AQUEOUS RING-OPENING METATHESIS POLYMERIZATIONS OF HETEROPOLYCYCLIC CARBOXYLIC-ACIDS WITH TRANSITION-METAL CHLORIDES

exo,exo-7-Oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid was polymerized by aqueous ring-opening metathesis polymerization using the trichlorides of ruthenium and osmium as precursors to the initiating and chain propagating species to yield poly(2,5-[3,4-bis(carboxylic acid)furanylene]vinylene)s. Ruthenium-derived initiators gave polymers with 60% of cis-vinylenes whereas polymerization initiated by osmium compounds was irreproducible, giving products with either 65 or 95% cis-vinylenes. The inclusion of acrylic acid or maleic acid in the reaction mixture caused a marked reduction in the time to precipitation of polymer and the ultimate yield. cis-But-2-ene-1.4-diol was found to affect the time to precipitation of polymer in a similar manner without a reduction in yield and allowed control of the polymer molecular weight over the range M(n) = 10(5) to 7 X 10(2) with respect to poly(ethylene oxide) standards.