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

Table 3

Stepwise stability constants for ML and ML₂ complexes of ligand (L₁) 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+	6.84 (0.08)	6.04 (0.11)	7.02 (0.09)	6.22 (0.10)	7.19 (0.10)	6.40 (0.11)
Co^2+	6.95 (0.09)	6.13 (0.10)	7.13 (0.09)	6.31 (0.10)	7.31 (0.11)	6.48 (0.11)
Ni^2+	7.02 (0.09)	6.19 (0.09)	7.20 (0.10)	6.37 (0.09)	7.38 (0.11)	6.54 (0.10)
Cu^2+	7.15 (0.09)	6.34 (0.09)	7.34 (0.09)	6.52 (0.10)	7.53 (0.11)	6.70 (0.10)

Standard deviations are given in parentheses.