Jean-Claude Bunzli - Ft-Ir Investigation of Rare-Earth and Metal-Ion Solvation .14. Interaction Between Uranyl Perchlorate and Dimethyl-Sulfoxide in Anhydrous Acetonitrile

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  Bunzli,J.C.G., Metabanzoulou,J.P. Helvetica Chimica Acta  1994 77 (1) 140-149

  Abstract: The interaction between the uranyl ion   and perchlorate in anhydrous acetonitrile has been investigated   by FT-IR and Raman spectroscopy. Vibrations assigned to   uncoordinated (u), monodentate (m), and bidentate (b) perchlorate   anions were identified in 0.075M solutions. Quantitative data   indicate that perchlorate is distributed as follows: 37 +/- 2%   are uncoordinated, 36 +/- 7% are monodentate, and 27 +/- 7% are   bidentate. This is in agreement with the conductivity of the   solutions which is at the lower end of the range accepted for 1:   1 electrolytes. The splittings nu(4)-nu(1)(m) and nu(8) nu(1)(b)   Of 147 and 246 cm(-1), respectively, point to a large   inner-sphere interaction. An equilibrium occurs between two   differently coordinated species. Various amounts of DMSO were   added to 0.05M perchlorate solutions (R' = [DMSO](l)/[UO22+](l) =   1-10). The nu(7) (SO) and nu(22) (CS) vibrations of DMSO were   used to determine the average number of coordinated DMSO   molecules per uranyl ion, which is close to 4. Some bidentate   perchlorate ions are still present in these solutions, but all   the MeCN molecules (2.6 on average) are expelled out of the inner   coordination sphere. The data can again be interpreted in terms   of an equilibrium between differently coordinated species. The   average coordination number of the uranyl ion is 4.4, as the   perchlorate salt in MeCN solution, and may be somewhat smaller in   the presence of DMSO. The possible presence of dimeric species is   also discussed

  Address (URL): WOS:A1994MW15900014