Lutetium, properties

Lost Child fable, 3 Lucile," 347 Lutetium, properties, 412 Lyman, T., 258... 

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 lanthanides comprise the largest naturally-occurring group in the periodic table. Their properties are so similar that from 1794, when J. Gadolin isolated yttria which he thought was the oxide of a single new element, until 1907, when lutetium was discovered, nearly a hundred claims were made for the discovery of elements... 

The last of the lanthanides, this metal is also the hardest and the densest of them. It is a component of cerium mischmetal. Lutetium has some applications in optoelectronics. Shows great similarities to ytterbium. Its discoverer, Georges Urbain, carried out 15 000 fractional crystallizations to isolate pure lutetium (record ). The element has special catalytic properties (oil industry). 176Lu is generated artificially and is a good beta emitter (research purposes). 177Lu has a half-life of six days and is used in nuclear medicine. 

Coordination compounds composed of tetrapyrrole macrocyclic ligands encompassing a large metal ion in a sandwich-like fashion have been known since 1936 when Linstead and co-workers (67) reported the first synthesis of Sn(IV) bis(phthalocyanine). Numerous homoleptic and heteroleptic sandwich-type or double-decker metal complexes with phthalocyanines (68-70) and porphyrins (71-75) have been studied and structurally characterized. The electrochromic properties of the lanthanide pc sandwich complexes (76) have been investigated and the stable radical bis(phthalocyaninato)lutetium has been found to be the first example of an intrinsic molecular semiconductor (77). In contrast to the wealth of literature describing porphyrin and pc sandwich complexes, re-... 

Lutetium reacts slowly with water and is soluble in weak acids. Its crystals exhibit strong magnetic properties, which are important to the study of magnetism. 

The composition may then be described as Ln (OEP) (OEP ). This is easily seen from the paramagnetism of Lu(0EP)2 which has the magnetic moment of a radical, i. e. 1,7 B. M, in the solid state (4) As lutetium ions other than diamagnetic fare not known, only a porphyrin radical state is left to explain the properties, A similar radical state has been found for another doubledecker molecule, lutetium bis(phthalocyaninate), Lu(Pc)2 which is hence to be described as Lu (Pc) (Pc ) (11,12). All the... 

Mono- and bimetallic lanthanide complexes of the tren-based macrobicyclic Schiff base ligand [L58]3- have been synthesized and structurally characterized (Fig. 15), and their photophysical properties studied (90,91). The bimetallic cryptates only form with the lanthanides from gadolinium to lutetium due to the lanthanide contraction. The triplet energy of the ligand (ca. 16,500 cm-1) is too low to populate the terbium excited state. The aqueous lifetime of the emission from the europium complex is less than 0.5 ms, due in part to the coordination of a solvent molecule in solution. A recent development is the study of d-f heterobimetallic complexes of this ligand (92) the Zn-Ln complexes show improved photophysical properties over the homobinuclear and mononuclear complexes, although only data in acetonitrile have been reported to date. 

Ionic radius I n1 II.S48 A. Metallic ratlins 1.715 A. Olher important physical properties of lutetium arc given under Rare-Earth Elements and Metals. 

Rare-earth bisphthalocyaninates, especially LuPc2, are one of the important objects of intense investigation because of their electrochemical (electrochromic effect), electrical, and optical properties. The ball-type four t-butyl-calix[4]arene bridged double decker lutetium(III) and indium(III) Pcs have also been prepared, Fig. 3 [42],... 

Because of their electrical, optical, and redox properties as well as the thermal and chemical stability, the Pcs also have been tried in the detection of volatile organic compounds and poisonous gases, which is very important for environment and human health. In the past decades, the possible applications of Pc thin film as sensor for atmospheric gaseous pollutants have been extensively studied [73, 74], Langmuir-Blodgett films of some multinuclear and multidouble-decker lutetium Pcs have also been used for those measurements [75,76], More details about conductivity and sensing properties of Pcs can be found elsewhere [77,78]. 

Rare Earth elements (REEs) elements that occur in the periodic table from lanthanum (La) to lutetium (Lu)—have similar chemical and physical properties due to their electronic configurations. 

Givord D., Givord F., Lemaire R. (1971) Magnetic properties of iron compounds with yttrium, lutetium and gadolinium. J. Phys. (Paris) 32, Cl-668. 

A comparison of some properties of Sc and Y with those of Lu and La is given in Table 2.5. All these properties favour the placement of lutetium and lawrencium, rather than lanthanum and actinium in group III B. 

According to Bohr s opinion, the rare-earth group consisted of elements where the four-quantum level was gradually filled up from 18 to 32 electrons. The number of electrons in the five- and six-quantum levels on the other hand remained imchanged. Bohr s quantum theory thus served as a useful explanation for the pronoimced similarity between the chemical and physical properties of the rare-earth elements. He mentioned that their mutual similarity must be ascribed to the fact that we have here to do with the development of an electron group that lies deeper in the atom. He moreover emphasized that lutetium (Z = 71) had to be considered the last rare-earth element. Element 72 on the other hand did not belong to... 

It should be noted that although for decennia lanthanum and actinium could be found below yttrium in most periodic tables, some authors have placed lutetium below yttrium in the past. For instance, in the periodic table of Werner (1905a,b), there is an open place below yttrium at the position where lutetium is expected, but it should be realized that at that time lutetium had not yet been discovered (this was in 1907). However, Werner did not consider lanthanum as a homologue of yttrium, because of the differences in chemical properties between these two elements. Also in the circular system of Janet (Figure 28), the left-step table of Janet (Figure 32) and in the periodic table of Bohr (Figure 21), lutetium was placed below yttrium. 

Lanthanide elements (referred to as Ln) have atomic numbers that range from 57 to 71. They are lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). With the inclusion of scandium (Sc) and yttrium (Y), which are in the same subgroup, this total of 17 elements are referred to as the rare earth elements (RE). They are similar in some aspects but very different in many others. Based on the electronic configuration of the rare earth elements, in this chapter we will discuss the lanthanide contraction phenomenon and the consequential effects on the chemical and physical properties of these elements. The coordination chemistry of lanthanide complexes containing small inorganic ligands is also briefly introduced here [1-5]. 

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