DECOMPOSITION OF CYCLIC TRIPEROXIDES IN ESI-MS
Alexander Tsoglin*, **, Chagit Denekamp *
*Department of Chemistry and Institute of Catalysis Science and Technology, Technion - Israel
Institute of Technology, Haifa, Israel
** Department M4, Rafael Ltd., Haifa, Israel
Abstract
The current poster describes the dissociation of TATP (Triacetone Triperoxide) and its analogues
in ESI-MS2 experiments. The decomposition of these compound was studied using ammonium
(NH4+) and deuterated ammonium (ND4+) ion attachment and collision induced dissociation of
these ions. It is proposed that the two major dissociation products of [TATP-NH4]+ (240 Da) are
produced by a mechanism in which an oxirane intermediate undergoes rearrangement by the
migration of one of the methyl groups, to obtain an ion of m/z 74, that corresponds to a methyl
ester or its enolic isomer cation radical, or an ion of m/z 91, possibly a protonated carbonate
cation . This oxirane intermediate is similar to the Criegee intermediate of the know BaeyerVilliger reaction and the migration of the alkyl group is analogous to the mechanism of this
reaction as well. The protonating hydrogen in the carbonate cation originates from the
ammonium adduct, as shown by a labeling experiment. Thus, the collision induced dissociation
spectrum of the deuterium labeled [TATP-NH4]+ ion contains a product ion of m/z 92. Other
cyclic triperoxides follow the same fragmentation pattern, producing an ester (or enol) and a
protonated cyclic or acyclic carbonate (depending on the parent cyclic triperoxide). TATP
analogues that were investigated are 18-deuterated TATP (258 Da),
tri(methylethylketone)triperoxide (264 Da), tricyclohexylidene triperoxide (360 Da and
tricyclopentylidene triperoxide (318 Da).
References
A. Denekamp C., Gottlieb L., Tamiri T., Tsoglin A., Shilav R. and Kapon M.; Org. Lett., Vol.
7, No. 12, 2461-2464, 2005.
B. Snowden M., Bermudez A., Kelly D. R., Radkiewicz-Poutsma J. L.; J. Org. Chem, 69,
7148-7156, 2004.
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