Uranocene

• Bis ( η8 - cyclooctatetraene ) uranium
• Uranium cyclooctatetraenyl
• U ( COT) 2

Green crystals

Fixed

Risk

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Uranocene U ( C8H8 ) 2 is the most popular connection of cyclooctatetraene with an f - element and was one of the first organo- uranium compounds. To compound class of metallocenes include some textbooks also uranocene, although this is a bis ( cyclooctatetraenyl ) complex of uranium. Uranocene one of the Actinocenen, a group of metallocenes containing the elements of the actinides. It is so far the best studied BisAnnulen - metal system.

Representation

Uranocene was first prepared by the reaction of uranium tetrachloride and dipotassium cyclooctatetraene:

Properties

Uranocene is paramagnetic, pyrophoric and resistant to hydrolysis. The η8 - Cyclooctatetraenylgruppen are planar, as would 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 eclipsed to each other, with a D8h symmetry. Rotating the rings in solution, since the energy barrier is low.

The nature of the uranium cyclooctatetraenyl bond is subject to further investigation and debate. By photoelectron spectroscopy, it was shown that the binding in the shared uranocene 5f and 6d orbitals.

Similar compounds

Similar compounds of the form M ( C8H8 ) 2 are known for M = (Nd, Tb, Yb, and Th, Pa, Np and Pu). Furthermore, one including also the stable at the air derivative U ( C8H4Ph4 ) 2 and the Cycloheptatrienylion [U ( C7H7 ) 2] -.