Rare earth acetates

McCoy, H. N., The electrolysis of rare earth acetates and the separation of... 

Lossin, A. andMeyer, G. (1993)Anhydrous rare-earth acetates, M(CH3COO)3 (M = Sm-Lu, Y) with chain structures crystal structures of Lu(CH3COO)3 and Ho(CH3COO)3. Zeitschrift fur Anorganische und Allgemeine Chemie, 619, 1609-1615. 

The glycothermal reaction of rare earth acetate alone yields RE(OH)2(OAc), REO(OAc) (two polymorphs), and RE(OH)(OAc)2, depending on the ionic size of the RE ion. ° The acetate ions are not completely expelled from the coordination sites of the RE ion. However, in the presence of aluminum alkoxide as the starting material, acetate ions are fully eliminated from the product. Therefore anionic species (that is, >Al-0) facilitate cleavage of the bond between acetate and RE ions. 

These difficulties are overcome when solutions of certain rare earth acetates in aqueous potassium citrate are used as electrolytes. Such solutions may be made alkaline without causing precipitation of rare earth hydrous oxide. 

The required rare earth acetate-citrate solution is prepared from the crude material as described in part A for a pure europium compound. The electrolytic cells may be increased in size to handle any required quantity of solution. Electrolysis is carried out under conditions paralleling those described in part A. 

Kirin et al. (1965, 1967) and Kirin and Moskalev (1971) employed rare-earth acetates as the starting materials to prepare metal phthalocyaninates. It was demonstrated that apart from the monomeric half-sandwich complexes, the reactions also gave bis(phthalocyaninato) sandwich complexes, both of which remained poorly characterized at that time. These half-sandwich compounds are susceptible to de-complexation giving metal-free H2(Pc) upon heating in o-bromonaphthalene or treatment with concentrated sulfuric acid (Shklover and Plyushchev 1964). When a DMF solution of R(Pc)Cl is treated with NH4OH, R(Pc)(0H)-H20 is formed which is thermally unstable. Upon heating to 240°C, this compound converts to the dimeric species [R(Pc)]20 (Ni et al. 1987). 

High ortho-ortho novolacs are produced under weakly acidic conditions, by the use of specific catalysts, usually metal ion carboxylates. The first such resins were prepared by Bender and Farnham, using oxides of Zn, Mg, and A1 within the pH range of 4 to 7. Fraser et al used a broad range of salts of the divalent metals. Both groups of workers used a large excess of phenol, which was later removed by distillation. The use of acetates, lactates, formates, and benzoates was claimed to improve the solubility and activity of these catalysts, including rare earth acetates. ... 

The four triple bridging modes are the result of the combinations out of the two coordination modes, i.e., bidentate bridging and tridentate bridging. Of the four bridging modes, three of them are observed in anhydrous rare earth acetates ([REL3] ) with triple bidentate bridging mode, for RE = Sc with mixed triple bridging... 

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