Kaji and co-workers reported the emitter DMAC-bPmT, which contains two distal pyrimidines in lieu of phenyl groups in DMAC-TRZ. The computational study revealed that the presence of these more p-accepting pyrimidines stabilize the energy of the S2 and T2 states, bringing them closer in energy to the S1 and T1 states, which enhanced the reverse intersystem crossing rate constant (kRISC). Indeed, experimentally kRISC is 8.8×10 5 s -1 , which is three times faster than the kRISC of DMAC-TRZ, at 2.9×10 5 s -1 ; however, the trade-off is that the FPL of DMAC-bPmT of 70% is lower (FPL of 93% for DMAC-TRZ) and the emission in toluene is red-shifted at lPL of 520 nm (lPL 500 nm for DMAC-TRZ).