12 complex 1215 upon treatment with diiron nonacarbonyl and no a-indenyl complex analogous to 3, 4, or 5. We interpret this behavior as being due to the fact that formation of a uT allyl intermediate analogous to 8 is impossible in the case of 11. Also relevant to this point is the fact that benzosemibullvalene 13 yields only the u-7r allyl complex 14.1 b
