Potentiometric and Thermodynamic Studies of Some Schiff-Base Derivatives of 4-Aminoantipyrine and Their Metal Complexes

Table 4

Stepwise stability constants for ML and ML₂ complexes of ligand (L₂) in 10% (by volume) ethanol-water mixtures and 0.1 mol⋅dm⁻³ KCl at different temperatures.

M^𝑛+	298 K		308 K		318 K
	log 𝐾1	log 𝐾2	log 𝐾1	log 𝐾2	log 𝐾1	log 𝐾2
Mn^2+	7.33 (0.08)	6.74 (0.09)	7.50 (0.09)	6.90 (0.10)	7.67 (0.10)	7.07 (0.10)
Co^2+	7.54 (0.09)	6.85 (0.10)	7.72 (0.10)	7.02 (0.10)	7.90 (0.10)	7.20 (0.11)
Ni^2+	7.63 (0.09)	6.92 (0.10)	7.80 (0.11)	7.10 (0.09)	7.98 (0.11)	7.27 (0.10)
Cu^2+	7.78 (0.09)	7.07 (0.10)	7.97 (0.10)	7.26 (0.10)	8.16 (0.11)	7.44 (0.10)

Standard deviations are given in parentheses.