Tetrakis(cyclopentadienyl)uranium(IV), U(C₅H₅)₄, abbreviated U(Cp)₄, is an

organouranium compound Organouranium chemistry is the science exploring the properties, structure and reactivity of organouranium compounds, which are organometallic compounds containing a carbon to uranium chemical bond. The field is of some importance to the nuclear ...

composed of a uranium atom sandwiched between four

cyclopentadienide In chemistry, the cyclopentadienyl anion or cyclopentadienide is an aromatic species with a formula of and abbreviated as Cp−. It is formed from the deprotonation of the molecule cyclopentadiene. Properties The cyclopentadienyl anion i ...

rings.

Synthesis and properties

Tetrakis(cyclopentadienyl)uranium(IV) was first prepared in 1962 by

Ernst Otto Fischer Ernst Otto Fischer (; 10 November 1918 – 23 July 2007) was a German chemist who won the Nobel Prize for pioneering work in the area of organometallic chemistry. Early life He was born in Solln, a borough of Munich. His parents were Karl T. Fi ...

, who reacted

uranium tetrachloride Uranium tetrachloride is an inorganic compound, a salt of uranium and chlorine, with the formula UCl4. It is a hygroscopic olive-green solid. It was used in the electromagnetic isotope separation (EMIS) process of uranium enrichment. It is one o ...

with excess potassium cyclopentadienide in benzene and obtained the complex as red crystals at 6% yield: :UCl₄ + 4 KCp → U(Cp)₄ + 4 KCl Solid crystals of U(Cp)₄ are air-stable, but the benzene solution is extremely air-sensitive. Reduction of U(Cp)₄ with uranium metal yields tris(cyclopentadienyl)uranium(III), U(Cp)₃.

References

{{Authority control Organouranium compounds Metallocenes Cyclopentadienyl complexes Uranium(IV) compounds Substances discovered in the 1960s