Are disulfide bonds resilient to double ionization? Insights from coincidence spectroscopy and calculations.

Disulfide bonds (-S-S-) are commonly present in biomolecules and have also been detected in astrophysical environments. In this work, the stability of the disulfide bond towards double ionization is investigated using quantum chemical calculations and photoelectron photoion photoion coincidence (PEPIPICO) spectroscopy measurements on the prototype dimethyl disulfide (CHSSCH, DMDS) molecule. The experiments were performed using high energy synchrotron radiation photons before (2465.

Application of a multivariate normal distribution methodology to the dissociation of doubly ionized molecules: The DMDS (CH -SS-CH ) case.

Rationale: The ion-ion-coincidence mass spectroscopy technique brings useful information about the fragmentation dynamics of doubly and multiply charged ionic species. We advocate the use of a matrix-parameter methodology in order to represent and interpret the entire ion-ion spectra associated with the ionic dissociation of doubly charged molecules. This method makes it possible, among other things, to infer fragmentation processes and to extract information about overlapped ion-ion coincidences.