Thorium acyl system

Application of this picture to the present thorium acyl system (J,) suggests that a hydrogen atom migration to the electron deficient carbenoid p orbital must occur from a conformation (J) other than that found in the crystal structure (H) (Figure 1) to yield the cis product. These relationships are illustrated in eqs.(7) and (8) ... 

The conversion of CO + H2 (syn-gas) to hydrocarbons and oxygenates (Fischer-Tropsch chemistry)119 is of considerable industrial importance and recently the activation and fixation of carbon monoxide in homogeneous systems has been an active area for research.120,121 The early transition elements and the early actinide elements, in particular zirconium124 and thorium,125 126 supported by two pentamethylcyclopentadienyl ligands have provided a rich chemistry in the non-catalytic activation of CO. Reactions of alkyl and hydride ligands attached to the Cp2M centers with CO lead to formation of reactive tf2-acyl or -formyl compounds.125,126 These may be viewed in terms of the resonance forms (1) and (2) shown below. 

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