Synthesis of PNV Homo- and Copolymers by a ROMP Precursor Route

A new efficient synthesis of alkylated benzobarrelene monomers was developed. Polynaphthalenevinylene (PNV) homopolymers and copolymers were synthesized from these monomers using a molybdenum ring opening metathesis polymerization (ROMP) initiator. Addition of hexafluoro-t-butanol (HFB) and THF was found to yield a better controlled polymerization which produced well defined homopolymers and block copolymers. Polymers synthesized in the presence of HFB and THF had PDIs of 1.1–1.4. Aromatization of these precursor polymers by DDQ yielded PNVs. Electron withdrawing groups shifted the emission toward the red, and block copolymers showed luminescence of the block with the smaller bandgap.