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 practical uses.

Structure and synthesis

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

Reactions

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

(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

References