Vg. Koshechko et al., POLYMERIZATION OF PYRROLE AND PHENYLACETYLENE UNDER THE ACTION OF STABLE RADICAL IONS, Synthetic metals, 59(2), 1993, pp. 273-278
The possibility of pyrrole polymerization caused by chemically or elec
trochemically generated radical cations of para-substituted triphenyla
mines ((X-C6H4)3N.+A-, where X=-OCH3, A-=SbCl6- (I); X=-CH3, A-=SbCl6-
(II); X=-Br, A-=SbCl6- (III); X = -OCH3, A- = BF, - (IV)) and phenyla
cetylene polymerization in the presence of radical anions of anthracen
e were explored. Reaction of radical cations, RC(I)-(IV), with pyrrole
was shown to result in oxidative polymerization accompanied by simult
aneous doping and conductive polymer formation. In the cases of RC(I),
(II) and (IV), polypyrrole soluble in organic solvents, particularly
in CH3CN, was obtained. The pyrrole polymerization rate under the acti
on of radical cations and the properties of the resulting polymers wer
e found to be largely dependent on radical cation structure. Increasin
g radical cation oxidative ability in the trend I < II < III leads to
accelerating RC-pyrrole reaction, the resulting polypyrrole conductivi
ty rising, the number of paramagnetic centres changing and the soluble
polymer yield declining. It was ascertained that RC(IV) and anthracen
e radical anions are capable of acting as homogeneous catalysts, media
tors of electron transfer in the electrochemical polymerization of pyr
role and phenylacetylene, respectively. This allows the above processe
s to run at lower potentials.