Photophysical parameters determined for samples of 1c in toluene, CH₂Cl₂, and benzonitrile.

Solvent	Toluene	CH2Cl2	Benzonitrile
Φ em a	0.83	0.75	0.40
τ prompt b (ns)	6.27	3.00	1.10
τ delayed c (ns)	—l	10.2	55.9
k proc d (107 s−1)	—l	17.4	75.0
Φ proc e	—l	0.52	0.82
Φ prompt f	—l	0.40	0.15
Φ delayed g	—l	0.35	0.25
k −proc h (107 s−1)	—l	16.70	3.79
ΔGproci (kcal mol−1)	—l	−0.02	−1.77
J Coul j (cm−1)	265	69	25
ΔGCSk (kcal mol−1)	—l	−7.10	−8.92

^aQuantum yield of emission (see Table S7).

^bExcited state lifetime from the prompt fluorescence signal decay (see Table S8).

^cExcited state lifetime from the delayed fluorescence signal decay.

^d S ₁ → S^† rate constant.

^eQuantum yield of S₁ → S^† process.

^fQuantum yield of prompt fluorescence.

^gQuantum yield of delayed fluorescence.

^h S ^† → S₁ rate constant.

ⁱGibbs free energy of the S₁ ⇌ S^† equilibrium.

^jLong-range Coulomb coupling calculated from eqn (3).

^kGibbs free energy of the PDI–PDI photoinduced electron transfer calculated from eqn (4).

^lNot available.