Lanthanide compounds and complexes

The aim of this chapter is to review the chemistry of chalcogenolates in the last 10 years. The more recent reviews in this field included chalcogenolates of the s-block elements,early transition metal thiolates,metal complexes with selenolate and tellurolate ligands, copper(I), lithium and magnesium thiolates,functionalized thiolate complexes,pentafluorobenzenethiolate platinum group compounds, tellurium derivatives, luminescent gold compounds, and complexes with lanthanide or actinide. ... 

Actually, p.e. spectra of open-shell lanthanide elements and complexes show a particular resolution of different orbital states in addition to spin-orbit multiplicities (19). In the case of 5f-element complexes, the open shell systems thus far studied are those related to U(IV) complexes. The pattern of final state structure expected on ionizing one 5f electron from the ground configuration of 5f uranium compounds has been discussed previously [2]. It has been shown that of the 5/2 1/2 states which can be... 

However, the Fermi surface depends sensitively on details of the E-k relation, and the determination of the Fermi surface demands a more precise calculation for the eigenvalues than that for the cohesive energy. Therefore, for studies of the Fermi surface, these linearized methods should be applied carefully. Errors originating from linearized approximations should be minimized. Nevertheless, the LAPW method is valuable for calculations of the electronic structure in lanthanide compounds with complex crystal structures, such as LaCufi. 

Carbon monoxide [630-08-0] (qv), CO, the most important 7T-acceptor ligand, forms a host of neutral, anionic, and cationic transition-metal complexes. There is at least one known type of carbonyl derivative for every transition metal, as well as evidence supporting the existence of the carbonyls of some lanthanides (qv) and actinides (1) (see AcTINIDES AND THANSACTINIDES COORDINATION COMPOUNDS). 

Mn(II) > Mg(II).270 It should be underlined that titanium and zirconium alkoxides are efficient catalysts for both stages of reaction. Lanthanide compounds such as 2,2/-bipyridyl, acetylacetonate, and o-formyl phenolate complexes of Eu(III), La(III), Sm(III), Er(III), and Tb(III) appear to be even more efficient than titanium alkoxides, Ca or Mn acetates, Sb203, and their mixtures.273 Moreover, PET produced with lanthanides has been reported to exhibit better thermal and hydrolytic stability as compared to PET synthesized with the conventional Ca acetate -Sb203 catalytic system.273... 

Secondary amines can be added to certain nonactivated alkenes if palladium(II) complexes are used as catalysts The complexation lowers the electron density of the double bond, facilitating nucleophilic attack. Markovnikov orientation is observed and the addition is anti An intramolecular addition to an alkyne unit in the presence of a palladium compound, generated a tetrahydropyridine, and a related addition to an allene is known.Amines add to allenes in the presence of a catalytic amount of CuBr " or palladium compounds.Molybdenum complexes have also been used in the addition of aniline to alkenes. Reduction of nitro compounds in the presence of rhodium catalysts, in the presence of alkenes, CO and H2, leads to an amine unit adding to the alkene moiety. An intramolecular addition of an amine unit to an alkene to form a pyrrolidine was reported using a lanthanide reagent. 

Most lanthanide compounds are sparingly soluble. Among those that are analytically important are the hydroxides, oxides, fluorides, oxalates, phosphates, complex cyanides, 8-hydroxyquinolates, and cup-ferrates. The solubility of the lanthanide hydroxides, their solubility products, and the pH at which they precipitate, are given in Table 2. As the atomic number increases (and ionic radius decreases), the lanthanide hydroxides become progressively less soluble and precipitate from more acidic solutions. The most common water-soluble salts are the lanthanide chlorides, nitrates, acetates, and sulfates. The solubilities of some of the chlorides and sulfates are also given in Table 2. 

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