Neodymium containing compounds

Complexes Ln(bipy)2(N03)3 have been studied in more detail than the other bipy complexes all appear to have 10-coordinate structures with all nitrates present as bidentate ligands. The coordination geometry has been variously described as a bicapped dodecahedron and as a sphenocorona. Unlike the La complex, the Lu complex does not possess disorder about the twofold axis. Li N distances are 2.46-2.67(1) A and Lu—O distances in the range 2.426(9)-2.556(9) A. [Y(bipy)2(N03)3] is, like [Y(phen)2(N03)3], isostructural with its lanthanide analogues. Similarly, the structure of [Nd(bipy)2(N03)3] has been shown to be isostructural with [Ln(bipy)2(N03)3] (Ln = Y, La, Lu). A number of compounds Ln(bipy)3(N03)3 (Ln = Ce, Pr, Nd, Yb) have been reported the neodymium complex was shown to be [Nd(bipy)2(N03)3]. bipy, with the third bipy molecule not associating with the neodymium-containing complex. ... 

Recently similar complexes of neodymium have been prepared by Karraker 48) containing bromide and iodide in place of chloride. While their chemical properties are similar to the dimeric chloride compound their powder patterns suggest they may have different structures. Since they also have increasing amounts of solvent, the bromide containing three THF molecules and the iodide four, these may be complexes in which the halide bridge is broken by addition of another solvent molecule to give a monomer such as [Ln(COT)X 3 THF]. 

The lanthanide phthalocyanine complexes, obtained by conventional methods starting from metal salts at 170-290°C and phthalonitrile (Example 26), contain one or two macrocycles for each metal atom [5,6,8,63,82,84-98]. Thus, according to Refs. 6,63, and 85, the complexes having compositions LnPc2H, XLnPc (X- is halide anion), and Ln2Pc3 (a super-complex ) were prepared from phthalonitrile as a precursor the ratio of the reaction products depends on the synthesis conditions and the metal nature. The ionic structure Nd(Pc)+Nd(Pc)2 was suggested [85] and refuted [63] for the neodymium super-complex Nd2Pc3 the covalent character of the donor-acceptor bonds in this compound and other lanthanide triple-decker phthalocyanines was proved by the study of dissociation conditions of these compounds [63]. 

Evans et al. sequentially reacted the Nd carboxylate precursor Nd[C>2CC (CH3)2CH2CH3]3 % first with DEAC and then with TIBA. By this reaction catalytically active systems are obtained which polymerize IP. In the first reaction step in which Nd carboxylate is reacted with DEAC mixed ligand complexes are formed which contain neodymium and aluminum as well as halide and ethyl groups. Upon crystallization NdC -based compounds are obtained in which solvent is coordinated. These compounds exhibit a more complex... 

Properties Pink crystals. Soluble in water. Technical grade contains 75% neodymium salt, principal impurities praseodymium and samarium compounds. 

Praseodymium is difficult to obtain in pure compounds buffi because of its scarcity and close resemblance to other elements. The best methods of separation are as follows (1) Hot. out from a double magnesium nitrate scries such fractions us contain only lanthanum and praseodymium continue the fractionation of the same salt or of double ammonium nitrate, Praseodymium appears at the soluble end, but usually neodymium appears there also, even if its presence is unsuNficctcd at first. (2) Remove from the magnesium double nitrate series the fractions which contain only praseodymium and neodymium and continue the fractionation as the manganese double nitrate, when praseodymium separates in the least soluble portions, Other methods used are Crystallization of the oxalates from nitric add of the double ammonium nitrate or double carbonate. 

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