Laser desorption/fourier transform mass spectra of poly(phenylene sulfide), polyaniline,poly(vinyl phenol), polypyrene,and related oligomers: Evidence for carbon clusters and feasibility of physical dimension measurement

Laser desorption/Fourier transform mass spectra of poly(phenylene sulfide), polyaniline, poly(vinyl phenol), polypyrene, poly(p-phenylene), poly(1-methyl-2,5-pyrrolylene), poly(1-phenyl-2,5-pyrrolylene), and poly(2,5-thienylene) are compared. Poly(phenylene sulfide) fragments at C? S bonds during analysis, but rearrangement is minor. Evidence is found for dibenzothiophene moieties within the polymer chains. Unambiguous determination of the structure of polyaniline is not possible. Rearrangement appears to accompany chain scission. Completely aromatic polymers do not undergo similar reactions during analysis. Species with more carbons than can be accounted for by an integer multiple of six-membered rings arise from side reactions during dehydrocoupling of aromatic monomers. Carbon clusters, which are observed in the spectra of some aromatic polymers, appear to arise from laser volatilization and multiphoton ionization of large polynuclear components that are formed during synthesis. Negative ions of about 40–120 carbons and positive ions with about 120–400 atoms are detected. The results also suggest that the physical dimensions of some polymer molecules might be measured by Fourier transform mass spectrometry.