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75As NMR (Nuclear Magnetic Resonance) was used as a probe of arsenate interactions in solution. The linewidth at half-height of the 75As NMR signal of arsenate was studied as a function of solution pH and temperature. Below pH 11.5, the 75As signal was too broad to be detected, but at higher pH, up to pH = 13.5, the signal became much narrower. This indicates that the arsenate species AsO4(3-) is quite symmetric, but the asymmetry of HAsO4(2-) is sufficient to cause extensive quadrupolar relaxation of the 75As nucleus. A full pH range 75As and proton NMR study of the interaction of arsenate with ethanol, ethylene glycol, glycerol, ribose, mannose, glucose, gluconic acid and acetate was undertaken in order to follow arsenate ester formation. The 75As line broadening effects and the proton ligand shifts observed indicate that complexation of arsenate by ribose, mannose, glucose, ethanol, ethylene glycol, and glycerol occurs at pH 12.7. However, no significant interaction is detected by NMR with gluconic acid or acetate. The effect of the nucleoside adenosine is quite small and those of phosphate and of the nucleotides AMP and ADP are negligible. The interaction of arsenate with potential cationic centers, such as the basic amino acids lysine and arginine and some macrocyclic triamines, was also studied. Such interaction depends on the pKa for protonation of the amine groups.

Proton, 13C and 31P nuclear magnetic resonance spectroscopy has been used to study the complexation of M(VI), W(VI) and U(VI) oxocations with various aldoses, cyclic polyols and ribose-5-phosphate in aqueous solution. The aldoses D-mannose, D-lyxose and D-ribose from tridentate complexes with Mo(VI) and W(VI) at pH ≃ 5, via the 1,2,3-hydroxyl groups, which are cis to each other in these sugars. Other aldoe, like D-arabinose, D-glucos, D-xylose and D-galactose from weaker bidentate complexs with those ions because they can onl use the 1 and 3-cis hydroxyl groups in metal binding. These bidentate interactions also take place in the binding of U(VI) to D-ribose, at pH ≃ 110. However, sugars having 1,3,5-hydroxyl groups in the cis position do not from stable chelates with these oxocations, possibly due to steric crowding. In the case of ribose-5-phosphate, the phosphate group is the exclusive binding site for the three oxocations. except for U(VI) at ver basic pH(pH > 10), where the hdroxyl groups al...