Absolute binding energies of sodium ions to short chain alcohols, CnH2n+2O, n=1-4, determined by threshold collision-induced dissociation experiments and ab initio theory

Collision-induced dissociation of Na+(ROH) with xenon is studied using guided ion beam mass spectrometry. ROH includes the following eight short chain alcohols: methanol, ethanol, 1-propanol, 2-propanol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol. In all cases, the primary product formed corresponds to endothermic loss of the neutral alcohol. The only other products that are observed in these reactions are the result of ligand exchange processes to form NaXe+. The cross section thresholds are interpreted to yield 0 and 298 K bond energies for Na+-ROH after accounting for the effects of multiple ion-molecule collisions, internal energy of the reactant ions, and dissociation lifetimes. Ab initio calculations at several levels of theory compare favorably to the experimentally determined bond energies. Trends in the Nai binding energies are also compared to experimental values for the analogous Li+ systems.