The photophysical parameters extracted from the analysis of the transient photoluminescence decay curves according to the methods of Baleizão et al. and Dias et al. are summarized in Table . The activation energies, extracted from an Arrhenius analysis of the temperature-dependent time-resolved PL decays are in the range between 70-80 meV (Figure ), i.e., less than half of the ΔEST. We tentatively ascribe the difference between the estimated DEST and the activation energies to the presence of higher lying triplet states that facilitate RISC. 39 total FPL (λexc = 315 nm); (b) ratio of the integrated areas of delayed and prompt emission; (c) lifetime of the prompt fluorescence estimated using a mono-exponential fit at 300 K; average lifetime of delayed emission at 300 K; radiative decay rate constant of singlet excitons; (f) non-radiative decay rate constant of singlet excitons excluding 𝑘ISC; (g) intersystem crossing yield; (h) intersystem crossing rate constant; reverse intersystem crossing rate constant.