Direct heteroarylation polymerization of a π-conjugated polymer with degradable 1,2,4-oxadiazole linkers

The synthesis of π-conjugated polymers containing a degradable 1,2,4-oxadiazole linker by direct heteroaryl polymerization (DHAP) is reported. The 1,2,4-oxadiazole linker is stable to acidic and basic conditions, as well as thermally stable. The degradation of a small molecule model is achieved by reduction followed by acid hydrolysis. The polymerization is performed using phosphine-free and branching-suppressing DHAP conditions. DFT calculations are performed on the monomers to determine their affinity for β-branching defects. The synthesized polymers are photoluminescent and exhibit quantum yields of up to 0.40. Partial degradation of a representative polymer is observed using the same conditions for degradation as the small molecule model.