Excited state reactions in the cycle shown in Scheme 3 (K_SV = Stern–Volmer quenching rate, k_q = bimolecular rate constant, η_q = quenching yield, η_ce = cage escape yield, η_qη_ce = quantum yield)^a.

	PS (τ0/ps)
	[Fe(iii)(btz)3]3+, 1 (94)				[Fe(ii)(btz)3]2+, 2 (330)
	K SV/M−1	k q/109 M−1 s−1	η q ([Q]/M)	η ce	η q η ce ([Q]/M)
TEA	0.81b	8.4	0.31 (0.50)	0.29c	0 (≤0.50)d
C8F17I	n.a.e	n.a.	0 (≤0.45)f	n.a.	0.18c (0.45)g,h
5-Hexen-1-ol	n.a.	n.a.	0 (≤0.14)f	n.a.	0 (≤0.14)d

^aIn MeCN : MeOH (4 : 3).

^bStern–Volmer constant from steady state emission quenching.

^c±20%.

^dNo detectable products in ns-transient absorption.

^eNot applicable.

^fNo emission quenching up to indicated quencher concentration.

^gFrom ns-transient absorption.

^h η _ce ≥ 0.3 with η_q(0.45 M) ≤ 0.6 (based on k_q ≤ 2 × 10¹⁰ M⁻¹ s⁻¹).