Dipotassium cyclooctatetraenide


Dipotassium cyclooctatetraenide, sometimes abbreviated K2COT, is an organopotassium compound with the formula K2C8H8. It is a brown solid that is used as a precursor to cyclooctatetraenide complexes, such as uranocene. Analogs of K2C8H8 are known with ring substituents, with different alkali metals, and with various complexants.
of COT2−

Preparation and structure

Potassium cyclooctatetraenide is formed by the reaction of cyclooctatetraene with potassium metal:
The reaction entails 2-electron reduction of the polyene and is accompanied by a color change from colorless to brown.
The structure of K2C8H8 has been characterized by X-ray crystallography of the derivatives with diglyme complexed to the potassium cations. The C8H8 unit is planar with an average C-C distance of 1.40 A.