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Lutetium, 71Lu
Lutetium
Pronunciation/ljuːˈtiːʃiəm/ ​(lew-TEE-shee-əm)
Appearancesilvery white
Standard atomic weight Ar°(Lu)
Lutetium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Y
↑
Lu
↓
Lr
ytterbium ← lutetium → hafnium
Atomic number (Z)71
Groupgroup 3
Periodperiod 6
Block  d-block
Electron configuration[Xe] 4f14 5d1 6s2
Electrons per shell2, 8, 18, 32, 9, 2
Physical properties
Phase at STPsolid
Melting point1925 K ​(1652 °C, ​3006 °F)
Boiling point3675 K ​(3402 °C, ​6156 °F)
Density (at 20° C)9.840 g/cm3 [3]
when liquid (at m.p.)9.3 g/cm3
Heat of fusionca. 22 kJ/mol
Heat of vaporization414 kJ/mol
Molar heat capacity26.86 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1906 2103 2346 (2653) (3072) (3663)
Atomic properties
Oxidation statescommon: +3
0,[4] +1,? +2?
ElectronegativityPauling scale: 1.27
Ionization energies
  • 1st: 523.5 kJ/mol
  • 2nd: 1340 kJ/mol
  • 3rd: 2022.3 kJ/mol
Atomic radiusempirical: 174 pm
Covalent radius187±8 pm
Color lines in a spectral range
Spectral lines of lutetium
Other properties
Natural occurrenceprimordial
Crystal structure ​hexagonal close-packed (hcp) (hP2)
Lattice constants
Hexagonal close packed crystal structure for lutetium
a = 350.53 pm
c = 554.93 pm (at 20 °C)[3]
Thermal expansionpoly: 9.9 µm/(m⋅K) (at r.t.)
Thermal conductivity16.4 W/(m⋅K)
Electrical resistivitypoly: 582 nΩ⋅m (at r.t.)
Magnetic orderingparamagnetic[5]
Young's modulus68.6 GPa
Shear modulus27.2 GPa
Bulk modulus47.6 GPa
Poisson ratio0.261
Vickers hardness755–1160 MPa
Brinell hardness890–1300 MPa
CAS Number7439-94-3
History
Namingafter Lutetia, Latin for: Paris, in the Roman era
DiscoveryCarl Auer von Welsbach and Georges Urbain (1906)
First isolationCarl Auer von Welsbach (1906)
Named byGeorges Urbain (1906)
Isotopes of lutetium
Main isotopes[6] Decay
abun­dance half-life (t1/2) mode pro­duct
173Lu synth 1.37 y ε 173Yb
174Lu synth 3.31 y β+ 174Yb
175Lu 97.4% stable
176Lu 2.60% 3.701×1010 y β− 176Hf
ε[6]0.45% 176Yb
177Lu synth 6.65 d β− 177Hf
 Category: Lutetium
| references

Lutetium (/[invalid input: 'icon']l[invalid input: '(j)']uːˈtiːʃiəm/ lew-TEE-shee-əm) is a chemical element with the symbol Lu and atomic number 71. It is in the d-block of the periodic table, not the f-block, but the IUPAC classifies it as a lanthanide.[7] It is one of the elements that traditionally were included in the classification, "rare earths". One of its radioactive isotopes (176Lu) is used in nuclear technology to determine the age of meteorites. Lutetium usually occurs in association with the element yttrium and is sometimes used in metal alloys and as a catalyst in various chemical reactions.

Characteristics

Physical properties

Lutetium is a silvery white corrosion-resistant trivalent metal. It has the smallest atomic radius and is the heaviest and hardest of the rare earth elements.[8] Lutetium has the highest melting point of any lanthanide, probably related to the lanthanide contraction.

Chemical properties

Lutetium metal tarnishes slowly in air and burns readily at 150 °C to form lutetium(III) oxide:

4 Lu + 3 O2 → 2 Lu2O3

Lutetium is quite electropositive and reacts slowly with cold water and quite quickly with hot water to form lutetium hydroxide:

2 Lu (s) + 6 H2O (l) → 2 Lu(OH)3 (aq) + 3 H2 (g)

Lutetium metal reacts with all the halogens to form halides:

2 Lu (s) + 3 F2 (g) → 2 LuF3 (s)
2 Lu (s) + 3 Cl2 (g) → 2 LuCl3 (s)
2 Lu (s) + 3 Br2 (g) → 2 LuBr3 (s)
2 Lu (s) + 3 I2 (g) → 2 LuI3 (s)

The fluoride, chloride, and bromide are white, whereas the iodide is brown.

Lutetium dissolves readily in dilute sulfuric acid to form solutions containing the colorless lutetium(III) ions, which exist as a [Lu(OH2)9]3+ complex:[9]

2 Lu (s) + 3 H2SO4 (aq) → 2 Lu3+ (aq) + 3 SO2–
4 (aq) + 3 H2 (g)

Compounds

See also: Category:Lutetium compounds

In all its compounds, lutetium occurs in +3 valence state. Aqueous solutions of most Lu salts are colorless and form white crystalline solids upon drying. The soluble salts, such as chloride (LuCl3), bromide (LuBr3), iodide (LuI3), nitrate, sulfate and acetate form hydrates upon crystallization. The oxide (Lu2O3), hydroxide, fluoride (LuF3), carbonate, phosphate and oxalate are insoluble in water.[10]

Lutetium tantalate (LuTaO4) is the densest known stable white material (density 9.81 g/cm3)[11] and therefore is an ideal host for X-ray phosphors.[12][13] Thoria is more dense (10 g/cm3) and is also white, but radioactive.

Isotopes

Main article: isotopes of lutetium

Naturally occurring lutetium is composed of 1 stable isotope 175Lu (97.41% natural abundance) and 1 long-lived beta-radioactive isotope 176Lu with a half-life of 3.78×1010 years (2.59% natural abundance). The last one is used in radiometric dating (see Lutetium-hafnium dating). 33 radioisotopes have been characterized, with the most stable being naturally occurring 176Lu, and artificial isotopes 174Lu with a half-life of 3.31 years, and 173Lu with a half-life of 1.37 years. All of the remaining radioactive isotopes have half-lives that are less than 9 days, and the majority of these have half-lives that are less than half an hour. This element also has 18 meta states, with the most stable being 177mLu (T½=160.4 days), 174mLu (T½=142 days) and 178mLu (T½=23.1 minutes).

The known isotopes of lutetium range in atomic weight from 149.973 (150Lu) to 183.961 (184Lu). The primary decay mode before the most abundant stable isotope, 175Lu, is electron capture (with some alpha and positron emission), and the primary mode after is beta emission. The primary decay products before 175Lu are element 70 (ytterbium) isotopes and the primary products after are element 72 (hafnium) isotopes.

History

Lutetium (Template:Lang-la meaning Paris) was independently discovered in 1907 by French scientist Georges Urbain,[14] Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James.[15] All of these men found lutetium as an impurity in the mineral ytterbia, which was thought by Swiss chemist Jean Charles Galissard de Marignac (and most others) to consist entirely of the element ytterbium.

The separation of lutetium from Marignac's ytterbium was first described by Urbain and the naming honor therefore went to him. He chose the names neoytterbium (new ytterbium) and lutecium for the new element but neoytterbium was eventually reverted to ytterbium and in 1949 the spelling of element 71 was changed to lutetium.

The dispute on the priority of the discovery is documented in two articles in which Urbain and von Welsbach accuse each other of publishing results influenced by the published research of the other.[16][17]

The Commission on Atomic Mass, which was responsible for the attribution of the names for the new elements, settled the dispute in 1909 by granting priority to Urbain and adopting his names as official ones. An obvious problem with this decision was that Urbain was one of the four members of the commission.[18]

Welsbach proposed the names cassiopeium for element 71 (after the constellation Cassiopeia) and aldebaranium for the new name of ytterbium but these naming proposals were rejected (although many German scientists in the 1950s called the element 71 cassiopium).

Ironically, Charles James, who had modestly stayed out of the argument as to priority, worked on a much larger scale than the others, and undoubtedly possessed the largest supply of lutetium at the time.[19]

Occurrence and production

Monazite

Found with almost all other rare-earth metals but never by itself, lutetium is very difficult to separate from other elements. The principal commercially viable ore of lutetium is the rare earth phosphate mineral monazite: (Ce, La, etc.) PO4 which contains 0.003% of the element. The abundance of lutetium in the Earth crust is only about 0.5 mg/kg. The main mining areas are China, United States, Brazil, India, Sri Lanka and Australia. The world production of lutetium (in the form of oxide) is about 10 tonnes per year.[19] Pure lutetium metal has only relatively recently been isolated and is very difficult to prepare. It is one of the rarest and most expensive of the rare earth metals with the price about US$ 10,000 per kg, or about one-fourth that of Gold.[20][21]

Crushed minerals are treated with hot concentrated sulfuric acid to produce water-soluble sulfates of rare earths. Thorium precipitates out of solution as hydroxide and is removed. After that the solution is treated with ammonium oxalate to convert rare earths in to their insoluble oxalates. The oxalates are converted to oxides by annealing. The oxides are dissolved in nitric acid that excludes one of the main components, cerium, whose oxide is insoluble in HNO3. Several rare earth metals, including Lu, are separated as a double salt with ammonium nitrate by crystallization. Lutetium is separated by ion exchange. In this process, rare-earth ions are sorbed onto suitable ion-exchange resin by exchange with hydrogen, ammonium or cupric ions present in the resin. Lutetium salts are then selectively washed out by suitable complexing agent. Lutetium metal is then obtained by reduction of anhydrous LuCl3 or LuF3 by either an alkali metal or alkaline earth metal.[10]

2 LuCl3 + 3 Ca → 2 Lu + 3 CaCl2

Applications

Because of the rarity and high price, lutetium has very few commercial uses. However, stable lutetium can be used as catalysts in petroleum cracking in refineries and can also be used in alkylation, hydrogenation, and polymerization applications.

Some other applications include:

Precautions

Like other rare-earth metals, lutetium is regarded as having a low degree of toxicity, but its compounds should be handled with care nonetheless. Metal dust of this element is a fire and explosion hazard. Lutetium plays no known biological role in the human body.

References

  1. ^ "Standard Atomic Weights: Lutetium". CIAAW. 2024.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ a b Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  4. ^ Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017. and Arnold, Polly L.; Petrukhina, Marina A.; Bochenkov, Vladimir E.; Shabatina, Tatyana I.; Zagorskii, Vyacheslav V.; Cloke (2003-12-15). "Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation". Journal of Organometallic Chemistry. 688 (1–2): 49–55. doi:10.1016/j.jorganchem.2003.08.028.
  5. ^ Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
  6. ^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  7. ^ "IUPAC Provisional Recommendations for the Nomenclature of Inorganic Chemistry (online draft of an updated version of the "Red Book" IR 3-6)". 2004. Retrieved 2009-06-06.
  8. ^ Parker, Sybil P. (1984). Dictionary of Scientific and Technical Terms, 3rd ed. New York: McGraw-Hill.
  9. ^ "Chemical reactions of Lutetium". Webelements. Retrieved 2009-06-06.
  10. ^ a b Patnaik, Pradyot (2003). Handbook of Inorganic Chemical Compounds. McGraw-Hill. p. 510. ISBN 0070494398. Retrieved 2009-06-06.
  11. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/0925-8388(94)91069-3, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1016/0925-8388(94)91069-3 instead.
  12. ^ Shigeo Shionoya (1998). Phosphor handbook. CRC Press. p. 846. ISBN 0849375606.
  13. ^ C. K. Gupta, Nagaiyar Krishnamurthy (2004). Extractive metallurgy of rare earths. CRC Press. p. 32. ISBN 0415333407.
  14. ^ M. G. Urbain (1908). "Un nouvel élément, le lutécium, résultant du dédoublement de l'ytterbium de Marignac". Comptes rendus. 145: 759–762.
  15. ^ "Separation of Rare Earth Elements".
  16. ^ C. Auer v. Welsbach (1908). "Die Zerlegung des Ytterbiums in seine Elemente". Monatshefte für Chemie. 29 (2): 181–225. doi:10.1007/BF01558944.
  17. ^ G. Urbain (1909). "Lutetium und Neoytterbium oder Cassiopeium und Aldebaranium -- Erwiderung auf den Artikel des Herrn Auer v. Welsbach". Monatshefte für Chemie. 31 (10): I. doi:10.1007/BF01530262.
  18. ^ F. W. Clarke, W. Ostwald, T. E. Thorpe, G. Urbain (1909). "Bericht des Internationalen Atomgewichts-Ausschusses für 1909". Berichte der deutschen chemischen Gesellschaft. 42 (1): 11–17. doi:10.1002/cber.19090420104.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ^ a b John Emsley (2001). Nature's building blocks: an A-Z guide to the elements. US: Oxford University Press. pp. 240–242. ISBN 0198503415.
  20. ^ James B. Hedrick. "Rare-Earth Metals" (PDF). USGS. Retrieved 2009-06-06.
  21. ^ Stephen B. Castor and James B. Hedrick. "Rare Earth Elements" (PDF). Retrieved 2009-06-06.
  22. ^ Muriel Gargaud, Hervé Martin, Philippe Claeys (2007). Lectures in Astrobiology. Springer. p. 51. ISBN 3540336923.{{cite book}}: CS1 maint: multiple names: authors list (link)
  23. ^ Yayi Wei, Robert L. Brainard (2009). Advanced Processes for 193-NM Immersion Lithography. SPIE Press. p. 12. ISBN 0819475572.
  24. ^ Helmut Sigel (2004). Metal complexes in tumor diagnosis and as anticancer agents. CRC Press. p. 98. ISBN 0824754948.
  25. ^ Wahl RL (2002). "Instrumentation". Principles and Practice of Positron Emission Tomography. Philadelphia: Lippincott: Williams and Wilkins. p. 51.
  26. ^ Daghighian, F. Shenderov, P. Pentlow, K.S. Graham, M.C. Eshaghian, B. Melcher, C.L. Schweitzer, J.S. (1993). "Evaluation of cerium doped lutetium oxyorthosilicate (LSO)scintillation crystals for PET". Nuclear Science. 40 (4): 1045–1047. doi:10.1109/23.256710.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  27. ^ J. W. Nielsen, S. L. Blank, D. H. Smith, G. P. Vella-Coleiro, F. B. Hagedorn, R. L. Barns and W. A. Biolsi (1974). "Three garnet compositions for bubble domain memories". Journal of Electronic Materials. 3 (3): 693–707. doi:10.1007/BF02655293.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • Guide to the Elements - Revised Edition, Albert Stwertka, (Oxford University Press; 1998) ISBN 0-19-508083-1
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