Lutetium ionic complexes

Ytterbium and lutetium ionic complexes, derived from enantiopure substituted (R)-binaphthylamine ligands of the general formula [Li(THF) ][Ln[(f )C2oHi2(NR)2]2], have been investigated as catalysts for hydroamination/cyclization of several unsatu- rated amines CH2=CH(CH2) C(R2)CH2NH2 (n = 1 or 2). Complexes with isopropyl or cyclohexyl substituents on nitrogen atoms were found to be efficient catalysts for the formation of N-containing heterocycles under mild conditions with enantiomeric excesses up to 78%.124... 

At the same time the thermolysis of tert-butyl derivatives is of great significance for the synthesis of hydrides of III group metals, since it allowed to prepare the first complexes of a new type containing a 113-bridged hydrogen atom [9]. It has been found that the decomposition of Cp2ErBu-t(THF) in the presence of LiCl leads to an ionic complex with a trinuclear anion A. The decomposition of lutetium etherate... 

Separation Processes. The product of ore digestion contains the rare earths in the same ratio as that in which they were originally present in the ore, with few exceptions, because of the similarity in chemical properties. The various processes for separating individual rare earth from naturally occurring rare-earth mixtures essentially utilize small differences in acidity resulting from the decrease in ionic radius from lanthanum to lutetium. The acidity differences influence the solubiUties of salts, the hydrolysis of cations, and the formation of complex species so as to allow separation by fractional crystallization, fractional precipitation, ion exchange, and solvent extraction. In addition, the existence of tetravalent and divalent species for cerium and europium, respectively, is useful because the chemical behavior of these ions is markedly different from that of the trivalent species. 

The Lu—C cr-bonding distances range from 2.425(15) to 2.501(17) A. These distances are approximately 0.2 A shorter than the corresponding distance for a pentahapto cyclopentadienide lutetium bond as predicted from ionic radii. Coordination about the lutetium atom is a slightly distorted tetrahedron. The formal coordination number of four is extremely low for the lanthanides. The only other lanthanide complex with such a low coordination number is the 3-coordinate compound [Lu N(SiMes)2 3] 131). In both cases, the low coordination number is stabilized by the use of bulky hgands. 

Ion-exchange has been indispensable in the characterization of the transamericium elements and is also important for some of the preceding elements, particularly for tracer quantities of material. We have seen in the case of the lanthanides (Chapter 27) that the +3 ions can be eluted from a cation-exchange column by various complexing agents, such as buffered citrate, lactate or 2-hydroxybutyrate solutions, and that the elution order follows the order of the hydrated ionic radii so that the lutetium is eluted first and lanthanum last. 

In this chapter, a correlation between the ionic radius of the metal-complexing in double-decker phthalocyanines and positions of maxima Q-bands in the electronic absorption spectra were determined in dimethylformamide and chloroform. The increasing of ionic radius from holmium to lutetium caused a regular change in the position of the maxima Q-bands in the absorption spectra. The behavior of metal diphthalocyaninates in supramolecular systems was also investigated. It was revealed that a new band shifted to the red region appeared in absorption spectra of sandwich phthalocyaninates of lutetium, etbium and ytteibium in albumin solution. This particular behavior allows us to consider phthalocyanines as prototype of sensitive biosensor system. 

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