The tert‐Butyl Cation in H‐Zeolites: Deprotonation to Isobutene and Conversion into Surface Alkoxides

All experimental attempts to identify the tert-butyl carbenium ion in zeolites have been unsuccessful. Calculations with the hybrid MP2:DFT method predict that this ion is less stable than the isomeric surface species isobutene, isobutoxide, and tert-butoxide, but once it has been formed as an intermediate it will survive long enough (59 μs) to be detected by laser spectroscopy (see picture; O red, Si yellow, Al magenta, C green).