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

New complexons. XV. Chelating agents of the 1,2-diaminoisoalkane-N,N,N'N'-tetraacetic acid type and polarographic investigation of their complexing properties

V. Novák, J. Lučanský, and J. Majer

Pharm. Fak., Komensky-Univ., Bratislava

Abstract: The change in the chelate-forming properties of EDTA by the substitution of the H atom in the carbon chain of ethylenediamine with the isoalkyl group on a pair of new complex-forming agents, 3-methyl-1,2-diaminobutane-N,N,N',N'-tetraacetic acid (I) and 4-methyl-1,2-diaminopentane-N,N,N',N'-tetraacetic acid (II), is described. A polarographic method for detg. the logarithms of the stability consts. of I and II complexes with lanthanides and heavy metals cations at ionic strength 0.10 (KNO3) and temp. 20° was used. The synthesis of I and II is given. The logarithms of the stability consts. of the chelates of I and II with the cations of the heavy metals increase in the order Mn < Co < Zn < Pb < Cu; the I complexes have substantially higher stability as compared with those of EDTA. The special behavior of I in the series of the complexons EDTA-I-II to a certain degree can be explained by a steric-induction effect of the iso-Pr substituent and by the various acid-base properties in relation to the different character of the central atom complexes. The stability consts. of the lanthanide chelates increase with increasing at. no. Both complexons, I and II, and the compds. of the group of 1,2-diaminoisoalkane-N,N,N',N'-tetraacetic acid form more stable chelates than those of EDTA and diaminocyclohexanetetraacetic acid.

Full paper in Portable Document Format: 2210a733.pdf (in German)

Chemical Papers 22 (10) 733–742 (1968)