Carbonate complexes, actinide

Neck, V. Kim, J. I. 2000. An electrostatic approach for the prediction of actinide complexation constants with inorganic ligands - application to carbonate complexes. Radiochimica Acta, 88, 815-822. 

H20 (40) and CsPr(C03)2 (41). The powder X-ray diffraction technique was used to study most solid carbonates of lanthanides. Lanthanide/actinide complexes, M(C03)2 2re (n = 1 -3) have been... 

The first stable actinide complex of carbon monoxide was prepared by reaction of (Me3SiC5H4)3U (Cp sU) with CO in solution or in the solid state to produce Cp 3U(CO), which reversibly dissociates CO. Cp 3U(CO) exhibits a carbonyl stretch in the IR spectrum at 1976 cm, or approximately 170 cm lower than the uco for free carbon monoxide. This is taken as an indication of uranium-to-carbonyl jr-back bonding see Back Bonding). Electronic stracture calculations on the model complex CpsUCO indicated a significant U 5f-CO 2n... 

Tsutsui and Ely have extended the general method for preparing a-bonded actinide complexes to the synthesis of compounds containing lanthanide-carbon a-bonds (37,38,39). Using the reaction shown in eq.3, they synthesized a number of alkyl, aryl, and alkynyl derivatives. The metals chosen vary from Gd to Yb. Like their uranium analogs, they are oxygen and moisture sensitive, but they are surprisingly thermally stable. 

Cramer et al. synthesized an unusual class of complexes of the type (ti -C5H5)3UY, which contains M-carbon/nitrogen multiple bond character [229-234]. They were also the pioneers in synthesizing the first actinide complexes containing phosphorus hgands (Scheme 17). 

The crystal structures of some of the bis([8]annylene)actinide complexes are known. 0ranocene27,28 and thorocene28 are isostructural (Figure 3) with the only major difference being the metal-to-carbon bond... 

The results of Raman scattering experiments on Am(v) and Am(vi) ions in perchloric acid solutions have been reported [364]. The values for the polarized symmetric stretching frequencies (vj of the oxycations were found to be 730 cm" for Am(v) and 796 cm" for Am(vi) [364]. The Raman scattering of Am ions in carbonate solution showed a shift of Vj to 760 cm" for Am(vi) [365] and to 747 cmfor Am(v) [366]. A study of the correlation of the Raman spectra of actinyl(v) and actinyl(vi) ions in non-complexing perchlorate and complexing carbonate solutions, as well as the spectra of solid actinide (v) doublecarbonate compounds, was published by Madic et al. [366]. 

The purpose of this chapter is to survey and to analyze, in a necessarily brief and selective manner, actinide organometallic chemistry involving metal-carbon, metal-hydrogen, and metal-metal a bonds. Such linkages are fundamental building blocks of modem organometallic chemistry and catalysis. The nature of actinide complexes based upon coordination to multihapto organic n-electron systems was surveyed in Chapter 22. 

Madic C, Hobart D and Begun G 1983 Raman spectrometric studies of actinide (v) and-(vi) complexes in aqueous sodium carbonate solution and of sohd sodium actinide (v) carbonate compounds. Inorganic Chemistry 22(10), 1494-1503. 

Lundqvist, R. (1982) Hydrophilic complexes of the actinides. I. Carbonates of trivalent americium and europium. Acta Chem. 

Carbonates. Actinide carbonate complexes are of interest not only because of their fundamental chemistry and environmental behavior (150), but also because of extensive industrial appHcations, primarily in uranium recovery from ores and nuclear fuel reprocessing. 

Carbon monoxide [630-08-0] (qv), CO, the most important 7T-acceptor ligand, forms a host of neutral, anionic, and cationic transition-metal complexes. There is at least one known type of carbonyl derivative for every transition metal, as well as evidence supporting the existence of the carbonyls of some lanthanides (qv) and actinides (1) (see AcTINIDES AND THANSACTINIDES COORDINATION COMPOUNDS). 

With growing interest in the chemical behaviour of actinide ions in the environment (1), the complexation of these ions with carbonate anions has been recently attracting particular attention (2-10) due to the ubiquitous presence of carbonate ions in nature (11, 12) and their pronounced tendency to form complexes with heavy metal ions (7, 10-14). In spite of the carbonate complexation of actinides being considered important chemical reactions for understanding the chemistry of actinides in natural fluids, not many experiments have been devoted up to now to the quantitative study of the subject, though numerous qualitative observations are discussed in the literature. Although there are a few papers reporting the formation constants of carbonate complexes... 

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