Aqueous complexation of thorium(IV), uranium(IV), neptunium(IV), plutonium(III/IV), and cerium(III/IV) with DTPA.
Aqueous complexation of Th(IV), U(IV), Np(IV), Pu(III/IV), and Ce(III/IV) with DTPA was studied by potentiometry, absorption spectrophotometry, and cyclic voltammetry at 1 M ionic strength and 25 °C. The stability constants for the 1:1 complex of each trivalent and tetravalent metal were calculated. From the potentiometric data, we report stability constant values for Ce(III)DTPA, Ce(III)HDTPA, and Th(IV)DTPA of log β(101) = 20.01 ± 0.02, log β(111) = 22.0 ± 0.2, and log β(101) = 29.6 ± 1, respectively. From the absorption spectrophotometry data, we report stability constant values for U(IV)DTPA, Np(IV)DTPA, and Pu(IV)DTPA of log β(101) = 31.8 ± 0.1, 32.3 ± 0.1, and 33.67 ± 0.02, respectively. From the cyclic voltammetry data, we report stability constant values for Ce(IV) and Pu(III) of log β(101) = 34.04 ± 0.04 and 20.58 ± 0.04, respectively. The values obtained in this work are compared and discussed with respect to the ionic radius of each cationic metal.
Department of Chemistry, Oregon State University, Corvallis, Oregon 97330, USA.
M Alex
MA
Brown
Alena
A
Paulenova
Artem V
AV
Gelis
D002563:Cerium / Q000737:chemistry; D055664:Electrochemical Techniques; D009405:Neptunium / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D004369:Pentetic Acid / Q000737:chemistry; D011005:Plutonium / Q000737:chemistry; D013816:Thermodynamics; D013910:Thorium / Q000737:chemistry; D014501:Uranium / Q000737:chemistry; D014867:Water / Q000737:chemistry
D009942:Organometallic Compounds; D014867:Water; D002563:Cerium; D014501:Uranium; D011005:Plutonium; D013910:Thorium; D009405:Neptunium; D004369:Pentetic Acid