Synthesis, reactivity, and optoelectronic properties of poly(3‐alkenylthiophene) diblock copolymers

Poly(3‐hexylthiophene)‐ b ‐poly(3‐pentenylthiophene) and poly(3‐hexylthiophene)‐ b ‐poly(3‐undecenylthiophene) diblock copolymers have been synthesized by McCullough method. X‐ray diffraction analysis of the diblock copolymers displayed all the reflection peaks specific to regioregular poly(3‐hexylthiophene), indicating that the presence of poly(3‐alkenylthiophene) block does not affect the packing of the polymer in the solid state. The synthesized diblock copolymers were subjected to hydroboration/oxidation and hydrosilation to demonstrate the reactivity of the alkenyl substituents. Furthermore, poly(3‐hexylthiophene)‐ b ‐poly(3‐pentenylthiophene) was used as a chain transfer agent for the ruthenium‐catalyzed ring‐opening metathesis polymerization of cyclooctene to generate a polycyclooctene graft copolymer, which was hydrogenated to give poly(3‐hexylthiophene)‐ b ‐poly(3‐pentenylthiophene‐ g ‐polyethylene). The opto‐electronic properties and the morphology of the synthesized polymers have been investigated.