Table 2.

Protonation constants and stability constants of Ligand-T, Ligand-L and DOTA¹⁸.

log KiH	Ligand-Ta	Ligand-La	DOTAb
log K1H	11.30 (0.07)	13.53 (0.25)	11.14
log K2H	11.10 (0.09)	10.25 (0.12)	9.69
log K3H	10.30 (0.28)	9.90 (0.20)	4.85
log K4H	6.08 (0.30)	4.63 (0.19)	3.95
∑log KiH	38.78	38.31	29.62
log KGdL	30.01b	/	25.58(32)

^aI = 1.0 M NMe₄Cl, at 25 °C.

^bI = 1.0 M KCl, at 25 °C, where K_i^H = [H_iL]/[H_i-1L][H⁺], SD were shown in brackets.

^bI = 0.1 M NMe₄Cl, at 25 °C³¹.