US EPA

3579304 

Journal Article 

Potentiometric studies on the binary complexes of N-[tris(hydroxymethyl)methyl]glycine with Th4+, Ce3+, La3+ and UO22+ and medium effects on a Th-tricine binary complex 

Elroudi, OM; Alla, EMA; Ibrahim, SA 

1997 

Yes 

Journal of Chemical and Engineering Data
ISSN: 0021-9568
EISSN: 1520-5134 

42 

3 

609-613 

10.1021/je960350u 

WOS:A1997WY82500039 

https://pubs.acs.org/doi/10.1021/je960350u
Exit
 

The stability constants for Mn+-tricine binary complexes (1:1 and 1:2), where Mn+ = Th4+, Ce3+, La3+, and UO22+, have been determined pH-metrically in aqueous media at 25 degrees C and in the presence of 0.10 mol dm(-3) (KNO3). The binary Th-tricine (1:1) complex was studied in the presence of different organic solvents as well as in the presence of different ratios of dioxane and at different temperatures. The calculated stability constants have been discussed in terms of the nature of both the metal ion and tricine. It is suggested that tricine may act as a tridentate as well as a bidentate ligand. Solvent basicity and proportion in addition to the differences in stabilization of the free base by hydrogen bonding with solvent molecules as well as the electrostatic effect are the major factors responsible for the observed high stability of the Th-tricine binary complex. The thermodynamic parameters (Delta H, Delta G, and Delta S) for the formation of 1:1 Tn-tricine complex in the presence of 40% (w/w) dioxane at different temperatures (5-45 degrees C) were calculated.