Cyclopentadienylmolybdenum tricarbonyl dimer

Cyclopentadienylmolybdenum tricarbonyl dimer is the chemical compound with the formula Cp₂Mo₂(CO)₆, where Cp is C₅H₅. A dark red solid, it has been the subject of much research although it has no known practical uses.

Cyclopentadienylmolybdenum tricarbonyl dimer

Names
IUPAC name bis(tricarbonyl[η5-cyclopentadienyl]molybdenum)(Mo—Mo)
Other names cyclopentadienyl molybdenum carbonyl dimer Bis(tricarbonylcyclopentadienylmolybdenum)
Identifiers
CAS Number	12091-64-4 Y
3D model (JSmol)	Interactive image
ChemSpider	21241602
ECHA InfoCard	100.031.948
EC Number	235-156-0
PubChem CID	11113722
InChI InChI=1S/2C5H5.6CO.2Mo/c2*1-2-4-5-3-1;6*1-2;;/h2*1-5H;;;;;;;; Key: XCUPBPUEWLTPMQ-UHFFFAOYSA-N
SMILES [C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].C1=C[CH]C=C1.C1=C[CH]C=C1.[Mo].[Mo]
Properties
Chemical formula	Mo2(η-C5H5)2(CO)6
Molar mass	490.15 g·mol−1
Appearance	dark red crystalline solid
Melting point	222 °C (432 °F; 495 K)
Boiling point	dec.
Solubility in water	insoluble
Structure
Crystal structure	monoclinic
Dipole moment	0.112 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	flammable
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H312, H332
Related compounds
Related compounds	(η-C5H5)2Mo2(CO)4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Structure and synthesis

The molecule exists in two rotamers, gauche and anti.^[1] The six CO ligands are terminal and the Mo-Mo bond distance is 3.2325 Å.^[2] The compound is prepared by treatment of molybdenum hexacarbonyl with sodium cyclopentadienide followed by oxidation of the resulting NaMo(CO)₃(C₅H₅).^[3] Other methods have been developed starting with Mo(CO)₃(CH₃CN)₃ instead of Mo(CO)₆.^[4]

Reactions

Thermolysis of this compound in hot solution of diglyme (bis(2-methoxyethyl)ether) results in decarbonylation, giving the tetracarbonyl,^[4] which has a formal triple bond between the Mo centers (d_MoMo = 2.448 Å):^[5]

(C₅H₅)₂Mo₂(CO)₆ → (C₅H₅)₂Mo₂(CO)₄ + 2 CO

The resulting cyclopentadienylmolybdenum dicarbonyl dimer in turn binds a variety of substrates across the metal-metal triple bond.

Related compounds

• Cyclopentadienyltungsten tricarbonyl dimer
• Cyclopentadienylchromium tricarbonyl dimer