• • Novel MR-TADF skeleton: Breaking the fused ring with a linear conjugated diene linker enables simultaneous introduction of three MR units in one step, achieving high yield and reduced synthetic cost compared to traditional fused-ring extensions.
• • Pure-red emission: Both NF-CON1 and NF-CON2 emit at 620 nm with FWHM <35 nm in toluene, meeting the stringent color purity requirements for wide-color-gamut displays.
• • Efficient RISC: Singlet-triplet energy gaps of ~0.2 eV and RISC rates of ~3.0×10^5 s^-1 ensure rapid upconversion, supporting high internal quantum efficiency.
• • Solution-processability: Low reorganization energies (0.209 eV for NF-CON1, 0.194 eV for NF-CON2) and short delayed lifetimes (31–40 μs) mitigate exciton quenching, enabling efficient solution-processed OLEDs.