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Dimanganese decacarbonyl



Dimanganese decacarbonyl
IUPAC name Dimanganese decacarbonyl
Other names Manganese carbonyl
Decacarbonyldimanganese
Identifiers
CAS number 10170-69-1
RTECS number GG0300000
Properties
Molecular formula C10O10Mn2
Molar mass 389.98 g/mol
Appearance yellow crystals
Density 1.750 g/cm3
Melting point

154 °C

Boiling point

sublimes 60 °C
(0.5 mm Hg)

Solubility in water insoluble
Structure
Dipole moment 0 D
Hazards
Main hazards CO source
R-phrases 23/24/25
S-phrases 22-26-36/37/39-45
Related Compounds
Related compounds Co2(CO)8
Fe3(CO)12
Fe2(CO)9
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Dimanganese decacarbonyl is the chemical compound with the formula Mn2(CO)10. This metal carbonyl is an important reagent in the organometallic chemistry of manganese.[1]

Additional recommended knowledge

Contents

Synthesis

The compound was first prepared in low yield by the reduction of manganese iodide with magnesium under CO.[2] A more efficient preparation entails reduction of anhydrous MnCl2 with sodium benzophenone ketyl under 200 atmospheres of CO.[3] The availability of inexpensive Methylcyclopentadienyl manganese tricarbonyl ("MMT") has led to a low pressure route to Mn2(CO)10.[4]

Structure

Mn2(CO)10 has no bridging CO ligands: it can be described (CO)5Mn-Mn(CO)5. There are two kinds of CO ligands; one CO on each Mn is coaxial with the Mn-Mn bond, and four on each manganese that are perpendicular to it (equatorial). In the stable rotamer, the two Mn(CO)5 subunits are staggered. The overall molecule thus belongs to the point group D4d, which is an uncommon symmetry.

Reactions

Mn2(CO)10 is air stable as a crystalline solid, but solutions require Schlenk techniques. It finds limited use in organic synthesis.[5] Characteristic reactions:

  • Reduction of Mn2(CO)10 gives the manganese pentacarbonyl anion, which can be isolated as a salt:
Mn2(CO)10 + 2 Na → 2 Na[Mn(CO)5]

The anion is a versatile nucleophile. Protonation gives the hydride [HMn(CO)5], and methylation gives [(CH3)Mn(CO)5].

  • Halogenation of Mn2(CO)10proceeds with scission of the Mn-Mn bonds.
Mn2(CO)10 + Br2 → 2[Mn(CO)5Br]

Safety

Mn2(CO)10 is a volatile source of a metal and a source of CO.

References

  1. ^ Elschenbroich, C. ”Organometallics” (2006) Wiley-VCH: Weinheim. ISBN 978-3-29390-6
  2. ^ Brimm, E. O.; Lynch, M. A.; Sesny, W. J. "Preparation and Properties of Manganese Carbonyl" Journal of the American Chemical Society 1954, volume 76, page 3831 - 3835.
  3. ^ King, R. B. Organometallic Syntheses. Volume 1 Transition-Metal Compounds; Academic Press: New York, 1965. ISBN 0-444-42607-8
  4. ^ King, R. B.; Stokes, J. C.; Korenowski, T. F. "A Convenient Synthesis of Dimanganese Decarbonyl from Inexpensive Starting Materials at Atmospheric Pressure" Journal of Organometallic Chemistry 1968, volume 11, Pages 641-643.
  5. ^ Pauson, P. L. “Decacarbonyldimanganese” in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dimanganese_decacarbonyl". A list of authors is available in Wikipedia.
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