pi-conjugated poly(monosubstituted) acetylenes containing Sn(II) and Sn(IV) species: investigation with laser ionization mass spectrometry

Polyenes [HC=CR](n) (R = Ph, C13H9O), namely polyphenylacetylene (PPA) and polyethynylfluorenol (PEFI) containing Sn(II) and Sn(IV) in the polymer matrix, have been investigated using laser ionization mass spectrometry. The positive ion mass spectra show that carbon clusters linked to Sn, i.e. SnCnH+ (n = 1-25) are formed for PPA, while a higher degree of fragmentation occurs for PEFI which gives SnCnH+ (n = 1-8). The species SnCl3- is found in the negative ion patterns of the two polymers, regardless of whether the dopant was SnCl2 or SnCl4. This result suggests a lower stability of the tin complexes, formed by interaction with the polymer matrix, with respect to the iron chlorides or polyiodides species found in the LMS spectra of PPA/FeCl3 and PPA/I-2, respectively, previously studied.