Nomenclature
CAS number: 7440-00-8
Description and references
Nd; at. wt 144.242; at. no. 60; valences 2,
3, 4. A lanthanide; belongs to the cerium group of rare earth metals.
Naturally occurring isotopes (mass numbers): 142 (27.13%); 143 (12.18%);
144 (23.80%), radioactive, T 1/2 2.1 × 1015 years, α-emitter;
145 (8.30%); 146 (17.19%); 148 (5.76%); 150 (5.64%). Known artificial
radioactive isotopes: 127-141; 147; 149; 151; 152. Abundance in earth's
crust: 24-40 ppm. Commercially important sources are the rare earth
minerals monazite and bastnaesite; also found in cerite and gadolinite.
Discovered by von Welsbach in 1885. Sepn from Pr: F. H. Spedding et al., J. Am. Chem. Soc. 69, 2786 (1947); 76, 2557 (1954); Kauffman,
Blank, J. Chem. Educ. 37, 156 (1960); from other rare earths: Spedding et al., J. Am. Chem. Soc. 69, 2812 (1947). Metal prepd by electrolysis of the chloride: Matignon, Compt. Rend. 131, 891 (1900);
Sieverts, Roell, Z. Anorg. Chem. 150, 261 (1926); by reduction of the chloride: Bommer,
Hohmann, ibid. 248, 357 (1941). Spectrum: Alberston et al., Phys. Rev. 61, 167 (1942). 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. Review of toxicology: T. J. Haley, J. Pharm. Sci. 54, 663-670 (1965).
Brief review of properties: G. T. Seaborg, Radiochim. Acta 61, 115-122 (1993).
Properties
Silver-white metal, becomes yellowish on exposure
to air. Crystalline forms: hexagonal α-form, d 7.003, transforms to β-form at 868°; body-centered
cubic β-form, d 6.80, exists at >868°. mp 1021°. bp 3074°. Heat of fusion: 7.134 kJ/mol. Heat of sublimation (25°): 327.6
kJ/mol. E°(aq) Nd3+/Nd -2.44 V (calc). Experimental reduction
potentials (referred to a normal calomel electrode): -1.870, -1.960
V: Noddack, Brukl, Angew. Chem. 50, 362 (1937). Reacts slowly with cold water; rapidly
on heating.Derivative
Oxide.
Nd
2O
3; mol wt 336.48.
Nd 85.74%, O 14.26%.
Description and references
Commercial uses: Pings, Colo. Sch. Mines, Miner. Ind. Bull. 12, no.
2 (1969) 19 pp.
Properties
Blue powder, hexagonal structure, exhibits a slightly
red fluorescence. Prepd by heating the hydroxide, carbonate, nitrate
or oxalate. Very stable. Sol in dil acids; soly in water: 5.7×10-6 g-mol/l at 29°.Derivative
Hydroxide.
Nd(OH)
3; mol wt 195.26.
Nd 73.87%, O 24.58%, H 1.55%.
Properties
Bluish or pink precipitate; on heating at 300-350°
is converted into 2Nd2O3.3H2O, grayish-brown;
on further increase in temp is converted into Nd2O3.H2O.Derivative
Chloride.
NdCl
3; mol wt 250.60.
Nd 57.56%, Cl 42.44%.
Properties
Large purple prisms. Sol in water, in alcohol.
Forms addition compds with ammonia. A hexahydrate is obtained from
the aq soln; the hydrate is very sol in water (2.46 parts per 1 part
of water); mp 124°. LD50 in mice (mg/kg): 4000 s.c., 348.3 i.p.; in male mice (mg/kg): 600 i.p., 5250 orally; in rats (mg/kg): 150-250 i.p.; in guinea pigs (mg/kg): 70 i.v., 139.6 i.p.; in rabbits (mg/kg): 200-250 i.v. (Haley).Derivative
Sulfate.
Nd
2(SO
4)
3; mol wt 576.67.
Nd 50.03%, S 16.68%, O 33.29%.
Properties
Pinkish needles; prepd by heating the oxide with
concd sulfuric acid. Heat of formation 57.2 kcal. Sol in water;
heat of soln 36.5 kcal. Is dec at 700-800°. Forms several double
salts. A penta-, an octa-, and a pentadecahydrate have been prepared.Derivative
Nitrate.
Nd(NO
3)
3; mol wt 330.26.
Nd 43.68%, N 12.72%, O 43.60%.
Properties
Penta- and hexahydrates; prepd by adding the oxide
to nitric acid. LD50 (hexahydrate) in
female mice (mg/kg): 270 i.p.; in female rats (mg/kg): 270 i.p., 2750 orally, 6.4 i.v.; in male rats (mg/kg): 66.8 i.v. (Haley).Use
Oxide as glass coloring agent; in glass filter plate
laminated on color TV tubes to improve contrast and brightness; in
lasers. Alloyed with iron and boron to produce powerful permanent
magnets.