Calculating the Equilibrium Constants for All Monoazide Lanthanide Complexes in Aqueous Solution Based on the Formation of <math xmlns:mml="http://www.w3.org/1998/Math/MathML"><msubsup><mrow><mtext>Eu(III)/N</mtext></mrow><mrow><mn>3</mn></mrow><mrow><mo>−</mo></mrow></msubsup></math>: Table 2

Table 2: Selected equilibrium constants, β₁, for the monoazide complexes of lanthanides.


Ln	a	b	β₁ (mol⁻¹ L)	I (mol L⁻¹)	Method	Ref.

La(III)	(1.0000)	(0.000)	3.70	—	Mathematical	(c)
			4.20 ± 1.0	1.0	Spectrophotometry	7
			4.46 ± 1.02	3.0 (e)	Potentiometry	4
Ce(III)	1.0354	0.027	4.12	—	Mathematical	(c)
			4.36 ± 1.02	3.0 (e)	Potentiometry	4
Pr(III)	1.0639	0.051	4.52	—	Mathematical	(c)
			0.298 ± 0.03	2.0	Spectrophotometry (Scott method)	5
			0.246 ± 0.06	2.0	Spectrophotometry (dilution method)	5
Nd(III)	1.0869	0.053	4.68	—	Mathematical	(c)
			3.80 ± 1.0	1.0	Spectrophotometry	7
			0.501 ± 0.05	2.0	Spectrophotometry (Scott method)	5
			0.499 ± 0.02	2.0	Spectrophotometry (dilution method)	5
			2.5	NA	NMR, UV, and Raman	9
Pm(III)			3.31 ± 0.48	0.5 (e)	Radioanalysis	8
Sm(III)	1.1204	−0.007	4.26	—	Mathematical	(c)
			1.65 ± 0.04	2.0	Spectrophotometry (Scott method)	5
			1.69 ± 0.08	2.0	Spectrophotometry (dilution method)	5
Eu(III)			3.75 ± 0.33	0.5 (e)	Radio analysis	8
			2.5	NA	NMR, UV, and Raman	9
	1.1367	0.009	4.51 ± 0.11	2.0 (e)	Potentiometry	(d)
Gd(III)	1.1357	−0.143	3.18	—	Mathematical	(c)
Tb(III)	1.1693	−0.271	2.47	—	Mathematical	(d)
Dy(III)	1.1792	−0.366	2.01	—	Mathematical	(c)
Ho(III)	1.1796	−0.345	2.11	—	Mathematical	(c)
Er(III)	1.1900	−0.326	2.24	—	Mathematical	(c)
			3.90 ± 1.0	1.0	Spectrophotometry	7
			1.2	NA	NMR, UV, and Raman	9
Tm(III)	1.1833	−0.106	3.68	—	Mathematical	(c)
			3.21 ± 0.4	0.5 (e)	Radio analysis	8
Yb(III)	1.2023	−0.240	2.77	—	Mathematical	(c)
			2.5	NA	NMR, UV, and Raman	9
Lu(III)	1.2022	−0.053	4.26	—	Mathematical	(c)

All studies were performed at T = 25 °C [5,9] and there is no mention of temperature control; “a” and “b” are the parameters of (4) developed by Kumok and Serebrennikov [24]. “Mathematical” means obtained using (4) developed by Kumok and Serebrennikov [24]. (c) Calculated value in the present work using (4). (d) Present work. (e) NaClO₄ was used to maintain constant ionic strength. NA: not available.