These values are intermediate to those of DDiKTa (τp of 5.9 ns and τd of 159 µs) and DiKTa (τp of 4.8 ns and τd of 242 µs); in air, the delayed emission of DDiKTa-F was significantly though not completely quenched (Figure ). From these photophysical measurements the RISC rate constant (kRISC) of DDiKTa-F was determined to be 2.16 × 10 4 S -1 (Table ), which is intermediate to those of DDiKTa (kRISC of 1.77 × 10 4 S - 1 ) and DiKTa (kRISC of 2.52 × 10 4 S -1 ). a the FPL was measured using an integrating sphere under nitrogen (lexc =340 nm). b Obtained at 298 K, lexc = 340 nm. c Full-width at half-maximum; d Obtained from the onset of the SS PL spectrum at 77 K. e Obtained from the onset of the delayed emission spectrum (1-10 ms) at 77 K (lexc = 340 nm). f DEST = E(S1) -E(T1). g Measured at 300 K under vacuum, lexc = 379 nm.