PPV-precursors and their polymerisation mechanism: Anionic or rather radical

Conjugated polymers show great promise for use in light emitting diodes (LED's). Unfortunately, the stiff backbone of these polymers results in insoluble and infusible materials which are thereby difficult to process.; We overcome this problem by using a precursor route. In our research group a novel route to stable non-aqueous processible precursor polymers has been developed. A soluble, non-conjugated precursor polymer with a sulphoxide function is synthesised, which is then converted in situ to the final conjugated polymer by thermal treatment. The general concept of this new route is the base induced polymerisation of p-xylene-derivatives which have to fulfill two requirements: a leaving group in the {dollar}alpha{dollar} position and a polariser at the {dollar}alphasp{lcub}prime{rcub}{dollar} side. We here report on the study of the mechanism of the polymerisation of these p-xylene-derivatives. With an understanding of this mechanism, it is possible to control and modify this synthesis of PPV and its derivatives in a rational manner which results in control of yield and molecular weight of the polymer.