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

Table 5

Thermodynamic functions for ML and ML₂ complexes of ligand (L₁) in 10% (by volume) ethanol-water mixture and 0.1 mol⋅dm⁻³ KCl.

M^𝑛+	𝑇/K	Gibbs energy/kJ⋅mol^−1		Enthalpy/kJ⋅mol^−1		Entropy/J⋅mol^−1⋅K^−1
		−Δ𝐺1	−Δ𝐺2	Δ𝐻1	Δ𝐻2	Δ𝑆1	Δ𝑆2
	298	39.03	34.46			237.52	225.21
Mn^2+	308	41.39	36.68	31.75	32.65	237.50	225.10
	318	43.78	38.97			237.52	225.21
	298	39.66	34.98			242.64	223.92
Co^2+	308	42.05	37.21	32.64	31.75	242.52	223.91
	318	44.51	39.46			242.64	223.92
	298	40.06	35.32			243.98	225.07
Ni^2+	308	42.46	37.57	32.65	31.75	243.87	225.06
	318	44.94	39.82			243.98	225.07
	298	40.79	36.18			252.55	230.96
Cu^2+	308	43.29	38.45	34.46	32.65	252.43	230.84
	318	45.85	40.79			252.55	230.96