NONCLASSICAL ACTIVATION OF CARBON MONOXIDE BY ORGANOACTINIDES

This article reviews recent results on the carbonylation chemistry of bis(pentamethylcyclopentadienyl) thorium and uranium hydrocarbyl and dialkylamide complexes. Facile migratory insertion of carbon monoxide into metal-carbon and metal-nitrogen bonds is observed. In several cases bihaptoacyl and bihaptocarbamoyl complexes were isolated and characterized by single crystal x-ray diffraction. The great strength of the metal-oxygen bonding in these species is evident in metrical and spectral data, as well as in the reaction chemistry, which is decidedly alkoxycarbene-like. In the case of the bis(pentamethylcyclopentadienyl) actinide dialkyls, the final carbonylation products are C-C coupled cis-1,2-enediolate complexes, while for the corresponding bis(dialkylamides), the products are bis(carbamoyl) species. Both types of compound have been characterized by x-ray diffraction. The carbon monoxide chemistry observed here may be of relevance to mechanistic discussions of catalytic CO reduction, especially that involving actinide oxide or actinide oxide supported catalysts.