Binding energies determined from kinetic energy release measurements following the evaporation of single molecules from the molecular clusters H+(H2O)n, H+(NH3)n and H+(CH3OH)n

High resolution mass spectrometry in conjunction with a supersonic source of clusters has been used to record values for the average kinetic energy release that accompanies fragmentation of the molecular cluster ions: H+(H2O)n, H+(NH3)n and H+(CH3OH)n for n in the range 3–30. Using finite heat bath theory, these data have been transformed into binding energies for molecules attached to each of the three cluster systems. For n > 6 the results show quantitative agreement with the strengths of hydrogen bonds expected to be present in the clusters and it is concluded that each cluster fragments via the breaking of a single hydrogen bond.

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► Kinetic energy releases recorded for H+(H2O)n, H+(NH3)n and H+(CH3OH)n clusters.
► Results transformed into binding energies using finite heat bath theory.
► Results show a quantitative agreement with the strengths of hydrogen bonds.
► Concluded that each cluster fragments via the breaking of a single hydrogen bond.