Telechelic Helical Poly(quinoxaline-2,3-diyl)s Containing a Structurally Defined, Circularly Polarized Luminescent Terquinoxaline Core: Synthesis by Core-Initiated Bidirectional Living Polymerization

We have designed and synthesized divalent initiators that contain a fluorescent terquinoxaline unit with two palladium groups for the living polymerization of 1,2-diisocyanobenzenes. Using these divalent initiators, the bidirectional living polymerization of a monomer bearing (S)-butoxymethyl side chains afforded telechelic helical poly­(quinoxaline-2,3-diyl)­s (PQXs), which consist of a terquinoxaline unit at the center of the polymer chain and chiral oligomeric blocks on both sides. The location of the core unit was confirmed by NMR spectroscopy and photoluminescence measurements. Upon changing the solvent from CHCl3 to 1,1,2-trichloroethane, these PQXs exhibit both left- and right-handed circularly polarized luminescence with dissymmetry factors of approximately 1.0 × 10–3.