Transient absorption decays of the reference complex [Ru(bpy) 3 ] 2+ (12 µM in aerated H 2 O) at 455 nm and the [Cr(dqp) 2 ] 3+ (30 µM)–TAA-OMe (2 mM) pair in aerated CH 3 CN at 293 K at 717 nm under 416 nm excitation. Both solutions have identical absorbance at 416 nm (Supplementary Fig. 56a ). The concentrations of the 3 MLCT-excited [Ru(bpy) 3 ] 2+ and TAA-OMe · + were 1.56 and 0.20 ± 0.02 μM, respectively. In a and b , the relative concentrations of the photoproducts were derived from the measured ΔOD values at 455 nm for the reference ( 3 MLCT-excited [Ru(bpy) 3 ] 2+ ) and at 717 nm for the donor–acceptor pairs (TAA-OMe · + ), as well as the respective Δ ε values at the relevant observation wavelengths (Δ ε 455 = −10,100 M −1 cm −1 for [Ru(bpy) 3 ] 2+ (ref. 33 ) and Δ ε 717 = 32,600 ± 300 M −1 cm −1 for TAA-OMe · + ). This analysis yielded Ф CE values of 58 ± 2% for the [Ru(bpz) 3 ] 2+ –TAA-OMe pair and 13 ± 1% for the [Cr(dqp) 2 ] 3+ –TAA-OMe pair in CH 3 CN at room temperature, as marked by the dashed horizontal lines.
