Uranocene
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| General | ||||||||||
| Surname | Uranocene | |||||||||
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| Molecular formula | C 16 H 16 U | |||||||||
| Brief description |
green crystals |
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| properties | ||||||||||
| Molar mass | 446.33 g mol −1 | |||||||||
| Physical state |
firmly |
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| Hazard and safety information | ||||||||||
 Radioactive |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||
Uranocene U (C 8 H 8 ) 2 is the best-known compound of cyclooctatetraene with an f-element and was one of the first organo-uranium compounds. Some textbooks also include uranocene as a compound class of metallocenes , although this is a bis (cyclooctatetraenyl) complex of uranium . Uranocene is one of the actinocenes, a group of metallocenes that contain the elements of actinides . It is the bis [8] annulene metal system that has been best studied to date.
presentation
Uranocene was first produced by reacting uranium tetrachloride and dipotassium cyclooctatetraene :
properties
Uranocene is paramagnetic , pyrophoric and resistant to hydrolysis . The η 8 -cyclooctatetraenyl groups are planar, as is to be expected for a ring with 10 π electrons . They form a sandwich complex with the uranium atom in the center. In the solid state, the rings are ecliptic to one another, with a D 8h symmetry. The rings rotate in solution because the energy barrier is only small.
The nature of the uranium-cyclooctatetraenyl bond is the subject of further research and debate. By photoelectron spectroscopy it could be shown that binding in the uranocene 5f and 6d orbitals shared.
Similar connections
Similar compounds of the form M (C 8 H 8 ) 2 are known for M = ( Nd , Tb , Yb and Th , Pa , Np and Pu ). This also includes the derivative U (C 8 H 4 Ph 4 ) 2 , which is stable in air, and the cycloheptatrienyl ion [U (C 7 H 7 ) 2 ] - .
Individual evidence
- ↑ a b A. Streitwieser, U. Mueller-Westerhoff: Bis (cyclooctatetraenyl) uranium (Uranocene). A New Class of Sandwich Complexes That Utilize Atomic f Orbitals . In: J. Am. Chem. Soc. tape 90 , no. 26 , 1968, pp. 7364-7364 , doi : 10.1021 / ja01028a044 .
- ↑ Entry on uranium compounds in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)
- ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry uranium compounds with the exception of those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) , accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
- ↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling.
- ↑ Allan Zalkin, Kenneth N. Raymond: The Structure of di-π-cyclooctatetraeneuranium (Uranocene) , in: J. Am. Chem. Soc. , 1969 , 91 , pp. 5667-5668; doi: 10.1021 / ja01048a055 .
- ↑ JS Hager, J. Zahardis, RM Pagni, RN Compton, J. Li: Raman under nitrogen. The high-resolution Raman spectroscopy of crystalline uranocene, thorocene, and ferrocene . In: Journal of Chemical Physics . tape 120 , no. 6 , 2004, p. 2708-2718 , doi : 10.1063 / 1.1637586 .
- ↑ Lanthanides & Actinides: Organoactinides.
- ↑ DG Karraker, JA Stone, ER Jones, N. Edelstein: Bis (cyclooctatetraenyl) neptunium (IV) and Bis (cyclooctatetraenyl) plutonium (IV) . In: Journal of Chemical Physics . tape 92 , no. 16 , 1970, pp. 4841-4845 , doi : 10.1021 / ja00719a014 .
- ↑ D. Seyferth: Uranocen. The First Member of a New Class of Organometallic Derivatives of the f Elements . In: Organometallics . tape 23 , no. 15 , 2004, pp. 3562-3583 , doi : 10.1021 / om0400705 .
literature
- Christoph Elschenbroich : Organometallchemie , 6th edition, Teubner-Verlag, Wiesbaden 2008, ISBN 978-3-8351-0167-8 , pp. 587-591.
- Norman N. Greenwood , Alan Earnshaw : Chemistry of the Elements , 1st Edition, VCH Verlagsgesellschaft, Weinheim 1988, ISBN 3-527-26169-9 , pp. 416-419.
- AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1976.
- James E. Huheey : Inorganic Chemistry , 1st Edition, Walter de Gruyter, Berlin · New York 1988, ISBN 3-11-008163-6 , pp. 888-891.
- Nikolas Kaltsoyannis, Peter Scott: The f elements , ISBN 0-19-850467-5 .
