Table 3. Overall Stability Constants (log β) of the Cu²⁺ and Cu⁺ Complexes Formed by NO3S and TACN-n-Bu at T = 25 °C and I = 0.15 M NaNO₃^a.

	logβ
Equilibrium reactiona	NO3S	TACN-n-Bu
Cu2+ + HL+ ⇌ [CuHL]3+b	-	6.2 ± 0.1
Cu2+ + HL+ ⇌ [CuL]2+ + H+b	-	–0.04 ± 0.15
Cu2+ + L ⇌ [CuL]2+b	18.41 ± 0.05	-
Cu2+ + L + H2O ⇌ [CuL(OH)]+ + H+b	9.08 ± 0.03	-
Cu+ + L ⇌ [CuL]+c	18.36 ± 0.05	-

^aL represents the completely deprotonated form of the ligand as shown in Figure 1C. The reported uncertainty was obtained by the fitting procedure and represents one standard deviation unit.

^bObtained by UV–vis spectrophotometric titrations.

^cObtained from voltametric data.