Rhenium (Re)
transition-metalSolid
Peso atomico standard
186,207 uConfigurazione elettronica
[Xe] 6s2 4f14 5d5Punto di fusione
3185,85 °CPunto di ebollizione
5595,85 °CDensità
2,08e+4 kg/m³Stati di ossidazione
−3, −1, 0, +1, +2, +3, +4, +5, +6, +7Elettronegatività (Pauling)
1,9Energia di ionizzazione (1ª)
7,83352 eVAnno della scoperta
1925Raggio atomico
135 pmDettagli
Rhenium is a very dense, high-melting transition metal in group 7, chemically related to manganese and technetium but far less abundant in the crust. It is notable for retaining strength at extreme temperature and for forming stable high oxidation states, especially +7. Natural rhenium occurs mainly as a trace substitute in molybdenite rather than as separate ores, making it a by-product metal of copper-molybdenum processing.
The element is silvery white with a metallic luster; its density is exceeded only by that of platinum, iridium, and osmium, and its melting point is exceeded only by that of tungsten and carbon.
The usual commercial form of the element is powder, but it can be consolidated by pressing and resistance-sintering in a vacuum or hydrogen atmosphere. This process produces a compact shape in excess of 90 percent of the density of the metal.
Annealed rhenium is very ductile, and can be bent, coiled, or rolled. Rhenium is used as an additive to tungsten and molybdenum -based alloys to impart useful properties.
The name derives from the Latin rhenus for the Rhine river in Germany. Rhenium was discovered by x-ray spectroscopy in 1925 by German chemists Walter Noddack, Ida Tacke, and Otto Berg.
Rhenium was discovered by the German chemists Ida Tacke-Noddack, Walter Noddack and Otto Carl Berg in 1925. They detected rhenium spectroscopically in platinum ores and in the minerals columbite ((Fe, Mn, Mg)(Nb, Ta)2O6), gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10) and molybdenite (MoS2). Rhenium is present in these materials only in trace amounts. In 1928, Noddack and Berg were able to extract 1 gram of rhenium from 660 kilograms of molybdenite. Today, rhenium is obtained as a byproduct of refining molybdenum and copper.
Discovery of rhenium is generally attributed to Noddack, Tacke, and Berg, who announced in 1925 they had detected the element in platinum ore and columbite. They also found the element in gadolinite and molybdenite. By working up 660 kg of molybdenite in 1928 they were able to extract 1 g of rhenium.
Pure rhenium is a silvery-white to gray metallic solid with a bright luster when freshly prepared. It is hard, dense, and refractory, with one of the highest melting points among the elements. Powdered rhenium can be darker gray because of surface condition and particle size.
The largest use of rhenium is in nickel-based superalloys for turbine blades and other hot-section components, where small additions improve high-temperature strength and creep resistance. Rhenium is also used with platinum in reforming catalysts for petroleum refining. Tungsten-rhenium and molybdenum-rhenium alloys serve in high-temperature thermocouples, filaments, electrical contacts, and specialized X-ray tube targets. Its radioisotopes ¹⁸⁶Re and ¹⁸⁸Re have been studied and used in limited nuclear-medicine applications.
Rhenium is used in flash lamps for photography and for filaments in mass spectrographs and ion gages, but is most frequently used as an alloying agent in tungsten and molybdenum and as a catalyst for performing certain reactions to a type of hydrocarbon known as an olefin.
It is widely used as filaments for mass spectrographs and ion gauges. Rhenium-molybdenum alloys are superconductive at 10 K.
Rhenium is also used as an electrical contact material because it has good wear resistance and withstands arc corrosion. Thermocouples made of Re-W are used for measuring temperatures up to 2200C, and rhenium wire is used in photoflash lamps for photography.
Rhenium catalysts are exceptionally resistant to poisoning from nitrogen, sulfur, and phosphorus, and are used for hydrogenation of fine chemicals.
Isotopes in Geochronology
The rhenium-osmium dating method is of special interest for the dating of rhenium-bearing ores, gold deposits, copper-nickel deposits, and meteorites. This method is based on the beta-decay of 187Re (having a half-life of 41.6×109 years) to 187Os, an example of which appears in Fig. IUPAC.75.1 [515] H. M. Baioumy, L. B. Eglinton, B. Peucker-Ehrenbrink. Chem. Geol.285, 70 (2011)..
Isotopes in Medicine
186Re (with a half-life of 89 h) is a beta-emitting radioisotope that is used for cancer treatment, in particular for pain relief in bone cancer and in rheumatoid arthritis (see radiosynovectomy). It is produced from the stable isotope 185Re via the 185Re (n, γ) 186Re reaction [188] S. J. Adelstein, F. J. Manning. Isotopes for Medicine and the Life Sciences, pp. 20–25, National Academy Press, Washington DC (1995).. 186Re is also used for radiolabeling of cancer therapeutic agents [188] S. J. Adelstein, F. J. Manning. Isotopes for Medicine and the Life Sciences, pp. 20–25, National Academy Press, Washington DC (1995).. 188Re (with a half-life of 17 h) is used to irradiate coronary arteries with beta particles during insertion of an angioplasty balloon (a tiny balloon that is inserted into an artery and inflated to flatten plaque build-up and improve blood flow) and in palliative therapy, particularly for bone metastases. The beta irradiation can decrease scar tissue formation after the overstretching of arteries by angioplasty.
Rhenium chemistry spans oxidation states from negative values in carbonyl complexes to +7 in oxo compounds, with +4, +5, and +7 especially important. Perrhenic acid, HReO₄, and perrhenate salts containing ReO₄⁻ resemble perchlorates in charge and geometry but are less oxidizing under many conditions. Rhenium(VII) oxide, Re₂O₇, is the volatile anhydride of perrhenic acid. Rhenium disulfide, ReS₂, is a layered dichalcogenide with lower symmetry than many related sulfides. Dirhenium decacarbonyl, Re₂(CO)₁₀, is a common starting material in organorhenium chemistry.
See more information at the Rhenium compound page.
Massive rhenium metal is generally of low chemical reactivity, but dusts and fine powders present inhalation and fire-control concerns typical of refractory metals. Soluble perrhenate compounds can be absorbed and should be handled as toxicologically insufficiently characterized heavy-metal salts. Radioactive rhenium isotopes pose isotope-specific radiation hazards; their risk depends on half-life, emissions, chemical form, and administered or handled activity.
Rhenium is a trace element with no known essential biological role. In rocks it is commonly associated with sulfide minerals, especially molybdenite, and can be mobilized during weathering as the soluble perrhenate ion, ReO₄⁻. Seawater contains very low concentrations of dissolved rhenium, and marine sediments can record rhenium enrichment under reducing conditions. Industrial releases are mainly linked to mining, smelting, and catalyst handling.
Rhenium is obtained almost entirely as a by-product, principally from molybdenite concentrates generated in porphyry copper-molybdenum mining. During roasting, volatile rhenium oxides are captured from flue dusts and converted to ammonium perrhenate, NH₄ReO₄, or to metal powder. Supply is constrained because production depends on the output and processing choices of other metals rather than on primary rhenium mines. Demand is concentrated in aerospace superalloys and platinum-rhenium catalysts, so recycling from spent catalysts and high-value alloy scrap is important. Substitution is limited in some turbine applications, but alloy design can reduce rhenium content when supply or cost pressures are high.
Rhenium does not occur free in nature or as a compound in a distinct mineral species. It is, however, widely spread throughout the earth's crust to the extent of about 0.001 ppm. Commercial rhenium in the U.S. today is obtained from molybdenum roaster-flue dusts obtained from copper-sulfide ores mined in the vicinity of Miami, Arizona and elsewhere in Arizona and in Utah.
Some molybdenum contains from 0.002% to 0.2% rhenium. More than 150,000 troy ounces of rhenium are now being produced yearly in the United States. The total estimated Free World reserve of rhenium metal is 3500 tons. Rhenium metal is prepared by reducing ammonium perrhentate with hydrogen at elevated temperatures.
Rhenium is cosmically rare. Its stable and very long-lived isotopes are produced mainly by neutron-capture processes in earlier generations of stars, followed by dispersal into interstellar material. In planetary bodies it behaves as a siderophile and chalcophile trace element, so it partitions into metal and sulfide phases rather than forming abundant silicate minerals.
- Rhenium was one of the last stable elements to be discovered.
- Natural rhenium is dominated by ¹⁸⁷Re, which is radioactive with an extremely long half-life.
- The ¹⁸⁷Re-¹⁸⁷Os decay system is used for dating some sulfide ores and meteorites.
- Rhenium has a higher boiling point than any other element under standard tabulations.
- Perrhenate, ReO₄⁻, is often used as a nonradioactive chemical analogue for pertechnetate, TcO₄⁻.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 135 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 151 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 217 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Raggio metallico
- 128 pm Confronta Raggio metallico di tutti gli elementi →
- Densità
- 2,08 × 104 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,00885 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 3185,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 5595,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Conducibilità termica
- 48 W/(m·K) Confronta Conducibilità termica di tutti gli elementi →
- Capacità termica specifica
- 0,137 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 25,48 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Esagonale compatta Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 1,9 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 1,6
- Affinità elettronica
- 0,15 eV
- Energia di ionizzazione (1ª)
- 7,83352 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 16,600057 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 27,000093 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 39,100135 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 51,900179 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- −3, −1, 0, +1, +2, +3, +4, +5, +6, +7 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 7 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Xe] 6s2 4f14 5d5
Termodinamiche
- Calore di fusione
- 0,34927709 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 7,358657 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 8,032337 eV
- Calore di atomizzazione
- 8,032337 eV
- Entalpia di atomizzazione
- 8,021972 eV
Nucleari
- Protoni
- 75 Confronta Protoni di tutti gli elementi →
- Neutroni
- 110 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 41 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 1 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Re-185
- Anno della scoperta
- 1925
Abbondanza
- Abbondanza (crosta terrestre)
- 7e-4 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 4 × 10−6 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 276 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 32, 13, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-15-5 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 6S5/2
- InChI
- InChI=1S/Re
- Chiave InChI
- WUAPFZMCVAUBPE-UHFFFAOYSA-N
Configurazione elettronica Misurato
Re: 4f¹⁴ 5d⁵ 6s²[Xe] 4f¹⁴ 5d⁵ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d⁵ 6s²Modello atomico
Gli isotopi modificano il numero di neutroni, la massa e la stabilità — non la configurazione elettronica di un atomo neutro.
Modello atomico schematico, non in scala.
Impronta atomica
Spettro di emissione / assorbimento
Distribuzione isotopica
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 185 Stabile | 184,9529545 ± 0,0000013 | 37,4000% | Stabile |
Fase / Stato
Motivo: 3160,8 °C sotto il punto di fusione (3185,85 °C)
Schema non in scala
Punti di transizione di fase
Energie di transizione
Energia necessaria per fondere 1 mol al punto di fusione
Energia necessaria per vaporizzare 1 mol al punto di ebollizione
Energia necessaria per sublimare 1 mol al punto di sublimazione
Densità
In condizioni standard
In condizioni standard
Spettri atomici
Sono visualizzati 10 di 75. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Re I | 0 | 432 | 0 | 0 |
| Re II | +1 | 56 | 0 | 0 |
| Re III | +2 | 1381 | 1381 | 1381 |
| Re IV | +3 | 982 | 982 | 982 |
| Re V | +4 | 401 | 401 | 401 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Re I | 0 | 291 |
| Re II | +1 | 140 |
| Re III | +2 | 232 |
| Re IV | +3 | 162 |
| Re V | +4 | 80 |
| Re VI | +5 | 2 |
| Re VII | +6 | 2 |
| Re VIII | +7 | 2 |
| Re IX | +8 | 2 |
| Re X | +9 | 2 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +4 | 6 | N/D | 63 pm |
| +5 | 6 | N/D | 57.99999999999999 pm |
| +6 | 6 | N/D | 55.00000000000001 pm |
| +7 | 4 | N/D | 38 pm |
| +7 | 6 | N/D | 53 pm |
Composti
Isotopi (1)
Natural rhenium is a mixture of two stable isotopes. Twenty six other unstable isotopes are recognized.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 185 Stabile | 184,9529545 ± 0,0000013 | 37,4000% ± 0,0200% | Stabile | stable |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 131 pm
- Raggio covalente (Pyykkö, legame doppio)
- 119 pm
- Raggio covalente (Pyykkö, legame triplo)
- 110 pm
Raggi di van der Waals
- Batsanov
- 205 pm
- Alvarez
- 249 pm
- UFF
- 295,4 pm
- MM3
- 237 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 249 pm
- Raggio metallico (C12)
- 137 pm
Scale di numerazione
- Mendeleev
- 57
- Pettifor
- 59
- Glawe
- 58
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 5
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 62 a.u.
- Polarizzabilità dipolare (inc.)
- 3 a.u.
- C₆ (Gould–Bučko)
- 663 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 8,85 cm3/mol
- Densità elettronica di Miedema
- 6
Rischio di approvvigionamento ed economia
- Concentrazione della produzione
- 51
- Rischio relativo di approvvigionamento
- 6
- Distribuzione delle riserve
- 52
- Stabilità politica (principale produttore)
- 68
- Stabilità politica (principale detentore di riserve)
- 68
Transizioni di fase e allotropi
| Punto di fusione | 3458,15 K |
| Punto di ebollizione | 5863,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (14)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,4522 |
| 2 | p | 4,438 |
| 2 | s | 19,5902 |
| 3 | d | 13,5453 |
| 3 | p | 21,5655 |
| 3 | s | 22,3515 |
| 4 | d | 36,9456 |
| 4 | f | 39,0752 |
| 4 | p | 34,6268 |
| 4 | s | 33,6436 |
Dettaglio dei raggi cristallini (5)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 4 | VI | 77 | from r^3 vs V plots, from metallic oxides, | |
| 5 | VI | 72 | estimated, | |
| 6 | VI | 69 | estimated, | |
| 7 | IV | 52 | ||
| 7 | VI | 67 |
Modalità di decadimento degli isotopi (54)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 159 | p | — |
| 159 | A | — |
| 160 | p | 89% |
| 160 | A | 11% |
| 161 | p | 100% |
| 161 | A | — |
| 162 | A | 94% |
| 162 | B+ | — |
| 163 | B+ | — |
| 163 | A | 32% |
Fattori di diffusione dei raggi X (516)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 1,8209 |
| 10,1617 | — | 1,91145 |
| 10,3261 | — | 2,0065 |
| 10,4931 | — | 2,10629 |
| 10,6628 | — | 2,21103 |
| 10,8353 | — | 2,28753 |
| 11,0106 | — | 2,3602 |
| 11,1886 | — | 2,43518 |
| 11,3696 | — | 2,51255 |
| 11,5535 | — | 2,59237 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
7×10-4 milligrams per kilogram
Riferimenti (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
4×10-6 milligrams per liter
Riferimenti (1)
Sources
Sources of this element.
Rhenium does not occur free in nature or as a compound in a distinct mineral species. It is, however, widely spread throughout the earth's crust to the extent of about 0.001 ppm. Commercial rhenium in the U.S. today is obtained from molybdenum roaster-flue dusts obtained from copper-sulfide ores mined in the vicinity of Miami, Arizona and elsewhere in Arizona and in Utah.
Some molybdenum contains from 0.002% to 0.2% rhenium. More than 150,000 troy ounces of rhenium are now being produced yearly in the United States. The total estimated Free World reserve of rhenium metal is 3500 tons. Rhenium metal is prepared by reducing ammonium perrhentate with hydrogen at elevated temperatures.
Riferimenti (1)
- [6] Rhenium https://periodic.lanl.gov/75.shtml
Riferimenti
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Rhenium.
The element property data was retrieved from publications.