LA Metals

Fused Salt Electrolysis. Only light RE metals (La to Nd) can be produced by molten salt electrolysis because these have a relatively low melting point compared to those of medium and heavy RE metals. Deposition of an alloy with another metal, Zn for example, is an alternative. The feed is a mixture of anhydrous RE chlorides and fluorides. The materials from which the electrolysis cell is constmcted are of great importance because of the high reactivity of the rare-earth metals. Molybdenum, tungsten, tantalum, or alternatively iron with ceramic or graphite linings are used as cmcible materials. Carbon is frequently used as an anode material. 

M. H. West, M. M. Maitinez, J. B. Nielson, D. C. Court, and Q. D. Appeit, Synthesis of Uranium Metal UsingEaser-InitiatedTeduction of Uranium Tetrafluoride by Calcium Metal, LA-12996-MS, Los Alamos National Laboiatoiy, N.M., 1995. 

KEYWORDS ferromanganese, nodules, lakes, trace metals, LA-ICP-MS... 

The metallothermic reduction of the oxides by La produces the metals Sm, Eu, Tm, Yb, all having high vapour pressures. The reaction goes to completion due to the removal of the rare earths by volatilization from the reaction chamber (lanthanum has a low vapour pressure). The remaining rare earth metals (Sc, La, Ce, Pr, Nd, Y, Gd, Tb, Dy, Ho, Er, Lu) can be obtained by quantitative conversion of the oxides in fluorides, followed by reduction with Ca. The metallothermic reduction of the anhydrous rare earth chlorides could be also used to obtain La, Ce, Pr and Nd. The molten electrolysis can be applied to obtain only the first four lanthanide metals, La, Ce, Pr and Nd, because of the high reactivity of the materials that limits the operating temperatures to 1100°C or lower. 

The other doubledeckers containing the metals La, Pr, Nd, Sm -Lu have rather similar spectra that have less well distinct bands in the visible region. The extinction at 573 nm is much less than in A, Peaks occur at about 540 and 670 nm. The latter absorption is typical for 3T-cation radicals (10), Indeed, the composition Ln(0EP)2 can only be accomodated with the normal trivalent state of nearly all of the lanthanoid ions if one assumes that the... 

Complex LSB 9 is readily prepared either by the reaction of La(0 Pr)3 with 3 equiv. of B1NOL followed by the addition of NaO Bu (3 equiv.) or by the reaction of LaCl nfLO with sodium binaphthoxide. The complex 9 is stable to oxygen and moisture and has been proven to be effective in the catalytic Michael reaction of various enones with either malonates or p-keto esters. The Michael adducts with up to 92% ee were obtained in almost quantitative yield. Typical results with malonates are summarized in Table 8D.1 (Ln = lanthanide) [18], In general, the use of THF as solvent gave the best results except for the case of the LSB-catalyzed reaction of rmns-chalcone with dimethyl malonate, wherein the use of toluene was essential to give the adduct with good enantiomeric excess. The effects of the central metal (La, Pr, and Gd) on asymmetric induction were also examined in the same reaction, and LSB was found to be the best catalyst. 

Fig. 32a, b. Experimental 5s, 5 p X-ray photoelectron spectra for (a) atomic Xe7,8) and (b) metallic La and Ce10). Positions marked 6y arrows and thresholds refer to relativistic JSCF plus Fermi sea correlation (Af chosen to give perfect agreement with the experimental 5p levels). In (a), the vertical dashed lines denote theoretical94,951 relative intensities of the 5s, 5p25d and 5p26d levels... 

For the first time the possibility of the use of metal (La, Y) hydrides to prepare composite graphite electrodes was studied. The yield of DCB extracts of C2n/M C82 (M = Y, La, Ce, Gd) from soot obtained by evaporation of composite electrodes based on YH3, LaH3, CeH3 or GdH3 is 2-3 % higher (4-5 wt. % of the primary soot) than the yield of the extracts from soot synthesized using the electrodes based on metallic yttrium, lanthanum, cerium or gadolinium. EMF.v Y2 C84 and Ce2 C78 were produced, separated, and isolated for the first time. Their purity was justified by S8-MALDI mass spectrometry and they were characterized by UV-Vis-NIR absorption spectroscopy. 

Scheme 9.1 Preparation of the methylmanganese and -rhenium complexes 2a,b from the pentacarbonyl metallates la,b and their conversion into the acyl metal derivatives 3 (L = CO, PR3, NH2R) via migratory insertion of a carbonyl ligand into the M—CH3 bond (a M = Mn b M = Re)...

The lighter metals (La—Gd) are obtained by reduction of the trichlorides with Ca at 1000°C or more, whereas for others (Tb, Dy, Ho, Er, Tm, and also Y) the trifluorides are used because the chlorides are too volatile. Promethium metal is made by reduction of PmF3 with Li. Trichlorides of Eu, Sm, and Yb are reduced only to the dihalides by Ca, but the metals can be prepared by reduction of the oxides M203 with La at high temperatures. 

The electrodeposition of lanthanum. La, has been attempted in neutral and acidic EMICI-AICI3 ionic liquids [70, 71]. Lanthanum trichloride, LaCl3, is soluble in the acidic ionic liquid. The solubility of LaCl3 in the acidic ionic liquid containing AICI3 at 66.7 mol% is reported as 45 mmol kg at 25°C. The deposition of metallic La is not conhrmed, while the reduction of a trivalent lanthanum species is suggested in the presence of SOCI2. The electrodeposition of Al-La alloys has been also examined in the acidic ionic liquid where the content of La in the Al-La alloys is less than 0.1 at%. 

Prof. Mendeleeff admits for the three cerite metals La = 138,... 

The structnre of the heptaphosphides of the rare earth metals La, Ce, and Pr contains a polymeric polyanionic network to(P ) with seven-membered and large 20-membered rings, which, nevertheless, can be related in a simple way to the Py cage (see Section 6.5.2). 

Scrape a few laches off each end of two wirta with knife till metal la... 

Clean platea with knife until metal la ehiny where connectiona are to be made. 

NOTE If battery begins to fall after a few firings scrape the plstee and wires where connections are made tmtU metal la shiny. 

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