Photoreactive polyarylenevinylenes: Synthesis, characterization and photochemistry

The substitution of every second phenylene subunit in the well‐known poly(p‐phenylenevinylene) (PPV) by o,o′‐bridged biphenyl moieties leads to the novel poly(1,4‐phenylenevinylene‐2,2′‐biphenylylenevinylene) (PPVBV, 5) which can be prepared by palladium‐catalyzed aryl‐olefin coupling (Heck reaction). PPVBV possesses a high solubility in common organic solvents and good filmforming capabilities. It exhibits a thermochemical and photochemical reactivity comparable to that of the monomeric model compound 2,2′‐distyrylbiphenyl (3), which undergoes a [2+2]cycloaddition upon heating or irradiation.