Interaction of metal ions and protons with simple biomolecules. Structure information from bond energies and entropy effects

A modified version of the kinetic method that determines bond energies when entropy effects are not negligible is presented. The enthalpic and entropic data derived this way provide unique information on the structures of cationized biomolecules, as demonstrated for alkali ion adducts of nucleobases. The proton affinities of N- and C-terminal breakup products of protonated peptides are also evaluated by the kinetic method, in an effort to gain new insight on the decomposition mechanism of peptide ions.