Lutetium nitrates

Lutetium nitrate [Lu(NOj)j] is a fire and explosion hazard when heated. 

The leach liquor is first treated with a DEHPA solution to extract the heavy lanthanides, leaving the light elements in the raffinate. The loaded reagent is then stripped first with l.Smoldm nitric acid to remove the elements from neodymium to terbium, followed by 6moldm acid to separate yttrium and remaining heavy elements. Ytterbium and lutetium are only partially removed hence, a final strip with stronger acid, as mentioned earlier, or with 10% alkali is required before organic phase recycle. The main product from this flow sheet was yttrium, and the yttrium nitrate product was further extracted with a quaternary amine to produce a 99.999% product. 

In aqueous media lutetium occurs as tripositive Lu3+ ion. All its compounds are in +3 valence state. Aqueous solutions of all its salts are colorless, while in dry form they are white crystalline solids. The soluble salts such as chloride, bromide, iodide, nitrate, sulfate and acetate form hydrates upon crystallization. The oxide, hydroxide, fluoride, carbonate, phosphate, and oxalate of the metal are insoluble in water. The metal dissolves in acids forming the corresponding salts upon evaporation of the solution and crystallization. 

At the end of the 19th century, Urbain, using the fractional crystallization method, prepared 60g of dysprosium oxide after 10,000 crystallizations then, in 1907, after 15,000 successive nitrate crystallizations from nitric solution, he separated lutetium and ytterbium. 

Rare earth nitrates usually have the formula RE(N03 )3 nU20 where n = 6 for the lighter rare earth nitrates (lanthanum to neodymium) and n = 5 for the heavier rare earth nitrate (europium to lutetium) and this is caused by lanthanide contraction. 

The first structure of a [Ln(phen)2(N03)3] complex was reported in 1992 for the lanthanum compound.It closely resembled the established bipy analogue in that the three nitrate groups were bidentate and the lanthanum was 10-coordinate. The structural information was complemented by a multinuclear solution ( H-, C-, O-, and La) NMR study. The structure of the other extreme member of the series, the lutetium complex, was reported in 1996. Unlike the La complex, but like [Lu(bipy)2(N03)3], the study was not complicated by disorder. The complexes appear to form an isomorpohous and isostructural series. On moving from the lanthanum to the lutetium compound, the Ln—N distances decrease from 2.646(3)-2.701(3) A (La) to 2.462(8)-2.479(8) A (Lu), and the range of Ln—O distances decreases from 2.580(3)-2.611(3) A for the lanthanum compound to 2.364(8)-2.525(6) A for the lutetium complex. Several structures have subsequently been reported of other [Ln(phen)2(N03)3] systems. [Ln(phen)2(N03)3] (Ln = Pr, Lu, Dy, are isostructural the individual complex... 

Likewise, Komorsky-Lovric et al. investigated the behavior of lutetium bisphtha-locyanine with the voltammetry of microparticles [108]. This solid-state reaction (which may be studied with either square-wave or cyclic voltammetry) was shown to proceed via the simultaneous insertion/expulsion of anion ions. The oxidation was found to have quasi-reversible characteristics in electrolyte solutions containing perchlorate, nitrate, and chloride, whereas bromide and thiocyanate... 

A determination of the stability constants of aquo-complexes of Eu " in acetone showed that as the concentration of water in the solution of europium nitrate in acetone was increased, the first co-ordination sphere of europium(iii) became occupied by three water molecules which replaced three acetone molecules, and only then did the replacement of NO3 anions by water occur. An n.m.r. study of the hydration of lutetium(iii) nitrate in aqueous acetone showed the co-ordination number of lutetium to tend to six with increasing water concentration. The coexistence of several aquo(methyl sulphoxide)lutetium(iii) complexes were identified in the study of the complex formation between lutetium and dimethyl sulphoxide in acetone. 

The A, stretching frequencies were found to increase steadily in magnitude across the lanthanide period for the [Ln(H20)x(NC>3)](0Tf)2 salts starting at 1450 cm-1 for lanthanum (r3+ = 1.172 A, Z/r = 2.56) and ending at a value of 1497 cm1 for lutetium (r3+ = 1.00, Z/r = 3.00) (Table 4). This structural data correlates extremely well with the observed reactivity of the respective lanthanide(m) triflates for nitration and can be taken as strong evidence for the proposed mode of action. 

From the above structural analysis it becomes clear that metal triflates with charge-to-size ratios greater than "3" (i.e. greater than that of the smallest lanthanide lutetium) should be more effective nitration catalysts. We considered that the group IV metals hafnium (r4+ = 0.78 A, Z/r = 5.13) and zirconium (r4 = 0.79 A, Z/r = 5.06) might be suitable for such a purpose. In line with this reasoning we noted that hafnium(IV) triflate has been shown to be an effective catalyst for Friedel-Crafts acylations and alkylations where the corresponding lanthanide salts were less active.20... 

The lutetium hahdes (except the fluoride), together with the nitrates, perchlorates, and acetates, are soluble in water. The hydroxide oxide, carbonate, oxalate, and phosphate compotmds are insoluble. Lutetium compounds are all colorless in the solid state and in solution. Due to its closed electronic configuration (4f " ), lutetium has no absorption bands and does not emit radiation. For these reasons it does not have any magnetic or optical importance, see also Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Neodymium Praseodymium Promethium Samarium Terbium Ytterbium. 

Lu203 Eu (1 at. %) nanopowders were obtained by co-precipitation technique using ammonium hydrocarbonate NH4HCO3 (purity >99.5 %) as a precipitant. Aqueous lutetium and europium nitrate solution was prepared by dissolving of corresponding oxides (purity 99.99 %) in the nitric acid. The precursor precipitate was produced by adding a mother solution to ammonium... 

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