Thermal stability and bonding in the silver complexes of ethylenediaminetetraacetic acid

The solid silver-EDTA complexes AgH3Y .(3/4)H2O; Ag2H2Y; Ag3HY and Ag4Y .(1 /2)H2O (Y-4 is ethylenediaminetetraacetate anion) obtained by reaction of t he Ag+ ions with sodium salts of EDTA in different degrees of neutralizatio n in aqueous media have been characterized by means of potentiometric titra tions, IR spectrometry, elemental analysis and powder X-ray diffraction (XR D). Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) were used to investigated the thermal stability of the complexes as well as the decomposition pathways. The thermoanalytical results associated with infrar ed data lead to the conclusion that the silver-carboxylate group bonding is primarily ionic. (C) 2000 Elsevier Science B.V. All rights reserved.