Erbium praseodymium samarium

B. Evans, Assistant Chemist. Rare-Earth Information Center. Energy itnd Mineral Resources Research Institute. Iowa Slate University. Ames. I,A. http //www.cxternal.ameslab.gov/. Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Lutetium Neodymium Rare-Earth Elements and Metals Praseodymium Samarium Scandium Terbium Thulium Ytterbium and Yttrium Daniel F. Farkas, Oregon State University. Corvallis. OR. http // oregonstate.edu/. Food Processing... 

Rillings K.W., Roberts J.E. A thermal study ofthe trifluoroacetates and pentafluoropropionates of praseodymium, samarium and erbium. Thermochim. Acta 1974 10 285-298 Riman RE. Fluoride optical materials. In Sol-Gel Optics Processing and Applications, Klein L.C., ed. Boston Kluwer, 1994... 

It surprises most people to learn that several of the so-called rare earth elements are not actually that rare compared to much more familiar elements. Neodymium, praseodymium, samarium, gadolinium, dysprosium, erbium, and ytterbium are all more abundant than more familiar elements like bromine, uranium, or tin. Europium, holmium, terbium, lutetium, and thulium are more abundant than iodine, silver, or mercury. Yet few people have even heard of most of the rare earths. The reason is that rare earths tend not to concentrate in large ore deposits in the way that better known metals do. Historically there have been fewer profits to be made from mining rare earth elements, and there have been fewer applications developed for them in industry. 

Differential procedures were published for uranium [ ], neodymium admixed with yttrium [ ], and to neodymium-erbium, praseodymium-erbium, and praseodymium-neodymium-samarium mixtures [ ]. 

Squire found that improved conversions of aromatic compounds and higher yields of aromatic amine were obtained when the aromatic compound reacted with ammonia in the presence of water at elevated temperamre and pressure using a conditioned Ni/NiO/Zr02 cataloreactant [67]. Delpesco also provided a strategy for improving the conversions of aromatic compounds to aromatic amines by prolonging the life of cataloreactant at a temperamre from about 150-500 °C at a pressure of from about 10-1000 atm. To this end, a dopant such as an oxide of lanthanum, samarium, holmium, europium, erbium, praseodymium, neodymium, terbium, ytterbium, dysprosium, yttrium, or mixtures thereof was added into Ni/NiO/Zr02 cataloreactant [68]. 

Lanthanum Comm Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium... 

These include the following 14 elements cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmi-um, erbium, thulium, ytterbium, and lutetium. 

Aluminum, barium, beryllium, boron, dysprosium, erbium, europium, gadolinium, gallium, germanium, hafnium, holmium, lanthanum, molybdenum, neodymium, niobium, phosphorus, praseodymium, rhenium, samarium, scandium, silicon, strontium, tantalum, terbium, thulium, tin, titanium, tungsten, uranium, vanadium, ytterbium, yttrium, zirconium... 

Atomic number Symbol Element 21 Sc Scandium 39 Y Yttrium 57 La Lanthanum 58 Cfc Cerium 59 Pi Praseodymium 60 Nd Neodymium 61 Pm Promethium 62 Sm Samarium 63 Eu Europium 64 Gd Gadolinium 65 Tb Terbium 66 Dy Dysprosium 67 Ho Ilolmium 68 Er Erbium 69 Tm Thulmm 70 Yb Ytterbium 71 Lu Lutetium... 

Lanthanum 140.1 Cerium 140.9 Praseodymium 144.2 Neodymium (145) Promethium 150.4 Samarium 152.0 Europium 157.3 Gadolinium 158.9 Terbium 162.5 Dysprosium 164.9 Holmium 167.3 Erbium 168.9 Thulium 173.0 Ytterbium... 

The only complexes of lanthanum or cerium to be described are [La(terpy)3][C104]3 175) and Ce(terpy)Cl3 H20 411). The lanthanum compound is a 1 3 electrolyte in MeCN or MeN02, and is almost certainly a nine-coordinate mononuclear species the structure of the cerium compound is not known with any certainty. A number of workers have reported hydrated 1 1 complexes of terpy with praseodymium chloride 376,411,438), and the complex PrCl3(terpy)-8H20 has been structurally characterized 376). The metal is in nine-coordinate monocapped square-antiprismatic [Pr(terpy)Cl(H20)5] cations (Fig. 24). Complexes with a 1 1 stoichiometry have also been described for neodymium 33, 409, 411, 413, 417), samarium 33, 411, 412), europium 33, 316, 411, 414, 417), gadolinium 33, 411), terbium 316, 410, 414), dysprosium 33, 410, 412), holmium 33, 410), erbium 33, 410, 417), thulium 410, 412), and ytterbium 410). The 1 2 stoichiometry has only been observed with the later lanthanides, europium 33, 411, 414), gadolinium, dysprosium, and erbium 33). 

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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