Polymer, Vol.39, No.25, 6213-6217, 1998
Ions derived from linear polysulfide oligomers using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry
Attempts to produce detectable levels of ions from oligomers of linear polysulfides (LPs) H(SC2H4O-CH2OC2H4S)(n)H (n up to 24) by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry failed with all common matrix/cation combinations except 9-nitroanthracene containing silver trifluoracetate. The latter matrix yielded a series of species assigned to Ag(SC2H4OCH2OC2H4S)(n) representing the loss of two thiol hydrogen atoms, together with smaller quantities of other series Ag(SC2H4O-CH2OC2H4S)(n)(C2H4OCH2OC2H4S) and Ag(SC2H4OCH2OC2H4S)(n)(SC2H4OC2H4OCH2OC2H4S) when a conventional LP was utilised. Other LP structures were examined and these also gave argentated species; one LP (designated ZL-2264) gave a spectrum featuring silver isotope splitting of all of its peaks. At higher laser powers, or with high silver salt concentrations, or after extensive ageing of samples prior to laser irradiation, a totally new series of peaks emerged attributed to [(Ag2S)(n)Ag](+) with n reaching 11, i.e. containing 23 silver atoms.