Reaction enthalpies for M(+)L=M(+)+L, where M(+)=Na+ and K+ and L equals acetamide, N-methylacetamide, N,N-dimethylacetamide, glycine, and glycylglycine, from determinations of the collision-induced dissociation thresholds

With electrospray (ES), ions present in solution can be transferred to the gas phase. The method provides unique opportunities for studies of hitherto inaccessible ions. Collision-induced dissociation threshold measurements of gas phase ions produced by ES are described. The thresholds for the reactions M(+)L = M(+) + L, where M(+) is Na+ or K+ and L is acetone, dimethyl sulfoxide, acetamide, N-methylacetamide, N,N-dimethylacetamide, glycine, glycinamide, succinamide, and glycylglycine, were determined. Enthalpy changes for the reaction were derived from these data.