The emitters a-DMAC-TRZ and MA-TA are derivatives of DMAC-TRZ where adamantane groups are incorporated into the structure (Figure ). In a-DMAC-TRZ, the adamantane-functionalization of the donor moiety leads to a deformed structure that results in an increased optical gap and thus a bluer emission. Dual fluorescence is observed from two different conformers, but overall, the electroluminescence (EL) performance remains similar to the DMAC-TRZ OLED, with an EQEmax of 28.9%, yet with a lEL of 488 nm. In the report by Wada et al., the replacement of the distal phenyl moieties on the TRZ with adamantyl groups results in a weaker acceptor, leading to a blue-shifted electroluminescence compared to DMAC-TRZ. The adamantyl substitution also reduces the non-radiative decay leading to a ΦPL of 99%. The blue solution-processed device (lEL of 475 nm) shows an EQEmax at 22.1%. Conversely, replacement of the distal phenyl rings in TRZ by electron-withdrawing pyrimidines (DMAC-bPmT) results in a redshifted emission (lPL of 520 nm vs 500 nm for DMAC-TRZ in toluene). The delayed emission lifetime of DMAC-bPmT is 3.3 µs in toluene, which is shorter than that of DMAC-TRZ at 8.8 µs in the same medium. The RISC rate constant, kRISC, of DMAC-bPmT is 8.8×10 5 s -1 , is three times faster than that of DMAC-TRZ (2.9×10 5 s -1 ). However, its ΦPL of 70% in toluene is reduced compared to that of DMAC-TRZ (FPL = 93% in toluene).