Kinetics of dissociation of trivalent actinide chelates of TMDTA

• Published in: Inorganic chemistry 1989-03, Vol.28 (6), p.993-997
• Main Authors: MUSCATELLO, A. C, CHOPPIN, G. R, D'OLIESLAGER, W
• Format: Article
• Language: English
• Subjects: 400202 - Isotope Effects, Isotope Exchange, & Isotope Separation; 400702 - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials; ACETIC ACID; ACTINIDE COMPLEXES; ACTINIDE ISOTOPES; ACTINIDE NUCLEI; ALPHA DECAY RADIOISOTOPES; AMERICIUM 241; AMERICIUM COMPLEXES; AMERICIUM ISOTOPES; BERKELIUM 249; BERKELIUM COMPLEXES; BERKELIUM ISOTOPES; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BETA-PLUS DECAY RADIOISOTOPES; CALIFORNIUM 252; CALIFORNIUM COMPLEXES; CALIFORNIUM ISOTOPES; CARBOXYLIC ACIDS; CHEMICAL REACTION KINETICS; Chemistry; COMPLEXES; CURIUM 244; CURIUM COMPLEXES; CURIUM ISOTOPES; DATA; DAYS LIVING RADIOISOTOPES; DISSOCIATION; ELECTRON CAPTURE RADIOISOTOPES; EUROPIUM 152; EUROPIUM 154; EUROPIUM COMPLEXES; EUROPIUM ISOTOPES; EVEN-EVEN NUCLEI; Exact sciences and technology; EXPERIMENTAL DATA; HEAVY NUCLEI; HOURS LIVING RADIOISOTOPES; INFORMATION; Inorganic chemistry and origins of life; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTERMEDIAT; INTERMEDIATE MASS NUCLEI; INTERNAL CONVERSION RADIOISOTOPES; ISOTOPE APPLICATIONS; ISOTOPES; KINETICS; Kinetics and mechanism of reactions; MONOCARBOXYLIC ACIDS; NUCLEI; NUMERICAL DATA; ODD-EVEN NUCLEI; ODD-ODD NUCLEI; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; RADIOISOTOPES; RARE EARTH COMPLEXES; RARE EARTH ISOTOPES; RARE EARTH NUCLEI; REACTION KINETICS; TRACER TECHNIQUES; TRANSURANIUM COMPLEXES; YEARS LIVI; YEARS LIVING RADIOISOTOPES
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic00305a003

Measurements by a radiotracer technique show that the dissociation of TMDTA (trimethylenediamine-N,N-tetraacetic acid) chelates with Am, Cm, Bk, Cf, and Eu proceeds through an acid-catalyzed pathway. The rates of dissociation of An(TMDTA){sup {minus}} are 2 orders of magnitude faster than those of the corresponding EDTA chelates, presumably due to the greater lability of the nitrogen atom in the six-membered nitrogen-metal-nitrogen ring of TMDTA chelates. The rate of dissociation also decreased with decreasing metal ion radius. A proton-catalyzed mechanism similar to that for dissociation of EDTA complexes of lanthanide and actinide cations is consistent with the rate data. 19 refs., 6 figs., 2 tabs.