Pendant sulfone/phenoxazine-based homo- and copolymers were synthesized via the radical (co)­polymerization of 4-bromophenyl vinyl sulfide (BPVS) and styrene (St) followed by oxidation of the thus-produced sulfides, P­(BPVS) and P­(BPVS-r-St)­s, to the corresponding sulfones and Pd-catalyzed coupling with phenoxazine-substituted phenyl boronate ester (PXZPhBpin) to afford P­(PVSO2-PhPXZ) and P­(PVSO2-PhPXZ-r-St)­s, respectively. The prepared homo- and copolymers, featuring a π-conjugated phenylene unit between the electron-accepting sulfone (SO2) unit and the electron-donating phenyl phenoxazine (PhPXZ) unit in their side chains, exhibited thermally activated delayed fluorescence (TADF) and were used to fabricate organic light-emitting diodes (OLEDs). The device with spin-coated P­(PVSO2-PhPXZ) as an emitting layer showed a maximum external quantum efficiency (EQEmax) of 1.0%, whereas that with an emitting layer of spin-coated 75 mol %-St P­(PVSO2-PhPXZ-r-St) exhibited efficient bluish-green emission with EQEmax = 4.1%. The presented design strategy allows one to manipulate the polarity and electrochemical properties of pendant units as well as design molecular structures with suitable spacers between donor and acceptor units in the TADF side chain, thus helping to achieve the desired (opto)­electronic properties. Thus, this work significantly extends the range of nonconjugated TADF polymers and paves the way for the fabrication of next-generation OLEDs.

Synthesis of novel block and random copolymers, containing a carbazole unit and (di)phenylanthracene moiety in the side chains, has been described in this paper. Block and random copolymers composed of 4-bromophenyl vinyl sulfide (BPVS) and N -vinylcarbazole (NVC) were initially prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. Then, anthracene-based groups were introduced on the bromophenyl unit in the carbazole-containing copolymers by Pd-catalyzed coupling to yield functional copolymers with additional (di)phenylanthracene units. The resulting copolymers, having two distinct electronic functionalities, exhibited characteristic fluorescence resonance energy transfer, as confirmed by UV-vis and fluorescence spectra.

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