Cyclopentadienyltungsten tricarbonyl dimer is the organotungsten compound with the formula Cp<sub>2</sub>W<sub>2</sub>(CO)<sub>6</sub>, where Cp is C<sub>5</sub>H<sub>5</sub>. A dark red crystalline solid, it is the subject of research, although it has no or few practical uses.
The molecule exists in two rotamers, gauche and anti. The six CO ligands are terminal, and the W-W bond distance is 3.222 ÃÂ . The compound is prepared by treatment of tungsten hexacarbonyl with sodium cyclopentadienide followed by oxidation of the resulting NaW(CO)<sub>3</sub>(C<sub>5</sub>H<sub>5</sub>).