been studied by Olah. The spectra of... 

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