The relative reactivity and basicity of CH bonds in C3–C5 alkanes was studied using the strongest deuterated superacid, DF–SbF5, at various concentrations of SbF5. In all cases, at concentrations up to approximatively 18 mol% SbF5 in DF (HF), the predominant reaction, beside minor protolytic cleavage, was rapid isotope exchange of all C–H bonds via reversible protonation. The relative rate of exchange follows the Olah σ-basicity concept: ...
