Dipotassium cyclooctatetraenide

Dipotassium cyclooctatetraenide

Names
IUPAC name dipotassium cycloocatetraenediide
Identifiers
CAS Number	59391-85-4
3D model (JSmol)	Interactive image
ChemSpider	57575621
InChI InChI=1S/C8H8.2K/c1-2-4-6-8-7-5-3-1;;/h1-8H;;/q-2;2*+1/b2-1-,5-3-,8-6-;; Key: JEUFATMWOKTCQC-YGFQESQOSA-N InChI=1/C8H8.2K/c1-2-4-6-8-7-5-3-1;;/h1-8H;;/q-2;2*+1/b2-1-,5-3-,8-6-;; Key: JEUFATMWOKTCQC-YGFQESQOBL
SMILES [K+].c1=c[cH-]c=c[cH-]c=c1.[K+]
Properties
Chemical formula	C8H8K2
Appearance	beige solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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 (U(C₈H₈)₂). Analogs of K₂C₈H₈ are known with ring substituents, with different alkali metals, and with various complexants.

Ball-and-stick model of COT²⁻

Preparation and structure

Potassium cyclooctatetraenide is formed by the reaction of cyclooctatetraene with potassium metal:

2 K + C₈H₈ → K₂C₈H₈

The reaction entails 2-electron reduction of the polyene and is accompanied by a color change from colorless to brown.

The structure of K₂(diglyme)C₈H₈ 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.