The stability of bridgehead carbocations

The gas-phase stability of bridgehead carbocations has been determined by F ourier transform ion cyclotron resonance spectroscopy (FT ICR) based on dis sociative proton attachment (DPA) of bridgehead bromides, chlorides, and al cohols. When appropriate leaving group corrections are applied, the relativ e ion stabilities obtained from these precursors are identical. The relativ e rate constants (log it) for solvolysis of bridgehead derivatives correlat e with the stabilities of the cations over the entire reactivity range. The oretical calculations of the stabilities of the ions relative to those of t he respective hydrocarbons at the MP2/6-311G** level agree fully with the e xperimental data.