Yttrium lanthanides and

The measurement of stability constants of complexes of yttrium, lanthanide, and actinide ions with oxalate, citrate, edta, and 1,2-diaminocyclohexanetetra-acetate ligands has revealed that there is a slight increase in the stability of complexes of the /-electron elements, relative to the others. A series of citric acid (H cit) complexes of the lanthanides have been investigated by ion-exchange methods and the species [Ln(H2cit)]", [Ln(H2cit)2] , [Ln-(Hcit)], and [Ln(Hcit))2] were detected. Simple and mixed complexes of dl- and jeso-tartaric acid have been obtained with La " and Nd ions, and the stability constants of lactate, pyruvate, and x-alaninate complexes of Eu and Am " in water have been determined. 

Alkoxides of Yttrium, Lanthanides, and Actinides 3.4.4.1 Yttrium and lanthanum alkoxides... 

Scandium, Yttrium, Lanthanide, and Actinide-containing Oxo-aikoxides (Including Heterometallic Compounds) (Table 5.3)... 

Table 5.3 Scandium, yttrium, lanthanide, and actinide-containing oxo-alkoxides (including heterometallic compounds)...

The heavy mineral sand concentrates are scmbbed to remove any surface coatings, dried, and separated into magnetic and nonmagnetic fractions (see Separation, magnetic). Each of these fractions is further spHt into conducting and nonconducting fractions in an electrostatic separator to yield individual concentrates of ilmenite, leucoxene, monazite, mtile, xenotime, and zircon. Commercially pure zircon sand typically contains 64% zirconium oxide, 34% siUcon oxide, 1.2% hafnium oxide, and 0.8% other oxides including aluminum, iron, titanium, yttrium, lanthanides, uranium, thorium, phosphoms, scandium, and calcium. 

Table 4. Lanthanide and Yttrium Distribution in Mineral Sources, wt %, ...

For elimination of intramolecular energy losses, we have synthesized ligands with high hydrophobisity - perfluoro-P-diketones R -CO-CH -CO-R, (R = CgF j or CgF R = phenyl or a-thienyl), that without second ligand eliminate completely water molecules from the inner coordination sphere. These ligands we have used in analysis at determination of Sm, Eu, Nd, Yb microamounts in high-purity lanthanide and yttrium oxides. 

To avoid this confusion, and because many of the elements are actually far from rare, the terms lanthanide , lanthanon and lanthanoid have been introduced. Even now, however, there is no general agreement about the position of La, i.e, whether the group is made up of the elements La to Lu or Ce to Lu. Throughout this chapter the term lanthanide and the general symbol, Ln, will be used to refer to the fourteen elements cerium to lutetium inclusive, the Group 3 elements, scandium, yttrium and lanthanum having already been dealt with in Chapter 20. 

However, solubility, depending as it does on the rather small difference between solvation energy and lattice energy (both large quantities which themselves increase as cation size decreases) and on entropy effects, cannot be simply related to cation radius. No consistent trends are apparent in aqueous, or for that matter nonaqueous, solutions but an empirical distinction can often be made between the lighter cerium lanthanides and the heavier yttrium lanthanides. Thus oxalates, double sulfates and double nitrates of the former are rather less soluble and basic nitrates more soluble than those of the latter. The differences are by no means sharp, but classical separation procedures depended on them. 

Table 30.5 Stoichiometries and structures of reduced halides (X/M < 2) of scandium, yttrium, lanthanum and the lanthanides...

The yttrium, lanthanum and other lanthanide salts exploded after dehydration during heating to above 300°C. 

Mineral sources, lanthanide and yttrium distribution in, 14 6311 Mineral spirits, solvent for cosmetics, 7 832 Minerals processing, history of, 16 596t. 

Solvates of the monohydroxylic alcohols have been extensively studied. The expected pattern of more solvent molecules per chloride molecule is reported for the lanthanide and yttrium trichlorides. For scandium trichloride, the existence of ScCl3-2EtOH and ScCl3-2C6H13OH compares unexpectedly with the tris-alcoholates reported for the n-C6... 

Studies on the use of sulfoxides in the extraction of scandium (325, 440), yttrium (188), and the lanthanide series (456) have all been reported and seem to show considerable promise. 

The 3rd group of the Periodic Table (the 1st column within the block of the transition elements) contains the metals scandium, yttrium, lanthanum, and actinium. Lanthanum (atomic number 57) may be considered the earliest member of the family of metals, called lanthanides (general symbol Ln), forming, inside the principal transition series, an inner transition series (up to atomic number 71). Scandium and yttrium together with the lanthanides are also called rare earth metals (general symbol R). 

Antipyrine (l,5-dimethyl-2-Phenyl-3-Pyrazolone) is known to form hexakis complexes with the lanthanides and yttrium salts 38). The bright green fluores-... 

Weaver, J., C. Krafka, D. Lynch, and E. Koch, 1981b. Physics Data Optical Properties of Metals, Pt. II Noble Metals, Aluminum, Scandium, Yttrium, the Lanthanides and the Actinides, Fach-Informations-Zentrum, Karlsruhe. 

F. T. Edelmann, Scandium, yttrium and the lanthanide and actinide elements, excluding their zero oxidation state complexes in Comprehensive Organometallic Chemistry II (eds. E. W. Abel, EG. A. Stone and G. Wilkinson), Elsevier, Oxford, 1995, vol. 4 (ed.M.F. Lappert), ch. 2. 

A separation procedure was developed after a simplex optimisation of a nitric acid digestion to determine lanthanides and yttrium in rare earth ores and concentrates... 

The structure of Cs yCls has been determined from single crystal data.530 It contains DyCli- octahedra connected by cis corners to form chains, the connecting Dy—Cl—Dy angle being 180°. The heavier lanthanides and yttrium are isostructural. 

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