Uranyl ion effect

Leciejewicz J, Alcock NW, Kemp TJ (1995) Carboxylato Complexes of The Uranyl Ion Effects of Ligand Size and Coordinat. Geometry Upon Molecular and Crystal Structure. 82 43-84... 

Lammers M, Follmann H (1983) The Ribonucleotide Reductases A unique Group of Metallo-enzymes Essential for Cell Proliferation. 54 27-91 Le Brun NE, Thomson AJ, Moore GR (1997) Metal Centres of Bacterioferritins or Non-Heam-Iron-Containing Cytochromes bs57. 88 103-138 Leciejewicz J, Alcock NW, Kemp TJ (1995) Carboxylato Complexes of the Uranyl Ion Effects of Ligand Size and Coordinate. Geometry Upon Molecular and Crystal Structure. 82 43-84... 

The effect is more than just a matter of pH. As shown in Fig. XV-14, phospholipid monolayers can be expanded at low pH values by the presence of phosphotungstate ions [123], which disrupt the stmctival order in the lipid film [124]. Uranyl ions, by contrast, contract the low-pH expanded phase presumably because of a type of counterion condensation [123]. These effects caution against using these ions as stains in electron microscopy. Clearly the nature of the counterion is very important. It is dramatically so with fatty acids that form an insoluble salt with the ion here quite low concentrations (10 M) of divalent ions lead to the formation of the metal salt unless the pH is quite low. Such films are much more condensed than the fatty-acid monolayers themselves [125-127]. 

It is well-known that many organic excited states (e.g. the triplet state of benzophenone) can effectively abstract hydrogen atoms from organic compounds such as alkanes and alcohols. This behaviour is not commonly found for metal-containing compounds - a notable exception being the lowest excited state of uranyl ion which abstracts H atoms from alcohols, sugars etc., with the resultant formation of free radicals and U(V) compounds. Recent work has shown that it is very effective in inducing strand breaks in DNA (see Sect. 8). 

As already mentioned, UV-Vis spectroscopy is an effective tool to study metal complexes. For different actinide(IV) compounds in ILs (Np(IV), Pu(IV), U(IV) as [C4CiIm]2[AnCy complexes in [C4CiIm][Tf2N]) a similarity with solid complexes having an octahedral An(IV) environment was estimated [14,15]. In other ILs, for example, uranyl ions dissolved in [C4QIm] [NfO], [U02] may be present as a bare cation [16]. 

A review (91 references) on electrophilic and nucleophilic reactions of trivalent phosphorus acid derivatives, reactions of two-coordinate phosphorus compounds, and miscellaneous reactions has appeared.228 Earlier in this review we looked at the heavy-atom isotope effects on reactions of Co(III)-bound /vnitrophenyl phosphate,186 the uranyl ion hydrolysis of /vnitrophcnyl phosphodiesters (218)-(220),190 and the Th(IV) hydrolysis of these.191... 

Batzar, K. Goldberg, D.E. Newman, L.J. Effect of P-diketone structure on the synergistic extraction of uranyl ion by tributylphosphate, J. Inorg. Nucl. Chem. 29 (1967) 1511-1518. 

Table 1. M.O. energies (all in eV = 8065.48 cm-1) calculated for the uranyl ion, and in the first column, monatomic U+2 and oxygen atoms. The half-numbered quantum number is a> of linear symmetries. The two last columns give M.O. energies, neglecting effects of spin-orbital coupling, and hence characterized by X and parity...

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