Thermodynamic and kinetic parameters of compounds 1–3 obtained at 25 °C.

n	pKaa	pKcb	pKGSac	pKMSad	Π e	S f (mM)	k w g (10−3 min−1)	k OH g (103 M−1 min−1)	k h g (10−2 min−1)	k −2 (10−2 s−1)	Φ j
1	7.23 ± 0.06	−1.48 ± 0.02	5.74 ± 0.08	2.14 ± 0.04	3.6 ± 0.1	0.56 ± 0.05	4.2 ± 0.1	13 ± 2	5.0 ± 0.5	0.31h, 0.31i	0.73 ± 0.09
2	7.20 ± 0.03	−0.96 ± 0.03	6.19 ± 0.06	2.47 ± 0.04	3.7 ± 0.1	0.19 ± 0.03	2.8 ± 0.4	9.5 ± 0.4	2.0 ± 0.2	0.45h, 0.46i	0.37 ± 0.04
3	7.25 ± 0.05	−0.59 ± 0.02	6.56 ± 0.07	3.07 ± 0.04	3.5 ± 0.1	2.66 ± 0.28	1.7 ± 0.3	4.5 ± 0.4	0.26 ± 0.03	0.59h, 0.60i	0.22 ± 0.03

^aAverage values obtained from both ¹H NMR and UV-Vis data with eqn (1) and (2).

^bAverage values obtained from both ¹H NMR and UV-Vis data with either eqn (2) and van't Hoff analysis.

^cAverage values obtained from both ¹H NMR and UV-Vis data with eqn (2), (3) and (8).

^dValues obtained from UV-Vis data with eqn (8).

^eAverage values resulting from eqn (9).

^fSolubilities in aqueous KCl (20 mM).

^gAverage values resulting from before and after numerical refinement.

^hValues obtained from equilibration kinetics (eqn (4)).

ⁱValues obtained from relaxation kinetics (eqn (11)).

^jValues obtained from multiple pH jumps experiments with eqn (12). All data refer to experiments performed (at least) in duplicate (see Table S2 for more details).