|Author||Gustafson, R. L. ♦ Martell, A. E.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||CHEMISTRY ♦ ACETIC ACID ♦ AMINES ♦ CATECHOL ♦ CENTRIFUGATION ♦ CHELATES ♦ DTPA ♦ ELECTROLYTES ♦ ETHYLENE ♦ MEASURED VALUES ♦ MOLECULAR WEIGHT ♦ MOLECULES ♦ ORGANIC COMPOUNDS ♦ POLYMERS ♦ POTASSIUM NITRATES ♦ PYROCATECHOL ♦ QUANTITATIVE ANALYSIS ♦ SODIUM CHLORIDES ♦ SODIUM NITRATES ♦ SULFONIC ACIDS ♦ SULFUR COMPOUNDS ♦ THORIUM COMPLEXES ♦ THORIUM COMPOUNDS ♦ TIRON ♦ WEIGHT|
|Abstract||The application of ultracentrifuge measurements to the determination of molecular weights of charged metal chelates was investigated using the 1 : 1 Th(IV)-diethylenetriaminepentaacetate (DTPA) and 1: 1.5 Th(IV)-pyrocatechol-3,5- disulfonate (Tiron) systems. The Archibald nonequilibrium method of determining molecular weights as described bv Klainer and Kegeles was applied to the methods of dealing with charged polymers as outlined by Johnson, et al. The calculated values of the molecular weight of the monomeric Th(IV)-DTPA chelate (which was employed as a model system) were approximately 10 per cent lower than the actual value, presumably because of the fact that a nonideal supponting electrolyte, 1 M NaNO/sub 3/, was employed. The substitution of KNO/sub 3/ for NaNO/sub 3/ resulted in molecular weight values which were only 3 per cent below the theoretical value. Investigation of the 1: 1.5 Th(IV)-Tiron system of 1 M NaCl showed that a binuclear chelate is the predominant species. The effects of varying type and concentration of the supporting electrolyte were studied and discussed in terms of the primary and secondary salt effects. (auth)|
|Learning Resource Type||Article|
|Publisher Department||Clark Univ., Worcester, Mass.|
|Journal||Journal of the American Chemical Society|
|Organization||Clark Univ., Worcester, Mass.|
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