Poly(cyclopentadienylene vinylene)s: synthesis via ROMP, chemical and physical properties

Norbornene derivatives, bearing different substituents, were polymerized via ring-opening metathesis polymerization (ROMP). This paper mainly reports on possibilities of controlling the stereochemistry of the polymerization reaction to give stereoregular precursors to conjugated polymers. The precursor polymers were then converted to the corresponding conjugated polymers through thermal or base-induced elimination. Monomers used for the polymerization were norbornenebis(methylcarbonate), norbornenebis(S-methyldithiocarbonate) and benzonorbornadienes substituted with isopropylidene, methylbenzylidene, phenylbenzylidene and p-fluorophenyl-p-fluorobenzylidene groups at the bridge carbon. Resulting polymers were then converted to poly(cyclopentadienylene vinylene) or more rigid highly substituted poly(cyclopentadienylene vinylene)-bearing exocyclic double bonds. Characterization was carried out by spectroscopic methods on thin films (photoluminescence, IR, UV-Vis-NIR, 1H and 13C NMR spectroscopy).