Search results for "Uranium Compounds"
showing 4 items of 4 documents
Interaction of UO2(2+) with ATP in aqueous ionic media.
2005
Interaction of dioxouranium(VI) (uranyl) ion with ATP was studied by ligand/proton and metal/hydroxide displacement technique, at very low ionic strength and at I=0.15 mol L(-1), in aqueous Me4NCl and NaCl solutions, at t=25 degrees C. Measurements were carried out in the pH range 3-8.5, before the formation of precipitate. Computer analysis allowed us to find the quite stable species UO2(ATP)H2(0), UO2(ATP)H-, UO2(ATP)2-, UO2(ATP)2(6-), UO2(ATP)2H2(4-) and UO2(ATP)(OH)3- whose formation constants are (at I=0 mol L(-1)) logbeta(112)=18.21, logbeta(111)=14.70, logbeta(110)=9.14, logbeta(120)=12.84, logbeta(122)=24.82, and logbeta(11-1)=2.09, respectively. Different values were obtained in th…
IR fingerprints of U(VI) nitrate monoamides complexes: a joint experimental and theoretical study.
2010
Infrared spectra of 0.5 mol·L-1 uranium(VI) nitrate monoamide complexes in toluene have been recorded and compared with infrared spectra calculated by DFT. The investigated monoamides were N,N- dimethylformamide (DMF), N,N-dibutylformamide (DBF), and N,N- dicyclohexylformamide (DcHF). The validity of DFT calculations for describing uranium nitrate monoamide complexes has been confirmed as a fair agreement between experimental and calculated spectra was obtained. Furthermore, a topological analysis of the electron density has been carried out to characterize monoamide-uranium interactions. From this work, it appears that the increase of stability of uranylmonoamide complexes may be directly …
A theoretical study of the gas-phase chemi-ionization reaction between uranium and oxygen atoms
2005
The U+O chemi-ionization reaction has been investigated by quantum chemical methods. Potential-energy curves have been calculated for several electronic states of UO and UO+. Comparison with the available spectroscopic and thermodynamic values for these species is reported and a mechanism for the chemi-ionization reaction U+O -> UO++e(-) is proposed. The U+O and Sm+O chemi-ionization reactions are the first two metal-plus-oxidant chemi-ionization reactions to be studied theoretically in this way.
The Effect of Metal Cations on the Aqueous Behavior of Dopamine. Thermodynamic Investigation of the Binary and Ternary Interactions with Cd2+, Cu2+ a…
2021
The interactions of dopamine [2-(3,4-Dihydroxyphenyl)ethylamine, (Dop−)] with cadmium(II), copper(II) and uranyl(VI) were studied in NaCl(aq) at different ionic strengths (0 ≤ I/mol dm−3 ≤ 1.0) and temperatures (288.15 ≤ T/K ≤ 318.15). From the elaboration of the experimental data, it was found that the speciation models are featured by species of different stoichiometry and stability. In particular for cadmium, the formation of only MLH, ML and ML2 (M = Cd2+; L = dopamine) species was obtained. For uranyl(VI) (UO22+), the speciation scheme is influenced by the use of UO2(acetate)2 salt as a chemical; in this case, the formation of ML2, MLOH and the ternary MLAc (Ac = acetate) species in a …