The Gluconate Complexes. II. The Ferric-Gluconate System

Complexation of Uranium(VI) by Gluconate in Acidic Solutions: a Thermodynamic Study with Structural Analysis

“…Since their work four decades ago, little study of uranium complexation by gluconate has appeared in the literature, except for the work of Warwick et al for gluconate complexation of tetravalent U. 13 Therefore, the primary objectives of this study are: (1) to obtain reliable thermodynamic data for the complexation of gluconate with uranyl at I = 1.0 M and t = 25 °C, and (2) to obtain structural information on the resulting uranyl gluconate complexes. Thermodynamic parameters were determined by potentiometry and calorimetry.…”

“…And among them, only solution II was tested for HMQC and TOCSY. 1 H spectra were recorded averaging 200 scans for each spectrum. To minimize the lactonization of gluconic acid, 1 H NMR data were collected immediately after the solution was prepared (within 30 minutes, the collection was completed).…”

“…The data were collected using the States-TPPI hypercomplex method with 128 x 2 increments recorded with a total of 16 scans accumulated per t 1 increment. Acquisition times were 184 ms in t 2 and 46 ms in t 1 . An isotropic mixing time of 50 ms was used in conjunction with an MLEV-17c windowed mixing sequence, which used a spin locking field of 9.6 KHz.…”

“…1 H spectra of solutions I, II, III and IV are shown in Figure 5, and a 1 H-1 H TOCSY spectrum of solution II is depicted in Figure 6. The gluconate protons, to be consistent with the convention, are designated by α, β, γ, δ and ε as shown in the inset structure on the top-right corner of Figure 5.…”

“…Gluconate was added in large quantities to the nuclear materials processed at Hanford to facilitate dissolution of iron and aluminum [1][2][3][4][5][6][7][8][9] , and consequently, it directly affects f-element speciation in HLW. [10][11][12][13] This complicates waste processing for vitrification.…”