“…244,245 Mono-and dialkoxy-substituted PPVs can be prepared by a sulfonium precursor route as described for the synthesis of PPV (1). 87,232,240,[246][247][248][249][250] Delmotte et al 251 have studied the synthesis of poly(2,5-diethoxy-1,4-phenylene vinylene) (21) by the sulfonium precursor route and found that partial elimination of the sulfonium groups occurred when >1 equiv of base was used. This elimination was found to be selective for short conjugated fragments, yielding only tetraethoxystilbene units even when up to 35% of leaving groups had been eliminated.…”