A. M. Chekmarev

Solvent Effect on the Efficiency of Donor-Acceptor Interaction

Heats of solution and enthalpies of donor-acceptor interaction of several organic O-bases with SbCl5 in dichloroethane, benzene, nitrobenzene, butyl acetate, and acetone were determined by calorimetry. The correlation between the interaction enthalpies and the donor number of O-base is linear in all the solvents. The structure of an inert solvent does not affect the slope of the dependences and is manifested in mutual arrangement of the curves, with the shift being proportional to the donor number of the solvent.

Sorption of gaseous RuF5 on granulated fluoride sorbents

Published data on sorption decontamination from RuF5 of UF6 formed in the course of gas-fluoride reprocessing of spent nuclear fuel are summarized. Sorption of individual RuF5 on granulated fluoride sorbents, NaF (at 100 and 400°C) and MgF2 (at 125°C), is studied. The capacities of the granulated fluoride sorbents for RuF5 at these temperatures are determined. Sorption decontamination of UF6 from RuF5 on granulated fluoride sorbents is studied. The presence of UF6 in the gas does not affect significantly the sorption capacity of sodium and magnesium fluorides for RuF5.

Nonaqueous low-temperature nitration of uranium oxides in TBP

Nonaqueous low-temperature nitration of UO2 and U3O8 in the system TBP-chlorinated dilu-ent-NO2 was studied. The oxides dissolve to form uranyl nitrate. The influence exerted on the dissolution efficiency by the concentration of the donor solvent in the TBP-tetrachloroethylene system and by additions of water was examined. These dependences pass through a maximum. The influence of temperature on nitration of U3O8 and UO2 was studied, and the activation energies were determined (48.0 and 31.2 kJ mol−1, respectively). The partial orders of the nonaqueous nitration reactions with respect to NO2 were determined for U3O8 and UO2: 1.0 and 1.4, respectively.

Acceptor power of cations in donor-acceptor interactions

Published data concerning quantitative evaluation of the reactivity of cations in donor-acceptor interactions were analyzed. The “relative acceptor numbers” of C°2+, Mn2+, Ni2+, Al3+, and Ga3+ were determined polarographically: 2.16±0.32, 2.25±0.23, ∼1.70, 2.35±0.27, and 2.42±0.21, respectively. The known “relative acceptor numbers” for 21 cations were systematized, and a linear correlation between the ionization potentials and “relative acceptor numbers” of “hard” cations was revealed.

Conversion of rare-earth metal oxides in tributyl phosphate

Dissolution of gadolinium, europium, neodymium, dysprosium, and samarium oxides to give nitrates of these metals was studied in a system constituted by tributyl phosphate (30 vol %), tetrachloroethylene (70 vol %), and NO2. The activation energy of anhydrous dissolution of gadolinium oxide was calculated. The effect of water on the conversion efficiency of gadolinium oxide into nitrate was examined.