The analysis of conducting polymers by electrospray Fourier transform massspectrometry. Part I: ionene polymers

The analysis of synthetic 6-2, 6-3 and 6-4 ionene polymers by electrospray ionization Fourier transform mass spectrometry (ESI-FTMS) is reported here, This is the first in a series of papers on the analysis of conducting poly mers utilizing soft ionization techniques, thus allowing for the analysis o f intact molecular ions, The syntheses of these individual polymers result in a variety of compounds with different molecular structures which are rel ated to the normal linear ionene polymer, While the mechanisms by which the 6-2 and the 6-3 ionene polymers are synthesized are very similar, the synt hesis of 6-4 ionene proceeds differently, In addition, the presence of a ga s-phase bromide ion salt-bridged to the backbone of the polymer chain is ob served in the resulting mass spectra, as well as the possibility of intramo lecular cyclization. The latter has been proposed previously, This cyclizat ion process becomes more possible as the number of methylene groups in the linking chain increases, Finally, we observed that the presence of a bromid e ion in the sample helped the interpretation of sustained off-resonance ir radiation collisionally-activated dissociation (SORI-CAD), Based on the iso topic pattern provided by the halogens, a "built-in" label which can be tra ced from the fragment ions back to the parent ion peak is found to be usefu l in structural assignments.