Exploring the Scope of Through-Space Charge-Transfer Thermally Activated Delayed Fluorescence in Acrylic Donor–Acceptor Copolymers

A series of acrylic donor and acceptor monomers were prepared to investigate the effect of electronic and structural changes on the through-space charge-transfer (TSCT) thermally activated delayed fluorescence (TADF) phenomenon. Donor (D) and acceptor (A) monomers were copolymerized using a Cu(0) reversible-deactivation radical polymerization (RDRP) approach, resulting in nonconjugated polymers with molecular weights between 8 and 21 kDa and dispersities below 1.3. Many of the resulting polymers were found to exhibit TSCT TADF, while in several cases, phosphorescence appeared to dominate. Aggregation-induced emission was also observed in many cases, consistent with a TSCT mechanism requiring close D–A contact. The results indicate that the propensity for TSCT TADF of a given D–A pair cannot be predicted solely based on the value of the singlet–triplet energy gap (Δ E ST ) or the frontier orbitals of the monomers and that steric considerations are likely critical for efficient TSCT.