Title: Ytterbium
CAS Registry Number: 7440-64-4
Literature References: Yb; at. wt 173.04; at. no. 70; valences 2, 3. A rare earth metal of the yttrium group; member of the lanthanide series. Naturally occurring isotopes (mass numbers): 168 (0.13%); 170 (3.05%); 171 (14.3%); 172 (21.9%); 173 (16.12%); 174 (31.8%); 176 (12.7%); known artificial radioactive isotopes: 152-167; 169; 175; 177; 178. Estimated abundance in earth's crust: 2.66-3.1 ppm. Occurs in the rare earth minerals xenotime, ytterbite (gadolinite), monazite. Discovered independently: Urbain, Compt. Rend. 145, 759 (1907); and called aldebaranium: von Welsbach, Monatsh. Chem. 29, 181 (1908); 34, 1713 (1913). Sepn and purification: Urbain, Congress of Applied Chemistry [X] 94 (1909); Prandtl, Z. Anorg. Chem. 238, 321 (1938); Spedding et al., J. Am. Chem. Soc. 74, 2783 (1952); 76, 2557 (1954). Spectrum: Exner, Haschek et al., cited by Mellor, A Comprehensive Treatise on Inorganic and Theoretical Chemistry 5, 706 (1929). Toxicity study: Haley, J. Pharm. Sci. 54, 663 (1965). Reviews of prepn, properties and compds: The Rare Earths, F. H. Spedding, A. H. Daane, Eds. (Krieger, Huntington, N.Y., 1971, reprint of 1961 ed.) 641 pp; Hulet, Bode, "Separation Chemistry of the Lanthanides and Transplutonium Actinides", in MTP Int. Rev. Sci.: Inorg. Chem., Ser. One vol. 7, K. W. Bagnall, Ed. (University Park Press, Baltimore, 1972) pp 1-45; Moeller, "The Lanthanides", in Comprehensive Inorganic Chemistry vol. 4, J. C. Bailar Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 1-101; F. H. Spedding in Kirk-Othmer Encyclopedia of Chemical Technology vol. 19 (John Wiley & Sons, New York, 3rd ed., 1982) pp 833-854; Chemistry of the Elements, N. N. Greenwood, A. Earnshaw, Eds. (Pergamon Press, New York, 1984) pp 1423-1449. Brief review of properties: G. T. Seaborg, Radiochim. Acta 61, 115-122 (1993).
Properties: Silvery, ductile metal. Crystalline forms: face-centered cubic a-form, d 6.977, transforms to b-form at 798°; body-centered cubic b-form, d 6.54, exists at >798°. mp 819°. bp 1196°. Heat of fusion: 7.657 kJ/mol. Heat of sublimation (25°): 152.1 kJ/mol. Forms both di- and trivalent salts.
Melting point: mp 819°
Boiling point: bp 1196°
Density: d 6.977; d 6.54
Derivative Type: Oxide
Additional Names: Ytterbia
Molecular Formula: O3Yb2
Molecular Weight: 394.08
Percent Composition: O 12.18%, Yb 87.82%
Properties: Colorless mass, sol in dil acids.
Derivative Type: Hydroxide
Molecular Formula: Yb(OH)3
Molecular Weight: 224.06
Percent Composition: Yb 77.23%, O 21.42%, H 1.35%
Properties: Colorless gelatinous precipitate.
Derivative Type: Chloride
Molecular Formula: YbCl3
Molecular Weight: 279.40
Percent Composition: Yb 61.93%, Cl 38.07%
Properties: Hexahydrate, deliquescent crystals, d 2.575; mp 150-155°. LD50 in mice: 395 mg/kg i.p.; 6.7 g/kg orally (Haley).
Melting point: mp 150-155°
Density: d 2.575
Toxicity data: LD50 in mice: 395 mg/kg i.p.; 6.7 g/kg orally (Haley)
Derivative Type: Nitrate
Molecular Formula: Yb(NO3)3
Molecular Weight: 359.05
Percent Composition: Yb 48.19%, N 11.70%, O 40.10%
Properties: Tetrahydrate, transparent hygroscopic prisms from concd nitric acid. LD50 (hexahydrate) in rats: 255 mg/kg i.p.; 3.1 g/kg orally (Haley).
Toxicity data: LD50 (hexahydrate) in rats: 255 mg/kg i.p.; 3.1 g/kg orally (Haley)
Derivative Type: Sulfate
Molecular Formula: Yb2(SO4)3
Molecular Weight: 634.27
Percent Composition: Yb 54.56%, S 15.17%, O 30.27%
Properties: Octahydrate, lustrous colorless crystals, soly decreases with rise in temp.
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