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New complexons. III. Polarographic determination of the stability constants of the lanthanide complexes of meso-2,3-diaminobutane-N,N,N,N'-tetraacetic acid

V. Novák, J. Majer, and M. Svičeková

Komenský University, Bratislava

Abstract: cf. CA 62, 8983d. On the basis of the polarographic detns. of the exchange equil. systems, the logarithmic stability const. values of normal complexes of the meso-2,3-diaminobutane-N,N,N',N'-tetraacetic acid (I) with the lanthanides at μ = 0.10 (KNO₃) and 20° were described. Exchange equil. systems (43) with M as Pb, Cd, Eu, and Cu and M' as La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu were investigated. A potentiometrically measured value for the Cd(II)-I complex, 16.77 ± 0.04 [μ = 0.10 (KNO₃), 20°], was used for detg. all stability consts. The curve of the logarithmic stability consts. of the lanthanide-I complexes as a discontinuous function of the at. no. of the lanthanide forming the central ion of the complex increases over 4 units of log K with a characteristic break at Gd. The stability const. values of I are an order lower than those of EDTA.

Full paper in Portable Document Format: 1911a817.pdf (in Slovak)

Chemical Papers 19 (11) 817–825 (1965)