Gas-phase fragmentation reactions of protonated glycerol and its oligomers: Metastable and collision-induced dissociation reactions,associated deuterium isotope effects and the structure of [C3H5O]+, [C2H5O]+, [C2H4O]+. and [C2H3O]+ ions

The chemistry of glycerol subjected to a high-energy particle beam was explored by studying the mass spectral fragmentation characteristics of gas-phase protonated glycerol and its oligomers by using tandem mass spectrometry. Both unimolecular metastable and collision-induced dissociation reactions were studied. Collision activation of protonated glycerol results in elimiation of H₂O and CH₃OH molecules. The resulting ions undergo further fragmentations. The origin of several fragment ions was established by obtaining their product and precursor ion spectra. Corresponding data for the deuterated analogs support those results. The structures of the fragment ions of compositions C₃H₅O]⁺, C₂H₅O]⁺, C₂H₄O]^+. and C₂H₃O]⁺ derived from protonated glycerol were also identified. Proton-bound glycerol oligomers fragment principally via loss of neutral glycerol molecules. Dissociation of mixed clusters of glycerol and deuterated glycerol displays normal secondary isotope effects.