CYCLOPENTADIENYL-METAL COMPOUNDS .1. RELATION BETWEEN STABILITY AND DISSOCIATION ENERGIES OF METAL-CARBON COMPOUNDS IN M(SIGMA C5H5) COMPLEXES

The existence and thermal stability of CH(3) M(σC5H5) compounds has been viewed in terms of the bond dissociation energies involved, which predict the two‐center covalent two‐electron metal‐σC5H5 bond to be ∼30 kcal/mole less stable than the parent metal‐CH3 bond. The available experimental data are shown to be consistent with this prediction. Electron donating ligands can lead to stable two‐center diene‐type covalent metal‐C5H5 bonds, even where the two‐electron σ‐bond would not be stable. With the exception of group IIB, transition metals are not capable of forming stable metal‐σC5H5 complexes. Copyright © 1969 Verlag GmbH & Co. KGaA, Weinheim