Dipotassium cyclooctatetraenide

Dipotassium cyclooctatetraenide
Names
	Preferred IUPAC name Dipotassium cycloocatetraenediide
Identifiers
CAS Number	59391-85-4;
3D model (JSmol)	Interactive image;
ChemSpider	57575621;
PubChem CID	12716830;
	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.

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.^[1]

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.^[2]

References

^ A. L Wayda (1990). "Cyclooctatetraene Lanthanide Complexes. Lu(C8 H8 )Cl(THF) and Lu(C8 H8 )[o -C6 H4 CH2 N(CH3 )2 ](THF)". Cyclooctatetraene Lanthanide Complexes. Lu(C₈H₈Cl(thf) and Lu(C₈H₈)[o-C₆H₄CH₂N(CH₃)₂(thf). Inorganic Syntheses. Vol. 27. pp. 150–154. doi:10.1002/9780470132586.ch28. ISBN 9780470132586.
^ J. H. Noordik, T. E. M. van den Hark, J. J. Mooij and A. A. K. Klaassen (1974). "Dipotassium(I) cyclooctatetraenide-1-methoxy-2-(2-methoxyethoxy)ethane". Acta Crystallogr B. 30 (3): 833–835. doi:10.1107/S0567740874003840.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[1] A. L Wayda (1990). "Cyclooctatetraene Lanthanide Complexes. Lu(C8 H8 )Cl(THF) and Lu(C8 H8 )[o -C6 H4 CH2 N(CH3 )2 ](THF)". Cyclooctatetraene Lanthanide Complexes. Lu(C₈H₈Cl(thf) and Lu(C₈H₈)[o-C₆H₄CH₂N(CH₃)₂(thf). Inorganic Syntheses. Vol. 27. pp. 150–154. doi:10.1002/9780470132586.ch28. ISBN 9780470132586.

[2] J. H. Noordik, T. E. M. van den Hark, J. J. Mooij and A. A. K. Klaassen (1974). "Dipotassium(I) cyclooctatetraenide-1-methoxy-2-(2-methoxyethoxy)ethane". Acta Crystallogr B. 30 (3): 833–835. doi:10.1107/S0567740874003840.{{cite journal}}: CS1 maint: multiple names: authors list (link)

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