Perrhenic acid

Last updated
Perrhenic acid
ChemicalStructureOfPerrhenicAcid.png
Perrhenic-acid-3D-balls.png
Names
IUPAC name
Tetraoxorhenic(VII) acid
Other names
Hydrated rhenium(VII) oxide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.968 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 237-380-4
PubChem CID
RTECS number
  • TT4550000
  • InChI=1S/2H2O.7O.2Re/h2*1H2;;;;;;;;; Yes check.svgY
    Key: JOTGKJVGIIKFIQ-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/2H2O.7O.2Re/h2*1H2;;;;;;;;;/rH4O9Re2/c1-10(2,3)9-11(4,5,6,7)8/h4-5H2
    Key: JOTGKJVGIIKFIQ-SEUCOXMMAB
  • [OH2+][Re-2](=O)(=O)(=O)([OH2+])O[Re](=O)(=O)=O
Properties
H4Re2O9 (solid)
HReO4 (gas)
Molar mass 251.2055 g/mol
AppearancePale yellow solid
Boiling point sublimes
Soluble
Acidity (pKa)-1.25 [1]
Conjugate base Perrhenate
Structure
octahedral-tetrahedral (solid)
tetrahedral (gas)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Corrosive
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H302, H314, H332
P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P330, P363, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability (red): no hazard codeInstability (yellow): no hazard codeSpecial hazards (white): no code
3
Flash point Non-flammable
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Perrhenic acid is the chemical compound with the formula Re2O7(H2O)2. It is obtained by evaporating aqueous solutions of Re2O7. Conventionally, perrhenic acid is considered to have the formula HReO4, and a species of this formula forms when rhenium(VII) oxide sublimes in the presence of water or steam. [2] When a solution of Re2O7 is kept for a period of months, it breaks down and crystals of HReO4·H2O are formed, which contain tetrahedral ReO4. [3] For most purposes, perrhenic acid and rhenium(VII) oxide are used interchangeably. Rhenium can be dissolved in nitric or concentrated sulfuric acid to produce perrhenic acid.

Contents

Properties

The structure of solid perrhenic acid is [O3Re−O−ReO3(H2O)2]. [4] This species is a rare example of a metal oxide coordinated to water; most often metal–oxo–aquo species are unstable with respect to their corresponding hydroxides:

M(O)(H2O) → M(OH)2

The two rhenium atoms have different bonding geometries, with one being tetrahedral and the other octahedral, and with the water ligands coordinated to the latter.

Gaseous perrhenic acid is tetrahedral, as suggested by its formula HReO4.

Reactions

Perrhenic acid or the related anhydrous oxide Re2O7 converts to dirhenium heptasulfide upon treatment with hydrogen sulfide:

Re2O7 + 7 H2S → Re2S7 + 7 H2O

The heptasulfide catalyzes various reductions. [5]

Perrhenic acid in the presence of hydrochloric acid undergoes reduction in the presence of thioethers and tertiary phosphines to give rhenium(V) complexes with the formula ReOCl3L2. [6]

Perrhenic acid combined with platinum on a support gives rise to a useful hydrogenation and hydrocracking catalyst for the petroleum industry. [7] For example, silica impregnated with a solution of perrhenic acid is reduced with hydrogen at 500 °C.[ citation needed ] This catalyst is used in the dehydrogenation of alcohols and also promotes the decomposition of ammonia.

Catalysis

Perrhenic acid is a precursor to a variety of homogeneous catalysts, some of which are promising in niche applications that can justify the high cost of rhenium. In combination with tertiary arsines, perrhenic acid gives a catalyst for the epoxidation of alkenes with hydrogen peroxide. [8] Perrhenic acid catalyses the dehydration of oximes to nitriles. [9]

Perrhenic-acid-nitrile-formation.png

Other uses

Perrhenic acid is also used in the manufacture of x-ray targets. [10] [11]

See also

Related Research Articles

<span class="mw-page-title-main">Rhenium</span> Chemical element, symbol Re and atomic number 75

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 the third-highest melting point and second-highest boiling point of any element at 5869 K. 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.

<span class="mw-page-title-main">Group 7 element</span> Group of chemical elements

Group 7, numbered by IUPAC nomenclature, is a group of elements in the periodic table. It contains manganese (Mn), technetium (Tc), rhenium (Re) and bohrium (Bh). This group lies in the d-block of the periodic table, and are hence transition metals. This group is sometimes called the manganese group or manganese family after its lightest member; however, the group itself has not acquired a trivial name because it belongs to the broader grouping of the transition metals.

<span class="mw-page-title-main">Sulfoxide</span> Organic compound containing a sulfinyl group (>SO)

In organic chemistry, a sulfoxide, also called a sulphoxide, is an organosulfur compound containing a sulfinyl functional group attached to two carbon atoms. It is a polar functional group. Sulfoxides are oxidized derivatives of sulfides. Examples of important sulfoxides are alliin, a precursor to the compound that gives freshly crushed garlic its aroma, and dimethyl sulfoxide (DMSO), a common solvent.

<span class="mw-page-title-main">Technetium(VII) oxide</span> Chemical compound

Technetium(VII) oxide is the chemical compound with the formula Tc2O7. This yellow volatile solid is a rare example of a molecular binary metal oxide, the other examples being RuO4, OsO4, and the unstable Mn2O7. It adopts a centrosymmetric corner-shared bi-tetrahedral structure in which the terminal and bridging Tc−O bonds are 167pm and 184 pm respectively and the Tc−O−Tc angle is 180°.

<span class="mw-page-title-main">Ammonium perrhenate</span> Chemical compound

Ammonium perrhenate (APR) is the ammonium salt of perrhenic acid, NH4ReO4. It is the most common form in which rhenium is traded. It is a white salt; soluble in ethanol and water, and mildly soluble in NH4Cl. It was first described soon after the discovery of rhenium.

<span class="mw-page-title-main">Manganese heptoxide</span> Chemical compound

Manganese(VII) oxide (manganese heptoxide) is an inorganic compound with the formula Mn2O7. Manganese heptoxide is a volatile liquid with an oily consistency. It is a highly reactive and powerful oxidizer that reacts explosively with nearly any organic compound. It was first described in 1860. It is the acid anhydride of permanganic acid.

<span class="mw-page-title-main">Phosphine oxides</span> Class of chemical compounds

Phosphine oxides are phosphorus compounds with the formula OPX3. When X = alkyl or aryl, these are organophosphine oxides. Triphenylphosphine oxide is an example. An inorganic phosphine oxide is phosphoryl chloride (POCl3). The parent phosphine oxide (H3PO) remains rare and obscure.

<span class="mw-page-title-main">Rhenium(VII) oxide</span> Chemical compound

Rhenium(VII) oxide is the inorganic compound with the formula Re2O7. This yellowish solid is the anhydride of HOReO3. Perrhenic acid, Re2O7·2H2O, is closely related to Re2O7. Re2O7 is the raw material for all rhenium compounds, being the volatile fraction obtained upon roasting the host ore.

Rhenium trioxide or rhenium(VI) oxide is an inorganic compound with the formula ReO3. It is a red solid with a metallic lustre that resembles copper in appearance. It is the only stable trioxide of the Group 7 elements (Mn, Tc, Re).

<span class="mw-page-title-main">Sodium perrhenate</span> Chemical compound

Sodium perrhenate (also known as sodium rhenate(VII)) is the inorganic compound with the formula NaReO4. It is a white salt that is soluble in water. It is a common precursor to other rhenium compounds. Its structure resembles that of sodium perchlorate and sodium permanganate.

<span class="mw-page-title-main">Bromopentacarbonylrhenium(I)</span> Chemical compound

Bromopentacarbonylrhenium(I) is an inorganic compound of rhenium, commonly used for the syntheses of other rhenium complexes.

<span class="mw-page-title-main">Dirhenium decacarbonyl</span> Chemical compound

Dirhenium decacarbonyl is the inorganic compound with the chemical formula Re2(CO)10. Commercially available, it is used as a starting point for the synthesis of many rhenium carbonyl complexes. It was first reported in 1941 by Walter Hieber, who prepared it by reductive carbonylation of rhenium. The compound consists of a pair of square pyramidal Re(CO)5 units joined via a Re-Re bond, which produces a homoleptic carbonyl complex.

<span class="mw-page-title-main">Methylrhenium trioxide</span> Chemical compound

Methylrhenium trioxide, also known as methyltrioxorhenium(VII), is an organometallic compound with the formula CH3−ReO3. It is a volatile, colourless solid that has been used as a catalyst in some laboratory experiments. In this compound, rhenium has a tetrahedral coordination geometry with one methyl and three oxo ligands. The oxidation state of rhenium is +7.

<span class="mw-page-title-main">Oxotrichlorobis(triphenylphosphine)rhenium(V)</span> Chemical compound

Oxotrichlorobis(triphenylphosphine)rhenium(V) is the chemical compound with the formula ReOCl3(PPh3)2. This yellow, air-stable solid is a precursor to a variety of other rhenium complexes. In this diamagnetic compound, Re has an octahedral coordination environment with one oxo, three chloro and two mutually trans triphenylphosphine ligands. The oxidation state of rhenium is +5 and its configuration is d2.

<span class="mw-page-title-main">Rhenium(IV) oxide</span> Chemical compound

Rhenium(IV) oxide or rhenium dioxide is the inorganic compound with the formula ReO2. This gray to black crystalline solid is a laboratory reagent that can be used as a catalyst. It adopts the rutile structure.

The perrhenate ion is the anion with the formula ReO
4
, or a compound containing this ion. The perrhenate anion is tetrahedral, being similar in size and shape to perchlorate and the valence isoelectronic permanganate. The perrhenate anion is stable over a broad pH range and can be precipitated from solutions with the use of organic cations. At normal pH, perrhenate exists as metaperrhenate, but at high pH mesoperrhenate forms. Perrhenate, like its conjugate acid perrhenic acid, features rhenium in the oxidation state of +7 with a d0 configuration. Solid perrhenate salts takes on the color of the cation.

Organorhenium chemistry describes the compounds with Re−C bonds. Because rhenium is a rare element, relatively few applications exist, but the area has been a rich source of concepts and a few useful catalysts.

Rhenium compounds are compounds formed by the transition metal rhenium (Re). Rhenium can form in many oxidation states, and compounds are known for every oxidation state from -3 to +7 except -2, although the oxidation states +7, +4, and +3 are the most common. Rhenium is most available commercially as salts of perrhenate, including sodium and ammonium perrhenates. These are white, water-soluble compounds. The tetrathioperrhenate anion [ReS4] is possible.

<span class="mw-page-title-main">Rhenium trioxide chloride</span> Chemical compound

Rhenium trioxide chloride is an inorganic compound with the formula ReO3Cl. It is a colorless, distillable, diamagnetic liquid. It is a rhenium oxychloride. The material is used as a reagent in the preparation of rhenium compounds.

Rhenium trioxynitrate, also known as rhenium(VII) trioxide nitrate, is a chemical compound with the formula ReO3NO3. It is a white solid that readily hydrolyzes in moist air.

References

  1. http://www.iupac.org/publications/pac/1998/pdf/7002x0355.pdf [ bare URL PDF ]
  2. Glemser, O.; Müller, A.; Schwarzkopf, H. (1964). "Gasförmige Hydroxide. IX. Über ein Gasförmiges Hydroxid des Rheniums". Zeitschrift für anorganische und allgemeine Chemie (in German). 334 (1–2): 21–26. doi:10.1002/zaac.19643340105..
  3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN   978-0-08-037941-8.
  4. Beyer, H.; Glemser, O.; Krebs, B. "Dirhenium Dihydratoheptoxide Re
    2
    O
    7
    (OH
    2
    )
    2
    – New Type of Water Bonding in an Aquoxide" Angewandte Chemie, International Edition English 1968, Volume 7, Pages 295 - 296. doi : 10.1002/anie.196802951.
  5. Schwarz, D. E.; Frenkel, A. I.; Nuzzo, R. G.; Rauchfuss, T. B.; Vairavamurthy, A. (2004). "Electrosynthesis of ReS
    4
    . XAS Analysis of ReS
    2
    , Re
    2
    S
    7
    , and ReS
    4
    ". Chemistry of Materials. 16: 151–158. doi:10.1021/cm034467v.
  6. Parshall, G. W.; Shive, L. W.; Cotton, F. A. (1997). Phosphine Complexes of Rhenium. Inorganic Syntheses. Vol. 17. pp. 110–112. doi:10.1002/9780470132487.ch31. ISBN   9780470132487.
  7. Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN   0-12-352651-5.
  8. van Vliet, M. C. A.; Arends, I. W. C. E.; Sheldon, R. A. (1999). "Rhenium Catalysed Epoxidations with Hydrogen Peroxide: Tertiary Arsines as Effective Cocatalysts". J. Chem. Soc., Perkin Trans. 1 (3): 377–80. doi:10.1039/a907975k.
  9. Ishihara, K.; Furuya, Y.; Yamamoto, H. (2002). "Rhenium(VII) Oxo Complexes as Extremely Active Catalysts in the Dehydration of Primary Amides and Aldoximes to Nitriles". Angewandte Chemie International Edition . 41 (16): 2983–2986. doi:10.1002/1521-3773(20020816)41:16<2983::AID-ANIE2983>3.0.CO;2-X. PMID   12203432.
  10. http://www.gehealthcare.com/usen/service/time_material_support/docs/Radplus2100.pdf%5B%5D
  11. X-ray#Sources