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Transition Metal Ions and Amides, VI . Complexation of the neutral and the anionic forms of 3, 7‐diazanonanedioic acid diamide and 3, 7‐diazanonanedioic acid diethylamide with Cu 2+ and Ni 2+
Author(s) -
Kaden Thomas A.,
Zuberbühler Andreas D.
Publication year - 1974
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19740570203
Subject(s) - chemistry , deprotonation , amide , steric effects , chelation , monomer , medicinal chemistry , metal , derivative (finance) , metal ions in aqueous solution , stereochemistry , inorganic chemistry , polymer chemistry , ion , organic chemistry , polymer , financial economics , economics
Two tetradentate ligands, 3, 7‐diazanonanedioic acid diamide (DANA) and 3, 7‐diazanonanedioic acid diethylamide (DANEA) have been synthesized and their complexes with Cu 2+ and Ni 2+ studied potentiometrically and spectrophotometrically. Three monomeric species, ML, MH −1 L, and MH −2 L, are formed. In ML, the two carbonyl oxygens are bound to the metal ions. Whilst Cu 2+ gives complexes CuH −1 DANA + and CuH −1 DANEA + with one deprotonated amide group, the corresponding Ni 2+ chelates do not exist in detectable concentrations. CuH −2 DANA and NiH −2 DANA are formed below pH 9. In the case of the diethyl derivative DANEA, however, steric interaction strongly hinders coordination of two deprotonated amide groups.