Erbium carbonates

Nasonov and co-workers have investigated the phase equilibria of the aluminium-rare-earth-metal-carbon systems and given partial phase diagrams for the aluminium-(scandium, yttrium, lanthanum, gadolinium and erbium)-carbon systems (Nasonov 1981, Nasonov et al. 1988) in the Al-rich region at 572°C. However, we were unable to obtain their reports because of lack of international academic exchanges. 

In aqueous solution, erbium is always trivalent, Er3+. It forms water-insoluble trivalent salts, such as fluoride, ErFs, carbonate, Er2(COs)2, hydroxide, Er(OH)3, phosphate, ErP04, and oxalate Er2(C204)s. It also forms water-soluble salts, chloride, ErCls bromide, ErBrs iodide, Erls sulfate, Er2(S04)s and nitrate, Er(NOs)3. Evaporation of solutions generally yields hydrated salts. 

Roesky introduced bis(iminophosphorano)methanides to rare earth chemistry with a comprehensive study of trivalent rare earth bis(imino-phosphorano)methanide dichlorides by the synthesis of samarium (51), dysprosium (52), erbium (53), ytterbium (54), lutetium (55), and yttrium (56) derivatives.37 Complexes 51-56 were prepared from the corresponding anhydrous rare earth trichlorides and 7 in THF and 51 and 56 were further derivatised with two equivalents of potassium diphenylamide to produce 57 and 58, respectively.37 Additionally, treatment of 51, 53, and 56 with two equivalents of sodium cyclopentadienyl resulted in the formation of the bis(cyclopentadienly) derivatives 59-61.38 In 51-61 a metal-methanide bond was observed in the solid state, and for 56 this was shown to persist in solution by 13C NMR spectroscopy (8Ch 17.6 ppm, JYc = 3.6 2/py = 89.1 Hz). However, for 61 the NMR data suggested the yttrium-carbon bond was lost in solution. DFT calculations supported the presence of an yttrium-methanide contact in 56 with a calculated shared electron number (SEN) of 0.40 for the yttrium-carbon bond in a monomeric gas phase model of 56 for comparison, the yttrium-nitrogen bond SEN was calculated to be 0.41. 

S708>, and 2-phenyl-l,3-dioxolanes are cleaved cleanly to diols by the use of catalytic erbium triflate <20050BC4129>. A titanium silicate molecular sieve is effective in catalyzing methanolysis of l,3-dioxolan-2-one to give ethanediol and dimethyl carbonate <1996CC2281>. 

Erbium and lutetium oxalates [81] decomposed after long induction periods required for complete dehydration. The carbonates which then formed were unstable and dissociated to yield oxides. The extents of carbon monoxide disproportionation during breakdown of these reactants were smaller (17% for Er and 6% for Lu). 

In addition to the above, preparation in w/o microemulsions of nanoparticles of various other types of compounds, viz. silica-coated iron oxide, Fe203-Ag nanocomposite, oxides of ytrium, erbium, neodymium, vanadium and cobalt, titanates of barium and lead, ferrites of barium, strontium, manganese, cobalt and zinc, oxide superconductors, aluminates, zirconium silicate, barium tungstate, phosphates of calcium, aluminium and zinc, carbonates of calcium and barium, sulphides of molybdenum and sodium, selenides of cadmium and silver etc. have been reported. Preparative sources and related elaboration can be found in [24]. 

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. 

N. J. Berlin said that the spontaneous evaporation of the soln. gives yellowish-brown dehquescent crystals. P. T. Cleve obtained potassium yttrium chromate, K2Cr04.Y2(Cr04)3.wH20, as a yellow, crystalline powder, by the action of potassium dichromate on yttrium carbonate. G. Kriiss and A. Loose, and W. Muthmann and C. R. Bohm also prepared erbium chromate, and ytterbium chromate. 

Metallographically, the composition at x = 1.0 was also always single-phase and at X = 0.8 a carbon-rich phase precipitates in the grain boundaries because of the volatility of the erbium. In the two phase regions (from x = 0 to x = 0.4 and from 0.6 to 0.7) the ErjSijC phase coexists with ErjSi4. 

The bond angles at holmium and erbium as well as the lanthanide-carbon bond lengths in this electron deficient organolanthanide compounds (table 25) are comparable with those in other electron-deficient compounds with other metal atoms (Schumann and Bruncks, 1982 Schumann et al., 1984a). 

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