ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

New complexanes. IV. Potentiometric investigation of the complexes between meso- and racemic 2,3-diaminobutane-N,N,N',N'-tetraacetic acid and some bivalent cations

E. Dvořáková and J. Majer

Komenský University, Bratislava

Abstract: cf. CA 64, 6071g. The complexes of meso- (I) and racemic (II) forms of the title compd. with Cu, Cd, Zn, Mn, and Fe were studied potentiometrically at 20° and ionic strength 0.1 (KNO₃). The exchange equil. method with N(CH₂CH₂NH₂)₃ was used for Cu, Cd, and Zn, complexes, whereas Fe and Mn complexes were studied from equimolar neutralization curves. With both ligands only ML complexes are formed. Stability consts. for the complexes of I and II, resp., are (M  and log KML given): Cd, 16.77, 19.09;Zn, 17.13, 19.07; Cu, 19.90, 21.76; Mn, 14.11, 16.72; Fe, 15.11, 17.18. These values agree well with the results of polarographic method (CA 62, 8983d). The higher stability of chelates of II was ascribed to the differences in steric configuration of both ligands. The higher stability of Cu, Zn, and Co chelates of I when compared to those of ethylenediaminetetraacetic acid is caused by the higher basicity of N atoms in I.

Full paper in Portable Document Format: 204a233.pdf (in Slovak)

Chemical Papers 20 (4) 233–241 (1966)