| Abstract: | A series of ester enolates was investigated by the technique of collision-induced dissociation (CID) using a Fourier transform mass spectrometer. Two primary modes of fragmentation were observed which led to CID products characteristic of the acyl and alkoxyl moieties of the ester enolates. An investigation of the fragmentation mechanism revealed that the primary fragmentation mode appears to be a sensitive function of the structure and the proton affinities of the two possible product ions. In most cases the anion (ketenyl or alkoxide) with the lower proton affinity was observed as the threshold product, suggestive of a proton-bound dimer intermediate. Interesting secondary dissociations were observed to occur from the primary product ions, as alkoxide ions fragmented to enolate ions or other stabilized anions. |
