Macromolecules, Vol.28, No.2, 547-551, 1995
Soluble, High-Molecular-Weight Ladder Polymers Possessing a Poly(Phenylene Sulfide) Backbone
A novel route to aromatic ladder-type polymers consisting of linearly annulated six-membered rings is presented. The synthetic sequence involves a polycondensation of dithioresorcinols and aromatic dichlorodiketones to high molecular weight poly(thioether ketone)s under basic conditions. The polymer-analogous ring closure to the desired ladder structures was accomplished-by reducing the keto functionalities to the corresponding secondary polyalcohols followed by a Friedel-Crafts-analogous intramolecular cyclization. The course of the polycondensation and the subsequent polymer-analogous reaction steps was studied using model dimers. A uniform formation of completely Linear annulated six-membered rings was found for a-methylated dithioresorcinol as one of the starting compounds. The novel ladder polymers are attractive precursors for the synthesis of poly(arylene methide)s and polycations of the thioxanthylium type, which are isoelectronically related to the hitherto unknown poly[n]acene.
Keywords:POLYARYLENES;PALLADIUM