The proton affinities of amin-alkanes. A test case for the kinetic method

Metastable ion and collision-induced dissociations of proton bound pairs of n-, sec-, and tert-alkyl amines have been studied by tandem mass spectrome try. The logarithms of the product ion ratios were found to be linear funct ions of the proton affinities (PA) of the amines as expected for the "kinet ic method." However, the assumption that transition state entropies were cl osely similar for all pairs proved to be unjustified. Revised PA values for benzylamine and 2-phenylethylamine were proposed. (C) 2000 Elsevier Scienc e B.V.