Tetrakis(cyclopentadienyl)uranium(IV)

Tetrakis(cyclopentadienyl)uranium(IV)
Names
	IUPAC name Tetrakis(η5-cyclopentadienyl)uranium(IV)
	Other names Tetracyclopentadienyluranium; U(Cp)4
Identifiers
CAS Number	1298-76-6 ;
3D model (JSmol)	Interactive image;
ChemSpider	67033592 ;
PubChem CID	129665404;
	InChI InChI=1S/4C5H5.U/c41-2-4-5-3-1;/h41-5H;/q4*-1;+4 Key: OQDGQBKHUMGQKF-UHFFFAOYSA-N;
	SMILES [CH-]1C=CC=C1.[CH-]1C=CC=C1.[CH-]1C=CC=C1.[CH-]1C=CC=C1.[U+4];
Properties
Chemical formula	C20H20U
Appearance	red crystals
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). (what is ?) Infobox references

Tetrakis(cyclopentadienyl)uranium(IV), U(C₅H₅)₄, abbreviated U(Cp)₄, is an organouranium compound composed of a uranium atom sandwiched between four cyclopentadienide rings.

Synthesis and properties

Tetrakis(cyclopentadienyl)uranium(IV) was first prepared in 1962 by Ernst Otto Fischer, who reacted uranium tetrachloride with excess potassium cyclopentadienide in benzene and obtained the complex as red crystals at 6% yield:^[1]^[2]

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.^[1]

References

^ ^a ^b Seyferth, Dietmar (2004-07-01). "Uranocene. The First Member of a New Class of Organometallic Derivatives of the f Elements". Organometallics. 23 (15): 3562–3583. doi:10.1021/om0400705. ISSN 0276-7333.
^ Fischer, Ernst Otto; Hristidu, Yani (1962-04-01). "Notizen: Über Aromatenkomplexe von Metallen LVII. Uran-tetracyclopentadienyl". Zeitschrift für Naturforschung B. 17 (4): 275–276. doi:10.1515/znb-1962-0410. ISSN 1865-7117. S2CID 105017911.

[Seyferth2004-1] Seyferth, Dietmar (2004-07-01). "Uranocene. The First Member of a New Class of Organometallic Derivatives of the f Elements". Organometallics. 23 (15): 3562–3583. doi:10.1021/om0400705. ISSN 0276-7333.

[2] Fischer, Ernst Otto; Hristidu, Yani (1962-04-01). "Notizen: Über Aromatenkomplexe von Metallen LVII. Uran-tetracyclopentadienyl". Zeitschrift für Naturforschung B. 17 (4): 275–276. doi:10.1515/znb-1962-0410. ISSN 1865-7117. S2CID 105017911.

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