The mechanism is demonstrated using the B rgi-Dunitz approach. In order to generate each frame of the movie. Carbons 6 and 10 and Fe 2 were placed in the xz plane, so that Fe 2 lies to the right of carbons 6 and 10. The structure was centred on Fe 2 . The iron atoms are in grey, the carbons in black and the oxygens in red.
Depth is indicated by the sizes of the atoms.
References H.B. B rgi and J.D. Dunitz, Acc. Structure Correlation', ed. Heyde, Chapter 8. H. Adams, X. Chen, S. Heath and B.E. Mann, unpublished work. The PDB file follows.