Rhenium

Rhenium, 75Re
Rhenium
Pronunciation/ˈriːniəm/ ⓘ ​(REE-nee-əm)
Appearancesilvery-grayish
Standard atomic weight Ar°(Re)
Rhenium 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 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
Tc
↑
Re
↓
Bh
tungsten ← rhenium → osmium
Atomic number (Z)75
Groupgroup 7
Periodperiod 6
Block  d-block
Electron configuration[Xe] 4f14 5d5 6s2
Electrons per shell2, 8, 18, 32, 13, 2
Physical properties
Phase at STPsolid
Melting point3459 K ​(3186 °C, ​5767[3] °F)
Boiling point5903[3] K ​(5630 °C, ​10,170 °F)
Density (at 20° C)21.010 g/cm3 [4]
when liquid (at m.p.)18.9 g/cm3
Heat of fusion60.43 kJ/mol
Heat of vaporization704 kJ/mol
Molar heat capacity25.48 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 3303 3614 4009 4500 5127 5954
Atomic properties
Oxidation statescommon: +4, +7
−3,[5] −1,[5] 0,[6] +1,[5] +2,[5] +3,[5] +5,[5] +6,[5]
ElectronegativityPauling scale: 1.9
Ionization energies
  • 1st: 760 kJ/mol
  • 2nd: 1260 kJ/mol
  • 3rd: 2510 kJ/mol
  • (more)
Atomic radiusempirical: 137 pm
Covalent radius151±7 pm
Spectral lines of rhenium
Other properties
Natural occurrenceprimordial
Crystal structure ​hexagonal close-packed (hcp) (hP2)
Lattice constants
a = 276.10 pm
c = 445.84 pm (at 20 °C)[4]
Thermal expansion5.61×10−6/K (at 20 °C)[a]
Thermal conductivity48.0 W/(m⋅K)
Electrical resistivity193 nΩ⋅m (at 20 °C)
Magnetic orderingparamagnetic[7]
Molar magnetic susceptibility+67.6×10−6 cm3/mol (293 K)[8]
Young's modulus463 GPa
Shear modulus178 GPa
Bulk modulus370 GPa
Speed of sound thin rod4700 m/s (at 20 °C)
Poisson ratio0.30
Mohs hardness7.0
Vickers hardness1350–7850 MPa
Brinell hardness1320–2500 MPa
CAS Number7440-15-5
History
Namingafter the river Rhine (German: Rhein)
DiscoveryMasataka Ogawa (1908)
First isolationMasataka Ogawa (1919)
Named byWalter Noddack, Ida Noddack, Otto Berg (1925)
Isotopes of rhenium
Main isotopes[9] Decay
abun­dance half-life (t1/2) mode pro­duct
183Re synth 70 d ε 183W
184Re synth 35.4 d β+ 184W
184mRe synth 177.25 d IT 184Re
β+ 184W
185Re 37.4% stable
186Re synth 3.7185 d β− 186Os
ε 186W
186mRe synth 2×105 y IT 186Re
187Re 62.6% 4.16×1010 y β− 187Os

Rhenium is a chemical element; it has symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. It has one of the highest melting and boiling points of any element. It resembles manganese and technetium chemically and is mainly obtained as a by-product of the extraction and refinement of molybdenum and copper ores. It shows in its compounds a wide variety of oxidation states ranging from −1 to +7.

Rhenium was originally discovered in 1908 by Masataka Ogawa, but he mistakenly assigned it as element 43 (now known as technetium) rather than element 75 and named it nipponium. It was rediscovered in 1925 by Walter Noddack, Ida Tacke and Otto Berg,[10] who gave it its present name. It was named after the river Rhine in Europe, from which the earliest samples had been obtained and worked commercially.[11]

Nickel-based superalloys of rhenium are used in combustion chambers, turbine blades, and exhaust nozzles of jet engines. These alloys contain up to 6% rhenium, making jet engine construction the largest single use for the element. The second-most important use is as a catalyst: it is an excellent catalyst for hydrogenation and isomerization, and is used for example in catalytic reforming of naphtha for use in gasoline (rheniforming process). Because of the low availability relative to demand, rhenium is expensive, with price reaching an all-time high in 2008–09 of US$10,600 per kilogram (US$4,800 per pound). As of 2018, its price had dropped to US$2,844 per kilogram (US$1,290 per pound) due to increased recycling and a drop in demand for rhenium catalysts.[12]

  1. ^ "Standard Atomic Weights: Rhenium". CIAAW. 1973.
  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 Zhang, Yiming (2011-01-11). "Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks". Journal of Chemical & Engineering Data. 56.
  4. ^ a b c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  5. ^ a b c d e f g Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  6. ^ Re(0) is known in Re2(CO)10; see John E. Ellis (2006). "Adventures with Substances Containing Metals in Negative Oxidation States". Inorganic Chemistry. 45 (8): 3167–3186. doi:10.1021/ic052110i.
  7. ^ 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.
  8. ^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  9. ^ 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.
  10. ^ "Die Ekamangane". Naturwissenschaften (in German). 13 (26): 567–574. 1925-06-01. Bibcode:1925NW.....13..567.. doi:10.1007/BF01558746. ISSN 1432-1904. S2CID 32974087.
  11. ^ "From Hydrogen to Darmstadtium & More". American Chemical Society. 2003. p. 144.
  12. ^ "BASF Catalysts - Metal Prices". apps.catalysts.basf.com. Archived from the original on 2021-04-12. Retrieved 2018-04-11.


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