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)3.70Mathematical(c)
4.20 ± 1.01.0Spectrophotometry7
4.46 ± 1.023.0 (e)Potentiometry4
Ce(III)1.03540.0274.12Mathematical(c)
4.36 ± 1.023.0 (e)Potentiometry4
Pr(III)1.06390.0514.52Mathematical(c)
0.298 ± 0.032.0Spectrophotometry (Scott method)5
0.246 ± 0.062.0Spectrophotometry (dilution method)5
Nd(III)1.08690.0534.68Mathematical(c)
3.80 ± 1.01.0Spectrophotometry7
0.501 ± 0.052.0Spectrophotometry (Scott method)5
0.499 ± 0.022.0Spectrophotometry (dilution method)5
2.5NANMR, UV, and Raman9
Pm(III)3.31 ± 0.480.5 (e)Radioanalysis8
Sm(III)1.1204−0.0074.26Mathematical(c)
1.65 ± 0.042.0Spectrophotometry (Scott method)5
1.69 ± 0.082.0Spectrophotometry (dilution method)5
Eu(III)3.75 ± 0.330.5 (e)Radio analysis8
2.5NANMR, UV, and Raman9
1.13670.0094.51 ± 0.112.0 (e)Potentiometry(d)
Gd(III)1.1357−0.1433.18Mathematical(c)
Tb(III)1.1693−0.2712.47Mathematical(d)
Dy(III)1.1792−0.3662.01Mathematical(c)
Ho(III)1.1796−0.3452.11Mathematical(c)
Er(III)1.1900−0.3262.24Mathematical(c)
3.90 ± 1.01.0Spectrophotometry7
1.2NANMR, UV, and Raman9
Tm(III)1.1833−0.1063.68Mathematical(c)
3.21 ± 0.40.5 (e)Radio analysis8
Yb(III)1.2023−0.2402.77Mathematical(c)
2.5NANMR, UV, and Raman9
Lu(III)1.2022−0.0534.26Mathematical(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.