CAS No 7440-65-5 , yttrium

Title: Yttrium
CAS Registry Number: 7440-65-5
Literature References: Y; at. wt 88.90585; at. no. 39; valence 3. Group IIIb (3). A rare earth metal. Naturally occurring isotope (mass number): 89; known artificial radioactive isotopes: 80-88; 90-100. Estimated abundance in earth's crust: 28.1-31 ppm. Natural sources: xenotime, fergusonite, samarskite, yttrialite, gadolinite, and other rare earth minerals. Discovered in 1794 by Gadolin; separated as yttria in 1843 by Mosander; named by Ekeberg. Sepn by fractional precipitation: Bonardi, James, J. Am. Chem. Soc. 37, 2642 (1915); Willand, James, ibid. 38, 1198 (1916); Wichers et al., ibid. 40, 1615 (1918); by ion exchange: Spedding et al., ibid. 69, 2812 (1947); Mayer, Freiling, ibid. 75, 5647 (1953). Toxicity study: Cochran et al., Arch. Ind. Hyg. Occup. Med. 1, 637 (1950). 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; Vickery, "Scandium, Yttrium and Lanthanum", in Comprehensive Inorganic Chemistry vol. 3, J. C. Bailar Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 329-353; Moeller, "The Lanthanides", ibid. vol. 4, 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 1102-1110, 1423-1449.
Properties: Iron-gray, lustrous powder; darkens on exposure to light. Forms hexagonal close-packed crystals. d 4.4689. mp 1522°. bp 3338°. Heat of fusion: 11.43 kJ/mol. Heat of sublimation (25°): 424.7 kJ/mol. E°(aq) Y3+/Y -2.37 V (calc). Oxidizes on heating in air or oxygen; dec cold water slowly, boiling water rapidly.
Melting point: mp 1522°
Boiling point: bp 3338°
Density: d 4.4689
 
Derivative Type: Oxide
Synonyms: Yttria
Molecular Formula: O3Y2
Molecular Weight: 225.81
Percent Composition: O 21.26%, Y 78.74%
Properties: White powder, body-centered cubic structure, d 5.03. Obtained by igniting yttrium or its salts. Sol in dil acids; readily absorbs ammonia from the air; displaces ammonia from ammonium salts. LD50 i.p. in rats: 500 mg/kg (Cochran).
Density: d 5.03
Toxicity data: LD50 i.p. in rats: 500 mg/kg (Cochran)
 
Derivative Type: Hydroxide
Molecular Formula: Y(OH)3
Molecular Weight: 139.93
Percent Composition: Y 63.54%, O 34.30%, H 2.16%
Properties: White gelatinous ppt, dries to a white powder which absorbs CO2 from the air, obtained by the action of ammonium or alkali hydroxides on a soln of an yttrium salt.
 
Derivative Type: Chloride
Molecular Formula: YCl3
Molecular Weight: 195.26
Percent Composition: Y 45.53%, Cl 54.47%
Properties: Hexahydrate, colorless, deliquesc crystals. Sol in water, alc. Anhydr chloride obtained by heating in a stream of HCl.
 
Derivative Type: Carbonate
Molecular Formula: Y2(CO3)3
Molecular Weight: 357.84
Percent Composition: Y 49.69%, C 10.07%, O 40.24%
Properties: Trihydrate, white to reddish-white powder, prepd by hydrolysis of yttrium trichloroacetate. Insol in water. Sol in dil mineral acids.
 
Derivative Type: Sulfate
Molecular Formula: Y2(SO4)3
Molecular Weight: 466.00
Percent Composition: Y 38.16%, S 20.64%, O 41.20%
Properties: Octahydrate, monoclinic crystals. Sol in concd sulfuric acid with formation of Y(HSO4)3. Soly in water decreases with increase in temp. Forms double salts with alkali sulfates.
 
Derivative Type: Nitrate
Molecular Formula: Y(NO3)3
Molecular Weight: 274.92
Percent Composition: Y 32.34%, N 15.28%, O 52.38%
Properties: Hexahydrate, deliquesc crystals, sol in water, produces basic nitrates on partial decompn. LD50 i.p. in rats: 350 mg/kg (Cochran).
Toxicity data: LD50 i.p. in rats: 350 mg/kg (Cochran)
 
CAUTION: Potential symptom of overexposure to metal is eye irritation. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 338.
Use: Yttrium doped with rare earths as phosphors for color television receivers. Oxide for mantles in gas and acetylene lights. Chloride in prepn of pure metal. Yttrium aluminum garnets (YAGS) in lasers and for making artificial diamonds.