GetWiki

{|class=“wikitable“|+ Ionic radii (pm)

aluminium>Al	Sc	yttrium	>	lanthanum>La	Lu

			|86.1

Oxides and hydroxides

The oxide {{chem|Sc|2|O|3}} and the hydroxide {{chem|Sc(OH)|3}} are amphoteric:BOOK, Cotton, Simon, Lanthanide and actinide chemistry,books.google.com/books?id=lvQpiVHrb78C&pg=PA108, 2011-06-23, 2006, John Wiley and Sons, 978-0-470-01006-8, 108–, α- and γ-ScOOH are isostructural with their aluminium hydroxide oxide counterparts.JOURNAL, Christensen, A. Nørlund, Stig Jorgo Jensen, 1967, Hydrothermal Preparation of α-ScOOH and of γ-ScOOH. Crystal Structure of α-ScOOH, Acta Chemica Scandinavica, 21, 1121–126, 10.3891/acta.chem.scand.21-0121, free, Solutions of {{chem|Sc|3+}} in water are acidic due to hydrolysis.

Halides and pseudohalides

The halides {{chem2|ScX3}}, where X= Cl, Br, or I, are very soluble in water, but {{chem2|ScF3}} is insoluble. In all four halides, the scandium is 6-coordinated. The halides are Lewis acids; for example, {{chem2|ScF3}} dissolves in a solution containing excess fluoride ion to form {{chem2|[ScF6](3−)}}. The coordination number 6 is typical for Sc(III). In the larger Y3+ and La3+ ions, coordination numbers of 8 and 9 are common. Scandium triflate is sometimes used as a Lewis acid catalyst in organic chemistry.JOURNAL, 10.1055/s-1999-5997, SYNLETT Spotlight 12: Scandium Triflate, Deborah Longbottom, Synlett, 1999, 12, 2023, 1999, free,

Organic derivatives

Scandium forms a series of organometallic compounds with cyclopentadienyl ligands (Cp), similar to the behavior of the lanthanides. One example is the chlorine-bridged dimer, {{chem2|[ScCp2Cl]2}} and related derivatives of pentamethylcyclopentadienyl ligands.JOURNAL, Model Ziegler-Natta α-Olefin Polymerization Catalysts Derived from [{(η5-C5Me4)SiMe2(η1-NCMe3)}(PMe3)Sc(μ2-H)]2 and [{(η5C5Me4)SiMe2(η1NCMe3)}Sc(μ1CH2CH2CH3)]2. Synthesis, Structures and Kinetic and Equilibrium Investigations of the Catalytically active Species in Solution, Shapiro, Pamela J., etal, Journal of the American Chemical Society, 116, 11, 4623, 1994, 10.1021/ja00090a011,

Uncommon oxidation states

Compounds that feature scandium in oxidation states other than +3 are rare but well characterized. The blue-black compound {{chem2|CsScCl3}} is one of the simplest. This material adopts a sheet-like structure that exhibits extensive bonding between the scandium(II) centers.JOURNAL, Corbett, J. D., 1981, Extended metal-metal bonding in halides of the early transition metals, Accounts of Chemical Research, 14, 239–246, 10.1021/ar00068a003, 8, Scandium hydride is not well understood, although it appears not to be a saline hydride of Sc(II). As is observed for most elements, a diatomic scandium hydride has been observed spectroscopically at high temperatures in the gas phase. Scandium borides and carbides are non-stoichiometric, as is typical for neighboring elements.Holleman, A. F.; Wiberg, E. “Inorganic Chemistry” Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}.Lower oxidation states (+2, +1, 0) have also been observed in organoscandium compounds.JOURNAL, Polly L. Arnold, F. Geoffrey, N. Cloke, Peter B. Hitchcock, John F. Nixon, amp, 1996, The First Example of a Formal Scandium(I) Complex: Synthesis and Molecular Structure of a 22-Electron Scandium Triple Decker Incorporating the Novel 1,3,5-Triphosphabenzene Ring, Journal of the American Chemical Society, 118, 32, 7630–7631, 10.1021/ja961253o, JOURNAL, F. Geoffrey N. Cloke, Karl Khan, Robin N. Perutz, amp, 1991, η-Arene complexes of scandium(0) and scandium(II), Journal of the Chemical Society, Chemical Communications, 19, 1372–1373, 10.1039/C39910001372, JOURNAL, 5, Ana Mirela Neculai, Dante Neculai, Herbert W. Roesky, Jörg Magull, Marc Baldus, Ovidiu Andronesi, Martin Jansen, 2002, Stabilization of a Diamagnetic ScIBr Molecule in a Sandwich-Like Structure, Organometallics, 21, 2590–2592, 10.1021/om020090b, 13, JOURNAL, Polly L. Arnold, F. Geoffrey, N. Cloke, John F. Nixon, amp, 1998, The first stable scandocene: synthesis and characterisation of bis(η-2,4,5-tri-tert-butyl-1,3-diphosphacyclopentadienyl)scandium(II), Chemical Communications, 7, 797–798, 10.1039/A800089A,

History

Dmitri Mendeleev, who is referred to as the father of the periodic table, predicted the existence of an element ekaboron, with an atomic mass between 40 and 48 in 1869. Lars Fredrik Nilson and his team detected this element in the minerals euxenite and gadolinite in 1879. Nilson prepared 2 grams of scandium oxide of high purity.JOURNAL, Sur l’ytterbine, terre nouvelle de M. Marignac,gallica.bnf.fr/ark:/12148/bpt6k30457/f639.table, Comptes Rendus, Nilson, Lars Fredrik, 88, 1879, 642–647, fr, JOURNAL, Ueber Scandium, ein neues Erdmetall, Berichte der deutschen chemischen Gesellschaft, 12, 1, 1879, 554–557, Nilson, Lars Fredrik, 10.1002/cber.187901201157, de,zenodo.org/record/1425172, He named the element scandium, from the Latin Scandia meaning “Scandinavia”. Nilson was apparently unaware of Mendeleev’s prediction, but Per Teodor Cleve recognized the correspondence and notified Mendeleev.JOURNAL, Sur le scandium,gallica.bnf.fr/ark:/12148/bpt6k3046j/f432.table, Comptes Rendus, Cleve, Per Teodor, 89, 1879, 419–422, fr, BOOK, Weeks, Mary Elvira, The discovery of the elements, 1956, Journal of Chemical Education, Easton, PA,archive.org/details/discoveryoftheel002045mbp, 6th, Metallic scandium was produced for the first time in 1937 by electrolysis of a eutectic mixture of potassium, lithium, and scandium chlorides, at 700–800 Â°C.JOURNAL, Ãœber das metallische Scandium, Zeitschrift für anorganische und allgemeine Chemie, 231, 1–2, 1937, 54–62, Werner, Fischer, Brünger, Karl, Grieneisen, Hans, 10.1002/zaac.19372310107, de, The first pound of 99% pure scandium metal was produced in 1960. Production of aluminium alloys began in 1971, following a US patent.Burrell, A. Willey Lower “Aluminum scandium alloy” {{US patent|3,619,181}} issued on November 9, 1971. Aluminium-scandium alloys were also developed in the USSR.JOURNAL, Effect of Scandium on the Structure and Properties of Aluminum Alloys, Metal Science and Heat Treatment, 45, 2003, 246, 10.1023/A:1027368032062, V. V., Zakharov, 7/8, 2003MSHT...45..246Z, 135389572, Laser crystals of gadolinium-scandium-gallium garnet (GSGG) were used in strategic defense applications developed for the Strategic Defense Initiative (SDI) in the 1980s and 1990s.WEB, Hedrick, James B., Scandium,www.reehandbook.com/scandium.html, REEhandbook, Pro-Edge.com, 2012-05-09, dead,reehandbook.com/scandium.html," title="web.archive.org/web/20120602220148reehandbook.com/scandium.html,">web.archive.org/web/20120602220148reehandbook.com/scandium.html, 2012-06-02, JOURNAL,books.google.com/books?id=7cie1S3hpC0C&pg=PA26, Star-wars intrigue greets scandium find, New Scientist, 1987, 26, Tony, Samstag,

Applications

Aluminium alloys

File:Mig-29 on landing.jpg|thumb|right |Parts of the MiG-29 are made from Al-Sc alloy.JOURNAL, 10.1007/s11837-003-0224-6, The properties and application of scandium-reinforced aluminum, 2003, Zaki, Ahmad, JOM, 55, 35, 2, 2003JOM....55b..35A, 8956425, ]]The main application of scandium by weight is in aluminium-scandium alloys for minor aerospace industry components. These alloys contain between 0.1% and 0.5% of scandium. They were used in Russian military aircraft, specifically the Mikoyan-Gurevich MiG-21 and MiG-29.The addition of scandium to aluminium limits the grain growth in the heat zone of welded aluminium components. This has two beneficial effects: the precipitated {{chem2|Al3Sc}} forms smaller crystals than in other aluminium alloys, and the volume of precipitate-free zones at the grain boundaries of age-hardening aluminium alloys is reduced. The {{chem2|Al3Sc}} precipitate is a coherent precipitate that strengthens the aluminum matrix by applying elastic strain fields that inhibit dislocation movement (i.e., plastic deformation). {{chem2|Al3Sc}} has an equilibrium L12 superlattice structure exclusive to this system.JOURNAL, Knipling, Keith E., Dunand, David C., Seidman, David N., 2006-03-01, Criteria for developing castable, creep-resistant aluminum-based alloys – A review,www.hanser-elibrary.com/doi/abs/10.3139/146.101249, Zeitschrift für Metallkunde, 97, 3, 246–265, 10.3139/146.101249, 4681149, 0044-3093, A fine dispersion of nano scale precipitate can be achieved via heat treatment that can also strengthen the alloys through order hardening.JOURNAL, Knipling, Keith E., Karnesky, Richard A., Lee, Constance P., Dunand, David C., Seidman, David N., 2010-09-01, Precipitation evolution in Al–0.1Sc, Al–0.1Zr and Al–0.1Sc–0.1Zr (at.%) alloys during isochronal aging,www.sciencedirect.com/science/article/pii/S1359645410003393, Acta Materialia, en, 58, 15, 5184–5195, 10.1016/j.actamat.2010.05.054, 2010AcMat..58.5184K, 1359-6454, Recent developments include the additions of transition metals such as zirconium (Zr) and rare earth metals like erbium (Er) produce shells surrounding the spherical {{chem2|Al3Sc}} precipitate that reduce coarsening.JOURNAL, Booth-Morrison, Christopher, Dunand, David C., Seidman, David N., 2011-10-01, Coarsening resistance at 400°C of precipitation-strengthened Al–Zr–Sc–Er alloys,www.sciencedirect.com/science/article/pii/S135964541100543X, Acta Materialia, en, 59, 18, 7029–7042, 10.1016/j.actamat.2011.07.057, 2011AcMat..59.7029B, 1359-6454, These shells are dictated by the diffusivity of the alloying element and lower the cost of the alloy due to less Sc being substituted in part by Zr while maintaining stability and less Sc being needed to form the precipitate.JOURNAL, De Luca, Anthony, Dunand, David C., Seidman, David N., 2016-10-15, Mechanical properties and optimization of the aging of a dilute Al-Sc-Er-Zr-Si alloy with a high Zr/Sc ratio, Acta Materialia, en, 119, 35–42, 10.1016/j.actamat.2016.08.018, 2016AcMat.119...35D, 1359-6454, free, These have made {{chem2|Al3Sc}} somewhat competitive with titanium alloys along with a wide array of applications. However, titanium alloys, which are similar in lightness and strength, are cheaper and much more widely used.BOOK,books.google.com/books?id=aveTxwZm40UC&pg=PA2274, 2274, Schwarz, James A., Contescu, Cristian I., Putyera, Karol, CRC Press, 2004, 978-0-8247-5049-7, Dekker encyclopédia of nanoscience and nanotechnology, 3, The alloy {{chem2|Al20Li20Mg10Sc20Ti30}} is as strong as titanium, light as aluminium, and hard as some ceramics.JOURNAL, 10.1080/21663831.2014.985855, A Novel Low-Density, High-Hardness, High-entropy Alloy with Close-packed Single-phase Nanocrystalline Structures, Materials Research Letters, 3, 2, 95–99, 2015, Youssef, Khaled M., Zaddach, Alexander J., Niu, Changning, Irving, Douglas L., Koch, Carl C., free, Some items of sports equipment, which rely on lightweight high-performance materials, have been made with scandium-aluminium alloys, including baseball bats,JOURNAL, A batty business: Anodized metal bats have revolutionized baseball. But are finishers losing the sweet spot?, Metal Finishing, 104, 61, 10.1016/S0026-0576(06)80099-1, 2006, Steve, Bjerklie, 4, tent poles and bicycle frames and components.WEB,www.eastonbike.com/downloadable_files_unprotected/r&d_files/R&D-03%20Scandium.pdf, Easton Technology Report: Materials / Scandium, EastonBike.com, 2009-04-03, Lacrosse sticks are also made with scandium. The American firearm manufacturing company Smith & Wesson produces semi-automatic pistols and revolvers with frames of scandium alloy and cylinders of titanium or carbon steel.BOOK, James, Frank, Effective handgun defense,books.google.com/books?id=XT5TRli0OdcC&pg=PA207, 2011-06-08, 15 December 2004, Krause Publications, 978-0-87349-899-9, 207–, BOOK, Sweeney, Patrick, The Gun Digest Book of Smith & Wesson,books.google.com/books?id=eBxEBgJBG0MC&pg=PA34, 2011-06-08, 13 December 2004, Gun Digest Books, 978-0-87349-792-3, 34–, Since 2013, Apworks GmbH, a spin-off of Airbus, have marketed a high strength Scandium containing aluminium alloy processed using metal 3D-Printing (Laser Powder Bed Fusion) under the trademark Scalmalloy which claims very high strength & ductility. WEB,www.tctmagazine.com/additive-manufacturing-3d-printing-news/apworks-metal-additive-manufacturing-material-formula-1/, APWORKS’ Scalmalloy metal additive manufacturing material approved for use in Formula 1, TCT, 2023-10-11,

Light sources

The first scandium-based metal-halide lamps were patented by General Electric and made in North America, although they are now produced in all major industrialized countries. Approximately 20 kg of scandium (as {{chem2|Sc2O3}}) is used annually in the United States for high-intensity discharge lamps.Hammond, C. R. in CRC Handbook of Chemistry and Physics 85th ed., Section 4; The Elements. One type of metal-halide lamp, similar to the mercury-vapor lamp, is made from scandium triiodide and sodium iodide. This lamp is a white-light source with high color rendering index that sufficiently resembles sunlight to allow good color-reproduction with TV cameras.BOOK, Lighting Control: Technology and Applications, Robert S., Simpson, Focal Press, 2003, 978-0-240-51566-3,books.google.com/books?id=GEIhCl2T-2EC&pg=PT147, 108, About 80 kg of scandium is used in metal-halide lamps/light bulbs globally per year.JOURNAL, Scandium International Mining,scandiummining.com/site/assets/files/3650/file1.pdf, Hallgarten & Company, Dentists use erbium-chromium-doped yttrium-scandium-gallium garnet ({{chem2|Er,Cr:YSGG}}) lasers for cavity preparation and in endodontics.BOOK,books.google.com/books?id=vkVY3JwqvrgC&pg=PA464, 464–465, History of Laser Dentistry, Lasers in Dermatology and Medicine, 978-0-85729-280-3, Nouri, Keyvan, 2011-11-09, Springer,

Other

The radioactive isotope 46Sc is used in oil refineries as a tracing agent. Scandium triflate is a catalytic Lewis acid used in organic chemistry.JOURNAL, Pure and Applied Chemistry, 72, 7, 1373–1380, 2000, Green Lewis acid catalysis in organic synthesis, Shu, Kobayashi, Manabe, Kei,www.iupac.org/publications/pac/2000/7207/7207pdf/7207kobayashi_1373.pdf, 10.1351/pac200072071373, 16770637, The 12.4 keV nuclear transition of 45Sc has been studied as a reference for timekeeping applications, with a theoretical precision as much as three orders of magnitude better than the current caesium reference clocks.JOURNAL, Shvyd’ko, Yuri, Röhlsberger, Ralf, Kocharovskaya, Olga, etal, Resonant X-ray excitation of the nuclear clock isomer 45Sc, Nature, 622, 2023, 0028-0836, 37758953, 10584683, 10.1038/s41586-023-06491-w, 471–475,

Health and safety

Elemental scandium is considered non-toxic, though extensive animal testing of scandium compounds has not been done.BOOK, Biochemistry of Scandium and Yttrium, Chaim T., Horovitz, Birmingham, Scott D., Springer, 1999, 978-0-306-45657-2,books.google.com/books?id=1ZTQlCWKjmgC, The median lethal dose (LD50) levels for scandium chloride for rats have been determined as 755 mg/kg for intraperitoneal and 4 g/kg for oral administration.JOURNAL, Pharmacology and toxicology of scandium chloride, 51, Journal of Pharmaceutical Sciences, Thomas J., Haley, Komesu, L., Mavis, N., Cawthorne, J., Upham, H. C., 10.1002/jps.2600511107, 1962, 13952089, 11, 1043–5, In the light of these results, compounds of scandium should be handled as compounds of moderate toxicity. Scandium appears to be handled by the body in a manner similar to gallium, with similar hazards involving its poorly soluble hydroxide.JOURNAL, Ganrot, P. O., 1986, Metabolism and Possible Health Effects of Aluminum, Environmental Health Perspectives, 65, 363–441, 10.2307/3430204, 3430204, 2940082, 1474689, 0091-6765,

Notes

{{Notelist}}

References

{{Reflist|30em}}

Further reading

{{Library resources box|onlinebooks=yes}}

• BOOK, Eric R., Scerri, The Periodic System: Its Story and Its Significance, Oxford University Press, Oxford, UK, 2007, 62766695, 9780195305739,books.google.com/books?id=yPtSszJMOO0C,

External links

{{Wiktionary}}{{Commons}}

• Scandium at The Periodic Table of Videos (University of Nottingham)
• WebElements.com – Scandium
• EB1911, Scandium, x,

{{Scandium compounds}}{{Periodic table (navbox)}}{{Authority control}}{{Good article}}