Molybdenum hexacarbonyl

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Molybdenum hexacarbonyl
Stereo, skeletal formula of molybdenum hexacarbonyl Molybdenum-hexacarbonyl-2D.png
Stereo, skeletal formula of molybdenum hexacarbonyl
Ball and stick model of molybdenum hexacarbonyl Molybdenum-hexacarbonyl-from-xtal-3D-balls.png
Ball and stick model of molybdenum hexacarbonyl
Sample of molybdenum hexacarbonyl Mocarbonyl.JPG
Sample of molybdenum hexacarbonyl
Names
IUPAC name
Hexacarbonylmolybdenum(0)
Systematic IUPAC name
Hexacarbonylmolybdenum [1]
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.034.271 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 237-713-3
3798, 562210
MeSH Hexacarbonylmolybdenum
PubChem CID
UN number 3466
  • InChI=1S/6CO.Mo/c6*1-2; X mark.svgN
    Key: KMKBZNSIJQWHJA-UHFFFAOYSA-N X mark.svgN
  • O=C=[Mo](=C=O)(=C=O)(=C=O)(=C=O)=C=O
Properties
C6MoO6
Molar mass 264.01 g·mol−1
AppearanceVivid, white, translucent crystals
Density 1.96 g cm−3
Melting point 150 °C (302 °F; 423 K)
Boiling point 156 °C (313 °F; 429 K)
insoluble
Solubility slightly soluble in THF, diglyme, acetonitrile [2]
Structure
Orthogonal
Octahedral
0 D
Thermochemistry
−989.1 kJ mol−1
−2123.4 kJ mol−1
Hazards
GHS labelling:
GHS-pictogram-skull.svg
Danger
H300, H310, H315, H319, H330, H413
P261, P271, P280, P304+P340+P311, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
1
0
Safety data sheet (SDS) External MSDS
Related compounds
Related compounds
 Chromium hexacarbonyl


Tungsten hexacarbonyl
Seaborgium hexacarbonyl [3]

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO)6. This colorless solid, like its chromium, tungsten, and seaborgium analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.

Contents

Structure and properties

Mo(CO)6 adopts an octahedral geometry consisting of six rod-like CO ligands radiating from the central Mo atom. A recurring minor debate in some chemical circles concerns the definition of an "organometallic" compound. Usually, organometallic indicates the presence of a metal directly bonded via a M–C bond to an organic fragment, which must in turn have a C–H bond.

Like many metal carbonyls, Mo(CO)6 is generally prepared by "reductive carbonylation", which involves reduction of a metal halide with under an atmosphere of carbon monoxide. As described in a 2023 survey of methods "most cost-effective routes for the synthesis of group 6 hexacarbonyls are based on the reduction of the metal chlorides (CrCl3, MoCl5 or WCl6) with magnesium, zinc or aluminium powders... under CO pressures". [4]

Occurrence

Mo(CO)6 has been detected in landfills and sewage plants, the reducing, anaerobic environment being conducive to formation of Mo(CO)6. [5]

Inorganic and organometallic derivatives

Molybdenum hexacarbonyl is a popular reagent in research. [6] One or more CO ligands can be displaced by other ligands. [7] Examples:

Mo(CO)6 + bipy → Mo(CO)4(bipy) + 2 CO (bipy = 2,2′-bipyridine)
Mo(CO)6 + thf → Mo(CO)5(thf) + CO (thf = tetrahydrofuran), this reaction requires UV radiation

Mo(CO)6 + 2 pip → Mo(CO)4(pip) + 2 CO (pip = piperidine) Mo(CO)6 + 3 MeCN → Mo(CO)3(MeCN)3 + 3 CO (MeCN = acetonitrile)

Some of these species are suited for substitution. For instance, the reaction of [Mo(CO)4(piperidine)2] with triphenyl phosphine gives cis- and trans-[Mo(CO)4(PPh3)2]. [8] [Mo(CO)3(MeCN)3 serves as a source of "Mo(CO)3". For instance treatment with allyl chloride gives [MoCl(allyl)(CO)2(MeCN)2], whereas treatment with KTp and sodium cyclopentadienide gives [MoTp(CO)3]− and [MoCp(CO)3]− anions, respectively. These anions react with a variety of electrophiles. [9] A related source of Mo(CO)3 is cycloheptatrienemolybdenum tricarbonyl.

Organic synthesis

Mo(CO)6, [Mo(CO)3(MeCN)3], and related derivatives are employed as catalysts or reagents in organic synthesis for example, alkyne metathesis and the Pauson–Khand reaction. The hexacarbonyl can serve as a source of CO. [10]

Source of Mo atoms

Molybdenum hexacarbonyl is widely used in electron beam-induced deposition technique - it is easily vaporized and decomposed by the electron beam providing a convenient source of molybdenum atoms. [11]

Safety and handling

Like all metal carbonyls, Mo(CO)6 is a dangerous source of volatile metal as well as CO.

References

  1. ↑ "Hexacarbonylmolybdenum (CHEBI:30508)". Chemical Entities of Biological Interest (ChEBI). UK: European Bioinformatics Institute.
  2. ↑ Faller, John W.; Brummond, Kay M.; Mitasev, Branko (15 September 2006). "Hexacarbonylmolybdenum". Encyclopedia of Reagents for Organic Synthesis. Wiley. doi:10.1002/047084289X. hdl:10261/236866. ISBN   978-0-470-84289-8.
  3. ↑ Even, J.; Yakushev, A.; Dullmann, C. E.; Haba, H.; Asai, M.; Sato, T. K.; Brand, H.; Di Nitto, A.; Eichler, R.; Fan, F. L.; Hartmann, W.; Huang, M.; Jager, E.; Kaji, D.; Kanaya, J.; Kaneya, Y.; Khuyagbaatar, J.; Kindler, B.; Kratz, J. V.; Krier, J.; Kudou, Y.; Kurz, N.; Lommel, B.; Miyashita, S.; Morimoto, K.; Morita, K.; Murakami, M.; Nagame, Y.; Nitsche, H.; et al. (2014). "Synthesis and detection of a seaborgium carbonyl complex". Science. 345 (6203): 1491–3. Bibcode:2014Sci...345.1491E. doi:10.1126/science.1255720. PMID   25237098. S2CID   206558746.(subscription required)
  4. ↑ Bruno, Sofia M.; Valente, Anabela A.; Gonçalves, Isabel S.; Pillinger, Martyn (2023). "Group 6 Carbonyl Complexes of N,O,P-Ligands as Precursors of High-Valent Metal-Oxo Catalysts for Olefin Epoxidation". Coordination Chemistry Reviews. 478 214983. doi: 10.1016/j.ccr.2022.214983 . hdl: 10773/40120 . S2CID   255329673.
  5. ↑ Feldmann, J. (1999). "Determination of Ni(CO)4, Fe(CO)5, Mo(CO)6, and W(CO)6 in Sewage Gas by Using Cryotrapping Gas Chromatography Inductively Coupled Plasma Mass Spectrometry". Journal of Environmental Monitoring . 1 (1): 33–37. doi:10.1039/a807277i. PMID   11529076.
  6. ↑ Faller, J. W.; Brummond, K. M.; Mitasev, B. (2006). "Hexacarbonylmolybdenum". In Paquette, L. (ed.). Encyclopedia of Reagents for Organic Synthesis . New York: J. Wiley & Sons. doi:10.1002/047084289X.rh004.pub2. ISBN   0-471-93623-5.
  7. ↑ "The Synthesis & Spectroscopic Characterisation of Metal Carbonyl Complexes" (PDF). www.chm.bris.ac.uk. Archived from the original (PDF) on March 9, 2008.
  8. ↑ Darensbourg, D. J.; Kump, R. L. (1978). "A Convenient Synthesis of cis-Mo(CO)4L2 Derivatives (L = Group 5a Ligand) and a Qualitative Study of Their Thermal Reactivity toward Ligand Dissociation". Inorg. Chem. 17 (9): 2680–2682. doi:10.1021/ic50187a062.
  9. ↑ Elschenbroich, C.; Salzer, A. (1992). Organometallics: A Concise Introduction (2nd ed.). Weinheim: Wiley-VCH. ISBN   3-527-28165-7.
  10. ↑ Larhed, Mats; Odell, Luke; Russo, Francesco (2012). "Molybdenum Hexacarbonyl Mediated CO Gas-Free Carbonylative Reactions". Synlett. 23 (5): 685–698. doi:10.1055/s-0031-1290350.
  11. ↑ Randolph, S. J.; Fowlkes, J. D.; Rack, P. D. (2006). "Focused, Nanoscale Electron-Beam-Induced Deposition and Etching". Critical Reviews of Solid State and Materials Sciences. 31 (3): 55–89. Bibcode:2006CRSSM..31...55R. doi:10.1080/10408430600930438. S2CID   93769658.

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