Ruthenium

Edit links
This is a good article. Click here for more information.
Source: Wikipedia, the free encyclopedia.
Not to be confused with rubidium.

Ruthenium, 44Ru
Ruthenium
Pronunciation/ruːˈθiːniəm/ ​(roo-THEE-nee-əm)
Appearancesilvery white metallic
Standard atomic weight Ar°(Ru)
Ruthenium 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
Fe
↑
Ru
↓
Os
technetium ← ruthenium → rhodium
kJ/mol
Heat of vaporization619 kJ/mol
Molar heat capacity24.06 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2588 2811 3087 3424 3845 4388
Atomic properties
Thermal conductivity
117

αa 5.77 αc 8.80

αavr 6.78 W/(m⋅K)
Discovery and first isolation
Karl Ernst Claus (1844)
Isotopes of ruthenium
Main isotopes[8] Decay
abun­dance half-life (t1/2) mode pro­duct
96Ru 5.54%
stable
97Ru synth 2.9 d ε
97Tc
γ
 		–
98Ru 1.87% stable
99Ru 12.8% stable
100Ru 12.6% stable
101Ru 17.1% stable
102Ru 31.6% stable
103Ru synth 39.26 d
β−
103Rh
γ –
104Ru 18.6% stable
106Ru synth 373.59 d β−
106Rh
 Category: Ruthenium
| references

Ruthenium is a

Sudbury, Ontario, and in pyroxenite deposits in South Africa.[11]

Characteristics

Physical properties

Gas phase grown crystals of ruthenium metal

Ruthenium, a polyvalent hard white metal, is a member of the platinum group and is in group 8 of the periodic table:

Z Element No. of electrons/shell
26 iron 2, 8, 14, 2
44 ruthenium 2, 8, 18, 15, 1
76 osmium 2, 8, 18, 32, 14, 2
108 hassium 2, 8, 18, 32, 32, 14, 2

Whereas all other group 8 elements have two electrons in the outermost shell, in ruthenium, the outermost shell has only one electron (the final electron is in a lower shell). This anomaly is observed in the neighboring metals niobium (41), molybdenum (42), and rhodium (45).

Chemical properties

Ruthenium has four crystal modifications and does not tarnish at ambient conditions; it oxidizes upon heating to 800 °C (1,070 K). Ruthenium dissolves in fused alkalis to give ruthenates (RuO2−
4). It is not attacked by acids (even aqua regia) but is attacked by sodium hypochlorite at room temperature, and halogens at high temperatures.[11] Ruthenium is most readily attacked by oxidizing agents.[12] Small amounts of ruthenium can increase the hardness of platinum and palladium. The corrosion resistance of titanium is increased markedly by the addition of a small amount of ruthenium.[11] The metal can be plated by electroplating and by thermal decomposition. A ruthenium–molybdenum alloy is known to be superconductive at temperatures below 10.6 K.[11] Ruthenium is the only 4d transition metal that can assume the group oxidation state +8, and even then it is less stable there than the heavier congener osmium: this is the first group from the left of the table where the second and third-row transition metals display notable differences in chemical behavior. Like iron but unlike osmium, ruthenium can form aqueous cations in its lower oxidation states of +2 and +3.[13]

Ruthenium is the first in a downward trend in the melting and boiling points and atomization enthalpy in the 4d transition metals after the maximum seen at

Curie point.[15]

The reduction potentials in acidic aqueous solution for some common ruthenium ions are shown below:[16]

0.455 V Ru2+ + 2e− ↔ Ru
0.249 V Ru3+ + e− ↔ Ru2+
1.120 V RuO2 + 4H+ + 2e− ↔ Ru2+ + 2H2O
1.563 V RuO2−
4 + 8H+ + 4e−		 ↔ Ru2+ + 4H2O
1.368 V RuO−
4 + 8H+ + 5e−		 ↔ Ru2+ + 4H2O
1.387 V RuO4 + 4H+ + 4e− ↔ RuO2 + 2H2O

Isotopes

Main article: Isotopes of ruthenium

Naturally occurring ruthenium is composed of seven stable

radioisotopes, the most stable are 106Ru with a half-life of 373.59 days, 103Ru with a half-life of 39.26 days and 97Ru with a half-life of 2.9 days.[17][18]

Fifteen other radioisotopes have been characterized with

u (90Ru) to 114.928 u (115Ru). Most of these have half-lives that are less than five minutes except 95Ru (half-life: 1.643 hours) and 105Ru (half-life: 4.44 hours).[17][18]

The primary

beta emission. The primary decay product before 102Ru is technetium and the primary decay product after is rhodium.[17][18]

106Ru is a product of fission of a nucleus of uranium or plutonium. High concentrations of detected atmospheric 106Ru were associated with an alleged undeclared nuclear accident in Russia in 2017.[19]

Occurrence

See also: Category:Ruthenium minerals

Ruthenium is relatively rare,

spent fuel. An unusual ruthenium deposit can also be found at the natural nuclear fission reactor that was active in Oklo
, Gabon, some two billion years ago. Indeed, the isotope ratio of ruthenium found there was one of several ways used to confirm that a nuclear fission chain reaction had indeed occurred at that site in the geological past. Uranium is no longer mined at Oklo and there have never been serious attempts to recover any of the platinum group metals present there.

Production

Roughly 30 tonnes of ruthenium are mined each year

platinum group metal (PGM) mixtures varies widely, depending on the geochemical formation. For example, the PGMs mined in South Africa contain on average 11% ruthenium while the PGMs mined in the former USSR contain only 2% (1992).[25][26] Ruthenium, osmium, and iridium are considered the minor platinum group metals.[15]

Ruthenium, like the other platinum group metals, is obtained commercially as a by-product from

sponge metal that can be treated with powder metallurgy techniques or argon-arc welding.[11][31]

Ruthenium is contained in

neutron absorption by long-lived fission product 99
Tc. After allowing the unstable isotopes of ruthenium to decay, chemical extraction could yield ruthenium for use or sale in all applications ruthenium is otherwise used for.[32][33]

Ruthenium can also be produced by deliberate nuclear transmutation from 99
Tc. Given the relatively long half life, high fission product yield and high chemical mobility in the environment, 99
Tc is among the most often proposed non-actinides for commercial scale nuclear transmutation. 99
Tc has a relatively big neutron cross section and given that technetium has no stable isotopes, a sample would not run into the problem of neutron activation of stable isotopes. Significant amounts of 99
Tc are produced both by nuclear fission and nuclear medicine which makes ample use of 99m
Tc which decays to 99
Tc. Exposing the 99
Tc target to strong enough neutron radiation will eventually yield appreciable quantities of Ruthenium which can be chemically separated and sold while consuming 99
Tc.[34][35]

Chemical compounds

See also: Category:Ruthenium compounds

The

ruthenium trichloride, a red solid that is poorly defined chemically but versatile synthetically.[30]

Oxides and chalcogenides

Ruthenium can be

oxidized to ruthenium(IV) oxide (RuO2, oxidation state +4), which can, in turn, be oxidized by sodium metaperiodate to the volatile yellow tetrahedral ruthenium tetroxide, RuO4, an aggressive, strong oxidizing agent with structure and properties analogous to osmium tetroxide. RuO4 is mostly used as an intermediate in the purification of ruthenium from ores and radiowastes.[36]

Dipotassium ruthenate (K2RuO4, +6) and potassium perruthenate (KRuO4, +7) are also known.[37] Unlike osmium tetroxide, ruthenium tetroxide is less stable, is strong enough as an oxidising agent to oxidise dilute hydrochloric acid and organic solvents like ethanol at room temperature, and is easily reduced to ruthenate (RuO2−
4) in aqueous alkaline solutions; it decomposes to form the dioxide above 100 °C. Unlike iron but like osmium, ruthenium does not form oxides in its lower +2 and +3 oxidation states.[38] Ruthenium forms dichalcogenides, which are diamagnetic semiconductors crystallizing in the pyrite structure.[38] Ruthenium sulfide (RuS2) occurs naturally as the mineral laurite.

Like iron, ruthenium does not readily form oxoanions and prefers to achieve high coordination numbers with hydroxide ions instead. Ruthenium tetroxide is reduced by cold dilute potassium hydroxide to form black potassium perruthenate, KRuO4, with ruthenium in the +7 oxidation state. Potassium perruthenate can also be produced by oxidising potassium ruthenate, K2RuO4, with chlorine gas. The perruthenate ion is unstable and is reduced by water to form the orange ruthenate. Potassium ruthenate may be synthesized by reacting ruthenium metal with molten potassium hydroxide and potassium nitrate.[39]

Some mixed oxides are also known, such as MIIRuIVO3, Na3RuVO4, Na
2RuV
2O
7, and MII
2LnIII
RuV
O
6.[39]

Halides and oxyhalides

The highest known ruthenium halide is the

ruthenium tetrafluoride is probably also polymeric and can be formed by reducing the pentafluoride with iodine. Among the binary compounds of ruthenium, these high oxidation states are known only in the oxides and fluorides.[40]

Ruthenium trichloride is a well-known compound, existing in a black α-form and a dark brown β-form: the trihydrate is red.[41] Of the known trihalides, trifluoride is dark brown and decomposes above 650 °C, tribromide is dark-brown and decomposes above 400 °C, and triiodide is black.[40] Of the dihalides, difluoride is not known, dichloride is brown, dibromide is black, and diiodide is blue.[40] The only known oxyhalide is the pale green ruthenium(VI) oxyfluoride, RuOF4.[41]

Coordination and organometallic complexes

Main article: Organoruthenium chemistry
Tris(bipyridine)ruthenium(II) chloride
alkene metathesis
reactions.

Ruthenium forms a variety of coordination complexes. Examples are the many pentaammine derivatives [Ru(NH3)5L]n+ that often exist for both Ru(II) and Ru(III). Derivatives of bipyridine and terpyridine are numerous, best known being the luminescent tris(bipyridine)ruthenium(II) chloride.

Ruthenium forms a wide range compounds with carbon–ruthenium bonds.

tris(triphenylphosphine)ruthenium dichloride (RuCl2(PPh3)3), which converts to the hydride complex chlorohydridotris(triphenylphosphine)ruthenium(II) (RuHCl(PPh3)3).[30]

History

Though naturally occurring platinum alloys containing all six

coins, starting in 1828.[44]
Residues from platinum production for coinage were available in the Russian Empire, and therefore most of the research on them was done in Eastern Europe.

It is possible that the Polish chemist Jędrzej Śniadecki isolated element 44 (which he called "vestium" after the asteroid Vesta discovered shortly before) from South American platinum ores in 1807. He published an announcement of his discovery in 1808.[45] His work was never confirmed, however, and he later withdrew his claim of discovery.[20]

Jöns Berzelius and Gottfried Osann nearly discovered ruthenium in 1827.[46] They examined residues that were left after dissolving crude platinum from the Ural Mountains in aqua regia. Berzelius did not find any unusual metals, but Osann thought he found three new metals, which he called pluranium, ruthenium, and polinium.[11] This discrepancy led to a long-standing controversy between Berzelius and Osann about the composition of the residues.[7] As Osann was not able to repeat his isolation of ruthenium, he eventually relinquished his claims.[7][47] The name "ruthenium" was chosen by Osann because the analysed samples stemmed from the Ural Mountains in Russia.[48] The name itself derives from the Latin word Ruthenia; this word was used at the time as the Latin name for Russia.[7][b]

In 1844,

Kazan University, Kazan,[7] the same way its heavier congener osmium had been discovered four decades earlier.[21] Claus showed that ruthenium oxide contained a new metal and obtained 6 grams of ruthenium from the part of crude platinum that is insoluble in aqua regia.[7] Choosing the name for the new element, Claus stated: "I named the new body, in honour of my Motherland, ruthenium. I had every right to call it by this name because Mr. Osann relinquished his ruthenium and the word does not yet exist in chemistry."[7][49] In doing so, Claus started a trend that continues to this day – naming an element after a country.[50]

Applications

Approximately 30.9 tonnes of ruthenium were consumed in 2016, 13.8 of them in electrical applications, 7.7 in catalysis, and 4.6 in electrochemistry.[24]

Because it hardens platinum and palladium alloys, ruthenium is used in electrical contacts, where a thin film is sufficient to achieve the desired durability. With its similar properties to and lower cost than rhodium,[31] electric contacts are a major use of ruthenium.[22][51] The ruthenium plate is applied to the electrical contact and electrode base metal by electroplating[52] or sputtering.[53]

Ruthenium dioxide with lead and bismuth ruthenates are used in thick-film chip resistors.[54][55][56] These two electronic applications account for 50% of the ruthenium consumption.[20]

Ruthenium is seldom alloyed with metals outside the platinum group, where small quantities improve some properties. The added corrosion resistance in

jet engines. Several nickel based superalloy compositions are described, such as EPM-102 (with 3% Ru), TMS-162 (with 6% Ru), TMS-138,[58] and TMS-174,[59][60] the latter two containing 6% rhenium.[61] Fountain pen nibs are frequently tipped with ruthenium alloy. From 1944 onward, the Parker 51 fountain pen was fitted with the "RU" nib, a 14K gold nib tipped with 96.2% ruthenium and 3.8% iridium.[62]

Ruthenium is a component of

malignant melanomas of the uvea.[66] Ruthenium-centered complexes are being researched for possible anticancer properties.[67] Compared with platinum complexes, those of ruthenium show greater resistance to hydrolysis and more selective action on tumors.[citation needed
]

Ruthenium tetroxide exposes latent fingerprints by reacting on contact with fatty oils or fats with sebaceous contaminants and producing brown/black ruthenium dioxide pigment.[68]

Halloysite nanotubes intercalated with ruthenium catalytic nanoparticles[69]

Electronics

Electronics is the largest use of ruthenium.

organoruthenium compound (cyclohexadiene)Ru(CO)3.[73]

Catalysis

Many ruthenium-containing compounds exhibit useful catalytic properties. The catalysts are conveniently divided into those that are soluble in the reaction medium,

heterogeneous catalysts
.

Homogeneous catalysis

Solutions containing

Grubbs' catalysts
for example have been employed in the preparation of drugs and advanced materials.

ring-opening metathesis polymerization
reaction giving polynorbornene

Ruthenium complexes are highly active catalysts for

DPEN):[77][78]

[RuCl(S,S-TsDPEN)(cymene)]-catalysed (R,R)-hydrobenzoin synthesis (yield 100%, ee >99%)

A Nobel Prize in Chemistry was awarded in 2001 to Ryōji Noyori for contributions to the field of asymmetric hydrogenation.

Heterogeneous catalysis

Ruthenium-promoted cobalt catalysts are used in Fischer–Tropsch synthesis.[79]

Biology

The inorganic dye ammoniated ruthenium oxychloride, also known as

mucopolysaccharides
.

Emerging applications

Some ruthenium complexes

low-cost solar cell system.[80]

Many ruthenium-based oxides show very unusual properties, such as a quantum critical point behavior,[81] exotic superconductivity (in its strontium ruthenate form),[82] and high-temperature ferromagnetism.[83]

Health effects

Little is known about the health effects of ruthenium

ruthenium oxide (RuO4) are highly toxic and volatile.[85]

See also

Notes

  1. ^ The thermal expansion is anisotropic: the parameters (at 20 °C) for each crystal axis are αa = 5.77×10−6/K, αc = 8.80×10−6/K, and αaverage = αV = 6.78×10−6/K.[3]
  2. ^ a b c It was common to give newly discovered elements Latin names (for example, lutetium and hafnium, both discovered in early 20th century, are named after the Latin names for Paris and Copenhagen). Claus chose to name the element "in Honour of my Motherland",[6] and Claus was a Russian subject; as such, he chose the Latin name for Russia used back in the day, Ruthenia, as the basis for his name.[7]
    In contemporary Latin (as well as in contemporary English), Russia is usually referred to as Russia, and the name Ruthenia stands for a region in and around Zakarpattia Oblast in western Ukraine.[citation needed]

References

  1. ^ "Standard Atomic Weights: Ruthenium". CIAAW. 1983.
  2. ISSN 1365-3075
    .
  3. ^
    ISBN 978-1-62708-155-9
    .
  4. ^ "Ruthenium: ruthenium(I) fluoride compound data". OpenMOPAC.net. Retrieved 10 December 2007.
  5. ^ a b Haynes, p. 4.130
  6. ^ Matthey, Johnson. "The Discovery of Ruthenium". Johnson Matthey Technology Review. Retrieved 25 August 2020.
  7. ^ a b c d e f g Pitchkov, V. N. (1996). "The Discovery of Ruthenium". Platinum Metals Review. 40 (4): 181–188.
  8. doi:10.1088/1674-1137/abddae
    .
  9. ^ Summary. Ruthenium. platinum.matthey.com, p. 9 (2009)
  10. ^ PGM Market Report. platinum.matthey.com, p. 30 (May 2018)
  11. ^ a b c d e f g h Haynes (2016), p. 4.31.
  12. ^ Greenwood & Earnshaw (1997), p. 1076.
  13. ^ Greenwood & Earnshaw (1997), p. 1078.
  14. ^ Greenwood & Earnshaw (1997), p. 1075.
  15. ^ a b Greenwood & Earnshaw (1997), p. 1074.
  16. ^ Greenwood & Earnshaw (1997), p. 1077.
  17. ^
    ISBN 0-8493-0486-5
    . Section 11, Table of the Isotopes
  18. ^
    doi:10.1016/j.nuclphysa.2003.11.001
  19. PMID 31350352
    .
  20. ^
    ISBN 978-0-19-850340-8
    .
  21. ^ a b Greenwood & Earnshaw (1997), p. 1071.
  22. ^ a b c George, Micheal W. "2006 Minerals Yearbook: Platinum-Group Metals" (PDF). United States Geological Survey USGS. Retrieved 16 September 2008.
  23. ^ a b "Commodity Report: Platinum-Group Metals" (PDF). United States Geological Survey USGS. Retrieved 16 September 2008.
  24. ^ a b c Loferski, Patricia J.; Ghalayini, Zachary T. and Singerling, Sheryl A. (2018) Platinum-group metals. 2016 Minerals Yearbook. USGS. p. 57.3.
  25. ISBN 978-0-87335-100-3
    .
  26. NAID 20000798606
    .
  27. ISBN 978-3-527-30673-2
    .
  28. ISBN 978-0471238966
    .
  29. S2CID 96640406
    .
  30. ^
    ISBN 978-0-7514-0413-5
    .
  31. ^
    S2CID 267561907
    .
  32. S2CID 95804621
    .
  33. doi:10.1149/06621.0031ecst
    .
  34. doi:10.1016/S0022-3115(99)00107-5
    .
  35. doi:10.1016/j.crci.2004.05.002
    .
  36. S2CID 95804621
    .
  37. ^ Greenwood & Earnshaw (1997), p. [page needed].
  38. ^ a b Greenwood & Earnshaw (1997), pp. 1080–1081.
  39. ^ a b Greenwood & Earnshaw (1997), p. 1082.
  40. ^ a b c Greenwood & Earnshaw (1997), p. 1083.
  41. ^ a b Greenwood & Earnshaw (1997), p. 1084.
  42. ISBN 1-891389-53-X
  43. ^
    doi:10.1021/ed009p1017
    .
  44. doi:10.1595/003214004X4826669
    .
  45. OCLC 739088520
    .
  46. doi:10.1080/14786442708674516
    .
  47. doi:10.1002/andp.18290910119
    .
  48. doi:10.1002/andp.18280890609
    .
  49. ^ Claus, Karl (1845). "О способе добывания чистой платины из руд" [On the method of extracting pure platinum from ores]. Горный журнал (Mining Journal) (in Russian). 7 (3): 157–163.
  50. S2CID 237405162
    .
  51. doi:10.1016/j.ccr.2004.08.015
    .
  52. doi:10.1016/S0026-0576(00)83089-5
    .
  53. ISBN 978-0-87170-285-2
    .
  54. S2CID 135485712
    .
  55. hdl:11380/307664
    .
  56. ISBN 978-0-8247-1934-0
    .
  57. S2CID 267551174
    .
  58. ^ "Fourth generation nickel base single crystal superalloy. TMS-138 / 138A" (PDF). High Temperature Materials Center, National Institute for Materials Science, Japan. July 2006. Archived from the original (PDF) on 18 April 2013.
  59. ^ Koizumi, Yutaka; et al. "Development of a Next-Generation Ni-base Single Crystal Superalloy" (PDF). Proceedings of the International Gas Turbine Congress, Tokyo 2–7 November 2003. Archived from the original (PDF) on 10 January 2014.
  60. ^ Walston, S.; Cetel, A.; MacKay, R.; O'Hara, K.; Duhl, D.; Dreshfield, R. (December 2004). "Joint Development of a Fourth Generation Single Crystal Superalloy" (PDF). NASA.
  61. S2CID 136907279
    .
  62. ^ Mottishaw, J. (1999). "Notes from the Nib Works—Where's the Iridium?". The PENnant. XIII (2). Archived from the original on 4 June 2002.
  63. ISBN 978-1-84628-668-1
    .
  64. ISBN 978-90-5699-255-2
    .
  65. ISBN 978-0-306-44294-0
    .
  66. ISBN 978-3-8055-6392-5
    .
  67. PMID 17325786
    .
  68. ^ NCJRS Abstract – National Criminal Justice Reference Service. Ncjrs.gov. Retrieved on 2017-02-28.
  69. PMID 28458738
    .
  70. doi:10.1149/1.1640633
    .
  71. doi:10.1149/1.2131826
    .
  72. S2CID 104430143
    .
  73. S2CID 122854468
    .
  74. ISBN 978-0471238966
    .
  75. PMID 11028025
    .
  76. doi:10.1021/ja00253a051
  77. ^ Ikariya, Takao; Hashiguchi, Shohei; Murata, Kunihiko and Noyori, Ryōji (2005). "Preparation of Optically Active (R,R)-Hydrobenzoin from Benzoin or Benzil". Organic Syntheses: 10{{cite journal}}: CS1 maint: multiple names: authors list (link).
  78. doi:10.15227/orgsyn.092.0213
    .
  79. doi:10.1016/S0926-860X(99)00160-X
    .
  80. S2CID 39111991
    .
  81. S2CID 26241456
    .
  82. hdl:2433/49957
    .
  83. S2CID 136558050
    .
  84. ^ a b "Ruthenium". espimetals.com. Retrieved 26 July 2020.
  85. ^ a b "Ruthenium (Ru) - Chemical properties, Health and Environmental effects". lenntech.com. Retrieved 26 July 2020.

Bibliography

External links

Wikimedia Commons has media related to Ruthenium.
Look up ruthenium in Wiktionary, the free dictionary.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Ruthenium&oldid=1220253771"