Actinide elements cyclopentadienyls

Table 2. Preparation of tt-Cyclopentadienyl Complexes of the Actinide Elements...

Tetracyclopentadienyl complexes of several actinide elements (Th, Pa, U, and Np) have been made. Infrared data suggest that these all have similar molecular structures, and x-ray powder diffraction [SOI] was used to show the isomorphism of the compounds of Th, U, and Np. A single-crystal structural analysis [502] of U(CsHs)4 revealed that the molecules are tetrahedral and that all four cyclopentadienyl rings are > -bonded to the metal atom. Because of the higher coordination that this produces, the average U-C bond length (2.81 A) is longer than in the previously discussed structures. 

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