Journal
CHEMISTRY-A EUROPEAN JOURNAL
Volume 15, Issue 16, Pages 4172-4181Publisher
WILEY-BLACKWELL
DOI: 10.1002/chem.200801155
Keywords
actinides; complexation; coordination modes; oxa-amides; thermodynamics; uranium
Categories
Ask authors/readers for more resources
Complexation of U-VI with N,N,N',N'-tetramethyl-3-oxa-glutaramide (TMOGA) and N,N-dimethyl 3-oxa-glutaramic acid (DMOGA) was Studied in comparison with their dicarboxylate analogue, oxydiacetic acid (ODA). Thermodynamic parameters including stability constants, enthalphy. and entropy of complexation, were determined by spectrophotometry, potentiometry and calorimetry. Single-crystal X-ray diffraction, EXAFS spectroscopy. FT-IR absorption spectroscopy, and laser-induced luninescence spectroscopy were used to obtain structural information on the U-VI complexes. Like ODA, TMOGA and DMOGA form tridentate U-VI complexes, with three oxygen atoms (the amide. ether, and/or carboxylate oxygen) coordinating to the linear UO22+ ion through the equatorial plane. The stability constants, enthalphy, and entropy of complexation all decrease in the order ODA>DMOGA>TMOGA, showing that the complexation is entropy driven and the substitution of a carboxylate group with an amide group reduces the strength of complexation with U-VI due to the decrease in the entropy of complexation. The trend in the thermodynamic stability of the complexes correlates very well with the structural and spectroscopic data obtained by single-crystal X-ray diffraction, FT-IR spectroscopy. and laser-induced luminescence spectroscopy.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available