Metal-carbon bond orbitals, involved

Figure 13. Molecular orbital diagram of the mixing process involved In the Insertion of olefin into a metal-carbon bond. Orbital occupations are shown for the formal d° configuration on the metal. ...

Processes involving only one metal-carbon bond are even more subtle. Ligand loss as R avoids formal reduction of the metal and shows no new features, but where formal reduction does occur the fate of the electrons initially in the metal-carbon bond will depend on the properties of the Orbital correlation theory becomes inadequate, but the results of state correlation theory are encouraging, with the low lability of Cr(III) and Co(IV) alkyls being correctly predicted. 

Figure 4.3. Orbitals involved in the metal-carbon bonding in T -benzene complexes, (a) Orbitals involved in the transfer of charge from ligand to metal (b) orbitals involved in the transfer of charge from metal to ligand.

In contrast to the facile hydroboration, the corresponding carboboration involving four-electron processes does not occur readily. The short B—C bond, relative to those metal-carbon bonds that are known to participate in the four-electron carbometallation, may impose steric hindrance to carboboration. The presence of an empty p orbital. 

Unsaturated organic molecules, such as ethylene, can be chemisorbed on transition metal surfaces in two ways, namely in -coordination or di-o coordination. As shown in Fig. 2.24, the n type of bonding of ethylene involves donation of electron density from the doubly occupied n orbital (which is o-symmetric with respect to the normal to the surface) to the metal ds-hybrid orbitals. Electron density is also backdonated from the px and dM metal orbitals into the lowest unoccupied molecular orbital (LUMO) of the ethylene molecule, which is the empty asymmetric 71 orbital. The corresponding overall interaction is relatively weak, thus the sp2 hybridization of the carbon atoms involved in the ethylene double bond is retained. 

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