Cyclo-octatetraene sandwich complexes

The reaction of actinide tetrachlorides (thorium through plutonium) with the potassium salt of cyclo-octatetraene (COT) results in the formation of actocene complexes, rf — CgH8)2An, named by analogy with ferrocene. All these compounds have a sandwich structure in which two planar COT rings enclose a metal atom. 

The Huckel (4n-l-2) n-electron dianion of cyclo-octatetraene, CgH, forms complexes with a number of early transition-metal and actinide ions. The synthesis of the uranium sandwich complex, U(CgHg)2 (bis([8]annulene)uran-ium(iv), known as uranocene ), was an important milestone in organoactinide chemistry. The green, pyrophoric compound was first prepared as shown below [7,124] ... 

Half-sandwich complexes of Th(iv) with cyclo-octatetraene and substituted cyclo-octatetraenes are accessible through the approaches [173] ... 

Seven-electron ligands, mixed sandwich complexes, related azulene derivatives and cyclo-octatetraene complexes... 

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