COMPOSITION AND STRUCTURE OF COMPLEXES FORMED IN THE REACTION OF URANYL DI(2-ETHYLHEXYL)PHOSPHATE AND TRIBUTYL-PHOSPHATE OR DI-N-OCTYL SULFOXIDE IN BENZENE SOLUTIONS

This paper reports on P-31 NMR and IR studies of the interaction of tr ibutyl phosphate (TBP) and di-n-octyl sulfoxide (DOSO) with polymer mo lecules of uranyl di-2-ethylhexyl phosphate (UO(2)X(2))(p) (I) in C6H6 solutions. Detailed interpretations of the P-31 NMR spectra and the v (as)(POO) IR bands and determination of the fraction of nonequivalent phosphorus atoms of X(-) anions and uranium (VI) atoms as well as the concentration of U(VI)-bonded TBP in I have shown that only a single T BP or DOSO molecule is coordinated to the uranium atoms of polymer I a t C-TBP = 0.1-2 M or C-DOSO = 0.1-0.5 M In the case of 100% TBP, two T BP molecules are coordinated to some U(VI) atoms. Distribution of TBP (DOSO) molecules along the polymer chain agrees with the mean statisti cal value. The portion of terminal chelate POO-groups of X(-) anions i s determined The dependence of the degree of (UO(2)X(2))(p) . nL (L = TBP, DOSO) polymerization on C-L is obtained. Saturation of solutions with wafer only slightly affects the terminal P00-groups and has no ef fect on the distribution of L along the polymer chain of I.