|
Vol.
27 No. 6
November-December 2005
Critical Evaluation of Stability Constants of Metal Complexes of Complexones for Biomedical and Environmental Applications (IUPAC Technical Report)
Giorgio
Anderegg, Françoise Arnaud-Neu, Rita Delgado, Judith
Felcman, and Konstantin Popov
Pure
and Applied Chemistry
Vol. 77, No.
8, pp. 1445-1495 (2005)
This study involves evaluation of all reported proton and metal ion binding constants for the remaining commonly used complexones, and the identification of recommended values for use in chemical speciation calculations. Within these objectives, a priority was given to compounds of strong medical and environmental importance and to those (IDA and MIDA) that represent complex-forming fragments and decomposition products of higher denticity complexones.
Within a broad variety of applications, complexones have in common the regulation of metal concentrations in widely differing systems. Complexones are used in detergents, textile and paper processing, photographic developing solutions, scale solubilization in processing tanks, electroplating, and as components of agricultural micro-fertilizers. Annual industrial output of EDTA and other complexones in the thousands of tons.
This paper presents critical evaluations of available experimental data, published between 1945–2000, on stability constants of proton (hydron) and metal complexes for seven complexones of particular biomedical and environmental interest: iminodiacetic acid [2,2’-azanediyldiacetic acid, IDA], (methylimino)diacetic acid [2,2’-(methylazanediyl)diacetic acid, MIDA]; 2,2’,2’’,2’’’-{[(carboxymethyl)azanediyl]bis[(ethane-1,2-diyl)nitrilo]}tetraacetic acid (DTPA), 3,6,9,12-tetrakis(carboxymethyl)-3,6,9,12-tetraazatetradecanedioic acid (TTHA); 2,2’,2’’-(1,4,7-triazonane-1,4,7-triyl)triacetic acid (NOTA); 2,2’,2’’,2’’’-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA); 2,2’,2’’,2’’’-(1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetrayl)tetraacetic acid. Some typical errors in stability constant measurements for particular complexones are summarized. Higher quality data are selected and presented as “Recommended” or “Provisional.”
www.iupac.org/publications/pac/2005/7708/7708x1445.html
Page
last modified 28 October 2005.
Copyright © 2003-2005 International Union of Pure and
Applied Chemistry.
Questions regarding the website, please contact [email protected]
|